Shinako Yamamoto

Relative contribution of aging and menopause to changes in lean and fat mass in segmental regions

OBJECTIVE The aim of the study was to investigate the relative contribution of aging and menopause to the changes in lean and fat mass in segmental regions. MATERIALS AND METHODS Subjects were 365 pre- and 201 postmenopausal Japanese women aged between 20 and 70 years old. Age, height, weight, body mass index (BMI, Wt/Ht(2)), age at menopause, years since menopause (YSM), and menopausal status were recorded. Lean and fat mass of the arms, trunk, legs, total body, and the ratio of trunk fat mass to leg fat mass amount (trunk-leg fat ratio) were measured by dual-energy X-ray absorptiometry (DEXA). Regional (arms, lumbar spine, pelvis, legs, and total body) bone mineral density (BMD) were measured by DEXA. RESULTS Total body lean mass and regional BMD decreased (P < 0.001), while percentage of body fat, trunk fat mass, and trunk-leg fat ratio increased (P < 0.001) with aging and after menopause. On multiple regression analyses, trunk and total body lean mass were inversely correlated with menopausal status (P < 0.001 and 0.05, respectively) but not with age. Trunk fat mass, trunk-leg fat ratio, and percentage of body fat were positively correlated with age (P < 0.01) but not with menopausal status. Regional BMD were more inversely correlated with menopausal status (P < 0.001) than age. CONCLUSION Decrease in lean mass and BMD are more menopause-related, while the shift toward upper body fat distribution and overall adiposity are more age-related. Lean tissue is similar to bone tissue from the viewpoint of more undergoing menopausal effect.

Difference in the effect of adiposity on bone density between pre- and postmenopausal women.

OBJECTIVES Elevated bone mineral density (BMD) in obese women is partially attributable to the higher circulating estrogen levels derived from extraglandular aromatization in adipose tissue. However, it remains unclear whether there is an effect of overall adiposity on BMD in both pre- and postmenopausal women. The difference in the effect of overall adiposity on BMD between pre- and postmenopausal women was investigated. MATERIALS AND METHODS Subjects were 296 premenopausal women with regular menstruation and 233 postmenopausal women. Age, age at menarche, years since menopause (YSM, in postmenopausal women), weight, height, and body mass index were recorded. Total fat mass amount, lean mass amount, and percentage of body fat were measured by whole body scanning with dual-energy X-ray absorptiometry (DEXA). Lumbar spine BMD (L2-L4) was measured by DEXA. In each group, significant determinants of BMD were investigated using univariate and stepwise multiple regression analysis. RESULTS In postmenopausal women, YSM, lean mass amount, total fat mass amount, and height were significant determinants of BMD (R(2)=0.273, P<0.001). In premenopausal women, only two variables including lean mass amount and age at menarche were significant determinants of lumbar spine BMD (R(2)=0.110, P<0.001), but total fat mass amount and percentage of body fat were not significant determinants of BMD. CONCLUSION The effect of overall adiposity on BMD is more prominent in postmenopausal women than in premenopausal women.

The effect of menopause on regional and total body lean mass

OBJECTIVES To investigate the effect of menopause on regional and total body lean mass. METHODS Evaluation of 123 healthy premenopausal women (40.6 +/- 10.8 years) and 123 healthy postmenopausal women (61.8 +/- 7.5 years). All subjects were right side dominant. Regional (head, bilateral arms, trunk, and bilateral legs) and total body lean mass were measured using whole-body scanning by dual-energy X-ray absorptiometry. Baseline characteristics including age, height, weight, and menopausal state were recorded. These variables were compared between pre- and postmenopausal women. In all subjects, correlations between regional or total body lean mass and baseline characteristics were investigated using univariate and multiple regression analyses. RESULTS Height, and lean mass of the trunk, bilateral legs and total body were significantly lower in postmenopausal women than in premenopausal women, while lean mass of the bilateral arms did not differ between the two groups. On univariate regression analysis, bilateral arms lean mass was positively correlated with height (P < 0.001). Trunk, bilateral legs, and total body lean mass were inversely correlated with age and menopausal state (P < 0.001), but were positively correlated with height (P < 0.001). After adjusting for age and height, trunk lean mass was still correlated with menopausal state (P < 0.01). CONCLUSIONS Menopause induces lean mass loss, independent of aging and height. Trunk lean mass is more prone to decline with menopause than lean mass of other sites.

Relationship between body fat distribution and bone mineral density in premenopausal Japanese women

Objective To investigate the relationship between body fat distribution and bone mineral density (BMD). Methods Subjects were 282 premenopausal women (mean age ± standard deviation [SD], 38.8 ± 8.5 years; range, 20–51 years) with regular menstrual cycles. Baseline characteristics included age, age at menarche, height, weight, body mass index ([BMI], weight/height2), and parity. Anthropometric characteristics including the ratio of trunk fat mass to leg fat mass (trunk–leg fat ratio), percentage of body fat, and total body lean mass were measured by whole-body scanning with dual-energy x-ray absorptiometry. Lumbar spine BMD (L2–4) was also measured by dual-energy x-ray absorptiometry. Correlations of BMD to baseline and anthropometric characteristics were investigated using univariate and multivariate analysis. Results Although height, trunk–leg fat ratio, and total body lean mass were positively correlated with lumbar spine BMD (r = .18, P < .01; r = .17, P < .01; and r = .25, P < .001; respectively), age at menarche was inversely correlated with BMD (r = −.19, P < .01). On multivariable analysis, trunk–leg fat ratio, height, age at menarche, and total body lean mass were still independently correlated with lumbar spine BMD (P < .05). However, total fat mass was not correlated with BMD. Conclusion Upper body fat distribution rather than overall adiposity is associated with lumbar spine BMD in premenopausal women. Humoral factors associated with body fat mass appear to influence lumbar spine BMD.

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.

HTLV-1 provirus load in peripheral blood lymphocytes of HTLV-1 carriers is diminished by green tea drinking

Human T‐cell lymphotropic virus type 1 (HTLV‐1) is causatively associated with adult T‐cell leukemia (ATL) and HTLV‐1‐associated myelopathy/tropical spastic paraparesis (HAM/TSP). Since a high level of HTLV‐1 provirus load in circulating lymphocytes is thought to be a risk for ATL and HAM/TSP, diminution of HTLV‐1 provirus load in the circulation may prevent these intractable diseases. Our previous study (Jpn J Cancer Res 2000; 91: 34–40) demonstrated that green tea polyphenols inhibit in vitro growth of ATL cells, as well as HTLV‐1‐infected T‐cells. The present study aimed to investigate the in vivo effect of green tea polyphenols on HTLV‐1 provirus load in peripheral blood lymphocytes on HTLV‐1 carriers. We recruited 83 asymptomatic HTLV‐1 carriers to examine HTLV‐1 provirus DNA with or without administration of capsulated green tea extract powder. Thirty‐seven subjects were followed up for 5 months by measuring HTLV‐1 provirus load after daily intake of 9 capsules of green tea extract powder per day (equivalent to 10 cups of regular green tea), and 46 subjects lived ad libitum without intake of any green tea capsule. The real‐time PCR quantification of HTLV‐1 DNA revealed a wide range of variation of HTLV‐1 provirus load among asymptomatic HTLV‐1 carriers (0.2‐200.2 copies of HTLV‐1 provirus load per 1000 peripheral blood lymphocytes). Daily intake of the capsulated green tea for 5 months significantly diminished the HTLV‐1 provirus load as compared with the controls (P=0.031). These results suggest that green tea drinking suppresses proliferation of HTLV‐1‐infected lymphocytes in vivo.

Relationship of upper body obesity to menstrual disorders

Background. The purpose of the present study was to investigate the relative contribution of upper and lower body obesity to obesity‐related menstrual disorders.

Body fat distribution and body composition during GnRH agonist therapy.

Objective To identify the effects of GnRH agonist therapy on body composition (lean and fat mass components) and body fat distribution. Methods Fifteen women with uterine leiomyomas were given a GnRH agonist (leuprorelin acetate, 3.75 mg) monthly for 4 months. Weight, height, and body mass index (BMI, weight/height2) were recorded. Regional and total body composition, trunk-leg fat ratio, bone mineral density of the lumbar spine (L2–L4), and total body were assessed by whole-body scanning with dual-energy x-ray absorptiometry before and after treatment. Uterine volume was measured by transabdominal ultrasonography. Results The mean (± standard deviation [SD]) lean mass of total body, trunk, and leg decreased significantly (36.3 ± 4.9 to 35.4 ± 4.4 kg, P < .01; 18.8 ± 2.8 to 18.1 ± 2.8 kg, P < .05; and 11.4 ± 1.8 to 11.1 ± 1.6 kg, P < .05; respectively), whereas body fat mass, percentage of body fat, and trunk fat mass increased significantly (20.8 ± 4.8 to 21.8 ± 4.6 kg, P < .01; 34.9 ± 5.9 to 36.5 ± 5.2%, P < .01; and 8.6 ± 3.0 to 9.3 ± 3.0 kg, P < .01; respectively). Trunk-leg fat ratio increased significantly (1.03 ± 0.32 to 1.12 ± 0.33, P < .05). Weight, BMI, arm tissue composition (lean and fat mass components), and leg fat mass did not change during 4 months of GnRH agonist therapy. Bone mineral density and uterine volume decreased significantly. Conclusion Hypogonadism by GnRH agonist therapy induces lean mass loss, increased adiposity overall, and upper body fat accumulation.

The effects of physical exercise on body fat distribution and bone mineral density in postmenopausal women

OBJECTIVE The present cross-sectional study investigated the effects of physical exercise on body fat distribution and bone mineral density (BMD). METHODS Subjects were 57 postmenopausal women (mean age, 60.5+/-6.4 years) who had exercised regularly for at least 2 years. Controls were 130 age-matched sedentary women. Age, years since menopause (YSM), height, weight, and body mass index (BMI, wt./ht.(2)) were recorded. Total fat mass, percentage of body fat, trunk fat mass, leg fat mass, the ratio of trunk fat mass to leg fat mass (trunk-leg fat ratio), total body lean mass, percentage of body lean, and lumbar spine BMD (L2-L4) were measured by dual-energy X-ray absorptiometry. RESULTS Baseline characteristics and leg fat mass did not differ between the two groups. Total fat mass, percentage of body fat, trunk fat mass, and trunk-leg fat ratio were lower (P<0.05, P<0.01, P<0.01 and P<0.001, respectively), while total body lean mass, percentage of body lean mass, and lumbar spine BMD were higher in exercising women (P<0.05, P<0.05 and P<0.01, respectively). Performing physical exercise was inversely correlated with trunk-leg fat ratio (standardized regression coefficient=-0.178, P<0.01), but positively correlated with BMD (0. 203, P<0.01) irrespective of age, height, YSM, and total fat mass. CONCLUSION Physical exercise has beneficial effects on body fat distribution and BMD in postmenopausal women. Reduction of upper body fat distribution with physical exercise may be more attributable to the decrease in trunk fat mass.

Waist to Hip Circumference Ratio as a Significant Predictor of Preeclampsia, Irrespective of Overall Adiposity

Objective: To investigate whether abnormal body fat distribution is a significant predictor of the development of preeclampsia, irrespective of overall adiposity.