Showing papers by "Tomi Laitinen published in 2003"

Cardiovascular risk factors in childhood and carotid artery intima-media thickness in adulthood: the Cardiovascular Risk in Young Finns Study.

Abstract: ContextExposure to cardiovascular risk factors during childhood and adolescence may be associated with the development of atherosclerosis later in life.ObjectiveTo study the relationship between cardiovascular risk factors measured in childhood and adolescence and common carotid artery intima-media thickness (IMT), a marker of preclinical atherosclerosis, measured in adulthood.Design, Setting, and ParticipantsPopulation-based, prospective cohort study conducted at 5 centers in Finland among 2229 white adults aged 24 to 39 years who were examined in childhood and adolescence at ages 3 to 18 years in 1980 and reexamined 21 years later, between September 2001 and January 2002.Main Outcome MeasuresAssociation between cardiovascular risk variables (levels of low-density lipoprotein cholesterol [LDL-C], high-density lipoprotein cholesterol [HDL-C], and triglycerides; LDL-C/HDL-C ratio; systolic and diastolic blood pressure; body mass index; smoking) measured in childhood and adulthood and common carotid artery IMT measured in adulthood.ResultsIn multivariable models adjusted for age and sex, IMT in adulthood was significantly associated with childhood LDL-C levels (P = .001), systolic blood pressure (P<.001), body mass index (P = .007), and smoking (P = .02), and with adult systolic blood pressure (P<.001), body mass index (P<.001), and smoking (P = .004). The number of risk factors measured in 12- to 18-year-old adolescents, including high levels (ie, extreme age- and sex-specific 80th percentile) of LDL-C, systolic blood pressure, body mass index, and cigarette smoking, were directly related to carotid IMT measured in young adults at ages 33 through 39 years (P<.001 for both men and women), and remained significant after adjustment for contemporaneous risk variables. The number of risk factors measured at ages 3 to 9 years demonstrated a weak direct relationship with carotid IMT at ages 24 to 30 years in men (P = .02) but not in women (P = .63).ConclusionsRisk factor profile assessed in 12- to 18-year-old adolescents predicts adult common carotid artery IMT independently of contemporaneous risk factors. These findings suggest that exposure to cardiovascular risk factors early in life may induce changes in arteries that contribute to the development of atherosclerosis.

Weight loss and weight maintenance, ambulatory blood pressure and cardiac autonomic tone in obese persons with the metabolic syndrome.

Abstract: BackgroundCardiac autonomic function may play a role in obesity-associated hypertension. Most studies on the effects of weight loss on blood pressure and autonomic function do not distinguish between acute or continuing weight loss and steady-state weight maintenance after weight loss. ObjectivesWe

First-pass MR imaging in the assessment of perfusion impairment in patients with hypertrophic cardiomyopathy and the Asp175Asn mutation of the alpha-tropomyosin gene.

Abstract: PURPOSE: To assess first-pass magnetic resonance (MR) imaging in the evaluation of perfusion impairment in a genetically homogeneous population of patients with hypertrophic cardiomyopathy (HCM) and the Asp175Asn mutation of the α-tropomyosin gene and to evaluate the association between hypertrophy and perfusion. MATERIALS AND METHODS: Rest-stress first-pass MR imaging with gadopentetate dimeglumine was performed in 17 patients with HCM and the Asp175Asn substitution in the α-tropomyosin gene and in five control subjects. Global and segmental first-pass reserve index (FPR) measurements were derived from signal intensity versus time curves. Left ventricular (LV) wall thickness and LV mass index were measured on cine MR images. The Mann-Whitney test was used to evaluate the difference in FPR between the patient group and the control group. The Spearman correlation was used to evaluate the association between LV hypertrophy and FPR. RESULTS: Global FPR was significantly lower in the patients with HCM than in...

Effects of euglycaemic and hypoglycaemic hyperinsulinaemia on sympathetic and parasympathetic regulation of haemodynamics in healthy subjects.

Abstract: The effects of hypoglycaemia during hyperinsulinaemia, occurring under various pathophysiological conditions, on the cardiovascular regulatory system and vasculature are largely unknown. The aim of the present study was to investigate regulatory and haemodynamic responses to acute hyperinsulinaemia and consequent hypoglycaemia in 18 healthy subjects. Blood sampling and 5 min ECG and blood pressure recordings were performed at baseline and during the euglycaemic and hypoglycaemic phases of a hyperinsulinaemic clamp. Heart rate variability (HRV) and blood pressure variability (BPV) were assessed by using power spectral analysis, and baroreflex sensitivity (BRS) was assessed using the cross-spectral method. Stroke volume was assessed from the non-invasive blood pressure signal by the arterial pulse contour method. Euglycaemic hyperinsulinaemia did not change plasma catecholamine concentrations, HRV, BPV, BRS, heart rate, blood pressure, stroke volume, cardiac output or peripheral resistance. However, hyperinsulinaemic hypoglycaemia resulted in an 11.7-fold increase in the plasma adrenaline concentration (from 0.19 + 0.03 to 1.68 + 0.32 nmol/l;P < 0.001), and a modest 1.3-fold increase in the plasma noradrenaline concentration (from 1.74 + 0.22 to 2.02 + 0.19 nmol/l; P < 0.05) compared with baseline. Furthermore, we observed significant decreases in diastolic blood pressure (from 68 + 3t o 60+ 3 mmHg; P < 0.05) and peripheral resistance (from 24.1 + 1.2 to 18.5 + 1.1 mmHg · min −1 · l −1 ; P < 0.01). Stroke volume and cardiac output increased markedly from the euglycaemic to the hypoglycaemic period only (P < 0.01 for both). Hypoglycaemia did not influence HRV, BPV or BRS. Our findings indicate that hyperinsulinaemic hypoglycaemia is characterized by a significant increase in the plasma adrenaline concentration and by decreases in peripheral resistance and blood pressure. Counter-regulation during hyperinsulinaemic hypoglycaemia involves selective adrenomedullary sympathetic activation, and does not influence cardiac parasympathetic regulation or baroreflex control of heart rate.

Short-term blood pressure variability in renovascular hypertension and in severe and mild essential hypertension.

Abstract: This study was designed to examine short-term blood pressure variability (BPV) in patients with different severity and forms of chronic medically treated hypertension. Power spectral analysis of BPV was performed from continuous finger blood pressure (Finapres) recordings. Ten patients with renovascular hypertension (RVHT), 34 with severe essential hypertension (SEHT) and 29 with mild essential hypertension (MEHT) as well as healthy age- and sex-matched control subjects were studied. The RVHT group was characterized by reduced low frequency (LF) power of both systolic and diastolic BPV (P =0.004 and P =0.003 respectively) when compared with the control group. There was also a tendency to lower total power of diastolic BPV (P =0.094). On the contrary, the SEHT group had increased total power of diastolic BPV (P =0.044). However, in the SEHT group, we found no differences in the LF and high frequency power of systolic and diastolic BPV when compared with controls. The MEHT group presented with lower LF power of systolic and diastolic BPV (P =0.028 and P =0.003 respectively) and, in addition, high frequency power of diastolic BPV was lower than in the control group (P =0.020). When the hypertensive groups were compared with each other, total power and LF power of diastolic BPV (P =0.043 and P =0.039 respectively) were lower in the RVHT group than in the SEHT group. In addition, total power of diastolic BPV was lower (P =0.030) in the MEHT group than in the SEHT group. No differences were observed in BPV between the RVHT and MEHT groups. The results show that BPV in hypertensive patients groups behaved differently. This suggests that both the aetiology and severity of hypertension have a significant influence on short-term BPV measured in laboratory conditions and that different control mechanisms are operating in these clinically distinctly different hypertension groups.

Prolonged corrected QT interval is associated with acute and chronic hyperinsulinemia in nondiabetic subjects.

Abstract: Foussas et al. (1) observed that in type 2 diabetic patients intensive insulin treatment during acute coronary syndrome was associated with decreased QT dispersion, while the heart rate–corrected QT (QTc) interval tended to increase. This may be of concern because QTc prolongation is known to increase the risk of ventricular arrhythmia and sudden death. However, prognosis of diabetic patients with acute myocardial infarction can be improved by treatment of hyperglycemia with insulin (2). Apart from myocardial ischemia and infarction, different factors in diabetic patients contribute to the duration of QTc interval, such as insulin resistance, glucose …

Principal component regression approach for qt variability estimation principal component regression approach for qt variability estimation

Abstract: QT interval within an electrocardiogram (ECG) presents a measure for ventricular repolarization duration. In this paper, a new algorithm for quantifying the variation in the QT interval is presented. The algo- rithm is based on principal component regression and it does not necessitate the detection of T wave.