Showing papers in "Journal of Human Hypertension in 1998"
TL;DR: In hypertensive patients with atheromatous renal artery stenosis, percutaneous renal angioplasty results in a modest improvement in systolic BP compared with medical therapy alone, confined to patients with bilateral disease.
Abstract: Background: Data from randomised studies are lacking on the value of interventional procedures in the management of atheromatous renal artery stenosis. This randomised prospective trial compared the effects on blood pressure (BP) and renal function of percutaneous transluminal angioplasty vs medical therapy in hypertensive patients with both unilateral and bilateral disease. Methods: A total of 135 eligible patients were identified, of whom 55 (44%) were randomised. Eligible patients had sustained hypertension, with a minimum diastolic BP of 95 mm Hg on at least two anti-hypertensive drugs. Renal artery stenosis was defined by renal angiography as at least 50% stenosis in the affected vessel. All patients were observed during an initial 4-week run-in period on a fixed drug regimen and subsequent changes measured from this 4-week baseline. Results: Blood pressure fell during the run-in period in all groups. In patients with bilateral renal artery stenosis randomised to angioplasty, a statistically significant (P < 0.05) fall in bp was observed at latest follow-up (range 3–54 months). the mean fall in bp at latest follow- up in the angioplasty group, corrected for the medical group response, was 26/10 mm hg. in patients with unilateral renal artery stenosis, no statistically significant or clinically important differences in outcome were observed between the two groups. no significant differences or trends in serum creatinine were observed between or within any group during follow-up. major outcome events (death, myocardial infarction, heart failure, stroke, dialysis) were similar in the angioplasty and medical groups during follow-up. in the 40/135 patients undergoing angioplasty, serious or potentially serious complications attributable to the procedure were observed in 11 patients, bleeding at the arterial site (8 patients) being the most frequent. Conclusions: In hypertensive patients with atheromatous renal artery stenosis, percutaneous renal angioplasty results in a modest improvement in systolic BP compared with medical therapy alone. This benefit was confined to patients with bilateral disease. No patient was ‘cured’, renal function did not improve, and intervention was accompanied by a significant complication rate.
491 citations
TL;DR: This book not only helps you read a paper but tries to make you a better paper writer as well and fulfils its advertised aim of being a compressed introduction to the usefulness and potential applications of evidence-based medicine in the clinical setting.
Abstract: Do you need to read published papers? Or are you a scientific paper non-reader or recluse? This book (very thoughtfully) starts off by asking whether you need to read this book—how many textbooks actually ask you whether you need to use/read/buy it? The need for such a book is certainly there, as this excellent little book is intended to help existing readers read, and actually interpret, medical papers better. Current non-readers and scientific recluses may even be encouraged to open medical journals for once! The book provides an excellent practical and pragmatic approach to critical analysis of much of the uninspiring and unread published literature (which often makes you wonder how it got into print in the first place!). There is a systematic discussion on evidence-based medicine and a thoughtful practical section on how to search the medical literature. Despite the age of the Internet and computerised databases, even the most experienced Medline surfer often only manages to find approximately a third of the published material on a particular subject—handy tips are provided to improve searches, to increase one’s gain and to reduce eye strain or repetitive strain injury from a long, tiring session at the Medline computer terminal. The book describes the various sections of a published paper, including appraisal of the nature of the study and statistics for the non-statistician. It then discusses what you would hope to gain from reading a particular paper, including papers that report drug trials, diagnostic screening tests, systematic reviews and guidelines. It also has information on economic analyses and qualitative research. Finally, it gives some examples of how to implement evidence-based findings. Since much of clinical medicine is still not evidence-based, perhaps this goes some way to rectify this appalling state of affairs. I also found the Appendix with a checklist for finding, appraising and implementing evidence fairly helpful. Readers of this excellent book who are like me — struggling to understand much of the published literature and also to produce an intelligible published paper every so often—this book not only helps you read a paper but tries to make you a better paper writer as well. Perhaps my understanding of evidence-based medicine will improve after reading this book, and make me a better teacher and researcher. Perhaps it will make me reject more of the papers submitted to the journal I help edit! At the cost of £14.95, this book is an absolute bargain and it fulfils its advertised aim of being a compressed introduction to the usefulness and potential applications of evidence-based medicine in the clinical setting. I recommend it wholeheartedly as an obligatory read.
470 citations
TL;DR: A major challenge in reducing the SES gradient in BP is to understand and prevent the S ES differences in obesity, which are particularly large in women, and there is little evidence that adverse psycho-social factors associated with low SES cause chronic elevation in BP.
Abstract: Background: Mortality rates from hypertension related diseases such as coronary heart disease, hypertensive heart disease, stroke and end stage renal disease show an inverse association with socio-economic status (SES). Objectives: To review the published literature in order to assess whether (i) there is an association between SES and blood pressure (BP), and if so whether this is explained by (ii) SES differences in treatment rates, or (iii) SES differences in established risk factors for hypertension, or (iv) psycho-social factors associated with SES Method: A narrative systematic review of published articles identified from a MEDLINE search from 1966–1996 and manual searching of the retrieved articles’ bibliographies. Results: Lower SES was associated with higher mean BPs in almost all studies in developed countries. This inverse gradient was both stronger and more consistently found in women than in men. The magnitude of the association varied but generally was quite small, with age adjusted mean systolic BP differences of about 2–3 mm Hg between the highest and lowest SES groups. The finding of an SES gradient in BP, despite adjusting for treatment in some studies and the lack of consistent SES differences in hypertension treatment rates, makes differential treatment an unlikely explanation for the SES gradient in BP. A substantial part of the SES gradient was accounted for by the SES gradient in body mass index. Alcohol consumption across SES groups accounted for part of the association in men though few studies examined this issue specifically. In contrast, in undeveloped or developing countries a direct association between SES and BP has often been found which may reflect a higher prevalence of obesity, and higher salt and alcohol intakes among those of higher SES. The SES differences in BP were not detectable in most studies in children. There is little evidence that adverse psycho-social factors associated with low SES cause chronic elevations in BP. Conclusion: A major challenge in reducing the SES gradient in BP is to understand and prevent the SES differences in obesity, which are particularly large in women. Future research should be directed to this question.
394 citations
TL;DR: A systematic quantitative overview is needed to reconcile the inconsistencies of the results of individual studies and to quantify the size of such relationship.
Abstract: Published reports of 30 separate sets of analyses from 29 observational studies relating dietary intake of magnesium to blood pressure (BP) were identified through a comprehensive search using MEDLINE and BIDS-EMBASE. Three studies were prospective, 24 cross-sectional (25 reports), of which four also contained a longitudinal component, and two were obtained from baseline data in a trial. Various dietary methodologies were used: 24-h dietary recall (n = 12), food-frequency questionnaire (8), food record (7), and duplicate diet (2). Twelve reports compared magnesium intake or BP level between subgroups. Seven showed a negative association between magnesium intake and BP level, and five reported no association. From 18 of the 30 sets of analyses either a regression estimate or a Pearson correlation coefficient was reported. Many reports also allowed identification of subgroups by sex, age and race. Ninety population samples and subgroups could thus be identified from the 30 reports. All 11 Pearson-r correlation coefficients reported for systolic BP (SBP) (three significant, P < 0.05) and 10 (out of 12) Pearson-r correlation coefficients reported for diastolic BP (DBP) (four significant) were negative. Seven reports (13 subgroups for SBP, 11 subgroups for DBP) gave partial regression coefficients after adjustment; 10 (seven significant) and eight (six significant) were negative for SBP and DBP, respectively. For 13 subgroups in five papers, Pearson-r correlation coefficients were reported after adjustment for confounding factors. Eight (out of 13) showed a negative relationship for SBP and DBP. This review points to a negative association between dietary magnesium intake and BP. A systematic quantitative overview is needed to reconcile the inconsistencies of the results of individual studies and to quantify the size of such relationship.
131 citations
TL;DR: The Finapres device can provide an accurate estimate of diastolic and mean arterial pressure compared with the intra-arterial record and the apparent inaccuracy of the Finapre systolic pressure may have a physiological explanation.
Abstract: Accuracy and precision of blood pressure determination with the Finapres: an overview using re-sampling statistics
127 citations
TL;DR: Valsartan 80 mg and 160mg act additively with HCTZ 12.5 mg or 25 MG to lower MSDBP and MSSBP in patients with essential hypertension, and the addition of HCTz to valsartAn 80‷mg or 160‰mg was well tolerated.
Abstract: Objective: This study compares the antihypertensive efficacy and tolerability of valsartan, a novel angiotensin II antagonist, given with hydrochlorothiazide (HCTZ) vs placebo or vs valsartan or HCTZ alone. Design: 871 adult out-patients with essential hypertension participated in this double-blind study. Patients were randomised in equal number to receive either combination therapy of valsartan (80 mg or 160 mg) and HCTZ (12.5 mg or 25 mg), or valsartan (80 mg or 160 mg) or HCTZ (12.5 mg or 25 mg) alone, or placebo. Patients were treated once daily for 8 weeks and assessed at 2, 4 and 8 weeks after randomisation. Main outcome measures: The primary efficacy variable was change from baseline in mean sitting diastolic blood pressure (MSDBP) at end-point. The secondary variable was change in mean sitting systolic blood pressure (MSSBP) from baseline to end-point. Results: All active treatments produced a statistically significant difference in MSDBP (P < 0.001) from baseline to end-point compared with placebo. similar results were obtained for mssbp. all combination regimens produced a statistically significantly greater reduction in msdpb and mssbp than the corresponding monotherapies. dizziness and headache were the most common treatment-related adverse experiences reported. hypokalaemia, associated with the use of thiazide diuretics, was more commonly reported in the higher dose hctz 25 mg groups. Conclusions: Valsartan 80 mg and 160 mg act additively with HCTZ 12.5 mg or 25 mg to lower MSDBP and MSSBP in patients with essential hypertension. The addition of HCTZ to valsartan 80 mg or 160 mg was well tolerated.
109 citations
TL;DR: Recent experimental and epidemiological evidence supports the hypothesis that oestrogen deficiency may induce endothelial and vascular dysfunction and potentiate the age-related increase in systolic pressure, possibly as a consequence of a reduced compliance of the large arteries.
Abstract: Menopause is a normal aging phenomenon in women and consists of the gradual transition from the reproductive to the non-reproductive phase of life. The median age at the menopause is currently around 50 years. As a result of the increasing life expectancy in the first and second worlds, many women will be postmenopausal for over one-third of their lives. The influence of menopause per se on blood pressure remains uncertain. Recent experimental and epidemiological evidence supports the hypothesis that oestrogen deficiency may induce endothelial and vascular dysfunction and potentiate the age-related increase in systolic pressure, possibly as a consequence of a reduced compliance of the large arteries. However, the latter hypothesis requires further investigation.
108 citations
TL;DR: Most of the mercury and aneroid sphygmomanometers showed inaccuracy and unreliability and 56% vs 70% in the hospital setting and 61% in private medical practices were found to be inaccurate.
Abstract: The objective of this study was to assess the accuracy and reliability of mercury and aneroid sphygmomanometers. Measurement of accuracy of calibration and evaluation of physical conditions were carried out in 524 sphygmomanometers, 351 from a hospital setting, and 173 from private medical offices. Mercury sphygmomanometers were considered inaccurate if the meniscus was not '0' at rest. Aneroid sphygmomanometers were tested against a properly calibrated mercury manometer, and were considered calibrated when the error was 13 mm Hg in 7%. In summary, most of the mercury and aneroid sphygmomanometers showed inaccuracy (21% vs 58%) and unreliability (64% vs 70%).
107 citations
TL;DR: The role of the renin-angiotensin system in essential hypertension insofar as it contributes to the level of blood pressure, to the development of left ventricular hypertrophy, and in the evolution of complications such as stroke and myocardial infarction is less clear.
Abstract: The renin-angiotensin system is central to the pathophysiology of a number of cardiovascular disorders. Most obviously this is so with renin secreting tumours, but the system is of central importance in other disorders such as scleroderma renal crisis and most cases of malignant hypertension. Activation of the renin-angiotensin system in unilateral renal artery stenosis is pivotal to the development of hypertension and the disturbances in electrolyte and volume balance - most particularly in the hyponatraemic-hypertensive syndrome. Likewise, stimulation of the renin-angiotensin system is an important contributor, amongst many other systems, to the pathophysiology of cardiac failure. In diabetic nephropathy, the renin-angiotensin system is often suppressed as gauged by circulating levels of renin, yet it appears to make an important contribution to the progressive decline in renal function. Much less clear is the role of the renin-angiotensin system in essential hypertension insofar as it contributes to the level of blood pressure, to the development of left ventricular hypertrophy, and in the evolution of complications such as stroke and myocardial infarction. Blockade of the renin-angiotensin system with angiotensin-converting enzyme inhibitors has contributed to our understanding of the role of this system in cardiovascular disease. The advent of selective angiotensin II type-1 receptor blockers will further increase knowledge in this area.
93 citations
TL;DR: Irbesartan was as effective as the full dose range of enalapril and demonstrated an excellent tolerability profile, compared with other AII receptor antagonists.
Abstract: A randomised, double-blind comparison of the angiotensin II receptor antagonist, irbesartan, with the full dose range of enalapril for the treatment of mild-to-moderate hypertension
92 citations
TL;DR: It is concluded that the hearts of postmenopausal women respond more susceptibly to the concurrence of hypertension and obesity, and the prognostically less favourable concentric lvh is a common finding.
Abstract: Recent reports indicate that the prognostic implications of left ventricular hypertrophy (LVH) are more profound in women than in men. The prognosis of LVH is also related to the underlying geometric pattern. We therefore assessed the relation of separate and concurrent influences of obesity and hypertension on gender-specific patterns of LV adaptation. Five hundred and twenty participants of a community-based study (aged 52 to 67 years) were examined by M-mode echocardiography. Study subjects were divided into four groups: normals, obese, hypertensives, and subjects presenting with both obesity and hypertension. The groups were compared for various measures of left ventricular mass (LVM) and geometry. Relative to normal subjects, the increments in wall thickness, ventricle diameters, and LVM were all significant and of similar magnitude for obese men and women. Likewise, hypertensive men and women showed similar relative increments of LVM and wall thickness but no changes in end-diastolic internal diameters. Accordingly, obesity was predominantly associated with eccentric hypertrophy (men +/- 14%, women +17%, P<0.05 vs normals) and hypertension with concentric hypertrophy (men +16%, women +30%, P<0.01 vs normals). Women with concurrent obesity and hypertension presented with a further increase of LVM and wall thickness above values in the merely obese or hypertensive (P<0.001) and they displayed LVH more frequently than only obese or hypertensive women (P<0.05). We conclude that the hearts of postmenopausal women respond more susceptibly to the concurrence of hypertension and obesity. In particular the prognostically less favourable concentric LVH is a common finding. Our study may help to explain the higher risk associated with LVH in women.
TL;DR: Nebivolol, a long-acting, cardioselective, vasodilating beta-blocker which acts partly via the l-arginine/nitric oxide mechanism, appears potentially valuable for the treatment of hypertension.
Abstract: A double-blind, randomised, parallel-group trial was conducted in patients with essential hypertension in British general practices, of nebivolol 5 mg, atenolol 50 mg, and placebo each given once daily. Both active drugs, in comparison with placebo, caused highly significant and similar reductions in systolic and diastolic pressures without orthostatic effect, and small significant falls in heart rate. Both active drugs were well tolerated, nebivolol marginally more so. Nebivolol, a long-acting, cardioselective, vasodilating beta-blocker which acts partly via the l-arginine/nitric oxide mechanism, appears potentially valuable for the treatment of hypertension.
TL;DR: White coat hypertension is indeed associated with a larger left ventricular muscle mass than normotensives and these changes are independent of the actual 24-h BP load, and may reflect increased BP lability, sympathetic nervous system derangement, or a genetic propensity in people with white coat hypertension to stress-related hypertensive reactions, as part of a pre-hypertensive state.
Abstract: Background: The issue as to whether white coat hypertension is a pathologically significant entity, with associated target organ changes, or that the condition carries the same risk for target organ involvement as normotension, is undecided. Previous studies which have shown pathological correlates between white coat hypertension and target organ damage have not controlled for the most obvious confounder, mean 24 h blood pressure (BP). Methods and results: In this study we retrospectively identified 33 age and sex-matched pairs, one group with normal BP, the other with white coat hypertension. The white coat hypertensive group showed significantly greater left ventricular mass indexed for body surface area than normal controls (99.0 g/m 2 vs 78.3 g/m 2 , P < 0.001). The population was then further matched for 24-h mean BP (20 pairs), and was again compared for cardiac muscle changes. The significantly increased left ventricular mass index in the white coat population remained after controlling for 24-h mean BP (101.1 g/m 2 vs 81.0 g/m 2 , P< 0.021). Conclusion: White coat hypertension is indeed associated with a larger left ventricular muscle mass than normotensives and these changes are independent of the actual 24-h BP load, and may reflect increased BP lability, sympathetic nervous system derangement, or a genetic propensity in people with white coat hypertension to stress-related hypertensive reactions, as part of a pre-hypertensive state.
TL;DR: Losartan was well tolerated and produced a significant reduction in BP and left ventricular mass in hypertensive patients, and a remarkable reduction in left Ventricular mass index was reached.
Abstract: This study evaluated the anti-hypertensive efficacy, tolerability and effects on left ventricular mass of losartan, a selective angiotensin II receptor antagonist, after 22 months in patients with essential hypertension. The study included 77 hypertensive patients who were randomised at baseline to 22 months double-blind once-daily treatment with losartan 50 mg (L group n = 44 patients, mean age 54+/-9 years) or hydrochlorothiazide 25 mg (HCTZ group, n = 33 patients, mean age 56+/-7 years). Routine haematology, blood chemistry, standard electrocardiography, echocardiography and ambulatory non-invasive 24-h blood pressure (BP) monitoring were performed at baseline and after 10 and 22 months. The results showed good tolerability and a significant mean systolic and diastolic BP reduction in all groups (L group: 22 mm Hg and 11 mm Hg; HCTZ group: 11 mm Hg and 7 mm Hg, respectively for systolic and diastolic mean BP). Moreover, a remarkable reduction in left ventricular mass index was reached after 10 and 22 months only in the L group (L group: delta = -11 g/m2, P<0.02; HCTZ group: delta = -5 g/m2, P= 0.38). In conclusion, losartan was well tolerated and produced a significant reduction in BP and left ventricular mass in hypertensive patients
TL;DR: The function of the AT2 receptor is far from clear but this receptor appears to be important in fetal development, cell growth inhibition and differentiation processes and this review focuses on the possible functions of the At2 receptor.
Abstract: Angiotensin II mediates its effects through angiotensin receptors. The use of specific angiotensin receptor ligands and the cloning of these receptors allows their classification. So far, the AT1, AT2 and atypical angiotensin II receptors are recognised. The AT1 receptor is responsible for the classical effects of the renin-angiotensin system such as vasoconstriction, renal salt and water retention, central osmo-control and stimulation of cell growth. The function of the AT2 receptor is far from clear but this receptor appears to be important in fetal development, cell growth inhibition and differentiation processes. This review describes the angiotensin receptors and focuses on the possible functions of the AT2 receptor.
TL;DR: These results are unlikely to be due to unrelated secular trends, but seem to reflect a real relation between magnetic field disturbances and BP.
Abstract: Objective: Episodic reports suggest that geomagnetic disturbances of solar origin are associated with biological and clinical events, including increased arterial blood pressure (BP). We reassessed this aspect by relating solar activity levels to ambulatory BP measured in our out-patient population. Patients and methods: The ambulatory BP measurements of 447 consecutive untreated patients attending a hypertension out-patient clinic who did a monitoring for diagnostic purposes over 5 years were retrieved. The mean daytime, night-time and 24-h BP and heart rate values were related to the temporally corresponding geomagnetic index k-sum obtained by the nearest observatory. K-sum is a local measurement of the irregular disturbances of the geomagnetic field caused by solar particle radiation. Results: Significant to highly significant positive correlations were observed for k-sum with systolic (daytime and 24 h) and diastolic BP (daytime, night-time and 24 h), but not with heart rate. No correlations were found with the k-sum of 1 or 2 days before the monitorings. Multiple correlations which also included other potential confounding factors (date, age) confirmed a significant effect of k-sum on BP. Comparison made in season-matched subgroups of quiet and disturbed days (using three different criteria of definition), always showed significantly higher values in the disturbed days for all BP parameters except systolic night-time pressure. The difference between the quietest and the most disturbed days was of about 6 to 8 mm Hg for 24-h systolic and diastolic BP. Conclusion: These results are unlikely to be due to unrelated secular trends, but seem to reflect a real relation between magnetic field disturbances and BP.
TL;DR: The metabolic syndrome is more strongly associated with hyperinsulinaemia than with obesity but it is relatively uncommon in men with no history of cardiovascular disease or diabetes, and hypertensives were more likely to have lipid abnormalities and clustering of risk factors than normotensives even after adjustment for BMI.
Abstract: Background and aims: In recent years it has been proposed that hypertension is part of a cluster of metabolic risk factors (syndrome X) involving hyperlipidaemia and hyperglycaemia, with hyperinsulinaemia as the common link. This study has investigated: (1) the prevalence of the metabolic syndrome and its component variables and their relationship to body mass index (BMI) and non-fasting insulin levels in a general population; and (2) the distribution and clustering of metabolic variables in normotensives and hypertensives. Methods: Cross-sectional study of 5222 men aged 40-59 years with no history of coronary heart disease (CHD), diabetes mellitus or stroke drawn from general practices in 18 British towns. The men were a subgroup of the 7735 men in the British Regional Heart Study (BRHS) cohort whose baseline non-fasting serum was analysed for insulin, using a specific ELISA method. Main outcome measures: Hyperinsulinaemia, hyperglycaemia, high serum total cholesterol, high triglyceride and hyperuricaemia were defined as the top 20% of the distribution in the 5222 men. Low HDL-cholesterol was defined as the bottom 20%. Results: BMI and non-fasting insulin were both significantly and strongly associated with non-diabetic hyperglycaemia, lipid abnormalities (HDL-cholesterol, triglyceride and total cholesterol) and hyperuricaemia. BMI was strongly associated with hypertension whereas non-fasting insulin showed a much weaker relationship which was abolished after adjustment for BMI. However, only 2.9% of men showed the 'full metabolic syndrome' (hypertension, hyperglycaemia and dyslipidaemia) and a large proportion of these men were hyperinsulinaemic (65%) or obese (47%). Dyslipidaemia (any one of low-HDL-cholesterol, high triglyceride or high cholesterol) was common in both normotensives and hypertensives (40.5% vs 46.4%). Hypertensives showed significantly higher levels of total cholesterol, triglyceride, blood glucose, urate and more clustering of hyperglycaemia and dyslipidaemia than normotensives even after adjustment for BMI. Conclusion: Hypertensives were more likely to have lipid abnormalities and clustering of risk factors than normotensives even after adjustment for BMI. The metabolic syndrome is more strongly associated with hyperinsulinaemia than with obesity but it is relatively uncommon in men with no history of cardiovascular disease or diabetes. Given the weak relationship between hypertension and hyperinsulinaemia, the latter is unlikely to explain the higher levels of lipid abnormalities and clustering seen in hypertensives. Overweight/obesity may be primarily involved in the pathways to hypertension and lipid abnormalities but the unravelling of these relationships require more specific measures of adipose tissue distribution, composition and function.
TL;DR: It appears that nitrates better than other anti-hypertensive drugs can decrease pulse pressure, and should be advocated for the treatment of isolated systolic hypertension.
Abstract: With aging, pulse pressure increases. A high pulse pressure has been recognised as an important cardiovascular risk factor. The increase in pulse pressure with aging is mainly due to a decrease in large artery compliance. Compliance and distensibility are large artery wall properties. Compliance is the buffering capacity of the vessel. Distensibility reflects much more the elasticity of the artery. Compliance is related to distensibility and arterial diameter. These large artery wall properties can be measured non-invasively using new echo-tracking techniques. With these techniques it has been shown that the elasticity (distensibility) and the buffering capacity (compliance) of the common carotid artery is decreasing with aging, while diameter of the artery increases. This increase in diameter might be a compensating mechanism to limit the decrease in compliance. There are indications that the effect of aging on large artery wall properties may not be similar at all vascular territories. A decrease in compliance leads to a high pulse pressure and isolated systolic hypertension. The drug of choice for the treatment of isolated systolic hypertension should increase large artery compliance with no, or only minor effect on resistance vessels. This would lead to a decrease in pulse pressure without decreasing mean blood pressure. As a result, systolic but not diastolic blood pressure decreases. It appears that nitrates better than other anti-hypertensive drugs can decrease pulse pressure. They therefore have been advocated for the treatment of isolated systolic hypertension.
TL;DR: Hypothyroidism is a potentially important but overlooked cause of hypertension and restoration of euthyroidism with thyroxine therapy usually results in a substantial reduction in both systolic and diastolic blood pressure, especially in younger subjects.
Abstract: Correction of the causes of secondary forms of hypertension usually restores blood pressure to normal. Hypothyroidism is a potentially important but overlooked cause of hypertension and restoration of euthyroidism with thyroxine therapy usually results in a substantial reduction in both systolic and diastolic blood pressure, especially in younger subjects. The mechanism of hypertension in hypothyroidism is not completely understood: changes in circulating catecholamines, their receptors and the renin-angiotensin-aldosterone system have all been implicated. Effective treatment with thyroxine is readily available and inexpensive.
TL;DR: The analysis will assess the resource costs in terms of extra GP visits and hospitalisations arising from individuals switching and discontinuing treatments and the total costs of hypertension were estimated to be around £76.5 m per annum.
Abstract: There is much evidence to suggest that the treatment of hypertension reduces the risk of cardiovascular diseases and that it is cost-effective in most patients. However, the effectiveness of treatment relies on compliance and maintenance of treatment. Each pharmacological agent differs in terms of side effects. The existence of side effects can result in poor compliance and switching between treatments. A number of studies have reported high discontinuation rates for anti-hypertensive therapies. This potentially imposes costs on the health service. The aim of this study is to use the MEDIPLUS data set to consider the cost arising from switching and discontinuation of therapy. The analysis will assess the resource costs in terms of extra GP visits and hospitalisations arising from individuals switching and discontinuing treatments. The total costs of hypertension were estimated to be around 76.5 m pound sterling per annum, of which 26.9 m pound sterling can be attributed to patients who switch or discontinue therapy.
TL;DR: Previous evidence that hormone replacement therapy is safe in hypertensive, postmenopausal women is supported, and the data in the present study imply an acute, but small reduction of daytime bp due to transdermally administered 17-β-oestradiol in hypertension, furthermore oestrogen did not blunt or increase the dipping phenomena during the night in these women.
Abstract: The aim of this study was to investigate the acute effects of transdermally administered 17-beta-oestradiol on ambulatory blood pressure (BP) in hypertensive, postmenopausal women Thirteen postmenopausal women with ongoing treatment for hypertension were included in this placebo-controlled, double-blind cross-over study Ambulatory recordings of BP and heart rate were performed during 24 h on two occasions, separated by at least 1 week, after application of a patch containing either 100 microg per 24 h 17-beta-oestradiol or placebo Serum oestradiol was increased (P<0001) during active treatment (1392 +/- 211 pg/ml) compared with the baseline postmenopausal levels recorded during placebo (405 +/- 22 pg/ml) No rise in BP was found in office BP or during ambulatory recordings Daytime BP pressure was acutely reduced by approximately 3 mm Hg during the 24 h of treatment with oestrogen (SBP ns, DBP P<005), without any change in heart rate Nocturnal dipping in SBP and DBP was present during placebo conditions, and there were no signs of an increase in dipping during treatment with 17-beta-oestradiol This study supports previous evidence that hormone replacement therapy is safe in hypertensive women The data in the present study also imply an acute, but small reduction of daytime BP due to transdermal oestrogen in hypertensive, postmenopausal women Furthermore oestrogen did not blunt or increase the dipping phenomena during the night in these women
TL;DR: Risk indicators usually labelled as ‘minor’ (serum uric acid, ventilatory function or proteinuria), do have a strong predictive value in these individuals, and must be taken into account when evaluating the cumulative risk of the elderly, in order to avoid overtreatment of subjects with mildly elevated BP or cholesterol.
Abstract: Although a number of risk factors for cardiovascular morbidity and mortality have been identified in young and middle-aged adults, their prevalence and importance are less known in the elderly. Elderly people have a risk profile different from that of younger subjects, but representative data on risk factors for cardiovascular disease in the elderly are difficult to find in the literature. Some typical 'major' risk factors, like blood pressure (BP), total cholesterol or left ventricular hypertrophy, do not have a clear predictive role for cardiovascular mortality in the elderly, especially in the extreme ages, while risk indicators usually labelled as 'minor' (serum uric acid, ventilatory function or proteinuria), do have a strong predictive value in these individuals. This must be taken into account when evaluating the cumulative risk of the elderly, in order to avoid overtreatment of subjects with mildly elevated BP or cholesterol.
TL;DR: The necessity to carefully balance the benefits and risks of anti-hypertensive therapy in the elderly indicates that patients with suspected ISH should undergo careful BP measurements on at least three different occasions before the diagnosis is established and an orthostatic reaction should be evaluated.
Abstract: During recent decades the importance of perceiving isolated systolic hypertension (ISH) in cardiovascular pathophysiology has been changed from a benign condition to the major cardiovascular risk factor. Aging is per se associated with the deterioration in arterial compliance through both structural and functional changes in large arteries which mainly involves the intima and media. The observed changes result in a decrease of the lumen-to-wall ratio, the overall lumen cross-sectional area and an increase of arterial stiffness which especially involve the aorta and other elastic arteries. In addition to the structural changes in vessel walls, aging is associated with certain functional changes such as an increase in sympathetic system activity probably due to the age-related decreased sensitivity of beta-receptors. While the function of arterial wall alpha-receptors remains intact, in elderly subjects a shift towards arterial vasoconstriction can be observed. In many of the published studies the definition of ISH was based on the criterion 160/95 mm Hg or 160/90 mm Hg while in recognition of the high risk associated with systolic blood pressure (SBP) the WHO/ISH guidelines and Report of the Sixth Joint National Committee on Hypertension indicated that ISH should be diagnosed with SBP as > or =140 mm Hg and diastolic BP (DBP) as <90 mm Hg. Thus the setting down of normal values of SBP will lead to an earlier diagnosis and treatment of ISH. Several prospective studies, such as the US Hypertension Detection and Follow-up Programme, confirmed this and the Multiple Risk Factor Intervention Trial demonstrated that for any given level of DBP, higher SBP was associated with an increase in cardiovascular risk. Moreover, data from the Framingham Study show that ISH was associated not only with increased mortality but also cardiovascular morbidity. Risk of non-fatal stroke and myocardial infarction was increased three and two-times respectively in the presence of ISH. Three major up-to-date studies that included patients with ISH have been published. In concordance to the previously published SHEP and MCR trials, the most recent, the Systolic Hypertension in the Elderly Trial (SYST-EUR), demonstrated that active treatment significantly reduces the risk of stroke and all fatal and non-fatal cardiac end-points, including sudden death. Of note, these benefits were demonstrated with new anti-hypertensive classes such as dihydropiridyne calcium channel blocker (nitrendipine) and the angiotensin-converting enzyme inhibitor (enalapril). The necessity to carefully balance the benefits and risks of anti-hypertensive therapy in the elderly indicates that patients with suspected ISH should undergo careful BP measurements on at least three different occasions before the diagnosis is established and an orthostatic reaction should be evaluated. If non-pharmacological procedures fail, drug therapy should be considered, especially in elderly patients with a SBP over 160 mm Hg, since their risk of complications is markedly higher. Pharmacological treatment should also be strongly considered in patients with a SBP between 140 and 160 mm Hg with such concomitant cardiovascular risk factors as diabetes, angina pectoris, and left ventricular hypertrophy. The drug regimen should be simple, starting with a low dose of a single drug that is titrated slowly. The selection of the first-line anti-hypertensive agent should be based on a careful assessment of pathophysiological and clinical parameters in each individual geriatric patient.
TL;DR: It now appears, that the renin-angiotensin system is more complex than previously thought and capable of generating multiple, active peptides which elicit numerous diverse actions.
Abstract: Angiotensin II is recognised as the principle active peptide of the renin-angiotensin system, exerting effects on fluid and electrolyte homeostasis, and cardiovascular control including neural and long term trophic effects. However, recent studies indicate that other angiotensin peptides such as angiotensin III, angiotensin II (1-7) and angiotensin IV, may have specific actions. Interestingly, recent work involving angiotensin IV demonstrates that this peptide binds to specific receptors and may be involved in memory retention and neuronal development. Furthermore, our demonstration that a globin fragment, LVV-haemorphin-7, binds with high affinity to the angiotensin IV binding site and is abundant in the brain, indicates that this may represent a novel brain neuropeptide system. It now appears, that the renin-angiotensin system is more complex than previously thought and capable of generating multiple, active peptides which elicit numerous diverse actions.
TL;DR: Arterial hypertension is highly prevalent in this elderly population; awareness and BP control are within acceptable ranges but there is still room for improvement, particularly in elderly men.
Abstract: Objective: To study the prevalence, awareness, treatment and control of arterial hypertension in the elderly population in Belgium. Study group: An age- and sex-stratified sample of 2212 Belgian subjects aged 65 years or more, selected from the original cohort of the Belgian Interuniversity Research on Nutrition and Health (BIRNH) study; participation in this follow-up study was 72.6%. Methods: Blood pressure (BP) was measured at home by trained technicians using a standard protocol. Isolated systolic hypertension (ISH) was defined as a systolic BP ⩾160 mm Hg and a diastolic BP 75-year-old subjects this elevation was in two-thirds of the cases due to ISH; 84% of all female hypertensives were aware of the condition compared to 68% in men. Treatment advice had been given in a majority of the aware subjects and two-thirds of all treated persons was under control. Among a variety of independent variables and besides the gender difference, awareness was only related to smoking and to depression while control differed by region of residence. Conclusion: Arterial hypertension is highly prevalent in this elderly population; awareness and BP control are within acceptable ranges but there is still room for improvement, particularly in elderly men.
TL;DR: Although there remains a difference in socioeconomic profile between those of African and of European origin in Cuba, this has decreased over recent decades, suggesting that social, economic and psychological factors may play an important role in the observed racial gap in cardiovascular risk.
Abstract: The Caribbean nation of Cuba is comprised of over 10 million persons who trace their ancestry primarily to Africa and Spain. To date, little data on blood pressure (BP) or hypertension prevalence from Cuba have appeared in English language journals. Because the current government has pursued an active policy of reducing social differentiation on the basis of ethnic origin, Cuba provides an important population laboratory from which to advance the understanding of black-white differences in BP and hypertension. The authors conducted a population-based random sample among adults (aged > 15 years) in the city of Cienfuegos. Overall response rate was 95%, yielding 1633 participants who provided BP readings, self-reported racial group, demographic information, and treatment status. Overall prevalence of hypertension (SBP > or = 140 mm Hg or DBP > or = 90 mm Hg or currently treated) was 44% (46% among blacks and 43% whites; P = 0.19). Excess BP among black subjects was reduced slightly by excluding those under treatment, but attained statistical significance after adjustment for sex and age (P = 0.01). The black-white difference was small, however, relative to that observed in the United States. Racial differences in treatment status and control were also observed. Although there remains a difference in socioeconomic profile between those of African and of European origin in Cuba, this has decreased over recent decades. In the United States, the greater magnitude of social differentiation parallels a greater relative risk of BP elevation among blacks, suggesting that social, economic and psychological factors may play an important role in the observed racial gap in cardiovascular risk.
TL;DR: In vitro and in vivo findings suggest that local tissue AT1 receptor stimulation, being accompanied by the increased gene expression of TGF-β1 and extracellular matrix components may partially contribute to the pathogenesis of cardiovascular end-organ damage.
Abstract: Angiotensin AT 1 receptor antagonism and protection against cardiovascular end-organ damage
TL;DR: Results indicate that higher bp was associated with a relatively greater proportion of sodium and potassium excretion at night, compared to the second or third 24-h period, and further work is needed to clarify temporal sequence.
Abstract: The objective of this study was to examine associations of blood pressure (BP) with ratios of overnight to 24-h urinary excretion of sodium, potassium, and water. Each of 125 men 27-64 years of age, not taking diuretics, had BP measured during the day on a Monday. Beginning Monday evening, each participant provided three carefully timed 24-h urine collections, divided into daytime and overnight (bedtime to awakening) specimens. Proportion of total 24-h excretion of sodium, potassium, and water in the overnight specimen, standardised for creatinine excretion, was determined for each 24-h period. Associations of systolic and diastolic BP (SBP/DBP) with these proportions were examined with control for age, body mass index, alcohol intake, and heart rate. Mean BP was 116/71 mm Hg; 15 men were on non-diuretic anti-hypertensive therapy. Mean 24-h urinary excretion was 168 mmol for sodium, 68 mmol for potassium, and 16 mmol for creatinine. Mean overnight to 24-h proportions averaged over the 3 days were 30.7% for sodium, 22.0% for potassium, 32.1% for urinary volume, and 33.2% for creatinine. Partial correlations of SBP and DBP with the 3-day averages were 0.257 (P < 0.01) and 0.210 (P < 0.05) for sodium; 0.223 (P < 0.05) and 0.222 (P < 0.05) for potassium; 0.127 and 0.091 for urinary volume; and -0.033 and 0.014 for creatinine. Correlations for sodium proportions were larger for the first 24-h period, compared to the second or third 24-h period. These results indicate that higher BP was associated with a relatively greater proportion of sodium and potassium excretion at night. Further work is needed to clarify temporal sequence, ie, whether a relatively greater sodium and potassium excretion at night is a risk factor for higher BP (eg, via renal mechanisms), or whether higher BP results in relatively greater sodium and potassium excretion at night, or both.
TL;DR: It is confirmed that essential hypertension is associated with a defect in endothelium-dependent vasodilation (EDV) and an improvement in EDV was seen in hypertensive patients shortly after administration of captopril, but not nifedipine.
Abstract: The present study aimed to investigate the influence of the angiotensin-converting enzyme (ACE)-inhibitor captopril and the Ca-antagonist nifedipine on endothelium-dependent vasodilation (EDV) in the forearm of hypertensive patients. Twenty-three middle-aged untreated hypertensive patients underwent evaluation of EDV and endothelium-independent vasodilation (EIDV) in the forearm, by means of local intra-arterial infusions of methacholine (MCh, evaluating EDV) and sodium-nitroprusside (SNP, evaluating EIDV), before and 1 h after intake of either captopril (25 mg) or nifedipine (10 mg) in a randomised, double-blind fashion. A matched normotensive control group was investigated at baseline conditions only. Five of the hypertensives were also evaluated after 3 months of treatment with captopril 25 mg twice daily in an open pilot study. First, the vasodilation induced by methacholine (MCh), but not SNP, was significantly attenuated in the hypertensive patients compared to the normotensive controls (P < 0.001 at MCh 4 microg/min). Second, although the two drugs induced a similar decline in blood pressure (BP) 1 h after administration (-11 to 10 mm Hg/-8 to 7 mm Hg), captopril significantly potentiated the vasodilator response to MCh (+32+/-13%, MCh 4 micr og/min, P < 0.01) but not SNP, while nifedipine did not significantly alter the response to either MCh or SNP. The improvement in vasodilator response to MCh induced by captopril was closely related to the reduction in BP (r = 0.72, P < 0.01). Third, in the pilot study, 3 months of captopril treatment induced a significant potentiation of the vasodilator response to MCh (+34+/-17%, MCh 4 microg/min, P < 0.05) in parallel with a significant BP reduction (-22+/-24/13+/-13 mm Hg, P < 0.05), while the response to SNP was unchanged. In conclusion, the present study confirmed that essential hypertension is associated with a defect in EDV. Furthermore, an improvement in EDV was seen in hypertensive patients shortly after administration of captopril, but not nifedipine. In addition, a significant beneficial effect on EDV was seen in a small pilot study during long-term treatment with captopril.
TL;DR: Using an atraumatic non-invasive procedure, it was possible to show that ACE inhibition is able to maintain pulse pressure amplification, an important factor contributing to reduce the afterload of the heart.
Abstract: In subjects with essential hypertension, angiotensin-converting enzyme (ACE) inhibition increases arterial diameter, compliance and distensibility of peripheral muscular arteries in association with blood pressure reduction. Whether pulse pressure amplification is modified by ACE inhibition and whether changes in compliance and distensibility are due to a drug effect on the arterial wall, to the blood pressure reduction or to a combination of both factors, is largely ignored. In a randomised, double-blind crossover trial, we used the ACE inhibitor quinapril as a marker to evaluate the changes in: pulse pressure amplification (applanation tonometry), carotid compliance and distensibility (echo-tracking technique), and aortic distensibility (measured from pulse wave velocity). Quinapril decreased in the same extent carotid and brachial pulse pressure, thus causing a resetting of pulse pressure amplification toward normal values. Carotid compliance and distensibility as well as aortic distensibility increased significantly. Based on three-way analysis of variance, it was shown that, whereas the changes in carotid stiffness were exclusively due to blood pressure reduction and not to a drug-induced relaxation of the arterial wall, the changes in aortic distensibility were due to the combination of both factors. Thus, using an atraumatic non-invasive procedure, it was possible to show that: (i) ACE inhibition is able to maintain pulse pressure amplification, an important factor contributing to reduce the afterload of the heart; and (ii) ACE inhibition alters the hypertensive arterial wall in a very heterogeneous manner, with a maximal drug effect on muscular large arteries like the abdominal aorta, and not on elastic arteries like the carotid artery and the thoracic aorta.