Showing papers in "International Journal of Obesity in 1981"

The health consequences of moderate obesity.

Abstract: A longitudinal study of 855 50-year-old Swedish men, and a cross-sectional study of 50- and 60-year-old men examined the relationship between initial obesity and health status. Anthropometric measurements (body mass index, skinfold thicknesses, total body fat) were used to define degree of obesity; subjective, behavioral and clinical indices of health were analyzed. In the longitudinal study in which subjects were followed for 10-12 1/2 years, men who developed kidney stones and gallstones and diabetes were significantly more obese initially. Obesity also weakly correlated with increased risk of cerebrovascular stroke. However, obesity was not associated with subjects' recourse to medical care, with other diseases (angina, peptic ulcer, myocardial infarction) or with death. In the cross-sectional study, obese subjects tended to report more symptoms and were more likely to use prescription drugs, especially as more men being treated for hypertension were obese. Body fat was not related to subjective indicators of illness. It was concluded that obesity carries implications for health.

Gut hormone changes after jejunoileal (JIB) or biliopancreatic (BPB) bypass surgery for morbid obesity.

Abstract: The treatment of obesity by intestinal bypass provides a unique model for the investigation of gut hormone release from the functionally deranged bowel. We have examined the postprandial response of eight circulating gut or pancreatic peptide hormones in 16 preoperative obese patients, 20 patients with jejunoileal bypass, 38 patients with biliopancreatic bypass and 13 age and sex-matched controls. Basal and post-meal hormone concentrations were determined by specific radioimmunoassay methods. Reductions of the upper small intestinal hormones, motilin and gastric inhibitory polypeptide were found in both types of surgery. Conversely, the ileal hormones neurotensin and enteroglucagon were elevated following surgery. This pattern is consistent with the known distribution of these hormones. Variations of response due to surgical differences were noted for gastrin and the enteropancreatic axis, which was more markedly disturbed after biliopancreatic bypass. The alterations of hormone release closely reflect the anatomical changes induced by each particular surgical technique.

Appetitive behavior after gastric bypass for obesity.

Abstract: Eating behavior patterns were studied in 80 gastric bypass patients at 6, 12, and 24 months postoperatively. Significant reduction occurred in the amount of food eaten and in the frequency of eating. An unexpected result was the selective reduction of food eaten in certain food categories. The reduction of calorically-dense high carbohydrate foods indicates that gastric bypass surgery may have an effect on the digestion and absorption of food as well as the mechanical impairment of food intake secondary to the small stomach pouch.

Comparison of self-reported height and weight with controlled height and weight in women and men.

Abstract: Self-reported height and weight were compared with directly-measured controlled height and weight in 158 women with a median age of 34 years (16-62 years) and in 594 men with a median age of 37 (16-66 years). A model of two one-dimensional linear regressions with two independent variables was used in order to describe the combined influence of both controlled height and controlled weight on self-reported height and on self-reported weight. For both sexes there was a systematic tendency for tall and heavy persons to underestimate their height and weight and conversely for small and thin persons to overestimate these measurements. The influence of controlled weight on self-reported height was statistically significant (women: P less than 0.05; men: P approximately 0.05,) and so was the influence of controlled height on self-reported weight (women: P less than 0.002; men: P less than 0.001). The reported heights and weights of women and men converged towards a pair of desired measures for each sex, ie the values of height and weight for which the reported and the controlled values were identical. For women the desired measures were 159.6 cm and 45.2 kg, for men 176.7 cm and 68.9 kg. The demonstrated differences between self-reported and controlled body measures may invalidate data and conclusions of insurance studies and population surveys based on self-reported measures.

Cardiovascular risk factors and HDL-cholesterol levels in obesity.

Abstract: In 1332 patients with different degrees of obesity (344 men, mean age 36 +/- 13 years, Broca Index 1.46 +/- 0.23; 988 women, mean age 37 +/- 13 years, Broca Index 1.67 +/- 0.30), cardiovascular risk factors (RF), serum HDL-cholesterol, and insulin levels were investigated. The most frequent RF was diastolic hypertension (68 per cent), followed by systolic hypertension (56 per cent), glucose intolerance (55 per cent), hypertriglyceridemia (31 per cent), hyperuricemia (19 per cent) and hypercholesterolemia (18 per cent). Only 9.4 per cent of the patients were without RF, and these patients were younger and less obese than patients with RF. Compared with controls, HDL-cholesterol levels were decreased in obese patients, however, the negative linear correlation between relative body weight and HDL-cholesterol levels was only significant in women, not in men. HDL-cholesterol levels were higher in women than in men. Serum insulin levels were correlated positively with relative body weight and negatively with age. Partial correlation analysis revealed a stronger influence of age than body weight on blood pressure, serum levels of total cholesterol, LDL-cholesterol, triglycerides and blood glucose levels. Uric acid levels correlated positively, and HDL-cholesterol levels negatively with relative body weight alone and not with age. On the basis of prevalence of RF, low serum HDL-cholesterol and high insulin levels, obese patients must be considered at high risk with respect to the development of cardiovascular disease.

Insulin and renal sodium handling: clinical implications.

Abstract: Over the last ten years a large body of information has accumulated which indicates that physiologic changes in the plasma insulin concentration are capable of affecting electrolyte transport by the kidney as well as by variety of other tissues. In the present discussion the effect of insulin on the renal handling of sodium, potassium, phosphate, and calcium is reviewed, with an emphasis on sodium transport (Table 1). An attempt is made to relate the effects of insulin on sodium metabolism to four common clinical situations: (a) hypertension and obesity, (b) sodium wasting in diabetes mellitus, (c) natriuresis of starvation, and (d) sodium retention and edema following refeeding.

Epidemiology of obesity and hypertension.

Abstract: Based on the reviewed literature and the data from the dusseldorf Obesity Study there is a close association between obesity and hypertension. This association is found in adults, adolescents and children. Hypertension is the most frequent cardiovascular risk factor in obesity. The black population shows higher blood pressure levels than the white population within the same relative weight. Prospectively investigated normotensive obese subjects are more likely to develop hypertension than normal weight subjects. In Western population there is also an association between hypertension and age. This is not seen in tribal populations, where after the age of 20 years body weight does not increase, suggesting body weight to be an important factor for the regulation of blood pressure. Present epidemiological evidence strongly calls for detailed prospective studies of obesity and hypertension, in order to define particularly hypertension-prone obesity subtypes.

The historical development, efficacy and safety of very-low-calorie diets.

Abstract: The development of very-low-calorie diets (VLCD) over the lats 50 years is described, from the early work of the Pittsburgh group in 1930, using conventional food, to the present day liquid-formula diets containing all essential nutrients. Recent work has been concerned with the protein requirements of obese patients consuming 200-400 kcal (0.8-1.6MJ) VLCD. Independent studies indicate that the protein requirement is about 40-55 g/day without carbohydrate, and about 25-30 g/day when carbohydrate (30-45 g/day) is included. Although some workers use VLCD consisting only of protein, the author prefers those also containing carbohydrate because they prevent excessive ketosis, hyperuricemia, diuresis, electrolyte loss, re-feeding oedema, and may improve muscular endurance. Numerous clinical trials have shown VLCD to be highly effective in about 80 per cent of outpatients and give an average weight loss of 2 kg/week which is comparable to that seen in complete starvation. Clinical studies of up to 16 weeks and longer in numerous medical schools in Europe have demonstrated their safety in patients under medical supervision. Whilst the achievement of a normal body weight in most obese patients is now a reality, the main problem for the future is to achieve permanent weight loss.

Ephedrine as an anorectic: the story of the 'Elsinore pill'.

Abstract: Obese patients, age 18-60 years, overweight 20-80 per cent, entered a controlled, clinical study comparing the effects of two anorectic drugs, ie a prescription containing ephedrine and caffein ('Elsinore pills') and diethylpropion, with placebo. All 132 patients were instructed in a 1200-kcal diet, and 108 patients completed 12 weeks' treatment. There was a significantly better effect on body weight of diethylpropion (39 patients, median weight loss 8.4 kg, P less than 0.01) as well as of 'Elsinore pills' (38 patients, median weight loss 8.1 kg, P less than 0.01) compared to the effect of placebo treatment ( 31 patients, median weight loss 4.1 kg). Four patients treated with diethylpropion, and four patients treated with 'Elsionore pills' were withdrawn because of complaints of exaltation, tremor and insomnia. Tremor, in some cases only transient, was significantly more frequent in the 'Elsinore pill' group, but no serious side effects were observed.

Body weight reduction necessary to attain normotension in the overweight hypertensive patient.

Abstract: All 212 patients with essential hypertension and an overweight of at least 10 per cent in excess of ideal body weight, referred to out clinic in the years 1975-1979, were included in this study. The patients were advised to take a balanced low-calorie (about 1080 kcal/day) diet containing 83 g carbohydrates, 41.5 g fat and 85 g proteins. They were advised to eat salt freely. There were 40 patients who had four clinic visits or less and 49 others who could not follow their diet. Therefore the compliance-failure rate was 89/212, ie 42 per cent. Decrease in body weight resulted in a significant decrease in blood pressure, despite free ingestion of salt and with 24-h urine sodium which was not different from that obtained before dietary therapy was started. Over two-thirds of the compliant patients will achieve normal blood pressure with a loss of only one-half of their weight excess, even if at this point they are still overweight. In the group receiving no diuretic or any other anti-hypertensive therapy, 82.6 percent reached normal systolic blood pressures and 78.3 per cent reached normal diastolic blood pressures, but only 31/38 reached a body weight within 10 per cent of ideal body weight. It is concluded that most of overweight hypertensive patients can attain a normal blood pressure by reducing body weight, long before achieving the ideal weight.

Diet and the sympathetic nervous system: relationship to hypertension.

Abstract: Studies demonstrating an importance effect of dietary intake on the activity of the sympathetic nervous system of the rat are described. Utilizing techniques to measure the turnover rate of norepinephrine in heart, fasting has been shown to suppress, while overfeeding sucrose stimulates, the sympathetic nervous system. Studies in the spontaneously hypertensive rat (SHR) demonstrate that diminished caloric intake, or fasting, with maintenance of normal sodium intake, lowers the blood pressure; conversely, overfeeding sucrose on a constant sodium intake increases blood pressure in the SHR. Overfeeding an isocaloric ration of fat, in contrast to sucrose, has no effect on blood pressure in the SHR. Blood pressure responses in the normotensive Wistar-Kyoto (WKY) strain are in the same direction but much less marked than in SHR. The sympathetic nervous system response to fasting and sucrose overfeeding in the SHR resemble those that occur in WKY and other normotensive rat strains, at least in so far as the heart is concerned. These studies, thus, raised the possibility that diet-induced changes in sympathetic nervous system activity may contribute to diet-induced changes in blood pressure. According to this hypothesis the beneficial effect of weight loss in obese hypertensive subjects, and conversely, the detrimental effect of weight gain on the development of hypertension may reflect corresponding diet-induced changes in sympathetic activity. The well known relationship between obesity and hypertension may, therefore, derive at least in part from an effect of dietary intake on the sympathetic nervous system.

Control of body weight by lower gut signals.

Abstract: The importance of the terminal ileum in the control of food intake and body weight was studied in rats made obese by VMH knife cuts and in lean controls In the first study, 35 rats had either jejunoileal bypass, antibiotic infusion into the bypassed segment, resection of the bypassed segment of sham operation All three experimental treatments reduced food intake and produced large and statistically equivalent weight losses compared to the sham surgery control Apparently, physiological signals or bacterial toxins arising in the bypassed segment are not essential to the loss of body weight In the second study, 38 rats had either 5 or 10 cm segments of the terminal ileum transposed to mid-duodenum or upper jejunum or served as surgical controls As in the previous study, the experimental rats reduced their food intake and sustained a substantial loss of body weight Stimulation of the terminal ileum with nutrient-rich chyme was sufficient to cause most of the weight loss seen after jejunoileal bypass

The effect of a very-low-calorie diet with and without chronic exercise on thyroid and sex hormones, plasma proteins, oxygen uptake, insulin and c peptide concentrations in obese women.

Abstract: In 18 obese women a very-low-calorie diet (VLCD) has been combined with exercise (three times a week = 1650 kcal/week; 6.9 MJ) and compared with the effects of diet alone. The adherence and tolerance of the diet was quite good. Oxygen uptake decreased significantly only in the exercising group. Sex hormones binding globulin increased while prealbumin and retinol binding protein decreased in both groups. Changes in T4, T3, rT3, TSH, TBG and insulin secretion appeared to be equal in both groups. No significant differences between the two groups have been found with respect to body weight, body fat and lean body mass loss. Glucose tolerance deteriorated in the diet only group but remained unchanged in the group combining diet and exercise. Insulin production after oral glucose load did not change in either of the two groups. A more pronounced decrease in c peptide concentration has been observed in exercising groups. Sex hormones binding globulin and testosterone concentration increased in both groups. No changes have been detected in the concentration of transcortin. It is concluded that during a short period of VLCD exercise did not produce a higher body weight loss nor a protective effect on lean body mass.

The effect of addition of exercise to a regime of dietary restriction on weight loss, nitrogen balance, resting metabolic rate and spontaneous physical activity in three obese women in a metabolic ward.

Abstract: Three obese women were studied for periods of 12-13 weeks while on a constant reducing diet (800 kcal/day) in a metabolic ward Body weight and nitrogen balance were measured throughout the study and patients kept continuous diary card records of their physical activity Fasting resting metabolic (BMR) was measured twice weekly using a ventilated hood apparatus Each patient acted as her own control by alternatively exercising (2 h/d on a bicycle ergometer) or not exercising for consecutive 3-4 week periods Rate of weight loss was not increased by this level of exercise over the 3-4 week periods This surprising result could not be explained by a decreased nitrogen loss since nitrogen balance was not significantly affected by the exercise, not could it be explained by a compensatory decrease in subsequent energy expenditure since BMR and spontaneous activity was not measurably affected by the exercise However, since exercise increases muscle glycogen stores it may have been this effect which negated the expected increase in weight loss during ther exercise programme

Evaluation and component analysis of a comprehensive weight control program.

Abstract: The long-term effectiveness of a four-week comprehensive dietary-behavioral weight control program was evaluated. Program components included a 700 kcal diet, nutritional education, medical and health education, behavior modification, and physical activity and exercise. Mean weight loss 12 months after treatment was 29.2 lb (13.2 kg) with 66 percent of patients losing 20 lb (9.1 kg) or more, 45 percent losing 30 lb (13.6 kg) or more and 29 percent losing 40 lb (18.1 kg) or more. These weight losses are higher than those generally reported for either behavioral or non-behavioral treatments. Comparison of successful versus unsuccessful patients revealed that exercise, cognitive restructuring, eating style, and social skills were most related to success.

Regulation of adipose-tissue lipolysis by phosphorylation of hormone-sensitive lipase.

Abstract: Hormone-sensitive lipase has been purified from rat adipose tissue to almost 50 per cent protein purity and partially characterized. The isolated enzyme can be phosphorylated by ATP-Mg2+ in the presence of the catalytic subunit of cyclic AMP-dependent protein kinase from the same tissue. Its activity towards emulsified triglyceride is thereby increased two-fold. The enzyme is phosphorylated also in the intact adipocyte, verifying the physiological relevance of the findings with the isolated enzyme. Noradrenaline causes a rapid increase in phosphorylation of the enzyme in intact adipocytes, immediately followed by a marked increase of its activity. Addition of dibutyryl-cyclic AMP to the adipocytes causes the same effects. The extent of phosphorylation of the enzyme after maximal noradrenaline stimulation of the adipocytes is rapidly decreased by insulin addition in close association with inhibition of the lipase activity. The results demonstrate that these hormones regulate the activity of the hormone-sensitive lipase, ie the rate of lipolysis in the adipocytes, by changes of the degree of phosphorylation of the enzyme.

Truncal vagotomy in morbid obesity.

Abstract: Vagotomy has been shown to reduce body weight in several species of experimental animals. Due to the relative safety and simplicity of the procedure and the long-clinical evaluation of vagotomy in ulcer disease, truncal vagotomy without drainage has been performed in a series of 21 morbidly obese patients. The mean maximum body weight was 12.8 +/- 3 kg (s.e.). In the 14 patients observed for 12-40 months, the mean weight decrease is 20 +/- 4 kg (range: 0-51). Apart from lesion of the oesophagus in one patient, there have been no operative complications. In one 45-year-old patient sudden death due to myocardial fibrosis occurred three years after the operation. Four patients have had short episodes of diarrhea, and vomiting has occurred in two patients who "tested the limits'. There is no evidence of gastric dilatation or ulcers, yet gastric stasis is prevalent. Three patients are failures, two not having reduced and the third regaining 28 of her initial 31 kg weight loss postoperatively. Five patients have participated in programs for weight reduction in which they claim greater ease in complying than before operation, due to the characteristic lack of hunger sensations in all of the successful patients. The mechanisms for weight reduction after vagotomy are not known, yet seem to involve other factors than delayed gastric emptying of solids. Longer follow-up is necessary for evaluation of this procedure in the treatment of morbid obesity.

Uncontrolled adipocyte proliferation is not the primary lesion in the genetically-obese Zucker rat.

Abstract: One of several hypotheses concerning the nature of the genetic lesion which produces obesity in the Zucker fatty rat is that a defect in control of cellular proliferation in adipose tissue leads to hypercellular-hypertrophic obesity with all its metabolic and behavioral sequalae. Three lines of evidence are presented which render this hypothesis untenable: (1) maximal cell enlargement precedes maximum rate of cell addition in adipose tissue; (2) lipectomized obese rats do not regenerate subcutaneous adipocytes; and (3) cultured adipocyte precursors from obese rat adipose tissue grow at the same rate as do cells cultured from lean tissue. An alternative hypothesis that an alteration in hepatic lipid metabolism may be the locus of the genetic lesion is presented along with evidence from in-vivo and in-vitro studies of hepatic lipogenesis in the Zucker rat.

Insulin and adipose tissue lipoprotein lipase activity in humans

Abstract: Insulin may be important in regulating adipose tissue lipoprotein lipase in the rat. Insulin appears to be necessary for the maintenance of enzyme activity in adipose tissue in humans since it is decreased in untreated diabetes and returns to normal with anti-hyperglycemic therapy. Other than this permissive role of insulin in maintenance of adipose tissue LPL activity in humans, there is little evidence that insulin, by itself, plays a primary role in the regulation of adipose-tissue lipoprotein lipase in man.

Influence of hypocaloric diet on alpha-adrenergic responsiveness of obese human subcutaneous adipocytes.

Abstract: Spontaneous and stimulated lipolytic activity of subcutaneous abdominal adipocytes from obese subjects treated by a hypocaloric diet (800-1000 kcal/d) for 13-15 d were studied. A strong increase in basal lipolytic activity of the adipocytes occurred after the restrictive diet treatment. Linked to this phenomenon, an important alpha-adrenergic antilipolytic effect of adrenaline appeared whereas, the beta-stimulating effect of isoproterenol (beta-adrenomimetic drug) was not affected. The increased alpha-inhibitory effect of adrenaline was shown to theophylline-stimulated adipocytes of energy-restricted subjects. It is concluded that after a period of hypocaloric diet, the adrenaline-dependent lipolysis of subcutaneous abdominal fat cells of obese subjects is reversed. The lipolytic response induced by adrenaline, described in the adipocytes of obese controls, develop towards an alpha-adrenergic antilipolytic response after the hypocaloric treatment. Our data suggest that, in states with increased rate of lipolysis, there is an increased readiness for alpha-adrenergic response.

Teenagers' perceptions of fat and slim people.

Abstract: One-hundred and thirty-eight 16-year-olds rated each of six stimulus figures: 'Fat young man', 'Fat young woman', 'Slim young man', 'Slim young woman', 'Me now', 'Me as I would like to be', on 28 seven-point personal rating scales. Principal component analyses derived one major and two minor components. Inspection of the major General evaluation component showed that the fat figures were negatively evaluated, and the slim figures positively evaluated. The students perceived themselves to be between these two extremes, but aspired more towards the slim figures. Differences between the perceptions of male female subjects and between those of Australian and European migrant parentage were also observed, particularly in relation to the minor components. The results indicate that stereotypes of obese and slim individuals are related to the sex, ethnicity and self-concepts of the perceiver.

Fatalities on the liquid-protein diet: an analysis of possible causes.

Abstract: Reports of deaths occurring in patients using variants of the liquid-protein diet (LPD) have raised some questions about the safety of this procedure for the management of obesity. Case reports involving 44 publicized deaths were reviewed. Possible causes of death including such factors as potassium and/or electrolyte deficiencies, inadequate or poor quality protein, imperfect patient selection or compliance, an associated medications or disease were examined. Data in eight patients are insufficient for analysis or show that the patients were not using a LPD. Of the remaining 36 patients 32 were inappropriately managed as judged by conservative standards. Four patients who may have been properly managed all had known preexisting cardiac disease. The analysis does not identify any single factor which is responsible for the deaths. It shows that the procedure was widely misused and suggests that this contributed in multiple ways to the fatalities. No properly managed patient died as a direct result of the LPD and the cardiac deaths could not be ascribed to the LPD. Since the LPD, when properly supervised, has demonstrated great promise in the management of obesity, it is suggested that caution be exercised in dismissing the LPD because of adverse publicity.

Adenosine and lipolysis.

Abstract: The present review briefly summarizes work from the author's laboratory aiming at the clarification of the role played by adenosine in the regulation of adipose tissue circulation and metabolism. Studies on isolated fat cells demonstrate that adenosine, in mumolar concentrations, can inhibit lipolysis induced by eg noradrenaline. The effect appears to be due to inhibition of cyclic AMP formation. Studies of subcutaneous adipose tissue in situ also demonstrate the effect of exogenous adenosine on lipolysis. Furthermore, adenosine causes vasodilation and inhibition of noradrenaline release from sympathetic nerve endings. The actions of adenosine are antagonized by theophylline and other methylxanthines in concentrations lower than those required to inhibit cyclic AMP breakdown. It is shown that adenosine is normally present in adipose tissue in approximately 0.3 microM concentration and that the level is increased by sympathetic nerve stimulation. From a quantitative comparison of adenosine levels and dose-effect relationships as well as from pharmacological studies it is concluded that adenosine is a physiological regulator of adipose tissue circulation and lipolysis, while the physiological role of adenosine as a transsynaptic modulator of noradrenaline release remains to be established.

Impaired regulation of adipose tissue lipoprotein lipase in obesity.

Abstract: Among the numerous alterations in adipose tissue metabolism in obesity is an increased activity of lipoprotein lipase (LPL), the rate-limiting enzyme in triglyceride assimilation. The present paper summarizes a series of experiments demonstrating that the regulation of LPL activity is also impaired in obesity. In normal subjects, glucose intake leads to an increase in adipose tissue LPL activity; this phenomenon can also be demonstrated by incubation of adipose tissue in an insulin-containing buffer in vitro. In contrast, the initially high enzyme activity of adipose tissue from obese subjects is non-responsive to glucose and insulin in vivo and in vitro. However, incubation of adipose tissue from obese subjects in the absence of glucose and insulin led to a rapid decline in enzyme activity and elicited a normal response to subsequent exposure to glucose and insulin. These data indicate that the hyperinsulinemia of the obese tissue donor may be of importance for the abnormalities of LPL activity. However, experiments with VMH-lesioned rats demonstrated that insulin levels and LPL activities could be dissociated. In obese and normal-weight rats, standardized with regard to insulin levels by abolition of endogenous insulin production by streptozotocin treatment and substitution with identical doses of insulin, LPL activities and regulation differed markedly, indicating that factors other than insulin are also involved in the dysregulation of LPL activity in obesity.

Growth of adipose tissue in infants, children and adolescents: variations in growth disorders.

Abstract: In order to identify factors important in the growth of adipose tissue, four groups of children were studied. Infants of gestational diabetic mothers demonstrated increased fat cell numbers as early as age two months, a finding which accelerated with increasing age, and which was associated with persistent hyperinsulinemia and increasing obesity. Children with growth hormone deficiency increased their adipose cell number following treatment with exogenous hormone. Patients with the Prader-Willi syndrome, who developed obesity after the age of two, did so primarily via increases in fat cell size. Identical twins who were concordant for birthweight continued to have similar weights and total adipocyte numbers, while in those with discordant birthweights the smaller twin displays lower body weight and adipose cell number. The data indicate that growth hormone and insulin, as well as genetic factors, which may be modified by the in-utero environment, are important determinants of human adipose tissue mass.