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

Effects of weight loss on testosterone, sex hormone-binding globulin, adiposity, and insulin sensitivity in women and men

OBJECTIVE

Testosterone and glucose disposal (Rd) are positively associated in adult men, whereas the opposite is reported in women. Sex-specific relationships between testosterone or sex hormone-binding globulin (SHBG) and Rd in men and women with and without obesity and following weight loss were examined.

METHODS

Adult men and women (n = 27/28; BMI = 20-41 kg/m2) underwent measurements of body composition, Rd, SHBG, and bioavailable (BioA) and total testosterone. Men and women (n = 17/15) with obesity completed a 16-week dietary weight-loss program with repeat testing.

RESULTS

BioA testosterone was lower in men with obesity and was related to Rd positively in men and negatively in women (p < 0.05). Across participants, weight loss increased Rd and SHBG (p < 0.01). BioA testosterone was unchanged in men; however, individual changes were independently related to Rd (p = 0.031). In women, BioA testosterone declined (p < 0.009) but was not related to Rd.

CONCLUSIONS

BioA testosterone was associated with Rd, positively in men and negatively in women. Weight loss reduced BioA testosterone in women; however, individual changes were associated with improved Rd in men. SHBG was a better correlate of improved Rd in women. Additional studies should identify mechanisms that drive sex differences and interventions that modify testosterone, reduce adiposity, and improve Rd across both sexes.

Comprehensive evaluation of disparities in cardiometabolic and reproductive risk between Hispanic and White women with polycystic ovary syndrome in the United States: a systematic review and meta-analysis

OBJECTIVE

We conducted a systematic review and meta-analysis to comprehensively compare cardiometabolic and reproductive health risk between Hispanic and White women with polycystic ovary syndrome in the United States in response to the call by the international guideline for polycystic ovary syndrome to delineate health disparities.

DATA SOURCES

Databases of MEDLINE, Web of Science, and Scopus were initially searched through October 25, 2020, and confirmed on February 1, 2021.

STUDY ELIGIBILITY CRITERIA

Observational studies comparing glucoregulatory, lipid profile, anthropometric, blood pressure, androgen, ovarian morphology, oligoanovulation, and infertility status between Hispanic and White women with polycystic ovary syndrome were included. The primary outcome was metabolic syndrome risk. Furthermore, major cardiovascular events (stroke, coronary heart disease, and heart failure) and mortality rate (cardiovascular death and total mortality) data were evaluated. Studies on adolescents (<2 years after menarche), pregnant, or menopausal-aged women (>50 years) were excluded.

METHODS

Data were pooled by random-effects models and expressed as mean differences and 95% confidence intervals. Risk of bias was assessed by the Newcastle-Ottawa Scale.

RESULTS

A total of 11 studies (n=2267; 589 Hispanic and 1678 White women) were eligible. All studies, including both White and Hispanic women, had high-quality assessment (Newcastle-Ottawa Scale score of ≥8). Hispanic women exhibited comparable metabolic syndrome prevalence (7% [95% confidence interval, -1 to 14]; P=.06; I2=0%); however, Hispanic women exhibited higher modified Ferriman-Gallwey score (0.60 [95% confidence interval, -0.01 to 1.21]; P=.05; I2=0%), fasting insulin (5.48 μIU/mL [95% confidence interval, 3.11-7.85]; P≤.01; I2=40.0%), and homeostatic model assessment of insulin resistance (1.20 [95% confidence interval, 0.50-1.89]; P≤.01; I2=43.0%) than White women. The 2 groups had comparable glucose, lipid profile, waist circumference, blood pressure, and androgen status (all P≥.08). Findings about group differences in certain reproductive outcomes (ie, ovarian dysmorphology and infertility) were contradictory and described only narratively as inclusion in the meta-analyses was not possible. No study reported on cardiovascular events or mortality.

CONCLUSION

Hispanic women with polycystic ovary syndrome exhibited greater impairments in glucoregulatory status than White women. Disparities in reproductive risks could not be concluded. The degree to which glucoregulatory aberrations translate into patient-pressing diseases (diabetes mellitus and infertility) remains a major roadblock given the paucity of available evidence. Our observations have supported the consideration of these disparities in the diagnostic, monitoring, and management practices for polycystic ovary syndrome and reinforced the need to elucidate mechanisms that account for the observed disparities to foster equity in polycystic ovary syndrome care.

Is menopause still evolving? Evidence from a longitudinal study of multiethnic populations and its relevance to women's health

Background

To reflect on the impact of changing patterns of delayed marriage and reproduction and to seek evidence as to whether menopause is still evolving, characteristics of the menopause transition were investigated within and between ethnic populations in this study.

Methods

A cross-sectional analysis was conducted using data on 747 middle-aged women obtained from the Study of Women’s Health Across the Nation (SWAN) from 1996 to 2008. The ethnic groups included: Afro-American, Chinese, Japanese, Caucasian, and Hispanic. Perimenopause age and duration, menopause age, and hormonal indicators of menopause were examined across five ethnicities.

Results

We found a similar window of menopause age within populations, but no significant difference in perimenopause and menopause age between populations. The rate of increase of follicle-stimulating hormone and testosterone differed significantly in Hispanics and African-Americans during the menopause transition period.

Conclusions

The broad window of variation in age at menopause within the population and the absence of significant differences between populations, in combination with population variation in menopause symptoms, suggest that menopause is a relatively recently evolved and still evolving trait. Under the mate choice theory of menopause, menopause is the result of the accumulation of infertility mutations in older women due to men’s preference for younger mates. We propose a shifting mate choice-shifting menopause model which posits that, as the age of mate choice/marriage shifts to older ages, so will the age at menopause, and that menopause is a transient phase of female fertility; it can de-evolve, be delayed, if not disappear completely. Integrated longitudinal menopausal studies linked with genomics and hormonal studies on diverse ethnic populations can provide valuable information bearing on women’s health and personalized medicine.

Lifestyle changes in women with polycystic ovary syndrome

BACKGROUND

Polycystic ovary syndrome (PCOS) affects 8% to 13% of reproductive-aged women and is associated with reproductive and metabolic dysfunction. Obesity worsens the presentation of PCOS and weight management (weight loss, maintenance or prevention of excess weight gain) is proposed as an initial treatment strategy, best achieved through lifestyle changes incorporating diet, exercise and behavioural interventions.

OBJECTIVES

To assess the effectiveness of lifestyle treatment in improving reproductive, anthropometric (weight and body composition), metabolic and quality of life factors in PCOS.

SEARCH METHODS

We searched the Cochrane Gynaecology and Fertility Specialised Register, the Cochrane Central Register of Controlled Trials (CENTRAL), MEDLINE, Embase, PsycINFO, CINAHL and AMED (date of last search March 2018). We also searched controlled trials registries, conference abstracts, relevant journals, reference lists of relevant papers and reviews, and grey literature databases, with no language restrictions applied.

SELECTION CRITERIA

Randomised controlled trials (RCTs) comparing lifestyle treatment (diet, exercise, behavioural or combined treatments) to minimal or no treatment in women with PCOS.

DATA COLLECTION AND ANALYSIS

Two authors independently selected trials, assessed evidence quality and risk of bias, and extracted data. Our primary outcomes were live birth, miscarriage and pregnancy. We used inverse variance and fixed-effect models in the meta-analyses. We reported dichotomous outcomes as an odds ratio and continuous outcomes as a mean difference (MD) or standardised mean difference (SMD).

MAIN RESULTS

We included 15 studies with 498 participants. Ten studies compared physical activity to minimal dietary and behavioural intervention or no intervention. Five studies compared combined dietary, exercise and behavioural intervention to minimal intervention. One study compared behavioural intervention to minimal intervention. Risk of bias varied: eight studies had adequate sequence generation, seven had adequate clinician or outcome assessor blinding, seven had adequate allocation concealment, six had complete outcome data and six were free of selective reporting. No studies assessed the fertility primary outcomes of live birth or miscarriage. No studies reported the secondary reproductive outcome of menstrual regularity, as defined in this review.Lifestyle intervention may improve a secondary (endocrine) reproductive outcome, the free androgen index (FAI) (MD -1.11, 95% confidence interval (CI) -1.96 to -0.26, 6 RCTs, N = 204, I2 = 71%, low-quality evidence). Lifestyle intervention may reduce weight (kg) (MD -1.68 kg, 95% CI -2.66 to -0.70, 9 RCTs, N = 353, I2 = 47%, low-quality evidence). Lifestyle intervention may reduce body mass index (BMI) (kg/m2) (-0.34 kg/m2, 95% CI -0.68 to -0.01, 12 RCTs, N = 434, I2= 0%, low-quality evidence). We are uncertain of the effect of lifestyle intervention on glucose tolerance (glucose outcomes in oral glucose tolerance test) (mmol/L/minute) (SMD -0.02, 95% CI -0.38 to 0.33, 3 RCTs, N = 121, I2 = 0%, low-quality evidence).

AUTHORS' CONCLUSIONS

Lifestyle intervention may improve the free androgen index (FAI), weight and BMI in women with PCOS. We are uncertain of the effect of lifestyle intervention on glucose tolerance. There were no studies that looked at the effect of lifestyle intervention on live birth, miscarriage or menstrual regularity. Most studies in this review were of low quality mainly due to high or unclear risk of bias across most domains and high heterogeneity for the FAI outcome.

Metabolic dysfunction in obese Hispanic women with polycystic ovary syndrome

STUDY QUESTION

Are certain ethnic groups with polycystic ovary syndrome (PCOS) at increased risk of metabolic disorders?

SUMMARY ANSWER

Obese Hispanic women with PCOS are at increased risk of metabolic disorders compared with age- and BMI-matched obese non-Hispanic white women with PCOS in the USA.

WHAT IS KNOWN ALREADY

Ethnic differences in body composition and metabolic risk are well established. PCOS is a common disorder in women of reproductive age and is associated with high rates of insulin resistance, glucose intolerance and dyslipidemia.

STUDY DESIGN, SIZE, DURATION

A cross-sectional observational study was performed at an Academic Medical Center on 60 women of reproductive age with PCOS.

PARTICIPANTS/MATERIALS, SETTING, METHODS

Blood was obtained after fasting from 17 Hispanic, 22 non-Hispanic black and 21 non-Hispanic white women with PCOS who were similar in age and BMI. Anthropometric parameters, insulin, lipid and lipoprotein levels (measured by nuclear magnetic resonance) were compared between the three groups.

MAIN RESULTS AND THE ROLE OF CHANCE

Age and BMI did not differ between the groups. Hispanic women with PCOS had higher waist-to-hip ratio (WHR) (P = 0.02), homeostasis model assessment of insulin resistance (HOMA-IR) (P = 0.03) and a more atherogenic lipid and lipoprotein profile consisting of lower high-density lipoprotein (HDL) (P = 0.02), higher low-density lipoprotein (LDL) particle number (P = 0.02), higher very low-density lipoprotein particle (VLDL) size (P = 0.03) and lower LDL (P = 0.03) and HDL particle size (P = 0.005) compared with non-Hispanic white women. The differences in HDL, HOMA-IR, VLDL and LDL size did not persist after adjustment for WHR while differences in LDL particle number (P = 0.04) and HDL size (P = 0.01) persisted.

LIMITATIONS, REASON FOR CAUTION

The sample size for the three groups was small but the findings were still significant. The women were mostly obese so the ethnic differences in metabolic disorders may not apply to non-obese women with PCOS.

WIDER IMPLICATIONS OF THE FINDINGS

Independent of BMI, obese, reproductive age, Hispanic women with PCOS in the USA had a greater degree of abdominal obesity, insulin resistance and dyslipidemia. Hispanic women with PCOS may benefit from more focused management of metabolic parameters.

STUDY FUNDING/COMPETING INTERESTS

This project was supported by the following National Institutes of Health grants: K23 DK080988-01A1 to S.S. and UL1RR029879 to CTSA at University of Illinois. None of the authors report any conflict of interests.

Endogenous sex hormones, metabolic syndrome, and diabetes in men and women

Endogenous sex hormones predict impairments of glucose regulation. Cross-sectional studies suggest that lower levels of testosterone in men and higher levels in women increase risk of metabolic syndrome and diabetes, whereas lower levels of sex hormone binding globulin in both men and women increase risk of metabolic syndrome and diabetes. In a systematic review, we summarize existing longitudinal studies, which suggest similar patterns. However, these studies are often limited to a single sex steroid measure. Whether these associations are primarily a marker of adiposity, and whether these associations differ between younger eugonadal vs older hypogonadal adults is also uncertain. The impact of exogenous sex steroid therapy may not reflect relationships between sex hormones and impaired glucose regulation that occur without supplementation. Therefore, examination of endogenous sex steroid trajectories and obesity trajectories within individuals might aid our understanding of how sex steroids contribute to glucose regulation.

Prepregnancy SHBG concentrations and risk for subsequently developing gestational diabetes mellitus

OBJECTIVE

Lower levels of sex hormone-binding globulin (SHBG) have been associated with increased risk of diabetes among postmenopausal women; however, it is unclear whether they are associated with glucose intolerance in younger women. We examined whether SHBG concentrations, measured before pregnancy, are associated with risk of gestational diabetes mellitus (GDM).

RESEARCH DESIGN AND METHODS

This was a nested case-control study among women who participated in the Kaiser Permanente Northern California Multiphasic Health Check-up examination (1984-1996) and had a subsequent pregnancy (1984-2009). Eligible women were free of recognized diabetes. Case patients were 256 women in whom GDM developed. Two control subjects were selected for each case patient and were matched for year of blood draw, age at examination, age at pregnancy, and number of intervening pregnancies.

RESULTS

Compared with the highest quartile of SHBG concentrations, the odds of GDM increased with decreasing quartile (odds ratio 1.06 [95% CI 0.44-2.52]; 2.33 [1.07-5.09]; 4.06 [1.90-8.65]; P for trend < 0.001), after adjusting for family history of diabetes, prepregnancy BMI, race/ethnicity, alcohol use, prepregnancy weight changes, and homeostasis model assessment of insulin resistance. Having SHBG levels below the median (<64.5 nmol/L) and a BMI ≥25.0 kg/m(2) was associated with fivefold increased odds of GDM compared with normal-weight women with SHBG levels at or above the median (5.34 [3.00-9.49]).

CONCLUSIONS

Low prepregnancy SHBG concentrations were associated with increased risk of GDM and might be useful in identifying women at risk for GDM for early prevention strategies.