Effect of the amount of body fat on the age-associated increase in serum cholesterol.

This study investigates the contribution of body fat stores on the age-associated increase in serum cholesterol and triglyceride levels. Percentage of body fat was measured by hydrostatic weighing, and serum cholesterol, triglyceride, low-density lipoprotein cholesterol, and high-density lipoprotein cholesterol levels were determined in a sample of 472 healthy men and women ages 18-50 years. In both sexes, body fat mass was significantly correlated with serum cholesterol (r = 0.

Weight loss in massive obesity: reciprocal changes in plasma HDL cholesterol and HDL binding to human adipocyte plasma membranes.

Human obesity is frequently associated with elevated plasma triglyceride and cholesterol concentrations and reduced high density lipoprotein (HDL) cholesterol, abnormalities that commonly revert to normal levels with weight loss. This study was undertaken to examine possible mechanism(s) associated with the changes in plasma HDL cholesterol concentrations in massively obese patients after weight loss. Ten massively obese patients (two men and eight women, age = 37.

Interactions of high density lipoprotein subclasses (HDL2 and HDLc) with dog adipocytes: selective effects of cholesterol and saturated fat feeding.

Adipose tissue is a cholesterol storage organ and derives its cholesterol primarily from circulating lipoproteins. The present study shows that adipocytes isolated from canine omental fat tissue interact specifically with high density lipoprotein subfractions lacking or enriched in apolipoprotein E, namely canine high density lipoprotein-2 (HDL2) and HDLc, respectively. While 125I-labeled HDL2 binding was inhibited similarly by both excess unlabeled HDLc and HDL2, 125I-labeled HDLc interaction was inhibited by its homologous ligand only.

Selective uptake of HDL cholesterol ester by human fat cells.

In humans, high-density lipoprotein (HDL)-cholesterol ester turnover exceeds that of HDL apoproteins by severalfold or more, suggesting an independent catabolic fate of these constituents. The present study investigated the cellular uptake and dissociation of HDL labeled in its apoproteins with 125I and in its cholesterol ester with [3H]cholesteryl palmityl ether, a nonhydrolyzable cholesterol ester analogue. Approximately 50% of cell-associated 125I-HDL2 and 125I-HDL3 was released from prelabeled adipose cells by incubating the latter in the presence or absence of unlabeled lipoproteins for 2 h.

Physical training and changes in regional adipose tissue distribution.

Obesity has been associated with numerous metabolic complications, such as changes in the concentration and/or composition of plasma lipoproteins, glucose intolerance and hyperinsulinemia leading to diabetes and hypertension. The relation of obesity to cardiovascular disease has not, however, been consistently reported. Recent prospective studies have clearly indicated that the distribution of adipose tissue was a significant cardiovascular risk factor and numerous studies have shown that metabolic disturbances were more closely associated with the level of abdominal fat than excess adiposity per se.

Relationships between body fatness, adipose tissue distribution and blood pressure in men and women.

The relationships between body fatness, fat distribution and blood pressure (BP) were studied in 234 women and 238 men, aged 18-50 years. In both sexes, subcutaneous (s.c.

Sensitivity to overfeeding: the Quebec experiment with identical twins.

The role of the genotype in the response to short-term overfeeding was assessed by submitted six pairs of male monozygotic twins to a 4.2 MJ (1000 kcal) per day energy intake surplus for a period of 22 consecutive days. Individual differences in fat mass and fat-free mass gains were observed in response to overfeeding but they were not randomly distributed.

Abdominal adipose tissue and serum HDL-cholesterol: association independent from obesity and serum triglyceride concentration.

It has been recently shown that an excess of abdominal fat was associated with reduced serum HDL-cholesterol level, supporting previous studies that have reported a relationship between fat distribution and cardiovascular risk factors. Since a negative relationship has been observed between serum triglyceride and HDL-cholesterol concentrations, the associations between body fat distribution and HDL-cholesterol level was studied with control over serum triglycerides in a sample of 429 healthy adult men. The relative distribution of subcutaneous fat, as reflected by the trunk to extremity skinfolds (T/E) ratio and the absolute amount of subcutaneous abdominal fat, obtained by the measurement of the abdominal skinfold thickness, were significantly correlated with serum triglycerides (r = 0.

Interaction of high density lipoprotein with adipocytes in a new patient with Tangier disease.

A 56-year-old man, the offspring of a consanguineous first cousin marriage, presented with clinical, morphological, and biochemical features of familial deficiency of high-density lipoproteins (Tangier disease). Of 8 first- and second-degree relatives examined, 4 had either plasma apo A-I or HDL cholesterol concentrations 2 standard deviations below normal population mean on at least 1 occasion. The patient and a majority of his relatives also had high plasma apo B concentrations relative to their levels of cholesterol.

Regional variation in HDL metabolism in human fat cells: effect of cell size.

Abdominal obesity is related to reduced plasma high-density lipoprotein (HDL) cholesterol, and both are associated with cardiovascular disease risk. We have observed that plasma membranes from abdominal subcutaneous adipocytes have a greater HDL binding capacity than omental fat cell plasma membranes. The present study examined whether these binding characteristics could be due to differences in fat cell size or cholesterol concentration between the two adipose depots.

Acute effects of endurance exercise on human adipose tissue metabolism.

In order to study the acute effects of exercise on adipose tissue metabolism, 27 sedentary male subjects, 18 to 27 years of age, performed a prolonged aerobic exercise test. Biopsies of adipose tissue were obtained from the suprailiac fat depot before and immediately after a 90-minute period of exercise on ergocycle at an average intensity of 88% of maximal heart rate. Fat cells, isolated by collagenase digestion, were measured for their glucose conversion into triglycerides and for lipolytic activity.

Genotype-influenced changes in serum HDL cholesterol after short-term overfeeding in man: association with plasma insulin and triglyceride levels.

Six pairs of male monozygotic (MZ) twins were submitted to a 22-day overfeeding period during which they ingested a daily surplus of 1,000 kcal above their individual daily energy needs in the form of a mixed diet. Serum lipids, lipoproteins, and apoprotein A and B concentrations were measured before and after the overfeeding period. Percentage of body fat, fasting plasma glucose, and insulin levels as well as plasma glucose and insulin concentrations after a glucose challenge were also measured before and after overfeeding.

The role of body fat in insulin sensitivity of endurance athletes.

The purpose of the study was to assess the role of adiposity in the enhanced insulin sensitivity observed in endurance athletes (EA). An oral glucose tolerance test (75 g glucose) was administered to nine EA and to 23 sedentary subjects (SS). Two different strategies were used to investigate the problem.

Genotype-controlled changes in body composition and fat morphology following overfeeding in twins.

This study investigated the effects of overfeeding on the body composition and fat morphology characteristics of 6 pairs of male monozygotic twins. Each participant was submitted to a 22-day overfeeding period, supplemented by an additional 1000 kcal/day. Significant changes were observed in body composition and fat morphology as shown by increases in body weight, fat mass, sum of 9 skinfolds, and fat cell diameter.

Genotype dependency of adaptation in adipose tissue metabolism after short-term overfeeding.

The present study investigated the interaction of genotype and short-term overfeeding on adipose tissue metabolism of six pairs of male monozygotic twins. The sedentary nonobese twins were submitted to a 22-day overfeeding period in which their normal daily intake was supplemented by an additional 1,000 kcal/day. A fat tissue biopsy was performed in the suprailiac region before and after overfeeding to determine fat cell diameter and basal and maximal stimulated epinephrine, norepinephrine, and isoproterenol lipolysis from collagenase-isolated fat cells.

Genotype dependency of the thermic effect of a meal and associated hormonal changes following short-term overfeeding.

The purpose of this experiment was to assess the effects of short-term overfeeding (mixed diet) on the thermic effect of a meal (TEM) and associated hormonal changes and to investigate the role of the genotype in the observed changes. Six pairs of male sedentary monozygotic (MZ) twins consumed an extra 1,000 kcal per day over their individual level of energy expenditure while maintaining a sedentary existence. Resting metabolic rate (RMR) and TEM following a 4.

Influence of caffeine on the resting metabolic rate of exercise-trained and inactive subjects.

The effect of caffeine on the resting metabolic rate (RMR) was investigated in endurance exercise-trained (N = 14) and inactive (N = 10) male individuals. Subjects were also classified into regular and non-regular consumers of caffeine. After an overnight fast, RMR was measured using an indirect calorimetry open circuit system.

Adipose tissue lipid accumulation pathways in marathon runners.

Eighteen male marathon runners (mean marathon performance: 2 h 36 min, SD = 7.0 min; VO2 max = 64.1 +/- 15.

Evidence for a regional component of body fatness in the association with serum lipids in men and women.

Four hundred and seventy-two subjects (234 women and 238 men), 18 to 50 years of age, participated in percent body fat determination from underwater weighing, assessment of 6 subcutaneous skinfold thicknesses, and a 12-hour fast blood sampling for measurement of serum triglycerides (TG), high-density lipoprotein cholesterol (HDL-C), total cholesterol (CHOL), and HDL-C/CHOL ratio. Even though women were significantly fatter than men, they had lower TG, CHOL, and higher values of HDL-C/CHOL ratio. Correlational and variance analyses showed that body fatness seemed to be more closely associated with serum lipids in men than in women.

Concentrations of fusidic acid, cloxacillin, and cefamandole in sera and atrial appendages of patients undergoing cardiac surgery.

The concentrations of cefamandole, cloxacillin and fusicid acid were measured in the serum and heart tissue of 100 recipients of these drugs before cardiac surgery. During cardiopulmonary bypass, mean (+/- standard deviation) peak concentrations in serum of all patients were 63.0 +/- 34.

Characterization of high density lipoprotein binding to human adipocyte plasma membranes.

Freshly isolated human adipocytes showed specific uptake of 125I-labeled human high density lipoprotein (HDL2 and HDL3), a portion of which could be released by subsequent incubation with excess unlabeled ligand. To study the mechanism of HDL binding, sucrose gradient-purified adipocyte plasma membranes were incubated with radioiodinated lipoprotein particles under equilibrium conditions in the absence (total binding) or presence (nonspecific binding) of 100-fold excess unlabeled ligand. Specific binding of HDL2 and HDL3, calculated by subtracting nonspecific from total binding, was Ca++ independent, unaffected by EDTA, and not abolished by pronase treatment of the membranes.

The effects of exercise-training on energy balance and adipose tissue morphology and metabolism.

The effects of exercise training on energy expenditure, energy intake, fat cell size and adipose tissue lipolysis have been reviewed. Individuals engaged in regular and intense training programmes, e.g.

Lack of relationship between changes in adiposity and plasma lipids following endurance training.

In order to study the effect of alterations in fat morphology and metabolism induced by exercise-training on plasma lipids, 13 healthy young men were subjected to a 20-week aerobic training program on bicycle. Training significantly increased maximal aerobic power (VO2 max) (P less than 0.001) and decreased per cent body fat (P less than 0.