Body composition changes by DXA, BIA and skinfolds during exercise training in women

Purpose

Few studies have examined responsiveness of bioimpedance (BIA) to detect changes over time in body composition using a longitudinal design. Accuracy of BIA and skinfold thickness in estimating body composition among 39–64 year-old women was investigated using dual-energy X-ray absorptiometry (DXA) as a criterion method both cross-sectionally and during a training intervention.

Methods

97 women had percentage of fat assessed using DXA, skinfolds and eight-polar BIA using multi-frequency current. Fat mass and lean mass were estimated by DXA and BIA. Measurements were performed before and after the 21-week training intervention.

Results

At baseline relative to DXA, BIA under predicted percentage of fat (?6.50 %) and fat mass (?3.42 kg) and overestimated lean mass (3.18 kg) considerably. Also skinfold measurement under predicted percentage of fat compared to DXA, but the difference was smaller (?1.69 % units). Skinfold measurement overestimated percentage of fat at low values and underestimated at high values (r ² = 0.535). A significant bias was detected between DXA and BIA’s estimate of change in percentage of fat, fat mass and lean mass. Compared to DXA, BIA and skinfolds underestimated the training-induced positive changes in body composition.

Conclusions

BIA and skinfold methods compared to DXA are not interchangeable to quantify the percentage of fat, fat mass and lean mass at the cross-sectional design in middle-aged women. Moreover, exercise training-induced small changes in body composition cannot be detected with BIA or skinfold method, even though DXA was able to measure statistically significant within-group changes in body composition after training.     

Relationships between adiponectin,leptin, and blood lipids in physically active postmenopausal females

The aim of this study was to investigate the possible relationships between adiponectin and leptin with blood lipids (CHOL, HDL‐C, LDL‐C, and TG) in physically active postmenopausal women. One hundred and thirty‐four physically active practicing gymnastics (2–3 times per week) women between the ages of 51 to 85 years participated in this cross‐sectional study. Body height, body mass, waist‐to‐hip circumference ratio (WHR), and BMI were used as anthropometrical parameters. Body composition parameters (fat%, fat mass, fat free mass) were measured by DXA. The fasting adiponectin, leptin, CHOL, HDL‐C, LDL‐C, and TG were measured. From the anthropometrical and body composition parameters, only WHR correlated significantly with adiponectin (r = ?0.306). In addition, adiponectin correlated with TG (r = ?0.277) and leptin (r = ?0.381). Leptin was positively related to body mass (r = 0.261), and BMI (r = 0.274) from anthropometrical parameters and body fat% (r = 0.288) and fat mass (r = 0.298) from body composition variables. No relationships emerged between leptin and blood lipids. We found that there are some significant relationships between adiponectin, leptin and anthropometrical and body composition parameters in physically active postmenopausal females. From blood lipids, only TG correlated significantly with adiponectin. Am. J. Hum. Biol. 22:609–612, 2010. © 2010 Wiley‐Liss, Inc.     

Validation of hand‐held bioelectrical impedance analysis with magnetic resonance imaging for the assessment of body composition in overweight women

Methods of assessing body composition suitable for use in clinical trials should be accurate, reliable, and easy to perform. One such technique routinely implemented is hand‐held bioelectrical impedance analysis (BIA). The validity of this method, however, in body composition assessment of overweight women is not known. The aim of this study was to validate the hand‐held BIA technique with magnetic resonance imaging (MRI) for the assessment of body composition in overweight women. Fat mass, percent fat mass, fat‐free mass, and percent fat‐free mass values estimated by hand‐held BIA were compared to those measured by MRI. Thirty‐one Caucasian women (50.1 ± 8.2 years, body mass index of 26.9 ± 3.1 kg/m²) participated in the study. BIA measurements were highly reproducible (technical error (TE) was 0.06 ± 0.07 kg for fat mass and 0.08 ± 0.11% for percent fat mass), but were significantly different (P < 0.0001) for each body composition parameter when compared to MRI. BIA underestimated fat mass by 2.3 ± 3.3 kg and percent fat mass by 5.6 ± 3.9%. Likewise, BIA overestimated fat free mass by 7.4 ± 2.7 kg and percent fat free mass by 5.6 ± 3.2%. No relationship between the bias and the mean of the two measurements was noted suggesting that bias is not related to measurement size. Although hand‐held BIA gives reproducible findings, the bias noted for all body composition parameters puts into question the validity of this regional impedance device for use in clinical trials in overweight women.Am. J. Hum. Biol. 19:429–433, 2007. © 2007 Wiley‐Liss, Inc.     

Relationship among leptin, neuropeptide Y, and galanin in young women and in postmenopausal women

OBJECTIVE: To determine whether hormonal status may affect neuropeptide Y (NPY), galanin, and leptin release in postmenopausal women and in young women. DESIGN: Forty-eight postmenopausal women aged 47-65 years and 35 young women aged 26-39 years were investigated. RESULTS: Plasma leptin concentrations increased with increasing body mass index in both young and postmenopausal women and were significantly higher in obese postmenopausal women than in obese young women (p < 0.01). Plasma NPY levels in obese young and postmenopausal women were significantly higher than in lean women (p < 0.01 and p < 0.01, respectively) and were significantly higher in obese and nonobese postmenopausal women than in young women (p < 0.05 and p < 0.001, respectively). Plasma galanin levels in postmenopausal women, both lean and overweight, were significantly lower than in young women (p < 0.01 andp < 0.01, respectively). In obese postmenopausal women, plasma galanin concentrations were lower without differing significantly from those in obese young women. However, they were significantly higher than that in lean postmenopausal women (p < 0.001). CONCLUSIONS: Our results suggest that the differences is plasma leptin, NPY, and galanin between postmenopausal women and young women may be related to body mass index rather than to differences in hormonal status and that the higher NPY levels in both lean and obese postmenopausal women than in young women indicate that factors other than body mass index may be involved.     

Serum leptin levels and body composition in postmenopausal women: effects of hormone therapy

OBJECTIVE: To confirm the effect of postmenopausal hypoestrogenism and hormone therapy (HT) on body composition and serum leptin levels. DESIGN: Prospective, longitudinal study evaluating body composition (body mass index, and total and percent fat mass and lean mass measured at the arms, legs and trunk) with dual-energy x-ray absorptiometry and serum leptin levels by radioimmunoassay in 44 healthy postmenopausal women randomized to receive either no treatment (n = 22) or transdermal 17beta-estradiol (50 microg/day) in continuous regimen and nomegestrol (5 mg/day for 12 days/month) in a sequential regimen (n = 22). RESULTS: One year after the beginning of the study, in untreated women, total and trunk fat mass and percent fat were significantly increased, whereas trunk lean mass was significantly decreased. On the contrary, women treated with HT did not show any significant difference in body composition parameters. In untreated women, serum leptin levels were significantly increased at the end of the study in comparison with baseline values. Serum leptin levels at the other times evaluated were not significantly different from baseline values. In women treated with HT, serum leptin levels did not show significant changes throughout the study. CONCLUSIONS: Untreated postmenopausal women show an increase in total and percent fat mass and a centralization of fat distribution. Serum leptin levels parallel this increase, resulting in significantly higher levels 1 year after the study. Women treated with HT are protected against these changes. This may represent a protective mechanism against cardiovascular diseases.     

Is there a role for leptin in the endocrine and metabolic aberrations of polycystic ovary syndrome?

Immunoreactive serum leptin was analysed in 49 women with polycystic ovary syndrome (PCOS) distributed on a wide range of body mass index (BMI; kg/m2) and in 32 normally menstruating women with comparable age, BMI, physical activity and dietary habits. All women with PCOS had increased androgen concentrations and obese women with PCOS (BMI > or = 25, n=24) also showed decreased insulin sensitivity and a preferential accumulation of truncal-abdominal body fat. Anthropometric and hormonal variables, insulin sensitivity, and pancreatic beta-cell activity were investigated in all women. Percentage body fat was calculated using gender-specific regression equations based on skinfold measurements. Serum leptin concentrations were higher in obese than in non-obese women (P < 0.001), but did not differ between the women with PCOS and controls, nor did they differ between glucose intolerant and glucose tolerant, or hirsute and non-hirsute women with PCOS. Both groups showed strong correlations between serum leptin concentrations and percentage body fat, BMI, body fat distribution, fasting plasma insulin and C-peptide, early insulin secretion, the free androgen index (FAI), and the degree of insulin resistance. After correcting for percentage body fat, only the FAI in the women with PCOS remained significant (P < 0.05). However, in a multiple regression analysis with both percentage body fat and the FAI as independent variables, the FAI increased only minimally (2%) the explained variation in leptin concentrations. Thus, serum leptin concentrations are almost exclusively determined by the total amount of body fat, independent of its location, and do not confirm the hypothesis that leptin is involved in the development of the hormonal and metabolic abnormalities in the PCOS.      

Menopause,fat and lean distribution in obese women

Objectives: Whether menopause per se influences fat distribution independently of the effect of aging remains controversial. The lack of consistency in the menopause related changes in body fat distribution may be the result of differences in the methods for measuring fat distribution or in the characteristics of the women studied. The aim of this cross sectional study in obese women was to compare total body composition and regional fat and lean distribution, in premenopausal, perimenopausal and postmenopausal women. Methods: Body composition was assessed by dual energy X-ray absorptiometry (DEXA) in premenopausal (n = 26), perimenopausal (n = 24) and postmenopausal (n = 73) obese women with no intercurrent diseases. Results: It was shown that postmenopausal obese (n = 73) women had a higher proportion of total fat mass in the trunk and a lower proportion of total fat and lean mass in the femoral and leg regions than premenopausal women after adjustment for age and total fat mass. In the same analysis, perimenopausal women had a lower proportion of total fat in the leg and femoral regions and of total lean in the femoral region than premenopausal women; they had a regional body composition similar to that of postmenopausal women. Conclusion: The present data indicate that in obese women, post menopause and perimenopause are associated with differences in fat and lean distribution, independently of age and total fat.     

纳西族成人各项肥胖指标与体脂率的关系

目的 探讨纳西族各项肥胖指标与体脂率的关系。 方法 选取云南省丽江市玉龙县687名18~90岁成年纳西族人,运用人体测量法和生物电阻抗法测量其体重、身高、胸围、腰围、臀围、肱二头肌皮褶、肱三头肌皮褶、肩胛下皮褶、髂嵴上皮褶、髂前上棘皮褶、体质量指数（BMI）、内脏脂肪等级和体脂率等指标,并将各项指标分别与体脂率进行统计分析。 结果 纳西族成人的平均体脂率男性为正常水平,女性属于肥胖。按照内脏脂肪等级为标准,纳西族男性和女性均在正常范围内。根据腰围的判断标准,纳西族男性腰围在正常范围内,而女性腰围属于腹型肥胖。相关分析表明,纳西族成人的体重、胸围、腰围、臀围、肱二头肌皮褶、肱三头肌皮褶、肩胛下皮褶、髂嵴上皮褶、髂前上棘皮褶、BMI、内脏脂肪等级与体脂率均成正相关。纳西族男性内脏脂肪等级与体脂率相关性最强,其次是BMI;纳西族女性胸围与体脂率相关性最强,其次是腰围。 结论 纳西族成人各项肥胖指标均与体脂率成正相关,相关程度存在性别、地区和民族差异。     

Leptin production in pre- and postmenopausal women

OBJECTIVES: To investigate the differences in leptin production between pre- and postmenopausal women. METHODS: Subjects were 75 pre- and 75 postmenopausal women. Age, height, weight, and body mass index (BMI, wt/ht(2)) were recorded. Serum leptin levels were measured by RIA. Total body fat mass and percentage of body fat mass were measured by whole-body scanning with dual-energy X-ray absorptiometry. Serum leptin levels, the ratio of serum leptin levels to total body fat mass (leptin-fat mass ratio), baseline characteristics, and anthropometric variables were compared between the two groups. In all subjects (n=150), relationship of serum leptin levels with menopausal status (pre- and postmenopause) was investigated by univariate and multiple regression analysis. RESULTS: Serum leptin levels in premenopausal women 8.4+/-4.8 ng/ml, which did not differ from that in postmenopausal women (9.2+/-7.1 ng/ml). Total body fat mass, percentage of body fat mass, and BMI did not differ between the two groups. Leptin-fat mass ratio in premenopausal women was 0.43+/-0.17 ng/ml/kg, which did not differ from that in postmenopausal women (0.44+/-0.24 ng/ml/kg). On both univariate and multiple regression analysis, serum leptin levels were not correlated with menopausal status. CONCLUSIONS: Menopausal status does not have a significant impact on leptin production.     

Serum Leptin and Skeletal Differences between Obese and Non-Obese Patients with Chronic Obstructive Pulmonary Disease

ObjectiveChronic obstructive pulmonary disease (COPD) affects body composition, adipokine secretion, and skeletal integrity. The aim was to determine the association between leptin, body mass (BM) and body composition parameters - fat mass (FM) and fat mass index (FMI), lean tissue mass (LTM), lean tissue mass index (LTMI) and bone mineral density (BMD) in 67 male COPD patients.MethodsBM, body composition and biochemical indicators were measured or calculated using standard methods. Data were analyzed according to groups: non-obese (N = 48, BMI 21.0-29.9 kg/m²) and obese (N = 19, BMI ≥ 30.0 kg/m²).ResultsIn the non-obese group statistically significant correlations were observed: negative ones of age with most BMD T scores, positive ones of BMI with all T scores, FM, FMI, LTMI and leptin, of FMI with leptin and all T scores, and of LTMI with most T scores. In the obese group also statistically significant correlations were found: positive ones of BMI with FMI, LTM, leptin and T scores (trochanter, total hip); of FMI with leptin; and of leptin with total hip T score.ConclusionA positive relationship between FMI and BMD was found only in non-obese but not in obese COPD patients. Leptin concentration was associated positively with the total hip T score only in obese COPD patients, suggesting its protective role on the skeleton of obese COPD patients.Key Words: Body mass, Body mass index, Fat mass, Fat mass index, Lean tissue mass, Lean tissue mass index, 25-OH vitamin D, Leptin, Bone mineral density     

A comparison of dual energy X-ray absorptiometry and bioelectrical impedance analysis to measure total and segmental body composition in healthy young adults

The aim of this study was to investigate the accuracy of BIA in the measurement of total body composition and regional fat and the fat free mass in the healthy young adults. Four hundred and three healthy young adults (167 women and 236 men) aged 18–29 years were recruited from the Mid-West region of Ireland. Multi frequency, eight-polar bioelectrical impedance analysis (BIA) and dual energy X-ray absorptiometry (DXA) were used to measure the total body and segmental (arm, leg and trunk) fat mass and the fat free mass. BIA was found to underestimate the percentage total body fat in men and women (p < 0.001). This underestimate increased in men with >24.6% body fat and women with >32% body fat (p < 0.001). Fat tissue mass in the trunk segment was overestimated by 2.1 kg (p < 0.001) in men and underestimated by 0.4 kg (p < 0.001) in women. BIA was also found to underestimate the fat free mass in the appendages by 1.0 kg (p < 0.001) in men and 0.9 kg (p < 0.001) in women. Compared to dual energy X-ray absorptiometry, bioelectrical impedance analysis underestimates the total body fat mass and overestimates fat free mass in healthy young adults. BIA should, therefore, be used with caution in the measurement of total body composition in women and men with >25% total body fat. Though statistically significant, the small difference (~ 4%) between the methods indicates that the BIA may be used interchangeably with DXA in the measurement of appendicular fat free mass in healthy young adults.     

6～8岁骨龄不同体型女性儿童体脂率测量方法比较

目的比较6~8岁骨龄段女性儿童不同的体脂率测量方法的效果,尝试建立适合我国该骨龄段女性儿童的皮褶厚度推算体脂率公式。方法抽样选取59名6~8岁骨龄段女性儿童,依据身体质量指数(BMI)分组标准分为偏瘦组、正常组和超重组3个组别,分别采用双能量X线吸收法(DEXA)、皮褶厚度法、生物电阻抗法(BIA)测试每位受试者的体脂率,以DEXA测量结果为校标,比较上述方法在推测和测量全身体脂率的差异水平。并以皮褶厚度法建立体脂率推测公式。结果对6~8岁骨龄段女性儿童正常组和超重组,BIA法与DEXA测量结果之间相关显著;日本长岭公式显著高估6~8岁骨龄段偏瘦组和正常组女性儿童的体脂率,姚兴家公式显著低估了超重组女性儿童的体脂率,而元田恒公式显著高估了3种体型女性儿童的体脂率;本研究得出皮褶厚度法推算体脂率公式为:全身体脂率=3.919+0.715×髂嵴上部皮褶+0.592×肱三头肌部皮褶。结论相对于以日本长岭公式、元田恒公式、姚兴家公式进行的皮褶厚度推算法,生物电阻抗手段更能有效测量6~8岁骨龄段女性儿童正常和超重群体体脂率;髂嵴上部和肱三头肌部皮褶厚度能联合评价6~8岁骨龄段女性儿童全身体脂率。     

Effect of percutaneous androgen replacement therapy on body composition and body weight in postmenopausal women

Objectives: This study was carried out to assess the effect of topical androgen replacement therapy on body weight, body composition and fat distribution in postmenopausal women. Methods: 39 healthy postmenopausal women (51.4±2.24 years), with increasing body weight, were prospectively studied for 6 months. Body composition (fat mass, kg, %) was measured by means of dual-energy X-ray absorptiometry (DXA). Hormonal and lipid parameters were also measured. Subjects were divided into two groups. An androgen gel (group A) or placebo gel (group P) was topically administered to the abdominal and gluteo-femoral regions. DXA was performed before commencement of topical treatment and after 6 months. Results: A highly significant total body weight reduction was found in group A (68.0±13.1 to 65.4±11.8 kg). Abdominal fat (37.3±11.2 to 35.1±9.7%), gluteo-femoral fat (46.3±6.6 to 45.4±7.7%), total body fat (38.2±7.9 to 36.1±8.6%) and BMI (24.8±4.3 to 23.7±3.8) were also found to have decreased significantly in this group. No significant reduction in body weight (kg) and body fat (%) could be measured in the placebo group. No influence on lipid parameters was found although total testosterone increased significantly in group A (0.29±0.24 to 0.72±0.17 ng/ml). Conclusions: Topically applied androgen is capable of reducing abdominal fat accumulations as well as total body weight in postmenopausal women with unexplained weight gain. In contrast to systemic androgen application, topical administration has no effect on the lipid profile. Gluteal fat, however, is less effectively influenced by androgens.     

Plasma leptin levels in obese and non-obese postmenopausal women before and after hormone replacement therapy

Objective: the aim of this study was to investigate the effect of hormone replacement therapy (HRT) on plasma leptin levels in postmenopausal women, and the relationship between the plasma leptin levels and obesity. Methods: premenopausal women with normal cycles (n=30; mean ages, 35.4±8.3 years) and postmenopausal women (n=45; mean ages, 49.5±4.7 years) were randomly selected. Women were classified as obese (BMI>27 kg/m²) and as non-obese (BMI<27 kg/m²). Blood samples were obtained from the premenopausal women at the beginning of cycle, and from the postmenopausal women before and 6 months after HRT. Plasma leptin levels were measured by radioimmunassay. Results: plasma leptin levels were significantly higher in premenopausal women than in postmenopausal women (18.60±5.0; 3.67±2.44 ng/ml, respectively, P<0.001). Obese premenopausal women (n=15) had significantly higher plasma leptin levels (24. 60±7.81 ng/ml) in comparison with the levels of the non-obese premenopausal women (n=15; 12.50±4. 63 ng/ml) (P<0.001). Although there was no significant difference in the plasma leptin levels between obese (n=25) and non-obese (n=20) postmenopausal women before HRT, plasma leptin levels were significantly elevated in both obese and non-obese postmenopausal women after HRT (P<0.001), and the obese women had significantly higher plasma leptin levels than the non-obese (29.05±10.53; 14.78±6.76 ng/ml, respectively, P<0.001). Conclusion: HRT is effective in the elevation of the plasma leptin levels in postmenopausal women, and in obese women the increase of the plasma leptin levels are more marked than the non-obese women after HRT.     

Validity of skinfold and girth based regression equations for the prediction of body composition in obese adults

The validity of generalized and obese population-specific body composition prediction equations for estimating percent fat was examined. Thirty-eight clinically obese women (mean ± SD, % fat = 46.4 ± 5.2%, body mass = 97.2 ± 17.7 kg, age = 41.8 ± 13.3 years) and 16 clinically obese men (% fat = 39.2 ± 3.8%, body mass = 126.7 ± 24.6 kg, age = 43.0 ± 11.6 years) had % body fat estimated by hydrostatic weighing (with RV measured) and had a series of skinfold and girth-based prediction equations applied to estimate % fat. The equations were chosen because they were said to be “generalized” or because they were “population specific” to obese samples of subjects. Results of the present study indicated that the majority of prediction equations were not valid estimators of % body fat in obese males and females. Of the equations that were valid estimators of % body fat (mean differences in % fat of < 3%, r ≥ 0.70, SE < 5%), all but one (Lohman, 1981) utilized girths as part of the prediction technique. It was concluded that generalized girth-based equations could be utilized for prediction of % body fat in obese subjects.     

Does body mass index reflect adequately the body fat content in perimenopausal women?

OBJECTIVE: To test whether BMI cut-off points for obesity, reflect adequately the actual obesity status, in a sample of perimenopausal women. For study's purposes, a new bioelectrical impedance analysis (BIA) equation was estimated. METHODS: 115 Greek, middle-aged women were tested. Body composition was estimated by dual X-ray absorptiometry and BIA method. Waist (WC) and hip circumference (HC) and skinfolds were also measured. RESULTS: The BIA equation predicted fat free mass (FFM) from height, weight, age and resistance (R(2)=0.88, S.E.E.=1.89 kg). The bias was not significant and the limits of agreement +/-3.6 kg. BMI, FFM, body fat percentage (BF%), waist-to-hip ratio (WHR), WC and HC did not differ between pre (N=37) and postmenopausal (N=48) women (at p=0.05). Both BF% and BMI correlated with WHR and WC (r(BF%-WHR)=0.287, p=0.009; r(BMI-WHR)=0.355, p=0.001 and r(BF%-WC)=0.72, p<0.0001; r(BMI-WC)=0.81, p<0.0001). The mean values for BF%, WC and WHR for women with normal BMI were 36.15% (+/-4.19), 72.53 cm (+/-3.64) and 0.749 (+/-0.05), whereas values for overweight women were 41.42% (+/-3.16), 83.06 cm (+/-7.55) and 0.787 (+/-0.05) and for obese these were 47.40% (+/-3.67), 95.10 cm (+/-8.52) and 0.814 (+/-0.05), respectively. CONCLUSION: The body composition analysis of the study sample revealed undesirably high BF%, even in subjects with BMI below 25, in whom BMI did not reflect the body fat content. However, BF was mainly distributed at the lower part of the body. Whether BMI or BF% is a more sensitive index for obesity related diseases, in perimenopausal period, remains to be defined.     

Plasma ghrelin concentration is a signal of decreased fat free mass in healthy elderly females

This study aimed to evaluate whether circulating ghrelin is associated with changes in different body composition parameters over a 12‐month prospective study period in healthy older females. On 41 postmenopausal women (mean age: 71.0 ± 6.5 years), ghrelin, leptin, insulin resistance (IR), and body composition parameters were assessed before and after the study period. Trunk fat: leg fat ratio (+3.6%), fat free mass (FFM) (?4.1%), glucose (+5.8%), and IR (+7.0%) were significantly changed (P < 0.05), whereas no changes in height, body mass, body mass index, fat mass (FM), %FM, trunk fat, leptin, ghrelin, and insulin were observed as a result of study period. At baseline, ghrelin correlated negatively (r > ?0.306; P < 0.05) with body mass, FM, %FM, trunk fat, FFM, leptin, insulin, and IR. Multivariate linear regression analysis demonstrated that baseline ghrelin concentration was significantly associated only with the mean change in FFM value over the 12‐month study period. In conclusion, basal ghrelin concentration predicted the loss of FFM in healthy elderly females. In addition, these results suggest that circulating ghrelin concentration could be regarded as a signal of decreased FFM in healthy elderly females. Am. J. Hum. Biol., 2009. © 2009 Wiley‐Liss, Inc.     

Postmenopausal women lose less visceral adipose tissue during a weight reduction program

OBJECTIVE: Visceral adipose tissue (VAT) is increased in the postmenopausal state, which may contribute to an increase in cardiovascular diseases. This study was undertaken to investigate whether there is a difference in the change of VAT during a weight reduction program between premenopausal and postmenopausal obese women. DESIGN: This study was a longitudinal clinical intervention of a weight reduction program, including lifestyle modification and adjuvant pharmacotherapy, for 12 weeks in 21 premenopausal and 19 postmenopausal obese women. Weight, height, body fat percentage, and waist and hip circumferences were measured. Visceral, subcutaneous, and total adipose tissue of the abdomen were determined by CT scan at the level of L4-L5 before and after weight reduction. RESULTS: The percent changes in VAT and the visceral-to-subcutaneous adipose tissue ratio, as well as waist circumference and waist-to-hip ratio, in the postmenopausal women were significantly less than those in the premenopausal women, whereas the percent changes in hip circumference, fat mass, total adipose tissue, and subcutaneous adipose tissue were similar in the two groups. The association between percent changes of VAT and the percent change of waist circumference is stronger in postmenopausal than in premenopausal women. CONCLUSIONS: The postmenopausal women lost less VAT compared with the premenopausal women during the weight reduction program. This may make it more difficult for postmenopausal women to overcome the increased risk of cardiovascular diseases compared with premenopausal women.     

Lower serum leptin concentrations in rugby players in comparison with healthy non-sporting subjects – relationships to anthropometric and biochemical parameters

Leptin is a protein hormone synthesized by adipocytes. Its serum concentrations reflect the total body fat content. Serum leptin concentrations are significantly higher in obese than in lean people and in women than in men. However little information about the influence of physical activity on serum leptin concentrations is available. We have compared the body weight, the body mass index (BMI), the body fat content (measured by caliper as skinfold thickness) and the serum concentrations of leptin, triglycerides, total, high density and low density lipoprotein (LDL) cholesterol in 14 top rugby players and 10 healthy controls. We found that serum leptin, total and LDL cholesterol concentrations were significantly lower in the rugby players group than in the control subjects. The body weight and BMI were significantly higher in the rugby players, while the body fat content was only slightly (non-significantly) higher in the control group. The serum leptin concentrations in both groups positively correlated with the?BMI and body fat content and also with LDL concentrations in the control group. The serum leptin concentrations in the rugby players were lower than in the non-sporting subjects despite a similar body fat content in both groups. We would therefore suggest the possibility that regular hard physical training decreases serum leptin concentrations not only by the decrease of total body fat content, but also by a separate mechanism, which is not directly dependent on the changes in the amount of body adipose tissue.     

Difference in the effects of body composition on bone mineral density between pre- and postmenopausal women

Objective: This study was to investigate whether the effect of lean and fat mass component on bone mineral density (BMD) differs between pre- and postmenopausal women. Materials and methods: Subjects were 360 pre- and 193 postmenopausal Japanese women with right side dominance. Age, height, and years since menopause (YSM, in postmenopausal women) were recorded. Body fat and lean body mass were measured by whole body scanning with dual-energy X-ray absorptiometry (DEXA). BMD of the vertical axis (L2-4 of the lumbar spine, pelvis, bilateral legs, and total body) and horizontal axis (arms) were also measured by DEXA. Results: In premenopausal women, lean body mass was independently correlated with BMD of the left arm (partial correlation COEFFICIENT=0.417), right arm (0.430), L2-4 (0.285), pelvis (0.276), left leg (0.403), right leg (0.412), and total body (0.377) (P<0.001). However, body fat mass was not correlated with several BMD sites except for pelvis BMD (0.187, P<0.01). In postmenopausal women, body fat mass was independently correlated with BMD of the left arm (0.248, P<0.01), L2-4 (0.188, P<0.05), pelvis (0.263, P<0.01), left leg (0.228, P<0.01), right leg (0.319, P<0.001), and total body (0.188, P<0.01)). However, lean body mass was correlated with BMD in only three segmental regions including left arm (0.175), right arm (0.217), and left leg (0.210; P<0.05). Conclusion: Lean body mass is a significant determinant of BMD in premenopausal women, while body fat mass is a significant determinant in postmenopausal women.