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PubMed1999

Alterations in body weight and composition consequent to 20 wk of endurance training: the HERITAGE Family Study.

BACKGROUND: Obesity is a major public health problem in the United States. The role of physical activity and formal exercise in controlling body weight has not been clearly determined. OBJECTIVE: This study determined the magnitude of change in body weight and composition across sex, race, and age in response to 20 wk of endurance training. DESIGN: Men and women (n = 557) of various ages (16-65 y) and 2 races (black and white) exercised on cycle ergometers 3 d/wk for a total of 60 exercise sessions starting at 55% of maximal oxygen consumption (VO(2)max) for 30 min/session and building to 75% of VO(2)max for 50 min/session, where it was maintained during the last 6 wk. Skinfold-thickness measurements, circumferences, body composition (by hydrostatic weighing), and body fat distribution (by computed tomography scan at L4-L5 and the waist-hip ratio) were determined before and after training. RESULTS: All skinfold-thickness and circumference measures, waist-hip ratio, body mass index, total body mass, fat mass, percentage body fat, and computed tomography scan measures of total, subcutaneous, and visceral abdominal fat decreased with training, whereas total body density and fat-free mass increased. These changes were significant, but small. There were several differences in training response by sex and race, but not by age. CONCLUSIONS: A short-term exercise intervention can induce favorable changes in body composition, but the magnitude of these changes is of limited biological significance. Increasing physical activity likely has a major effect on body-composition and fat distribution characteristics only when it is of a greater magnitude and sustained for much longer periods

Adolescent↗
PubMed2004

[Analysis of disturbances in carbohydrate metabolism in the adult population of Yecla (Murcia, Spain)].

OBJECTIVE: To determine the prevalence of impaired fasting glucose (IFG or GBA), impaired glucose tolerance (IGT) and type 2 diabetes mellitus (DM2) in the adult population of Yecla. RESEARCH, DESIGN, AND METHODS: We performed a population-based cross-sectional study (on Primary Care Field) with stratified and random sampling (393) from 17 500 residents in Yecla with sanitary card and aged > or =30 years. We studied 286 subjects (107 declining to participate) and 261 of them (125 men and 136 women) underwent an oral glucose tolerance test (OGTT). MAIN MEASUREMENTS: World Health Organization (WHO-99) and American Diabetes Association (ADA-97) criteria were used for diagnosis of unknown DM2, GBA and IGT. Socio-demographic and anthropometric variables were measured. Plasma lipid, glycosylated haemoglobin (HbA1C), microalbuminuria and insulin levels also were measured. Insulin resistance was evaluated by the HOMA method. RESULTS: According ADA-97 criteria the prevalence of DM2 and GBA was 2.65 (CI+/-1.95) and 4.3% (+/-2.5) respectively. Underwent an OGTT, the age-adjusted prevalence of DM2, IGT and GBA (using the Spanish population of July 02) was 6.7 (95%CI, 3,7-9,7); 13.2 (95%CI, 9.1-17.3) and 0.2% (95%CI, 0-1.8) respectively. The known DM2 was 5,9% (95%CI, 3.8-8) and the global prevalence of DM2 was 12.6% (95%CI, 9.6-15.6). The diabetes was associated with overweight, overage and higher insulin, HbA1C and insulin resistance levels. CONCLUSIONS: There is a high prevalence of DM2 in Yecla (known/unknown 0.87/1). The ADA97 criteria only detected 53% of the unknown DM2. The 78% of normoglycemics subjects had overweight or upper-body fat distribution and diabetics people had higher BMI (Body Mass Index), Hypertension, insulinemia, HbA1C and insulin resistance levels than normoglycemics and IGT subjects.

Adult↗
PubMed2000

Hormones and body composition in humans: clinical studies.

Leptin in relation to body fat and hormonal regulation of body fat distribution will be treated. Leptin circulating levels are strongly related to the percentage of body fat and in women leptin values are always twofold those observed in men. A role of androgens has been suggested to explain this gender difference. Insulin resistance may contribute to the wide variation in leptin levels. Leptin levels and insulin resistance are increased at the end of pregnancy and normalize after delivery. Furthermore, insulin resistance is associated with elevated plasma leptin levels independent of body fat mass and leptin levels are significantly related to insulin sensitivity independent of BMI. Energy restriction can strongly influence leptin levels, overcoming the effects of body composition changes. The shift from a state of triglycerides storage to a state of release could down-regulate leptin production. Triglyceride flux at the intra-abdominal level depends on the balance between insulin and corticosteroids, which have liposynthetic activity, and between sexual and growth hormones, which have lipolytic activity. Both hormonal and body composition change with ageing, primarily due to a decrease in lipolytic activity, with consequent prevalence of liposynthesis and visceral fat accumulation. Enlargement of intra-abdominal adipose cells is more gradual in men and more abrupt in women after menopause.

Adipose Tissue↗
PubMed2003

Agreement analysis of variables involved in lipodystrophy syndrome definition in HIV-infected patients.

BACKGROUND: Lipodystrophy studies in HIV-infected patients have usually defined abnormalities in body fat by clinical evaluation and patient questionnaires. Despite the risk for bias with these subjective approaches, agreement analysis among the large number of variables employed was seldom performed. OBJECTIVE: To analyze consistency between the usual approaches for definition of abnormalities in body fat distribution. DESIGN: We evaluated agreement between the clinical and questionnaire findings for abnormalities in body fat in an HIV patient population under antiretroviral treatment followed in our institution, using different criteria for definitions of body fat abnormalities within the same data set. METHODS: Kappa analysis for consistency and receiver-operator characteristic (ROC) curve analysis were performed. RESULTS: Low levels of agreement between clinical and patient perspectives were observed. Only one combination of criteria showed adequate agreement results. The waist/hip ratio showed low levels of agreement with all other variables, and no clear discriminative point was observed by ROC curve analysis. The ratio between the trunk fat content and the leg fat content assessed by dual energy x-ray absorptiometry (DEXA) scan demonstrated better agreement and more clear discriminative values for both male and female patients. CONCLUSION: Agreement analyses may help in the selection of the subjective variable methodology and in the inclusion of consistent and nonredundant objective measurements for diagnosis of abnormalities in body fat.

Adipose Tissue↗
PubMed2003

Counseling for physical activity in overweight and obese patients.

Obesity has reached epidemic proportions in the United States. More than 60 percent of U.S. adults are now overweight or obese (defined as at least 30 lb [13.6 kg] overweight), predisposing more than 97 million Americans to a host of chronic diseases and conditions. Physical activity has a positive effect on weight loss, total body fat, and body fat distribution, as well as maintenance of favorable body weight and change in body composition. Many of the protective aspects of exercise and activity appear to occur in overweight persons who gain fitness but remain overweight. Despite the well-known health and quality-of-life benefits of regular physical activity, few Americans are routinely active. Results of research studies have shown that physician intervention to discuss physical activity (including the wide array of health benefits and the potential barriers to being active) need not take more than three to five minutes during an office visit but can play a critical role in patient implementation. This article describes elements of effective counseling for physical activity and presents guidelines for developing physical activity programs for overweight and obese patients.

Body Mass Index↗
PubMed1998

Fat distribution in obese and nonobese children and adolescents.

BACKGROUND: It is not known whether fat deposition in obese children and adolescents occurs in the body's central or peripheral regions. METHODS: A representative sample of children was drawn from the schools of Zaragoza, Spain. The population selected comprised 1728 children ranging in ages from 6 to 14.9 years. Of the original sample, 368 children (21.29%) were excluded because of chronic diseases or refusal to participate. The waist-to-hip circumference ratio and the triceps-to-subscapular skin-fold thickness ratio were calculated and served as indexes of body fat distribution. The children were divided into tertiles according to standard deviation score of body mass index. RESULTS: Both in boys and in girls, waist-to-hip circumference ratio was higher in tertile 3 than in the other two tertiles, and triceps-to-subscapular skinfold thickness ratio was lower in tertile 3 than in the other two tertiles. Waist-to-hip circumference ratio was higher and triceps-to-subscapular skinfold thickness ratio was lower in obese than in nonobese children and adolescents of both sexes. CONCLUSIONS: Increased adiposity may be accompanied by an increase of fat depot in the abdominal region. In obese children and adolescents, fat deposition seems to occur in the body's central regions.

Adipose Tissue↗
PubMed2025

Polygenic scores for obstructive sleep apnoea reveal pathways contributing to cardiovascular disease.

BACKGROUND: Obstructive sleep apnoea (OSA) is a common chronic condition, with obesity its strongest risk factor. Polygenic scores (PGSs) summarise the genetic liability to phenotype and can provide insights into relationships between phenotypes. Recently, large datasets that include genetic data and OSA status became available, providing an opportunity to utilise PGS approaches to study the genetic relationship between OSA and other phenotypes, while differentiating OSA-specific from obesity-specific genetic factors. METHODS: Using race/ethnic diverse samples from over 1.2 million individuals from the Million Veteran Program, FinnGen, TOPMed, All of Us (AoU), Geisinger's MyCode, MGB Biobank, and the Human Phenotype Project, we developed and assessed PGSs for OSA, both without (BMIunadjOSA-PGS) and with adjustment for the genetic contributions of BMI (BMIadjOSA-PGS). FINDINGS: Adjusted odds ratios (ORs) for OSA per 1 standard deviation of the PGSs ranged from 1.38 to 2.75. The associations of BMIadjOSA- and BMIunadjOSA-PGSs with CVD outcomes in AoU shared both common and distinct patterns. Only BMIunadjOSA-PGS was associated with type 2 diabetes, heart failure, and coronary artery disease, while both BMIadjOSA- and BMIunadjOSA-PGSs were associated with hypertension and stroke. Sex stratified analyses revealed that BMIadjOSA-PGS association with hypertension was driven by females (OR = 1.1, p-value = 0.002, OR = 1.01 p-value = 0.2 in males). OSA PGSs were also associated with body fat measures with some sex-specific associations. INTERPRETATION: Distinct components of OSA genetic risk are related and independent of obesity. Sex-specific associations with body fat distribution measures may explain differing OSA risks and associations with cardiometabolic morbidities between sexes. FUNDING: R01AG080598.

Humans↗
PubMed1993

Relationship of body fat percentage and fat distribution with dehydroepiandrosterone sulfate in premenopausal females.

Dehydroepiandrosterone (DHEA) has an antiobesity effect in rodents, and elevated endogenous levels of its sulfate ester (DHEAS) are associated with reductions in risk for cardiovascular disease (CVD) in men. To examine the association of body fat and fat distribution, established correlates of CVD and CVD risk factors, with circulating DHEAS levels in women, we measured trunk and limb skinfold thicknesses and circumferences, total and regional body fat from dual energy x-ray absorptiometry (DXA), and serum levels of DHEAS in 96 healthy Caucasian females aged 28-39 yr. Body mass index, percentage fat from DXA and the waist-to-hip ratio were not significantly correlated (r < or = 0.15, P > or = 0.156) with serum DHEAS levels, regardless of statistical control for age, smoking behavior, and fasting status. However, the ratio of trunk/total skinfold thicknesses (r = 0.23, P = 0.030) and the percentage of total fat located on the trunk from DXA (r = 0.32, P = 0.002) were positively correlated with DHEAS, whereas the ratio of leg/total skinfold thicknesses (r = -0.25, P = 0.015) and the percentage of total fat located on the legs from DXA (r = -0.25, P = 0.015) were inversely correlated with DHEAS after adjusting for age, smoking, and fasting status. With the exception of the trunk/total skinfold thickness ratio, the correlations of DXA- and skinfold-derived estimates of fat distribution remained significant (P < or = 0.033) even after further adjustment for percentage fat or body mass index. It is concluded that increased amounts of total fat located on the trunk and decreased amounts of total fat located on the legs are associated with increased serum DHEAS concentrations in normally menstruating females.

Adipose Tissue↗
PubMed1999

Climacteric modifications in body weight and fat tissue distribution.

OBJECTIVE: To estimate the effects of climacteric modifications on body weight and fat distribution. METHODS: From 8764 women attending the authors' Menopause Clinic, 1075 untreated, normal healthy women were selected and divided into three groups: premenopausal (n = 380), perimenopausal (n = 263) and postmenopausal (n = 432). The total body fat tissue mass and distribution were analyzed using the dual energy X-ray method. RESULTS: Body weight and body mass index (BMI) were significantly higher in perimenopausal and postmenopausal than in premenopausal women. The mean total body fat and the percentage of fat with respect to soft tissue were significantly (p < 0.05) higher in the perimenopausal and postmenopausal groups than in the premenopausal group. The amount of fat tissue and the regional fat percentage with respect to total fat tissue were higher in the trunk (p < 0.05) and arm (p < 0.05) regions in perimenopausal and postmenopausal than in premenopausal women. In the postmenopausal group, the leg fat tissue was significantly (p < 0.05) less than in the premenopausal and perimenopausal groups. Total body and leg lean tissue was significantly (p < 0.01) less in postmenopausal than in premenopausal and perimenopausal women. In the premenopausal group, body weight and BMI were positively correlated with age (r = 0.37 and r = 0.54, respectively). No significant correlations were observed in the perimenopausal group. In postmenopausal women, body weight and BMI were loosely correlated with age (r = 0.13 and r = 0.11, respectively). In three groups of 63 age-matched women, with similar BMI, the percentage of total body fat with respect to soft tissue was significantly (p < 0.001) higher in the perimenopausal and postmenopausal groups than in the premenopausal group. Regarding body fat distribution, the percentage of fat with respect to total fat tissue was significantly higher in the trunk (p < 0.001) region in perimenopausal and postmenopausal women than in premenopausal women. In the leg region, the percentage of fat with respect to total fat tissue was significantly (p < 0.05) higher in the premenopausal group than in the postmenopausal group. In the arm region, a slight but not significant (p < 0.08) difference was shown in fat distribution among the three groups. CONCLUSIONS: Climacteric changes rather than the aging process are relevant for prediction of body weight and fat distribution, especially for perimenopausal and postmenopausal women, who show a shift to a central, android fat distribution.

Adipose Tissue↗
PubMed2001

Relationships among serum testosterone levels, body fat and muscle mass distribution in women with polycystic ovary syndrome.

We investigated the relationships among serum testosterone levels, body fat and muscle mass distribution in women with polycystic ovary syndrome (PCOS). Subjects were 67 women with PCOS (mean age +/- standard deviation, 28.8 +/- 6.6 years). Baseline characteristics included age and height. Trunk-leg fat ratio and trunk-leg muscle ratio were assessed with dual-energy x-ray absorptiometry. Serum testosterone and dehydroepiandrosterone sulfate levels were measured with radioimmunoassays. Relationships among serum testosterone levels, body fat and muscle mass distribution were investigated using Pearson and partial correlation tests. Serum testosterone levels were positively correlated with trunk-leg fat ratio (r = 0.398, P < 0.01), but were inversely correlated with trunk-leg muscle ratio (r = -0.332, P < 0.05). Trunk-leg muscle ratio was inversely correlated with trunk-leg fat ratio (r = -0.360, P < 0.01). Serum testosterone levels were still correlated with trunk-leg fat ratio (r = 0.500, P < 0.001) and trunk-leg muscle ratio (r = -0.286, P < 0.05), after adjusting for age and height. Trunk-leg fat ratio was still correlated with trunk-leg muscle ratio, after adjusting for age, height, and serum testosterone levels. Based on these results, we concluded that higher serum testosterone levels may contribute to the upper body fat distribution and peripheral muscle mass distribution. In addition, peripheral muscle mass distribution may also contribute to the upper body fat distribution.

Absorptiometry, Photon↗
PubMed1996

Gender differences in serum leptin levels in humans.

Leptin, the product of the ob gene, is an adipose tissue-derived hormone that appears to regulate both satiety and thermogenesis. In the present report, we have reexamined the relationship between circulating leptin concentration and body fat in humans using a more valid measure of adiposity (hydrodensitometry) and have extended these observations to examine the influence of regional body fat distribution and cardiorespiratory fitness. Fasting serum leptin concentration was 6.9 +/- 0.3 ng.ml-1 in males (N = 333) and 15.2 +/- 1.3 ng.ml-1 in females (N = 63). Interestingly, total fat mass did not differ between groups (males 20.5 +/- 0.5 kg; females 20.4 +/- 1.5 kg), suggesting that females have higher leptin levels per unit fat mass. In a multiple regression model, fat mass was the best predictor of serum leptin concentration in males, accounting for 51% of the variance in leptin concentration. In females, percentage body fat was the best predictor of leptin, accounting for 49% of the variance. In both groups, the relationship between leptin and adiposity remained significant after adjusting for age, maximal treadmill time, waist circumference, and fasting insulin concentration. These observations support previous conclusions that circulating leptin is primarily a function of adiposity and demonstrate for the first time that this relationship is independent of fat distribution or cardiorespiratory fitness. The data also suggest that there is a gender dichotomy in the relationship between leptin and body fat mass in humans.

Adult↗
PubMed2006

Visceral and truncal subcutaneous adipose tissue are associated with impaired capillary recruitment in healthy individuals.

CONTEXT: Central adiposity is associated with cardiovascular risk independently of total adiposity. Microvascular dysfunction is thought to contribute to obesity-associated insulin resistance and hypertension and may thus link central adiposity with cardiovascular risk. OBJECTIVE: Our objective was to investigate how body fat distribution relates to microvascular function and the role of adipocytokines in these relationships. DESIGN, SETTING, AND PARTICIPANTS: We cross-sectionally studied 51 healthy adults and 29 of their prepubertal children born at the VU University Medical Center in Amsterdam. MAIN OUTCOME MEASURES: We measured visceral and abdominal sc adiposity with magnetic resonance imaging and truncal and peripheral sc adiposity with skinfold thickness. Postocclusive skin capillary recruitment was assessed with videomicroscopy. Concentrations of C-reactive protein, IL-6, and TNF-alpha were combined in an inflammation score. RESULTS: In adults, visceral adipose tissue and trunk/extremity skinfold ratio were inversely associated with capillary recruitment (partial correlation coefficients, -0.32, P = 0.03, and -0.37, P < 0.01, respectively). The inflammation score was inversely associated with capillary recruitment (r = -0.50; P < 0.01) and statistically explained 41% of the association between visceral adipose tissue and capillary recruitment. In children, trunk/extremity skinfold ratio was inversely associated with capillary recruitment (r = -0.49; P = 0.01), but other measures of adiposity were not. CONCLUSION: Our data in adults suggest a role for visceral adiposity and its associated proinflammatory state in capillary dysfunction and its possible sequelae such as hypertension and insulin resistance. Also, our findings in children and adults suggest that truncal sc adiposity is detrimental for capillary perfusion and that this process may start before puberty.

Abdominal Fat↗
PubMed1997

Hyperviscosity and microproteinuria in central obesity: relevance to cardiovascular risk.

OBJECTIVES: To investigate the role of blood rheology changes in the occurrence of glomerular proteinuria in obese patients with central fat distribution. SUBJECTS: Fifty-nine obese out-patients (31 with central and 28 with peripheral body fat distribution) and 24 healthy subjects. MEASUREMENTS: Blood and plasma viscosity (Rotational viscometer CV100 HAAKE), erythrocyte deformability (whole-blood filtration time), fibrinogen (nephelometry), urinary excretion rates of albumin, IgG, transferrin and IgA (nephelometry). RESULTS: Higher blood viscosity (at low and high shear-rates), plasma viscosity, fibrinogen, erythrocyte aggregability and lower erythrocyte deformability were found in patients with central obesity than in patients with peripheral obesity (P < 0.01) and in healthy subjects (P < 0.001). Furthermore an increased urinary excretion rate of albumin (P < 0.001), IgG (P < 0.001), transferrin (P < 0.01) and IgA (P < 0.05) was found in patients with central obesity than in the other two groups. Blood hyperviscosity (at shear-rate 1 s-1 and 1/200 ratio) significantly correlated with the amount of urinary excretion of proteins independently of the other clinical and metabolic variables. CONCLUSIONS: The data demonstrated haemorheologic disorders related to pathologic proteinuria in patients with central obesity. The interaction between these two components may increase the risk of widespread cardiovascular disease.

Adult↗
PubMedDate not supplied

Changing the metabolic profile by large-volume liposuction: a clinical study conducted with 123 obese women.

Adipose tissue is a metabolically active tissue. The hypertrophic fat cells of obese patients produce increased quantities of leptin and tumor necrosis factor-alpha (TNF-alpha) and are less sensitive to insulin. This study aimed to determine whether aspirating large amounts of these subcutaneous fat cells by large-volume liposuction (LVL), could change the metabolic profile in 123 obese women. All the patients had a main central body fat distribution (waist-hip ratio, 0.91+/-0.01) and a body mass index of 32.8 +/- 0.8 kg/m). They were studied for 90 days after LVL to determine their changes in insulin sensitivity, resting metabolic rate, serum adipocytokines, and inflammatory marker levels. During 3 months of follow-up evaluation, LVL resulted in a significantly improved insulin sensitivity, resting metabolic rate, serum adipocytokines, and inflammatory marker levels. Such parameters correlate with a decrease in fat mass and waist-hip ratio. Interestingly, no significant changes were seen between the first (21 days) and second (90 days) metabolic determinations after LVL. However, these findings, confirm other preliminary data published previously, and could change the actual role of LVL in the multidisciplinary treatment of obesity.

Adipocytes↗
PubMed1994

Associations between insulin sensitivity, and free fatty acid and triglyceride metabolism independent of uncomplicated obesity.

Insulin resistance is associated with hypertriglyceridemia and elevated free fatty acid (FFA) concentrations in obese and diabetic individuals, but it is unclear to what extent this relationship is independent of obesity and is present in healthy individuals. We studied 92 healthy middle-aged males selected from the top, middle, and lowest quintiles of the insulin sensitivity index (Si) determined in a group of 182 men using the minimal model of glucose disappearance. Plasma FFA, triglyceride, glucose, insulin, and C-peptide concentrations were measured during a 3-hour intravenous glucose tolerance test (IVGTT). The low-Si (most insulin-resistant) group had more central body fat distribution (subscapular/triceps skinfold thickness) and a higher median body mass index (BMI) of 26.8 (range, 21.1 to 41.1) kg.m-2 compared with the middle- and high-Si groups with BMIs of 24.9 (19.1 to 31.5) and 23.7 (18.8 to 33.2) kg.m-2 (P < .05). Relatively minor glucose intolerance in the low-Si group was no longer significant when central adiposity was accounted for. Glucose tolerance was maintained by increased insulin secretion, leading to IVGTT insulin responses twofold and fourfold higher in the middle- and low-Si groups, respectively, compared with the high-Si group (P < .01). Fasting FFA and triglyceride concentrations were increased in the low-Si group relative to the other groups independent of BMI or central adiposity (P < .01). During the IVGTT, FFA decreased to similar minimum concentrations in all three groups. Triglyceride concentrations during the IVGTT increased above their minimum levels, particularly in the low-Si group (P < .001).(ABSTRACT TRUNCATED AT 250 WORDS)

Adult↗
PubMed1995

The influence of body build on estimates of body composition from anthropometric measurements in premenopausal women.

OBJECTIVE: To assess the influence of body build on the bias and limits of agreement for estimates of body fat obtained from anthropometric prediction equations when compared with the same data obtained by dual energy X-ray absorptiometry (DEXA). SURVEY DESIGN AND SUBJECTS: Ninety-one premenopausal women, aged between 20 and 54 years, were chosen to represent a range of skeletal body build (relative sitting height 0.50-0.56) and body fatness [body mass index (BMI) 18-34 kg/m2]. Measurements of weight, sitting height, stature, skinfold thickness, waist, umbilical and hip circumference and total body resistance and reactance were made on all subjects by standard techniques after an overnight fast. A DEXA measurement of total body fat, fat-free soft tissue and total body bone mineral mass was also obtained within 2 weeks of the anthropometric assessment. RESULTS: At the group level the mean difference (bias) between DEXA and the anthropometric estimates of body fat was similar for all three anthropometric estimates ranging from 2.7 kg with impedance to 1.8 kg with skinfold thickness. The 95% limits of agreement were also similar, ranging from +/- 5.3 kg with body mass index to +/- 4.1 kg with impedance. Umbilical circumference, BMI and the amount of bone mineral expressed as a proportion of the fat-free soft-tissue mass were all significantly (P < 0.01) correlated with the level of bias between DEXA and the anthropometric estimates of body fat. This was not the case for relative sitting height or measures of body fat distribution. Regression equations which included BMI or umbilical circumference in combination with the predicted estimates of body fat essentially eliminated the association between the level of bias in predicted body fat and the level of body fatness. They also reduced the 95% limits of agreement between DEXA and the anthropometric estimates of body fat. CONCLUSIONS: Using DEXA estimates of body fat as the standard of reference our results suggest that the comparability and precision of body fat estimates derived from age- and/or sex-specific anthropometric prediction equations based on skinfolds and BMI, but not impedance, can be improved by adjusting for differences in BMI and umbilical circumference respectively.

Absorptiometry, Photon↗
PubMed2005

Weight, fat mass, and central distribution of fat increase when women use depot-medroxyprogesterone acetate for contraception.

OBJECTIVE: To compare longitudinal changes in weight, body fat, and ratio of central to peripheral fat mass among first-time depot-medroxyprogesterone acetate (DMPA) users to women using no hormonal contraception, and to evaluate user characteristics associated with that change. DESIGN: Prospective longitudinal study. SUBJECTS: Healthy women, aged 18-35 y, using DMPA for contraception (n=178) and women using no hormonal contraception (n=145). MEASUREMENTS: Weight, body fat, and the central distribution of fat, measured at 3-month intervals for 30 months, by electronic scale and dual-energy X-ray absorptiometry (DEXA). The ratio of central to peripheral distribution of body fat was computed by dividing the body fat in the conventional DEXA trunk region of interest (ROI) by the ROI's that encompass the arms, hips and legs. RESULTS: Women using DMPA had a significantly greater increase in all measures of fatness than women using no hormonal method of contraception (P<0.03). The observed weight of DMPA users increased from a mean of 69.4 kg (s.d.=16.9) at baseline to 75.5 kg (s.d.=25.0) at 30 months; an increase of 6.1 kg (8.8.%). Fat mass increased from a mean of 25.3 kg (s.d.=12.6 kg) at baseline to 31.4 kg (s.d.=17.8); an increase of 6.1 kg (23.6%) in DMPA users. The ratio of central to peripheral fat mass in DMPA users changed from 0.95 (s.d.=0.155) at baseline to 1.01(s.d.=0.198) at 30 months. In contrast, weight, fat mass and the ratio of central to peripheral fat mass of control participants remained virtually unchanged over the same time period. Women with higher baseline physical activity levels had a smaller increase in body fat (P=0.003) and the fat ratio (P=0.03), but not weight (P=0.48). No other user characteristics including, smoking, past oral contraceptive use or previous pregnancies predicted change in level of fatness. CONCLUSIONS: This study has demonstrated a change in body composition toward greater fatness and toward a central redistribution of fat among DMPA users as compared to controls and provides important information to be used when counseling women regarding contraceptive methods. Given the potential long-term implication of these changes, further study is recommended to determine whether the gains in fatness are reversed following DMPA discontinuation and to examine the role of progestins in the development and maintenance of obesity.

Absorptiometry, Photon↗
PubMed1989

Evidence of genetic influence on central body fat in middle-aged twins.

The heritability of centrally and peripherally deposited subcutaneous body fat, as measured by thickness of subscapular and triceps skinfolds respectively, was examined in 173 monozygotic and 178 dizygotic pairs of white male twins, ages 54 to 65 years, who participated in the second examination of the National Heart, Lung, and Blood Institute's Twin Study. The heritability of two indices of body fat distribution (subscapular/triceps ratio and subscapular-triceps difference) and two indices of overall obesity (body mass index and sum of skinfolds) were also assessed. Evidence for a genetic influence on central deposition of body fat was suggested in that the classical estimate of heritability for subscapular skinfold thickness was 0.77 (p less than 0.0001). After adjusting subscapular skinfold for the overall level of obesity, heritability was reduced but remained highly significant (0.40, p = 0.003). Heritability estimates for triceps skinfold thickness and for the two fat distribution indices were substantially lower and were not statistically significant after adjustment for overall obesity. High classical estimates of heritability were also observed for both measures of overall obesity: 0.70 for BMI and 0.73 for sum of skinfolds. However, these two estimates were biased upward because of lower total variances among monozygotic compared to dizygotic twins in this sample. The more conservative and unbiased among-component estimates also suggested substantial heritability for each measure (0.35, p = 0.08 and 0.53, p = 0.01, respectively). The heritability of overall obesity emphasizes the importance of adjusting measures of fat distribution for overall obesity before assessing its heritability.

Adipose Tissue↗