The effect of weight loss on change in waist-to-hip ratio in patients with type II diabetes.

This study sought to determine whether weight loss would alter body fat distribution in obese men and women with type II diabetes. Subjects were 60 women and 33 men who participated in a year-long weight loss program. Weight losses of women and men, respectively, averaged 13.4 kg and 16.8 kg at six months and 11.2 kg and 13.1 kg at one year. WHR decreased significantly in both genders: for women, WHR decreased from 0.95 at baseline to 0.93 at six months and 0.94 at one year; for men WHR decreased from 0.99 at baseline to 0.96 at six months and 0.96 at one year. Subjects with greater upper body obesity at baseline did not lose more weight than subjects with less upper body obesity, but they did have greater reductions in WHR at six months in both genders and at one year in men. The magnitude of WHR reduction was strongly related to the amount of weight lost in men, but was not related to weight loss in women. Improvements in fasting glucose, fasting insulin, and HbA1 were significantly related to weight loss, but not to reductions in WHR. Thus, participation in a weight loss program had beneficial effects on body fat distribution in patients with type II diabetes, but these changes in WHR were not independently associated with improvements in glycemic control.     

The role of the opioid peptides in the development of hyperinsulinemia in obese women with abdominal body fat distribution.

In this study, we investigated the hypothesis that increased opioid activity may be involved in the development of hyperinsulinemia in women with obesity and abdominal body fat distribution. Two groups of nine obese body (body mass index [BMI], 30 to 40 kg/m2) women with abdominal (A-ob) (waist to hip ratio [WHR] greater than 0.85) or gluteo-femoral (F-ob) (WHR greater than or equal to 0.80) fat distribution were examined and compared with eight normal-weight controls. Basal beta-endorphin levels were higher in the A-ob group than in the other groups. Each woman underwent two oral glucose tolerance tests (OGTT, 75 g glucose). A bolus of naloxone (0.8 mg) followed by a constant infusion of naloxone (0.04 mg/kg/h) or saline was also administered during the glucose challenge in random order, and blood samples for glucose, insulin, and C-peptide were collected at regular times after glucose administration. No difference was observed in basal or stimulated glucose concentrations between the three groups, nor between the saline or naloxone study. However, basal and stimulated insulin levels were significantly higher in obese women (particularly in the A-ob group) than in controls. Naloxone administration, however, did not significantly modify insulin and C-peptide glucose-stimulated concentrations in controls and in the F-ob group, whereas it significantly reduced (by approximately 47%) insulin levels in the A-ob group. Partial correlation coefficients showed a significant negative correlation between percent variation of glucose-stimulated insulin incremental areas during the naloxone study and the WHR in all women considered together (r = .544, P less than .025).(ABSTRACT TRUNCATED AT 250 WORDS)     

Associations between regional body fat distribution, fasting plasma free fatty acid levels and glucose tolerance in premenopausal women

The associations between total adiposity, body fat distribution measured by computed tomography (CT) and estimated by the waist-to-hip ratio (WHR), regional fat cell morphology, fasting plasma free fatty acid (FFA) levels and glucose tolerance were studied in a sample of 37 premenopausal women aged 35.3 +/- 4.6 years (mean +/- s.d.). Body fat mass, CT-derived abdominal and femoral fat areas, as well as the abdominal fat cell weight were all significantly associated with fasting plasma FFA levels (0.34 less than r less than 0.49, 0.005 less than P less than 0.05), and with the glucose and insulin areas during the oral glucose tolerance test (OGTT) (0.36 less than r less than 0.70, 0.0001 less than P less than 0.05). No associations were found between the WHR, the femoral fat cell weight and fasting plasma FFA levels or glucose area during the OGTT. However, the WHR and the femoral fat cell weight were positively associated with insulin area. Plasma FFA levels were positively correlated with the glucose area during the OGTT, whereas no association was found between plasma FFA levels and the insulin area. Covariance analysis indicated that this effect of plasma FFA levels on the magnitude of glucose response to OGTT was independent from that of total adiposity or regional body fat distribution variables. These results emphasize the importance of plasma FFA levels as a correlate of glucose tolerance and suggest that the associations previously reported between obesity, regional body fat distribution, fat cell size and glucose tolerance are, at least partly, mediated by variations in plasma FFA levels.     

Effect of obesity and body fat distribution on sex hormones and insulin in men

To investigate the relationship between body fat distribution, sex hormones, and hyperinsulinemia in male obesity, we examined 52 obese men (body mass index [BMI], 35.0 +/- 6.1, mean +/- SD) and 20 normal-weight controls. Their waist to hip circumference ratio (WHR), which was used as an index of fat distribution, was 0.985 +/- 0.052 and 0.913 +/- 0.061 (P less than .005), respectively. Compared with controls, obese men presented significantly lower levels of total (357 +/- 132 v 498 +/- 142 ng/dL; P less than .005) and free testosterone (14.2 +/- 2.9 v 17.1 +/- 2.6 pg/mL; P less than .05) and sex hormone-binding globulin (SHBG; 41.7 +/- 31.9 v 66.2 +/- 18.6 nmol/L; P less than .001) without any significant difference on the other sex steroid or on gonadotropin concentrations. Fasting and glucose-stimulated insulin and C-peptide levels were significantly higher in obese than in controls, and in obese with the WHR value greater than 0.97 (corresponding to the distribution median) than in those with WHR lower or equal to 0.97. BMI was negatively correlated with testosterone (P less than .005), free testosterone (P less than .01), and SHBG (P less than .001) and positively with fasting (P less than .001) and glucose-stimulated (P less than .005) C-peptide concentrations, whereas no relationship was found between these variables and WHR values. On the contrary, WHR was significantly correlated with fasting and post-glucose insulin levels (P less than .05), but not with those of sex steroids.(ABSTRACT TRUNCATED AT 250 WORDS)     

Relationship of body fat topography to insulin sensitivity and metabolic profiles in premenopausal women

The relationship of body fat distribution to metabolic profiles was determined in 80 healthy premenopausal white women of a wide range of obesity levels [percentage of ideal body weight (% IBW) 92-251]. Distribution of fat between the upper and lower body was assessed from the waist/hips girth ratio (WHR), which varied from 0.64 to 1.02. In 23 women, in vivo insulin sensitivity was also determined from the steady-state plasma glucose (SSPG) level at comparable insulin levels of approximately 100 microU/mL attained by the intravenous infusion of somatostatin, glucose, and insulin. Increasing WHR was accompanied by progressively increasing fasting plasma insulin levels (r = 0.47, P less than 0.001), insulin and glucose areas after glucose challenge (r = 0.53, P less than 0.001; r = 0.50, P less than 0.001, respectively) and fasting plasma triglyceride concentrations (r = 0.48, P less than 0.001). Obesity level was similarly correlated with these metabolic indices. Partial and multiple regression analysis and analysis of variance with a linear contrast model revealed that the effects of body fat topography were independent of, and additive to, those of obesity level. Within obese subjects alone (%IBW: 130), %IBW had no predictive value, but WHR remained a significant predictor of plasma glucose, insulin, and triglyceride concentrations. The WHR also correlated with the plasma cholesterol level, but this association was largely dependent on its relationship to %IBW. Both WHR and %IBW correlated with the insulin resistance index, SSPG (r = 0.60, P less than 0.01; r = 0.61, P less than 0.01, respectively).(ABSTRACT TRUNCATED AT 250 WORDS)     

The relative contribution of androgens and insulin in determining abdominal body fat distribution in premenopausal women.

To investigate the relative contribution of insulin and sex hormones in determining the abdominal pattern of fat distribution in premenopausal women, five groups of age-matched subjects were examined: Group 1 consisted of 14 normal weight eumenorrheic women (NO); Group 2 of 9 obese eumenorrheic women (OB); Group 3 of 14 normal weight hyperandrogenic women with polycystic ovary syndrome (NO-HA); Group 4 of 10 obese hyperandrogenic women with polycystic ovary syndrome (OB-HA) and, finally, Group 5 of 10 obese hyperandrogenic women with polycystic ovary syndrome and acanthosis nigricans (OB-HA-AN). Both the two normal weight groups and the three obese groups were matched for body mass index values. Sex hormone pattern showed significantly higher LH and testosterone levels in hyperandrogenic women with respect to NO and OB women but obese hyperandrogenic groups (OB-HA and OB-HA-AN) presented significantly lower LH concentrations than NO-HA. Fasting and glucose-stimulated insulin levels were significantly higher in OB than NO, in OB-HA and OB-HA-AN than in OB and NO-HA, and in OB-HA-AN than in OB-HA, without any significant difference between OB and NO-HA. Body fat distribution, expressed by the waist to hip ratio (WHR), showed progressively higher values (p less than 0.01) from NO to OB, NO-HA, OB-HA and, particularly, OB-HA-AN women. Determination coefficients r2 obtained from simple regression analysis showed that the sum of insulin values during the glucose tolerance test and testosterone levels had a more significant power in determining WHR variability.(ABSTRACT TRUNCATED AT 250 WORDS)     

Clinical and hormonal characteristics of obese amenorrheic hyperandrogenic women before and after weight loss

We studied a group of obese hyperandrogenic amenorrheic women to determine the effects of weight loss on anthropometry, hormonal status, menstrual cycles, ovulation, and fertility. Fourteen women had polycystic ovaries, two the hyperandrogenism-insulin resistance-acanthosis nigricans syndrome, one hirsutism of adrenal origin, and three idiopathic chronic anovulation. The duration of amenorrhea before the study ranged from 3-17 months [mean, 8.6 +/- 4.5 (+/- SD)]. All women ate a hypocaloric diet for a period of 8.0 +/- 2.4 months. Weight loss ranged from 4.8 to 15.2 kg (mean, 9.7 +/- 3.1 kg; 1.35 +/- 0.56 kg/month) and the waist to hip ratio, which was used as a measurement of body fat distribution, decreased from 0.86 +/- 0.1 to 0.81 +/- 0.06 (P less than 0.0001). The women's mean plasma testosterone and LH concentrations decreased significantly (P less than 0.001 and P less than 0.005, respectively). A significant positive correlation was found between the decreases in plasma testosterone levels and the decreases in glucose-stimulated insulin levels. Moreover, the decreases in the waist to hip ratio correlated positively with the decreases in glucose-stimulated insulin levels and inversely with the decreases in plasma 17 beta-estradiol. No relationships were found between weight loss and the changes in plasma insulin, steroid, and gonadotropin concentrations. The responsiveness to the weight reduction program was evaluated by comparing the number of menstrual cycles during the study period with the number reported before it. Eight women had significantly improved menstrual cyclicity (responders), while 12 did not (nonresponders). The clinical characteristics and hormone values were similar in responder and nonresponder women. In the group as a whole, 33% of the menstrual cycles during the study were ovulatory, and 4 pregnancies occurred. Hirsutism improved significantly in more than half of the women, as did acanthosis nigricans when present. We conclude that weight loss is beneficial in all obese hyperandrogenic women regardless of the presence of polycystic ovaries, the degree of hyperandrogenism, and the degree and distribution of obesity.     

Hormonal influences on the relationships between body fatness, body fat distribution, lipids, lipoproteins, glucose and blood pressure in French working women

The independent associations between overall obesity, body fat distribution, lipids, lipoproteins, glucose, blood pressure and some hormonal factors (sex hormone-binding globulin (SHBG), corticosteroid binding globulin (CBG) and fasting insulin) were cross-sectionally examined in 205 French working women. After adjustment for age, overall adiposity assessed by body mass index (BMI) was significantly associated with most metabolic parameters, whereas regional adiposity assessed by the waist-hip ratio (WHR) was significantly associated only with triglyceride, systolic and diastolic blood pressure. Blood pressure, glucose but not triglyceride, were also negatively and significantly correlated with SHBG and positively with fasting insulin. Negative independent associations were found between SHBG and both BMI and WHR, whereas CBG was positively associated only with WHR. Fasting insulin was no longer related to WHR after adjustment for BMI. After controlling for the effect of SHBG or insulin, the associations between triglyceride, blood pressure and both BMI and WHR were not substantially modified. After adjustment for BMI and WHR, fasting insulin was independently associated with both HDL cholesterol and diastolic blood pressure. In conclusion, in these French women, hormonal factors under study appeared to have little influence on the relationships between body fatness, body fat distribution, metabolic variables and blood pressure.     

A prospective study of body fat distribution and weight loss

Previous studies have suggested an association between adipose tissue cellularity and body fat distribution, and between adipose tissue cellularity and ability to lose weight. To determine whether there was an association between body fat distribution and ability to lose weight, we prospectively studied 187 severely obese women. The women were all 50 percent or more above ideal body weight, with personal physician documentation of no known major illnesses. Weights were recorded at the beginning and end of a 3-week hospitalization and every 3 months following hospitalization, for up to 2 years. The ratio of waist girth to hip girth (WHR) was used as an index of body fat distribution. A statistical analysis which adjusted for age and weight on admission did not find any association between WHR and weight loss during hospitalization, or at any time up to 2 years after hospital discharge. We conclude that the WHR index of body fat distribution is not a useful prognostic indicator of weight change for severely obese women with refractory obesity.     

Fat oxidation, body composition and insulin sensitivity in diabetic and normoglycaemic obese adults 5 years after weight loss

OBJECTIVE: To investigate whether normal glucose-tolerant and type II diabetic overweight adults differ in response to weight regain with regard to substrate oxidation and metabolic parameters. METHODS: A total of 15 overweight-obese subjects: seven normal glucose tolerant (NGT) and eight with type II diabetes (DM) were restudied 5 y after significant weight loss. Prediet, after 28 days calorie restriction and at 5 y, subjects were characterised for weight, height, waist-to-hip ratio (WHR) and body composition by dual-energy X-ray absorptiometry. Fasting glucose, insulin, leptin and lipid levels were measured and subjects underwent euglycaemic-hyperinsulinaemic clamp (insulin 0.25 U/kg/h for 150 min). Indirect calorimetry was performed resting and in the final 30 min of the clamp. Dietary assessment was by 4-day diet-diary. RESULTS: Both NGT and DM groups regained weight at 5 y and were not different to prediet. Total body fat (%) and WHR were higher at 5 y compared to prediet in both groups. Fasting glucose was increased in NGT subjects at 5 y, and fasting insulin was higher in both groups at 5 y compared to prediet. Insulin sensitivity (GIR) was similar at 5 y compared to prediet, but at 5 y DM subjects were more insulin resistant than NGT subjects. At 5 y, both DM and NGT groups had significantly reduced basal fat oxidation and no significant suppression of fat oxidation with insulin. Clamp respiratory quotient levels at 5 y were significantly higher in NGT compared to DM subjects. CONCLUSION: Reduced basal fat oxidation, and reduced variation in substrate oxidation in response to insulin develop with fat regain and fasting hyperinsulinaemia in both NGT and DM obese adults.     

Effects of body composition and exercise capacity on glucose tolerance, insulin, and lipoprotein lipids in healthy older men: A cross-sectional and longitudinal intervention study

The relationships of age, body composition, and physical conditioning status to glucose tolerance, insulin, and lipoprotein levels were examined in 77 healthy, nonsmoking white male volunteers, aged 46 to 73 years with no evidence of coronary artery or endocrine-metabolic disease. The men had a wide range of body fat (13% to 39%), indexed as waist-to-hip ratio (WHR, 0.84 to 1.08), and maximal aerobic capacity (VO2max, 17 to 48 mL/kg.min). Multiple regression analysis with age, VO2max, WHR, and percent body fat as independent variables demonstrated that fasting plasma insulin, triglyceride (TG), and high density lipoprotein cholesterol (HDL-C) levels were independently related to both percent body fat and WHR. In contrast, fasting plasma glucose levels and insulin responses during oral glucose tolerance tests (OGTT) correlated independently with percent body fat, and glucose responses to OGTT correlated only with WHR. Although fasting plasma TG and HDL-C correlated with glucose and insulin levels, in multiple regression analyses only percent body fat and WHR were the significant independent variables. Fasting total and low density lipoprotein cholesterol values were not related to these variables. To test the effects of weight loss and exercise training on these relationships, 20 obese men of comparable age, percent body fat, WHR, and VO2max were randomly assigned to weight loss or aerobic exercise training programs. A 12% +/- 3% loss in body weight (P less than .01, mean +/- SD) resulted in a 19% +/- 9% decline in body fat (P less than .01) with no change in fat free mass, WHR, or VO2max.(ABSTRACT TRUNCATED AT 250 WORDS)     

Viscerally obese women with normal body weight have greater brachial-ankle pulse wave velocity than nonviscerally obese women with excessive body weight

OBJECTIVE: To confirm the association of visceral obesity and brachial-ankle pulse wave velocity (baPWV) and to compare metabolic indices and baPWV between individuals who have normal body weight but are viscerally obese and individuals with excessive body weight who are not viscerally obese. PATIENTS AND MEASUREMENTS: We recruited a total of 150 women, aged 22 to 67 years. We assessed body composition, measured by computed tomography (CT), and divided the study population into four groups, based on visceral adipose tissue area (normal, normal body weight but viscerally obese, excessive body weight but not viscerally obese, and excessive body weight and viscerally obese). The baPWV was measured, using a volume plethysmographic instrument. RESULTS: Despite lower levels of total body fat, the women who had a normal body weight but were viscerally obese had a higher plasma triglyceride level and baPWV measurement and greater subcutaneous fat area (SFA) and thigh SFA than the women with excessive body weight who were not viscerally obese. After adjustment for age, mean blood pressure (BP), body mass index (BMI), triglyceride levels, fasting insulin levels, and free fatty acid (FFA) levels, baPWV was independently correlated with abdominal visceral fat area, as measured by CT (P = 0.001). CONCLUSIONS: Mean baPWV was higher in women with normal body weight who were viscerally obese than in women who had excessive body weight but were not viscerally obese, and abdominal visceral fat was an independent factor for baPWV. These results suggest that early detection and intervention in viscerally obese individuals, even those within a normal BMI range, could be needed to prevent atherosclerosis and cardiovascular disease (CVD).     

The relationship between body fat distribution and weight loss in obese adolescent girls.

Recent studies have demonstrated an association between the pattern of body fat distribution and the occurrence of cardiovascular risk factors. In this study, we evaluated changes in body fat distribution as defined by several anthropometric criteria during a six week weight reduction programme in 110 obese adolescent girls (mean age 15.2 +/- 0.4 years). The standardized regimen included a mixed diet of 1032 kcal/day and a daily exercise programme of 1-2 h duration. The mean weight loss was 8.6 +/- 2.8 kg, decreasing the body mass index (BMI) from 31.4 +/- 4.7 to 28.2 +/- 4.9 kg/m2 (P < 0.01). The reduction in body weight was accompanied by a significant decrease in the waist-to-hip ratio (WHR) from 0.86 +/- 0.06 to 0.81 +/- 0.05 (P < 0.01). The initial WHR was correlated with the degree of weight loss independent of the initial weight (r = 0.34, P < 0.001). Categorized according to the waist-to-hip ratio girls in the upper tertile (WHR > 0.88) lost significantly more weight than girls in the lower tertile (WHR < 0.80) (9.8 +/- 2.7 vs. 6.8 +/- 2.5 kg, P < 0.01). These findings suggest that girls with an abdominal type of obesity benefit more from a weight reduction programme than girls with a gluteal-femoral type of obesity.     

Apolipoprotein concentrations in obese subjects with upper and lower body fat mass distribution

In order to assess the relationship between obesity and serum lipids, a homogenous group of adult men and premenopausal women is assessed for body mass index, body fat distribution reflected by the waist/hip ratio (WHR), serum lipid parameters and apolipoproteins. Body fat distribution is distinguished in an abdominal and gluteal-femoral type using a cut-off point of 1.00 for the ratio of waist-to-hips girth for men. In women the cut-off value is considered as 0.80 but was also evaluated when considered as 0.85. In the next step tertiles for WHR are created to show a graded relationship between WHR and lipoprotein fraction. The results indicate that WHR is an important determinant for most atherosclerosis-related lipids and apoproteins: in both men (P less than 0.05) and women (P less than 0.005) WHR is significantly correlated with apolipoprotein B. Using multiple regression analysis, in women WHR seems to be the most important dependent variable, where body mass index is not significantly contributing to the explained variance. In men, however, besides WHR age is the most significant variable, although age distribution is similar in men and women. Using tertiles of WHR, we show a clear graded relationship with most lipids and lipoproteins; this gives additionally an argument to confirm that in women WHR = 0.80 is the most accurate cut-off value for abdominal obesity. This study demonstrates that both obese men and women with an abdominal fat mass distribution show a lipid and apoprotein profile that is less favorable than that seen in gluteal-femoral obese subjects insofar as the risk of coronary artery disease is concerned.     

Decrease in visceral fat following diet-induced weight loss in upper body compared to lower body obese premenopausal women

BACKGROUND: Obesity is associated with numerous metabolic disturbances, such as insulin resistance, diabetes mellitus type 2, dyslipidemia, and hypertension. An excess of fat within the abdomen, so-called visceral adiposity, confers a greater and independent health risk of metabolic and cardiovascular complications than does adipose tissue accumulation elsewhere. The present study aimed to investigate a possible differential effect of diet-induced weight loss in visceral fat mass and metabolic parameters in obese individuals with the upper body (UBO) and lower body (LBO) obese phenotype. METHODS: The obese subjects were prescribed a liquid, very-low calorie diet to reduce 50% of their overweight (15% body weight loss). Specific body fat measurements (MRI, BIA), anthropometrics, and fasting metabolic parameters were obtained in control subjects and two groups of obese subjects (UBO and LBO) before and after weight loss. RESULTS: Weight loss was accompanied by significant decreases in total, subcutaneous, and visceral fat in both UBO and LBO women. The largest reduction in visceral fat mass was found in the UBO women (absolute decrease 223+/-32 cm(2) vs 122+/-91 cm(2) in LBO women; P=0.01), while the amount of visceral fat was reduced to normal levels in LBO women (155+/-25 cm(2) after weight loss vs 143+/-17 cm(2) in controls; P=NS). Furthermore, weight loss significantly lowered fasting glucose, total cholesterol, and LDL cholesterol concentrations in UBO women. CONCLUSION: The obese phenotype is preserved after body weight loss. UBO women have to lose a larger amount of overweight in order to bring the amount of fat in the visceral depot down to normal levels and to obtain normalization of their cardiovascular risk profile.     

Insulin-leptin-visceral fat relation during weight loss

INTRODUCTION: The relation between insulin-leptin-visceral fat axis during weight loss has not been studied previously. AIMS: To evaluate the insulin, leptin, and abdominal adiposity relation during weight loss in patients with upper body obesity. METHODOLOGY: Twenty volunteers (7 men, 13 women) with mean age 50.6+/-6.3 (SD) and upper body obesity (weight 105.4+/-12.3 kg, BMI 35.9+/-2.5 kg/m2) were recruited. Participants were enrolled in a one-arm clinical study using a calorie-deficient diet and an escalating dose regimen of sibutramine, starting with 5 mg daily and increasing in 5-mg increments to 20 mg per day. Body weight, insulin, leptin, glucose, lipids, abdominal computed tomography (CT), and total body electrical conductance (TOBEC) were measured serially at weeks 0, 4, 8, 12, and 24. RESULTS: Eighteen patients completed the 6-month study: one man and one woman discontinued because of adverse events. With diet and sibutramine, body weight was significantly and continuously reduced throughout the 6-month study. There was a 16.0% (p = 0.0001) reduction in body weight (p < 0.001) and 22.5% (p = 0.0001) decrease in total body fat mass. Abdominal CT scans showed a 28.3% (p = 0.0001) reduction in total abdominal fat, a 26.0% (p = 0.0001) reduction in subcutaneous fat (p < 0.001), and a 31.0% (p = 0.0003) reduction in visceral fat (p < 0.001). There was a 32.0% (p = 0.0008) reduction in leptin levels and 37.9% (p = 0.0001) reduction in insulin levels between baseline and week 4, but no further significant reduction in leptin and insulin levels was observed for the duration of the study. There was a significant correlation between insulin and leptin concentrations throughout the study (p = 0.0001). Leptin was presented as a function of insulin measured at the same time. Significant associations between visceral abdominal fat, subcutaneous fat, and leptin were also observed. CONCLUSION: In this study, we found that leptin and insulin were related in weight loss. The data suggest that insulin may act as a strong regulator of leptin secretion during weight loss and that circulating leptin levels can be predicted by insulin level. Using sibutramine in conjunction with hypocaloric diet reduced body weight and decreased fat mass significantly. Visceral and subcutaneous abdominal fat depots were shown to decrease. Whether sibutramine exerts any selective reduction of visceral abdominal fat as opposed to total body fat mass will require further clinical investigation.     

Association of body mass and body fat distribution with serum melatonin levels in obese women either non-operated or after jejunoileostomy

The association of body mass index (BMI) and body fat distribution (as measured by waist-to-hip circumference ratio; WHR) with serum melatonin (MEL) levels determined at 02 and 14 h were examined in 22 non-operated obese women and 21 obese women who underwent jejunoileostomy for morbid obesity 2 to 6 years earlier as well as in 20 gender and age-matched healthy controls with normal body weight. All non-operated obese women either with moderate or morbid obesity had significantly higher MEL concentration at 14 h compared with controls, whereas the amount of MEL secreted at 02 h was elevated only in morbidly obese women. The mean differences between serum MEL levels at 14 h and 02 h (delta MEL) was reduced in morbidly obese women - it may be due to desynchronisation of its circadian rhythmicity. Among women who underwent jejunoileostomy for morbid obesity the values of MEL were normalized only in those with a noted body mass reduction and with BMI and WHR indexes less than 28 kg/m2 and 0.83, respectively. MEL correlated positively with BMI and WHR indexes at 14 h in all subjects studied. Negative correlation was noted between the relative values of delta MEL and BMI in both non-operated and operated obese women with BMI indexes >31 kg/m2.     

Studies in the distribution of body fat. II. Longitudinal effects of change in weight

Information on the effects of age, sex, obesity and weight change on the fat distribution pattern has not been systematically reported. As an index of body fat distribution, the waist hip circumference ratio (WHR) was computed in 370 men and 177 women aged 22-86 years, participants of the Baltimore Longitudinal Study of Aging. For cross-sectional analysis, initial data on the participants were analyzed; for longitudinal study, the changes in the measurements related to weight change during a 5-year follow-up were analyzed. From cross-sectional analysis: (1) waist circumference is larger in men than in women and increases progressively with age; (2) hip circumference shows no consistent age or sex differences; (3) thus, the well known sex differences in WHR are totally attributable to differences in waist circumference; (4) increases in WHR with age occur in both men and women. From longitudinal analysis of weight change: (1) changes in waist and hip circumferences are correlated directly with changes in weight in both sexes, but there are large differential sex effects; (2) in men, waist changes dominate; (3) in women, waist and hip changes are nearly the same; (4) thus, weight changes in men have large effects on the WHR, while in women changes in WHR are very small. Men, as a group, have a more dangerous fat distribution pattern than women, but men as a group will show a more beneficial pattern of change in WHR with weight control than women.     

Exercise is required for visceral fat loss in postmenopausal women with type 2 diabetes

This study examined the effects of aerobic exercise without weight loss, a hypocaloric high monounsaturated fat diet, and diet plus exercise (D+E) on total abdominal and visceral fat loss in obese postmenopausal women with type 2 diabetes. Thirty-three postmenopausal women (body mass index, 34.6 +/- 1.9 kg/m(2)) were assigned to one of three interventions: a hypocaloric high monounsaturated fat diet alone, exercise alone (EX), and D+E for 14 wk. Aerobic capacity, body composition, abdominal fat distribution (magnetic resonance imaging), glucose tolerance, and insulin sensitivity were measured pre- and postintervention. Body weight ( approximately 4.5 kg) and percent body fat ( approximately 5%) were decreased (P < 0.05) with the D and D+E intervention, whereas only percent body fat ( approximately 2.3%) decreased with EX. Total abdominal fat and sc adipose tissue (SAT) were reduced with the D and D+E interventions (P < 0.05), whereas visceral adipose tissue (VAT) decreased with the D+E and EX intervention, but not with the D intervention. EX resulted in a reduction in total abdominal fat, VAT, and SAT (P < 0.05) despite the lack of weight loss. The reductions in total abdominal fat and SAT explained 32.7% and 9.7%, respectively, of the variability in the changes in fasting glucose levels, whereas the reductions in VAT explained 15.9% of the changes in fasting insulin levels (P < 0.05). In conclusion, modest weight loss, through either D or D+E, resulted in similar improvements in total abdominal fat, SAT, and glycemic status in postmenopausal women with type 2 diabetes; however, the addition of exercise to diet is necessary for VAT loss. These data demonstrate the importance of exercise in the treatment of women with type 2 diabetes.     

Decreased hepatic insulin extraction in upper body obesity: relationship to unbound androgens and sex hormone binding globulin

Hyperinsulinemia is a well-recognized entity of simple obesity. It is demonstrated that hyperinsulinemia is associated with upper body fat and fat cell hypertrophy. Androgen excess and lower levels of sex hormone binding globulin (SHBG) may produce fat cell hypertrophy and hyperinsulinemia as well. We measured serum insulin and C-peptide levels during an OGTT in two groups of obese premenopausal women to determine whether the hyperinsulinemia is due to hypersecretion or due to a diminished hepatic extraction of insulin. In this study, we found no correlation between the insulin and C-peptide levels or their ratio and the degree of obesity. However, a significant correlation was found between the waist-to-hip circumference ratio (WHR), used as an index of body fat distribution, and the areas of insulin (r = 0.55; P less than 0.001) and C-peptide (r = 0.51; P less than 0.001). SHBG and free androgen index (FAI) were also significantly related to these areas. The peripheral C-peptide/insulin molar ratio has been assumed to reflect changes in hepatic insulin extraction while the corrected C-peptide response reflects beta-cell function. WHR was negatively related to this ratio (r = -0.44; P less than 0.005) and SHBG showed a positive correlation (r = 0.34; P less than 0.05). Stepwise multiple regression analysis revealed that the 2-h insulin and C-peptide values and both curve areas can be explained up to 40-80% by sex hormones and anthropometric variables. Also the C-peptide/insulin molar ratio is dependent in a first step on WHR (r2 = 0.23; P less than 0.01).(ABSTRACT TRUNCATED AT 250 WORDS)