Do changes in sex steroid hormones precede or follow increases in body weight during the menopause transition? Results from the Study of Women's Health Across the Nation

Sex steroid levels and response to weight loss interventions among postmenopausal women in the diabetes prevention program

OBJECTIVES

To examine whether estrogen use potentiates weight loss interventions via sex steroid levels and whether endogenous sex steroid levels predict response to weight loss interventions among women not using estrogen.

METHODS

The Diabetes Prevention Program randomized overweight or obese dysglycemic participants to lifestyle change with the goals of weight reduction of >7% of initial weight and 150 minutes per week of exercise, metformin, or placebo. In this secondary analysis, we examined sex steroid levels and reductions in weight and waist circumference (WC) among postmenopausal women using (n = 324) and not using (n = 382) oral estrogen.

RESULTS

Estrogen users and nonusers randomized to lifestyle change and metformin both lost significant amounts of weight compared to placebo. Reductions in weight and WC over 1 year associated with randomization arm were not associated with baseline sex steroid levels among estrogen users or nonusers.

CONCLUSIONS

Among estrogen users, baseline sex steroids were not associated with reductions in weight or WC, suggesting that exogenous estrogen does not potentiate weight loss by altering sex steroids. Among nonestrogen users, baseline sex steroids were not associated with reductions in weight or WC.

Estrogen: a master regulator of bioenergetic systems in the brain and body

Estrogen is a fundamental regulator of the metabolic system of the female brain and body. Within the brain, estrogen regulates glucose transport, aerobic glycolysis, and mitochondrial function to generate ATP. In the body, estrogen protects against adiposity, insulin resistance, and type II diabetes, and regulates energy intake and expenditure. During menopause, decline in circulating estrogen is coincident with decline in brain bioenergetics and shift towards a metabolically compromised phenotype. Compensatory bioenergetic adaptations, or lack thereof, to estrogen loss could determine risk of late-onset Alzheimer's disease. Estrogen coordinates brain and body metabolism, such that peripheral metabolic state can indicate bioenergetic status of the brain. By generating biomarker profiles that encompass peripheral metabolic changes occurring with menopause, individual risk profiles for decreased brain bioenergetics and cognitive decline can be created. Biomarker profiles could identify women at risk while also serving as indicators of efficacy of hormone therapy or other preventative interventions.

Sex hormone binding globulin and sex steroids among premenopausal women in the diabetes prevention program

CONTEXT

It is unknown whether intensive lifestyle modification (ILS) or metformin changes sex steroids among premenopausal women without a history of polycystic ovarian syndrome (PCOS).

OBJECTIVES

We examined 1-year intervention impact on sex steroids (estradiol, testosterone, dehydroepiandrosterone, and androstenedione [A4]) and SHBG and differences by race/ethnicity.

PARTICIPANTS

A subgroup of Diabetes Prevention Program participants who were premenopausal, not using estrogen, without a history of PCOS or irregular menses, and who reported non-Hispanic white (NHW), Hispanic, or African-American race/ethnicity (n = 301).

INTERVENTIONS

Randomization arms were 1) ILS with the goals of weight reduction of 7% of initial weight and 150 minutes per week of moderate intensity exercise, 2) metformin 850 mg twice a day, or 3) placebo.

RESULTS

Neither intervention changed sex steroids compared to placebo. ILS, but not metformin, increased median SHBG by 3.1 nmol/L (~11%) compared to decreases of 1.1 nmol/L in the placebo arm (P < .05). This comparison remained significant after adjustment for changes in covariates including waist circumference. However, associations with glucose were not significant. Median baseline A4 was lower in Hispanics compared to NHWs (5.7 nmol/L vs 6.5 nmol/L, P < .05) and increases in A4 were greater in Hispanics compared to NHWs (3.0 nmol/ vs 1.2 nmol/L, P < .05), and these differences did not differ significantly by intervention arm. No other racial/ethnic differences were significant.

CONCLUSIONS

Among premenopausal glucose-intolerant women, no intervention changed sex steroids. ILS increased SHBG, although associations with glucose were not significant. SHBG and sex steroids were similar by race/ethnicity, with the possible exception of lower baseline A4 levels in Hispanics compared to NHWs.

Adipokines, adiposity, and vasomotor symptoms during the menopause transition: findings from the Study of Women's Health Across the Nation

OBJECTIVE

To test relationships between adipokines, adiposity, and vasomotor symptoms (VMS), including how these associations vary by menopause stage.

DESIGN

A subcohort of the longitudinal cohort Study of Women's Health Across the Nation completed questionnaires, physical measures, and a fasting blood draw annually for 8 years. Associations between a poorer adipokine profile (lower adiponectin, lower high-molecular-weight [HMW] adiponectin, higher leptin, lower soluble leptin receptor, higher monocyte chemoattractant protein 1 [MCP-1]) and VMS were tested with the use of generalized estimating equations adjusting for potential confounders. Interactions by menopause stage (pre-/early perimenopause, late peri-/postmenopause) were tested.

SETTING

Community.

PATIENT(S)

A total of 536 women ages 42-52 at baseline.

INTERVENTION(S)

None.

MAIN OUTCOME MEASURE(S) VMS RESULT(S)

Associations between adipokines and hot flashes varied by menopause stage, with a poorer adipokine profile associated with higher odds of hot flashes early in the transition (adiponectin(log): odds ratio [OR] 0.68, 95% confidence interval [CI] 0.51-0.90; HMW adiponectin(log): OR 0.70, 95% CI 0.58-0.85; leptin(log): OR 1.23, 95% CI 0.99-1.54; multivariable models including body mass index [BMI]), but not later in the transition. The direction of associations between BMI and VMS also varied by menopausal stage. Higher MCP-1 was associated with more night sweats (OR 1.37, 95% CI 1.06-1.76) across menopausal stages.

CONCLUSION(S)

An adverse adipokine profile was associated with more VMS, particularly early in the menopause transition.

Age-associated changes in hypothalamic-pituitary-testicular function in middle-aged and older men are modified by weight change and lifestyle factors: longitudinal results from the European Male Ageing Study

OBJECTIVE

Health and lifestyle factors are associated with variations in serum testosterone levels in ageing men. However, it remains unclear how age-related changes in testosterone may be attenuated by lifestyle modifications. The objective was to investigate the longitudinal relationships between changes in health and lifestyle factors with changes in hormones of the reproductive endocrine axis in ageing men.

DESIGN

A longitudinal survey of 2736 community-dwelling men aged 40-79 years at baseline recruited from eight centres across Europe. Follow-up assessment occurred mean (±S.D.) 4.4±0.3 years later.

RESULTS

Paired testosterone results were available for 2395 men. Mean (±S.D.) annualised hormone changes were as follows: testosterone -0.1±0.95  nmol/l; free testosterone (FT) -3.83±16.8  pmol/l; sex hormone-binding globulin (SHBG) 0.56±2.5  nmol/l and LH 0.08±0.57  U/l. Weight loss was associated with a proportional increase, and weight gain a proportional decrease, in testosterone and SHBG. FT showed a curvilinear relationship to weight change; only those who gained or lost ≥15% of weight showed a significant change (in the same direction as testosterone). Smoking cessation was associated with a greater decline in testosterone than being a non-smoker, which was unrelated to weight change. Changes in number of comorbid conditions or physical activity were not associated with significant alterations in hypothalamic-pituitary-testicular (HPT) axis function.

CONCLUSIONS

Body weight and lifestyle factors influence HPT axis function in ageing. Weight loss was associated with a rise, and weight gain a fall, in testosterone, FT and SHBG. Weight management appears to be important in maintaining circulating testosterone in ageing men, and obesity-associated changes in HPT axis hormones are reversible following weight reduction.

Physical activity and cardiovascular risk factors at menopause: the Nord-Trøndelag health study

BACKGROUND

Lowered physical activity levels may partially explain changes in metabolic risk factors in women after menopause.

OBJECTIVES

To evaluate the association between physical activity and metabolic risk factors at baseline and after 11 years, as well as the change in that association over time in women who were premenopausal and ≥ 40 years at baseline.

METHODS

Subjects in a Norwegian population-based health survey answered questionnaires and had body and serum measurements during 1995-1997 (HUNT 2) and in a follow-up study during 2006-2008 (HUNT 3). Repeated-measures analyses were used to estimate the association between physical activity and metabolic factors, adjusting for age, smoking status, education, alcohol intake, and parity. Adjustment for hormonal treatment and medication was made, as appropriate.

RESULTS

In women remaining premenopausal, a higher physical activity score in HUNT 3 was associated with lower weight (p < 0.01) and waist-hip ratio (p < 0.01) and higher high density lipoprotein (HDL) cholesterol in HUNT 3 (p < 0.01). In women that were postmenopausal by the time of follow-up, a higher physical activity score in HUNT 3 was associated with lower weight (p < 0.01), waist-hip ratio (p < 0.01), triglycerides (p < 0.01), and higher total cholesterol (p < 0.05), HDL cholesterol (p < 0.01), and diastolic blood pressure (p < 0.05) in HUNT 3. The association of total physical activity score with weight and waist-hip ratio was stronger in HUNT 3 than in HUNT 2 (p < 0.01).

CONCLUSION

Increased physical activity may reduce the risk of adverse outcomes and use of pharmacological management in women of menopausal age.

Menopause, atherosclerosis, and coronary artery disease

Women have coronary heart disease (CHD) later than men. This review describes studies of CHD risk factors or outcomes based on studies of premenopausal women followed through the menopause transition, and prospective cohort studies of younger or older women with CHD risk markers or disease outcomes in the context of their menopause history. Major early reports from both types of studies are included in order to put more recent work in context. Most attention has been paid to the Healthy Women Study (HWS), Study of Women's Health across the Nation (SWAN), the Nurses' Health Study (NHS), and the Rancho Bernardo Study (RBS) because they continue to produce recent publications designed to distinguish the effect of age from the effect of menopause. Understanding these differences has important implications for women's cardiovascular health, but remains incomplete. Transition studies have relatively short (<10 years) follow-up and exclude women with surgical menopause. Cohort studies suggest that women with oophorectomy are at greater risk for CHD than intact women, pointing to a greater risk from testosterone deficiency than from estradiol levels.

Central adiposity and decreased heart rate variability in postmenopause: a cross-sectional study

OBJECTIVE

To investigate the impact of waist circumference (WC) on heart rate variability in 87 apparently healthy, postmenopausal women.

METHODS

In this cross-sectional study, time- and frequency-domain heart rate variability indices were determined at rest and during sympathetic stimulation with mental stress. Patients were stratified according to WC ≥ or < 88 cm. The mean (± standard deviation) age was 55 ± 5 years. The median time since menopause was 6 (range 1-22) years. Age and time since menopause were similar.

RESULTS

The mean body mass index was 27.12 ± 4.49 kg/m². Metabolic syndrome was diagnosed in 26 (29.5%) participants. Thirty-eight participants (43.6%) had hypertension. Women with WC ≥ 88 cm had higher body mass index, glucose and insulin (both fasting and after a 75-g oral glucose tolerance test), HOMA, triglycerides, and free androgen index (p < 0.05). The metabolic syndrome was more frequent in women with WC ≥ 88 cm (24.13% vs. 5.74%; p < 0.01). At rest, women with WC ≥ 88 cm presented lower vagal modulation, expressed by a reduction in the mean of all normal RR intervals (mean RR) (p < 0.01) and root mean square of successive differences of adjacent RR intervals (rMSSD) (p < 0.05) than women with WC < 88 cm. Mental stress significantly increased sympathetic modulation in both groups, expressed by reduction in high frequency (HF), increase in low frequency (LF) and LF/F ratio, and reduction in mean RR and rMSSD.

CONCLUSIONS

Less favorable metabolic profile and lower cardiac vagal modulation with preserved sympathetic responsiveness were found in participants with WC ≥ 88 cm, suggesting that central adiposity may be associated with decreased heart rate variability in apparently healthy, postmenopausal women.