Leptin and body composition in healthy postmenopausal women

BACKGROUND: Leptin has been proposed to be involved in central control of adiposity and fat distribution but the role of this peptide is controversial. The aim of our study was to test the relationship between serum leptin and body composition, fat distribution, and some biochemical markers such as fasting insulinemia and lipoproteins in a population of healthy Italian postmenopausal women. METHODS: One hundred and twenty-three postmenopausal women (62.1+/-8.7 years) were evaluated. Body composition (fat and lean mass) was assessed by dual-energy X-ray absorptiometry (DXA). Two regions of interest were determined for regional fat analysis. Serum leptin and insulinemia were measured by radioimmunoassay, lipoproteins with colorimetric methods and apolipoproteins nephelometrically. RESULTS: Plasma leptin levels are strongly related to total fat mass, in grams (r=0.73, p<0.001) or as a percentage of soft tissue (r=0.75, p<0.001), and to adiposity, calculated as ratio between lean and fat mass (r=0.76, p<0.001). A significant correlation was also found between serum leptin and central fat distribution (r=0.29, p<0.01). As concerns biochemical markers, serum leptin was significantly related to fasting insulin (r=0.38, p<0.001), total cholesterol (r=0.29, p<0.01), Apolipoprotein-B (r=0.35, p<0.001), and triglycerides (r=0.22, p<0.05). When corrected for total fat mass, the partial correlation coefficients remain significant for percentage of total body fat (r=0.27, p<0.01), adiposity (r=0.23, p<0.01), and fat proportion in android region (r=0.18, p<0.05). CONCLUSIONS: These data indicate that leptin levels are related to adiposity and fasting insulin levels; indeed fast insulin mantains significant correlation with leptin (r=0.23, p<0.01) after controlling for fat mass. Android distribution of fat mass in elderly women is associated with leptin concentration.     

Magnesium, insulin resistance and body composition in healthy postmenopausal women

OBJECTIVE: This study was conducted to determine the association between magnesium (Mg), body composition and insulin resistance in 136 sedentary postmenopausal women, 50 to 77 years of age. METHODS: Diabetics, hypertensives and women on hormonal replacement therapy were excluded and the remaining 74 were divided according to BMI> or =25 (obese: OG) and BMI<25 kg/m(2) (non-obese: NOG). Nutritional data disclosed that intakes were high for protein and saturated fat, low for carbohydrates, polyunsaturated fat and Mg and normal for the other nutrients, according to recommended dietary allowances (RDA). Mg values in red blood cells (RBC-Mg) and plasma (P-Mg), were determined, as were fasting glucose, and insulin levels, Homeostasis Model Assessment (HOMA), body mass index (BMI), body fat percent (BF %), abdominal fat (AF) and free fat mass (FFM). RESULTS: RBC-Mg values were low in both groups when compared with normal values. There were significant differences in body composition parameters, HOMA and insulin levels, with higher basal insulin levels in OG. RBC-Mg was directly correlated with insulin, HOMA and FFM in both groups, according to Pearson correlations. HOMA in OG was also directly correlated with BMI, FFM and AF. In NOG, HOMA was only correlated with FFM. The low RBC-Mg levels observed were probably due to low Mg intake and to deregulation of factors that control Mg homeostasis during menopause. CONCLUSIONS: Both Mg deficit and obesity may independently lead to a higher risk for insulin resistance and cardiovascular disease.     

Blood pressure and body composition changes in women

To determine which of two measures of adiposity change (total weight or percentage fat determined by volume displacement) is more strongly associated with change in blood pressure, a longitudinal study was made of 68 women aged 15–59. The initial physical characteristics of the subjects were the following: mean age, 41.2 years; average weight, 127.1 lb; average percentage body fat, 24.4%; mean systolic blood pressure, 119.8 mm Hg; and mean diastolic blood pressure, 77.8 mm Hg. Changes over an average period of 25 months consisted of a mean weight loss of 2.0 lb, percentage body fat decrease of 1.3%, and systolic and diastolic blood pressure lowering of 1.5 and 1.4 mm Hg. For all women, the correlation coefficient for change in systolic blood pressure with change in percentage body fat by volume displacement was r = 0.28 (P < 0.05). This value, although slightly higher than that obtained using body weight in this study, is not significantly different from it. Results for diastolic blood pressure were similar. Partial correlation, adjusting for age, initial weight, and percentage body fat did not change the values. These findings suggest that the use of change in percentage body fat did not provide any improvement in the relationship between changes in blood pressure and in weight.     

Eight-year longitudinal changes in body composition in healthy Swiss adults

OBJECTIVE: Significant changes in body composition occur during lifetime. This longitudinal study (8.0 +/- 0.8 yrs) in a cohort of healthy sedentary and physically active men (n = 78) and women (n = 53), aged 20 to 74 yr describes: 1) the longitudinal changes in weight and body composition and 2) their associations with age and physical activity. Method: Fat-free mass (FFM) and body fat (BF) were assessed by bioelectrical impedance analysis (BIA). Subjects who regularly performed >3 hours per week of endurance type physical activity were classified as "Active". Others were classified as "Sedentary". Subjects were also separated by age (<45 yr vs > or =45 yr). RESULTS: FFM increased by 1.7 +/- 2.8 kg in men <45 yr who gained 4.0 +/- 5.0 kg of body weight and was maintained (0.5 +/- 1.6 kg) in women <45 y who gained 1.6 +/- 3.0 kg of weight. A weight gain of 1.2 +/- 3.3 kg in men > or =45 yr was accompanied by stable FFM (-0.1 +/- 2.3 kg), and of 1.0 +/- 3.2 kg was accompanied by a loss of FFM in women > or =45 yr. In active men > or =45 yr, maintenance of FFM was associated with smaller weight gains than in sedentary; sedentary men > or =45 yr decreased FFM with larger weight gains than active subjects. Sedentary women <45 yr were able to gain FFM; the active women maintained, but did not gain FFM with smaller weight gains than in sedentary women. FFM decreased in >/=45 yr women despite of small weight gains. CONCLUSION: Weight change is clearly associated with a change in FFM. Weight gain is necessary to offset age-related FFM loss between 20 and 74 yrs. In active men, a FFM increase was associated with less weight gain than sedentary men. Future studies should evaluate the threshold of weight change and the level of physical activity necessary to prevent age-related losses of FFM.     

Seasonal changes in vitamin D status and bone turnover in healthy Irish postmenopausal women

OBJECTIVES: To examine the effect of season on biochemical markers of bone turnover in 51-to 75-year-old Irish women and to investigate whether such changes are related to vitamin D status. DESIGN: Longitudinal observational study. SETTING: Cork, Ireland (52 degrees N). SUBJECTS: 76 apparently healthy, free-living postmenopausal women (aged 51-75 years), not taking any medication and free from any condition likely to affect vitamin D status or calcium/bone metabolism. RESULTS: Serum 25-hydroxyvitamin D [S-25(OH)D] showed a clear seasonal variation with significantly higher (p < 0.001) values during late summer than late winter. Both urinary pyridinoline (Ur-Pyr) (p < 0.01) and deoxypyridinoline (Ur-Dpyr) (p < 0.001), but not serum parathyroid hormone or osteocalcin, showed a marked seasonal variation with lowest values during late-summer. Stratifying women into those with S-25(OH)D levels > or = or <50 nmol/L (vitamin D adequate and inadequate, respectively) during late-winter, showed that Ur-Pyr and Ur-Dpyr in both groups were significantly (p < 0.05) lower during late summer, and the magnitude of the reduction from winter to summer was similar in both groups. CONCLUSION: Seasonal changes in bone resorption markers appeared to be linked to seasonal changes in vitamin D status. Further research is needed to investigate the impact of these changes on risk of bone loss and fracture.     

Resting metabolic rate and body composition of healthy Swedish women during pregnancy

Body weight, resting metabolic rate (RMR), total body potassium (TBK), and total body water were measured and total body fat (TBF) was calculated in a longitudinal study of 22 pregnant, healthy Swedish women. Measurements were made before pregnancy, at gestational weeks 16-18, 30, and 36, and 5-10 d and 6 mo postpartum. RMR increased more during pregnancy than previous estimates on well-nourished women showed and the increase was significantly correlated with the birth weight of the baby. TBK decreased during the first part of pregnancy; measurements at weeks 16-18 and 30 were significantly lower than the prepregnancy value and changes in TBK and RMR were significantly correlated. TBF gain during pregnancy was 5.8 +/- 4.0 kg and 60% was already gained by gestational weeks 16-18. Gain in fat was not correlated with birth weight.     

Comparison between three strength development methods on body composition in healthy elderly women

The effects of three strength development methods (during 6 weeks) were assessed on the body composition in 32 women, 62 to 75 years old and randomised in 3 groups. The first group (SC) has climbed and come down 300 stairs per session. The second group (ES) followed an electrostimulation programme on quadriceps muscles. The third group (SC+ES) has combined the stairs climbing with electrostimulation. Body composition and bone mineral density (BMD) was assessed using Absorptiometry machine before and after the programmes. None of the programmes has increased significantly BMD. Nevertheless, the SC+ES group BMD enhanced more on the trochanter (p<0,05) and the two legs (p<0,05) than the SC and ES groups BMD (interaction group/time). The combined activity (SC+ES) would deserve to be tested on a longer period.     

Energy expenditure,body composition,and biochemical indicators in healthy community women

A cross-sectional study was conducted on the associations between energy expenditure (EE), body composition (lean mass, fat mass, body mass index), and biochemical indicators (leptin, glucagon, insulin, cortisol, and triglycerides) among 17 sedentary African-American and Caucasian women living in the community (age, 40.7±6.0 years; body mass index, 32.8±9.0 kg/m²). Measurements included total, resting, and sleeping EE (via whole-room indirect calorimetery), body composition (via air-displacement plethysmography), body mass index, and biochemical indicators (leptin, glucagon, cortisol, insulin, and triglycerides). Analysis of associations between EE and body composition showed that EE increased with increasing body size, with lean mass explaining 79%, 71%, and 73% of the variability in total, resting, and sleeping EE, respectively. Analysis of associations between body composition and the biochemical indicators showed that leptin, glucagon, and insulin were positively correlated with increasing body size, whereas cortisol was negatively correlated with increasing body size. Analysis of associations between EE and biochemical indicators prior to controlling for body size showed that leptin was positively correlated with EE, and that the correlation between leptin and sleeping EE was significantly greater than the correlation between leptin and resting EE. After controlling for body size, the correlations between leptin and EE were no longer significant, and the partial correlation between leptin and sleeping EE was no longer significantly different from the partial correlation between leptin and resting EE. Glucagon was positively correlated with EE, but not after controlling for body composition. Future research should incorporate the use of sleeping EE in addition to resting EE, since clearly, for some biochemicals such as leptin and glucagon, this distinction is important. Methodological improvements may provide better insight into the effects of obesity modulating hormones.     

Energy expenditure, body composition, and biochemical indicators in healthy community women

A cross-sectional study was conducted on the associations between energy expenditure (EE), body composition (lean mass, fat mass, body mass index), and biochemical indicators (leptin, glucagon, insulin, cortisol, and triglycerides) among 17 sedentary African-American and Caucasian women living in the community (age, 40.7+/-6.0 years; body mass index, 32.8+/-9.0 kg/m2). Measurements included total, resting, and sleeping EE (via whole-room indirect calorimetery), body composition (via air-displacement plethysmography), body mass index, and biochemical indicators (leptin, glucagon, cortisol, insulin, and triglycerides). Analysis of associations between EE and body composition showed that EE increased with increasing body size, with lean mass explaining 79%, 71%, and 73% of the variability in total, resting, and sleeping EE, respectively. Analysis of associations between body composition and the biochemical indicators showed that leptin, glucagon, and insulin were positively correlated with increasing body size, whereas cortisol was negatively correlated with increasing body size. Analysis of associations between EE and biochemical indicators prior to controlling for body size showed that leptin was positively correlated with EE, and that the correlation between leptin and sleeping EE was significantly greater than the correlation between leptin and resting EE. After controlling for body size, the correlations between leptin and EE were no longer significant, and the partial correlation between leptin and sleeping EE was no longer significantly different from the partial correlation between leptin and resting EE. Glucagon was positively correlated with EE, but not after controlling for body composition. Future research should incorporate the use of sleeping EE in addition to resting EE, since clearly, for some biochemicals such as leptin and glucagon, this distinction is important. Methodological improvements may provide better insight into the effects of obesity modulating hormones.     

Characterization of body weight and composition changes during the sophomore year of college

Background  

Years spent in college represents a critical time for obesity development though little information is known regarding how body weight and composition changes beyond the first year of college. The aim of this study was to investigate changes in body weight and composition and the factors influencing those changes among sophomore females.     

Relationships between upper-arm anthropometry and soft-tissue composition in postmenopausal women.

The value of upper-arm anthropometry as a measure of lean- and fat-tissue masses in 140 normal postmenopausal white women was assessed by studying the relationships of these measures to total and regional fat, and lean masses measured by dual-energy x-ray absorptiometry. Midarm circumference (MAC) was highly correlated with total and regional fat masses (r = 0.85-0.89, P less than 0.0001) but less so with lean-tissue masses (r = 0.26-0.34). Triceps-skinfold thickness was also correlated with fat masses (r = 0.70-0.74, P less than 0.0001) but not with lean mass (r = 0.02-0.09). The derived index, arm muscle area (AMA), was less closely correlated with fat mass than was MAC (r = 0.59-0.61), but its correlation with lean-tissue mass was comparable to that for MAC (r = 0.37-0.43). Multiple-regression analysis confirmed that the anthropometric indices were more closely correlated with fat than with lean mass. It is concluded that all these indices are useful measures of fat mass but that none, including AMA, is a specific index of lean-tissue mass in normal postmenopausal women.     

Estrogenic effect of yam ingestion in healthy postmenopausal women

OBJECTIVE: Yam (Dioscorea) has been used to treat menopausal symptom folklorically. This study was to investigate the effects of yam ingestion on lipids, antioxidant status, and sex hormones in postmenopausal women. METHODS: Twenty-four apparently healthy postmenopausal women were recruited to replace their staple food (rice for the most part) with 390 g of yam (Dioscorea alata) in 2 of 3 meals per day for 30 days and 22 completed the study. Fasting blood and first morning urine samples were collected before and after yam intervention for the analyses of blood lipids, sex hormones, urinary estrogen metabolites and oxidant stress biomarker. The design was a one arm, pre-post study. A similar study of postmenopausal women (n = 19) fed 240 g of sweet potato for 41 days was included as a control study. Serum levels of estrone, estradiol and SHBG were analyzed for this control group. RESULTS: After yam ingestion, there were significant increases in serum concentrations of estrone (26%), sex hormone binding globulin (SHBG) (9.5%), and near significant increase in estradiol (27%). No significant changes were observed in serum concentrations of dehydroepiandrosterone sulfate, androstenedione, testosterone, follicular stimulating hormone, and luteinizing hormone. Free androgen index estimated from the ratio of serum concentrations of total testosterone to SHBG decreased. Urinary concentrations of the genotoxic metabolite of estrogen, 16alpha-hydroxyestrone decreased significantly by 37%. Plasma cholesterol concentration decreased significantly by 5.9%. Lag time of low-density lipoprotein oxidation prolonged significantly by 5.8% and urinary isoprostane levels decreased significantly by 42%. For the control subjects fed with sweet potato, all three hormone parameters measured were not changed after intervention. CONCLUSION: Although the exact mechanism is not clear, replacing two thirds of staple food with yam for 30 days improves the status of sex hormones, lipids, and antioxidants. These effects might reduce the risk of breast cancer and cardiovascular diseases in postmenopausal women.     

Endocrine changes in postmenopausal women after high-dose danazol therapy.

BACKGROUND: Purpose of the study was to investigate changes in the hormonal pattern in postmenopausal women after high dose danazol therapy. In 16 postmenopausal women (mean age 66.4 +/- 8.6) treated with danazol 1.2 g/die x21 we studied serum levels, before and after therapy, of FSH, LH, E2, fE2, T, fT, D4-A, DHEAS, SHBG. METHODS: FSH, LH, SHBG by IRMA kits (DPC); E2, T, DHEAS, D4-A by RIA kits (Sorin Biomedica) after celite microcolumn chromatography; fT by coat-A-count kit (DPC); fE2 by equilibrium dialysis; serum albumin by bromocresol-green colorimetric methods. RESULTS: After therapy there was a statistically significant decrease of LH by 13%, of FSH by 19%, SHBG by 84% and increase of fE2 by 24.5%, fT by 77%. Other hormones show changes that are not statistically significant. CONCLUSIONS: In postmenopausal women danozol therapy, even if at a higher dose, has about same effect on hormonal pattern as in normally cycling women. Danazol showed a clear antigonadotropic effect and can play a role in therapy when reduction of gonadotrophins and E2 secretion is desirable.     

The effect of controlled physical activity on the body composition of postmenopausal sedentary women]

OBJECTIVE: To evaluate the effect of a controlled physical activity program on the weight and body composition of healthy sedentary postmenopausal women. METHODS: From a group of 138 postmenopausal women volunteers, 18 of them were selected, using a survey that measured the frequency and intensity of their physical activity. These 18 women were classified as "sedentary," having an average daily energy expenditure (in terms of mL of oxygen per kg per minute) that was below 60% of the maximum oxygen consumption for their age. These 18 women underwent a general physical examination, laboratory tests, and spirometry to make certain that they did not have illnesses that would prevent them from participating in the planned controlled physical activity program. The activity program lasted 4 months, with three one-hour sessions per week. Before and after the program the following characteristics were evaluated for each participant: weight, body fat, and the fatty area and the lean area of the arm, the thigh, and the leg. In addition, energy intake was determined based on a record of food consumption, with the frequency of the consumption of specific foods assessed semiquantitatively. The Student's t test was used to compare the averages for all the measurements before and after the exercise program. When the variables did not have a normal distribution, the Wilcoxon signed rank sum test was utilized. RESULTS: At the end the program we found a reduction of 1.2 kg in weight and of 2.0 kg in body fat, while the lean mass increased by 1.0 kg. Also increasing were the lean area of the arm, of the thigh, and of the leg; the areas of fat in those parts of the body decreased. The differences were statistically significant for all the variables observed except for the lean area of the thigh. There were no significant differences between the women's energy intake at the beginning and the end of the program. CONCLUSIONS: The controlled physical activity program improved the body composition of this group of women, decreasing the fat deposits and increasing the lean body mass.     

Regional body composition in adolescents with anorexia nervosa and changes with weight recovery

BACKGROUND: Studies of regional fat distribution in adults with anorexia nervosa (AN) have shown decreased extremity fat at baseline and increased trunk fat with weight recovery, resulting in truncal adiposity. Little is known about fat distribution in adolescents with AN, especially with weight recovery. OBJECTIVE: We sought to determine whether regional fat distribution in adolescents with AN is comparable with that in healthy adolescents and whether weight recovery results in increased trunk fat and truncal adiposity. DESIGN: In 21 adolescent girls with AN and 21 control subjects matched for age and pubertal stage, we measured body-composition variables with dual-energy X-ray absorptiometry at baseline, 6 mo, and 12 mo. Weight recovery was defined as a > or = 10% increase in body mass index. RESULTS: At baseline, the girls with AN had a lower percentage of trunk fat than did the control subjects, whereas the percentage of extremity fat was not significantly different between the groups. Weight recovery in 13 subjects with AN resulted in an increased percentage of trunk fat and an increased ratio of trunk fat to extremity fat; however, this ratio did not exceed that of control subjects. CONCLUSIONS: In adolescents with AN, trunk fat rather than extremity fat is reduced. Weight recovery is associated with increased trunk fat and an increased ratio of trunk fat to extremity fat. In contrast with previous findings in adults, this most likely represents normalization of fat distribution rather than development of truncal adiposity.