Body composition and androgen pattern in the early period of postmenopause

Accumulation of central fat correlates with an adverse oxidative balance in non-obese postmenopausal women

The aim of the present study was to investigate whether accumulation of central fat is correlated with systemic oxidative stress (OxS) in non-obese apparently healthy postmenopausal women. Serum parameters of OxS (hydroperoxides and non-enzymatic antioxidants) along with body fat distribution, as assessed by dual-energy-X-ray absorptiometry (DXA), were evaluated in 134 non-obese postmenopausal women. Multiple regression analysis showed that central (trunk) fat significantly correlated with both markers of OxS independently of confounding factors (i.e. BMI, smoking, age, hypertension, legs and arms fat mass). In specific, the standardized regression coefficient was positive for hydroperoxides (β = 0.324, p < 0.05) and negative for antioxidants (β = -0.495, p < 0.01) level. In conclusion, the current data showed that the increase in central fat is an independent predictor of OxS condition among non-obese women in postmenopausal status. The possible pro-oxidant effects of the excess in central adiposity might be more harmful among post- than among pre-menopausal women, due to the postulated ability of E2 to contrast oxidative challenge and the related diseases.

A comparison of bone mineral density in normal weight and obese adolescents with polycystic ovary syndrome

STUDY OBJECTIVE

To evaluate whether there are any differences in bone mineral density (BMD) between normal weight and obese adolescents suffering from polycystic ovary syndrome (PCOS) with oligo/amenorrhea.

DESIGN

Prospective cohort study.

SETTING

Adolescent gynecology clinic in a general service hospital.

PARTICIPANTS

Subjects consisted of adolescents between 16 to 18 years of age presenting with oligo/ amenorrhea with ultrasound morphology of polycystic ovaries ± evidence of hyperandrogenism over 24 months. Controls consisted of consecutive eumenorrheic patients within the same age group.

INTERVENTIONS

All underwent full hormonal profile assessment, and dual energy X-ray absorptiometry and peripheral quantitative computed tomography scans.

MAIN OUTCOME MEASURES

Areal and volumetric BMD parameters.

RESULTS

Of 37 adolescents with PCOS, 12 (32%) were obese with BMI ≥25, of which 9/12 (75%) were hyperandrogenic. The control group consisted of 40 normal weight eumenorrheic girls. The PCOS group overall had lower lumbar spine BMD values as compared to the controls (0.91 vs 0.97 g/ cm(2), P = 0.033). The normal weight PCOS group had lower BMD at the spine (0.90 vs 0.97 g/ cm(2), P = 0.027), trochanter (0.66 vs 0.71 g/ cm(2), P = 0.039) as well as volumetric distal tibial core sites (268 vs 296 mg/ cm(3)) as compared to eumenorrheic controls, but there were no significant BMD differences between the obese PCOS group and the eumenorrheic controls.

CONCLUSIONS

Normal weight PCOS adolescents with oligo/amenorrhea have marginally lower BMD values than controls, but obese PCOS adolescents have BMD values compatible with eumenorrheic adolescents.

Body fat distribution is associated with lumbar spine bone density independently of body weight in postmenopausal women

OBJECTIVE

To assess the association between the body fat distribution and axial bone mineral density (BMD) in postmenopausal women with or without hormone replacement therapy (HRT).

DESIGN

Cross-sectional population-based study.

SETTING

University of Eastern Finland, Bone and Cartilage Research Unit, Kuopio, Finland.

POPULATION

198 postmenopausal women, mean age 67.5 (1.9 SD), mean BMI 27.1 (3.9 SD).

METHODS

Regional body composition and BMD assessed by dual X-ray absorptiometry (DXA, Prodigy).

MAIN OUTCOME MEASURES

Spinal and Femoral BMD.

RESULTS

Out of the body composition parameters, FM was the main determinant of postmenopausal bone mass. Only the lumbar spine (L2-L4) BMD, not the femoral neck BMD, was positively associated with the trunk FM. Positive trends for association were revealed between the spinal BMD and the trunk FM regardless of the use of HRT. Adjustments did not change the results.

CONCLUSIONS

Higher trunk fat mass was associated with the spinal BMD, but not with the hip BMD in postmenopausal women, irrespective of the HRT use. In addition to biological factors, uncertainties related to DXA measurements in patients with varying body mass may contribute to this phenomenon.

Visceral fat is more important than peripheral fat for endometrial thickness and bone mass in healthy postmenopausal women

OBJECTIVE

The purpose of this study was to investigate the influence of body mass index and body composition on endometrial thickness and bone mass.

STUDY DESIGN

This was a cross-sectional study that included 531 healthy postmenopausal women aged 48 to 65 years. Endometrial thickness was measured as double-layer thickness. Body composition was measured by dual energy x-ray absorptiometry, which divides the body into fat mass, lean mass, and bone mass, both for the total body and regional body compartments. An abdominal region was inserted manually. Statistics were Pearson correlations and analysis of variance.

RESULTS

Endometrial thickness and total body bone mass were correlated, respectively, to body mass index (r = 0.14, P <.01; r = 0.35, P <.001), total body fat mass (r = 0.14, P <.01; r = 0.38, P <.001), abdominal fat mass (r = 0.16, P <.001; r = 0.33, P <.001), peripheral fat mass (r = 0.10, P <.05; r = 0.41, P <.001), and abdominal/peripheral fat mass (r = 0.12, P <.01; r = 0.11, P <.01).

CONCLUSION

High body mass index and abdominal fat distribution correlate with increased endometrial thickness and bone mass.

Polycystic ovary syndrome, androgen excess, and the impact on bone

Polycystic ovary syndrome (PCOS) is a unique, natural model for the study of the influence of androgen excess on bone mass among women. Both thin and obese women develop PCOS, a presentation that allows for the evaluation of the effects of life-long obesity, alterations in body composition (central adiposity), and related metabolic abnormalities (hyperandrogenemia, hyperinsulinemia) on the skeleton. The relatively high prevalence of PCOS and its manifestation early in life render this disorder of particular importance in assessing the influence of androgens and androgen-estrogen balance on the attainment of maximal bone mass and subsequent development of osteoporosis later in life.

The pathophysiological implications of circulating androgens on bone mineral density in a normal female population

In this cross-sectional study performed on 147 healthy or osteoporotic, but otherwise normal premenopausal (n = 26 and n = 13, respectively) or postmenopausal (n = 40 and n = 68, respectively) women aged 40.1+/-9.9 and 61.9+/-8.9 years, respectively (range 20-82 years), serum ovarian and adrenal sex steroids and their relationship to bone mineral density (BMD) were evaluated. The levels of dehydroepiandrosterone sulfate (DHEAS), dehydroepiandrosterone (DHEA), androstenedione (AD), and estradiol correlated positively with BMD at the hip and spine as did serum testosterone with BMD at the spine. An inverse relationship was found between sex hormone binding globulin (SHBG) levels and BMD at the spine and hip. After adjustment for age, body mass, and sex steroid confounders, the bioavailable testosterone value (but not the DHEAS, DHEA, AD, or SHBG) values was demonstrated to be an independent determinant of BMD at the spine (beta 0.18, P<0.02) and hip (beta 0.24, P<0.02). Similarly, estradiol was found to be an independent determinant of BMD at the spine (beta 0.25, P<0.007). However, only SHBG levels (but not other steroid parameters) correlated positively with indices of bone remodeling, namely, serum osteocalcin and cross-linked telopeptide of type I collagen (ICTP). The present study suggests that a major decline in index of free testosterone (testosterone/SHBG) may influence the development of female osteoporosis. The clinical significance of circulating SHBG levels in the assessement of bone metabolic turnover remains to be established.

Physical activity and weight gain and fat distribution changes with menopause: current evidence and research issues

PURPOSE

At the onset of menopause a woman's body weight reaches its maximum. For any given subsequent body weight there is an increase in relative body fat and abdominal fatness with advancing age. The increased body fatness and abdominal fat distribution are associated with a high incidence of cardiovascular disease and certain cancers, particularly breast cancer. The aim of this analysis was to assess the role of physical activity for weight gain and changes in fat distribution occurring with menopause.

METHODS

A systematic review based on a Medline search was conducted.

RESULTS

According to cross-sectional observational studies postmenopausal women with high levels of physical activity have lower body fat and abdominal fat. Longitudinal studies show that physically active women are less likely to gain body fat and abdominal fat after menopause than sedentary women (Evidence category C). There are very few randomized controlled trials (RCT) comparing exercise with no intervention, and diet with diet plus exercise, and the results do not allow a firm conclusion as to whether physical activity may prevent or limit the gain of total fat and abdominal fat after menopause, or whether it may be effective as part of an obesity treatment program.

CONCLUSIONS

There is a need for RCT to evaluate the effect of increased physical activity and fitness as a tool for prevention of the changes in body composition associated with menopause and aging in normal weight women. The efficiency of different programs of exercise training as a treatment option in postmenopausal women with existing overweight and obesity should be investigated. RCT should have the appropriate design and size and use accurate methods to assess exercise compliance, body composition, and intra-abdominal adipose tissue.