Reproductive history and risk of type 2 diabetes mellitus in postmenopausal women: findings from the Women's Health Initiative

Reproductive factors, genetic susceptibility and risk of type 2 diabetes: A prospective cohort study

AIM

To explore the relationships of multiple reproductive factors with type 2 diabetes mellitus (T2DM) risk and the joint effects of reproductive factors and genetic susceptibility.

METHODS

We included 262,368 women without prevalent T2DM from the UK biobank. Cox proportional hazards regression models were employed to estimate the relationships of reproductive factors with T2DM risk and the joint effects of reproductive factors and genetic susceptibility.

RESULTS

During a mean follow-up of 12.2 years, 8,996 T2DM cases were identified. Early menarche (<12 years, hazard ratio (HR) 1.08 [95 % confidence interval (CI) 1.02;1.13]), late menarche (≥15 years, HR 1.11 [1.04;1.17]), early menopause (<45 years, HR 1.20 [1.12;1.29]), short reproductive lifespan (<30 years, HR 1.25 [1.16;1.35]), hysterectomy (1.31, HR [1.23;1.40]), oophorectomy (HR 1.28 [1.20;1.36]), high parity (≥4, HR 1.25 [1.17;1.34]), early age at first live birth (<20 years, HR 1.23 [1.16;1.31]), miscarriage (HR 1.13 [1.07;1.19]), stillbirth (HR 1.14 [1.03;1.27]), and ever used hormonal replacement therapy (HR 1.19 [1.14;1.24]) were related to a higher T2DM risk, while ever used oral contraceptives (HR 0.93 [0.89;0.98]) was related to a lower T2DM risk. Furthermore, women with reproductive risk factors and high genetic risk had the highest T2DM risk compared to those with low genetic risk and without reproductive risk factors.

CONCLUSION

Our findings show that multiple reproductive factors are related to T2DM risk, particularly in women with high genetic risk.

Cardiovascular and physiological risk factors in women at mid-life and beyond

Cardiovascular disease (CVD) is the leading cause of death in women. After menopause, sex-specific and gender-specific factors may play an important role in increasing CVD risk, with changes in sex hormones, body fat distribution, lipid and metabolic profile, and structural and functional vascular modifications. Premature and early-onset menopause are detrimental to cardiovascular health due to the early cessation of the protective effect of endogenous estrogen. An independent association of menopause with an increased risk of CVD has been documented in early menopause (<45 years). Sex-related differences are relevant in pharmacokinetics and pharmacodynamics; different enzyme formations, drug compatibility, efficacy, and side effects vary for different sexes. Despite some progress in sex and gender research in CVD, disparities remain. Menopausal hormone therapy (MHT) is available at mid-life for symptoms of menopause and may impact cardiovascular risk. Taken early, MHT may reduce CVD morbimortality. However, this is balanced against the risk of increased thrombosis. This paper reviews physiologic changes that contribute to cardiovascular risk in postmenopausal women and discusses clinical implications. Specifically, it explores the atheroprotective effects of estrogen and MHT and the associations between menopause with lipid levels, hypertension, body composition, and diabetes for women at mid-life and beyond.

Menopausal Hormone Therapy in Women with Type 2 Diabetes Mellitus: An Updated Review

Menopause is accompanied by several metabolic adaptations, which are related to insulin resistance, increased total body fat mass, and central abdominal fat accumulation, predisposing women to type 2 diabetes mellitus (T2DM) development. Metabolic syndrome has a high prevalence in postmenopausal women, indicating the loss of estrogen protection on metabolic and cardiovascular health. Moreover, earlier age at menopause has been related to increased risk of T2DM. Menopausal hormone therapy (MHT) has favorable results in glucose metabolism. Indeed, it reduces the risk of T2DM in women without this condition and improves glycemic control in women with T2DM. Before MHT initiation in women with clinical indications, it is imperative to assess their cardiovascular disease (CVD) risk, using official electronic algorithms for score calculation. The latter will determine regimen, dose, and administration route of MHT. Oral estrogens are preferable in women with low CVD risk, while transdermal administration is indicated in those with moderate and high CVD risk, as the risk of stroke and venous thromboembolism (VTE) is increased with oral administration. Oral 17β-estradiol is usually preferred in women with T2DM, as this route has more beneficial effects on glucose metabolism. Oral estrogens are also suggested in perimenopausal or recently postmenopausal women with low CVD risk. Although oral estrogens have favorable effects when indicated, the risk of VTE or stroke should always be considered. Micronized progesterone, dydrogesterone, and transdermal norethisterone are the progestogens used in postmenopausal women with T2DM and intact uterus. MHT should not be initiated in women > 60 years or > 10 years in menopause, as there is an increased thromboembolic risk in women with established atherosclerosis and no additional cardiovascular benefit in women without atherosclerosis. In conclusion, MHT administration in postmenopausal women with T2DM can be safe and effective as long as the therapeutic regimen has been properly selected according to their cardiovascular, metabolic, and fracture risk.

Sleep Characteristics are Associated with Risk of Treated Diabetes Among Postmenopausal Women

OBJECTIVE

The purpose of this study was to determine whether sleep characteristics are associated with incidence of treated diabetes in postmenopausal individuals.

METHODS

Postmenopausal participants ages 50-79 years reported sleep duration, sleep-disordered breathing, or insomnia at baseline and again in a subsample 3 years later. The primary outcome was self-reported new diagnosis of diabetes treated with oral drugs or insulin at any time after baseline. Multivariable Cox proportional hazards models were used.

RESULTS

In 135,964 participants followed for 18.1 (± 6.3) years, there was a nonlinear association between sleep duration and risk of treated diabetes. Participants sleeping ≤5 hours at baseline had a 21% increased risk of diabetes compared with those sleeping 7 hours (adjusted hazard ratio [aHR] 1.21; 95% confidence interval [CI], 1.00-1.47). Those who slept for ≥9 hours had a nonsignificant 6% increased risk of diabetes compared with those sleeping 7 hours (aHR 1.06; 95% CI, 0.97-1.16). Participants whose sleep duration had decreased at 3 years had a 9% (aHR 1.09; 95% CI, 1.02-1.16) higher risk of diabetes than participants with unchanged sleep duration. Participants who reported increased sleep duration at 3 years had a risk of diabetes (HR 1.01; 95% CI, 0.95-1.08) similar to those with no sleep duration change. Participants at high risk of sleep-disordered breathing at baseline had a 31% higher risk of diabetes than those without (aHR 1.31; 95% CI, 1.26-1.37). No association was found between self-reported insomnia score and diabetes risk.

CONCLUSIONS

Sleep-disordered breathing and short or long sleep duration were associated with higher diabetes risk in a postmenopausal population.

Women's reproductive risk and genetic predisposition in type 2 diabetes: A prospective cohort study

OBJECTIVE

To assess synergistic effects of reproductive factors and gene-reproductive interaction on type 2 diabetes (T2D) risk, also the extent to which the genetic risk of T2D can be affected by reproductive risk.

METHODS

84,254 women with genetic data and reproductive factors were enrolled between 2006 and 2010 in the UK Biobank. The reproductive risk score (RRS) was conducted based on 17 reproductive items, and genetic risk score (GRS) was based on 149 genetic variants.

RESULTS

There were 2300 (2.8 %) T2D cases during an average follow-up of 4.49 years. We found a significant increase in T2D risk across RRS categories (Ptrend < 0.001). Compared with low reproductive risk, high-mediate (adjusted hazard ratio [aHR] 1.38, 95 % CI 1.20-1.58) and high (aHR 1.84, 95 % CI 1.54-2.19) reproductive risk could increase the risk of T2D. We further observed a significant additive interaction between reproductive risk and genetic predisposition. In the situation of high genetic predisposition, women with low reproductive risk had lower risk of T2D than those with high reproductive risk (aHR 0.47, 95 % CI 0.30-0.76), with an absolute risk reduction of 2.98 %.

CONCLUSIONS

Our novo developed RRS identified high reproductive risk is associated with elevated risk of women's T2D, which can be magnified by gene-reproductive interaction.

Menarche age and the risk of diabetes: A cross-sectional study in South-Eastern Iran

Background and Aims

Diabetes is a major public health problem worldwide. This study aimed to determine the relationship between menarche age and overt diabetes in southeast Iran.

Methods

This cross-sectional study was conducted on 6094 eligible women between the ages of 35 and 70 participating in the Zahedan Adult Cohort Study. Demographic and background data, fertility, anthropometry, and disease history were collected based on a questionnaire. Menarche age was classified into five categories (under 12 years, 12, 13, 14, 15 years and more). Diabetes is defined as a blood sugar of 126 or more according to the definition by the American Diabetes Association. Data analysis was done using SPSS 26 software. Descriptive analysis was performed with frequency, percentage, mean, and standard deviation; and analytical analysis using chi-square and logistic regression tests. The significance level in this study was p < 0.05.

Results

The participants' mean age was 49.41 ± 8.88, and the mean age at menarche was 13 ± 1.49. 22.8% (1389 women) of participants with diabetes and 77.2% (4705 women) did not have diabetes. The findings showed that the chance of developing diabetes in women with a menarche age <12 years was significantly higher than in women with a menarche age of 13 years (reference) (OR = 1.23, 95% CI: 0.96, 1.51). This relationship was significant after adjusting variables such as body mass index, education level, fertility factors, history of diabetes, and reproductive diabetes (OR = 1.21, 95% CI: 0.90, 1.44, p = 0.04).

Conclusion

Our findings suggest that young age at menarche may be a risk factor for diabetes in adulthood. Further prospective studies are needed to confirm our findings. However, it is suggested to pay attention to it in diabetes screening so that, if possible, by identifying people at risk and implementing prevention programs, the adverse consequences of diabetes can be reduced.

Ethnic Differences in the Association Between Age at Natural Menopause and Risk of Type 2 Diabetes Among Postmenopausal Women: A Pooled Analysis of Individual Data From 13 Cohort Studies

OBJECTIVE

To investigate associations between age at natural menopause, particularly premature ovarian insufficiency (POI) (natural menopause before age 40 years), and incident type 2 diabetes (T2D) and identify any variations by ethnicity.

RESEARCH DESIGN AND METHODS

We pooled individual-level data of 338,059 women from 13 cohort studies without T2D before menopause from six ethnic groups: White (n = 177,674), Chinese (n = 146,008), Japanese (n = 9,061), South/Southeast Asian (n = 2,228), Black (n = 1,838), and mixed/other (n = 1,250). Hazard ratios (HRs) of T2D associated with age at menopause were estimated in the overall sample and by ethnicity, with study as a random effect. For each ethnic group, we further stratified the association by birth year, education level, and BMI.

RESULTS

Over 9 years of follow-up, 20,064 (5.9%) women developed T2D. Overall, POI (vs. menopause at age 50-51 years) was associated with an increased risk of T2D (HR 1.31; 95% CI 1.20-1.44), and there was an interaction between age at menopause and ethnicity (P < 0.0001). T2D risk associated with POI was higher in White (1.53; 1.36-1.73), Japanese (4.04; 1.97-8.27), and Chinese women born in 1950 or later (2.79; 2.11-3.70); although less precise, the risk estimates were consistent in women of South/Southeast Asian (1.46; 0.89-2.40), Black (1.72; 0.95-3.12), and mixed/other (2.16; 0.83-5.57) ethnic groups. A similar pattern, but with a smaller increased risk of T2D, was observed with early menopause overall (1.16; 1.10-1.23) and for White, Japanese, and Chinese women born in 1950 or later.

CONCLUSIONS

POI and early menopause are risk factors for T2D in postmenopausal women, with considerable variation across ethnic groups, and may need to be considered in risk assessments of T2D among women.

Early menopause and cardiovascular risk factors: a cross-sectional and longitudinal study

OBJECTIVE

The aim of the study is to evaluate the cross-sectional and longitudinal association of early natural menopause with changes in cardiovascular risk factors (CVRFs).

METHODS

Postmenopausal women from the Swiss CoLaus study, reporting age at natural menopause (ANM) and having CVRFs measurements (blood lipids, blood pressure, glucose, homeostatic model assessment for insulin resistance [HOMA-IR], and inflammatory markers) at baseline (2003-2006) and first follow-up (2009-2012) were eligible for analysis. Age at natural menopause was analyzed as a continuous variable and in categories (ANM <45 and ≥45 y old). Linear regression analysis and linear mixed models were used to assess whether ANM is associated cross-sectionally and longitudinally with changes in CVRFs. Models were adjusted for demographic characteristics, lifestyle-related factors, time since menopause, medication, and clinical conditions.

RESULTS

We analyzed 981 postmenopausal women. The cross-sectional analysis showed that women with ANM younger than 45 years had lower diastolic blood pressure (β = -3.76 mm Hg; 95% confidence interval [CI] = -5.86 to -1.65) compared with women whose ANM was 45 years or older. In the longitudinal analysis, ANM younger than 45 years was associated with changes in log insulin (β = 0.26; 95% CI = 0.08 to 0.45) and log homeostatic model assessment for insulin resistance levels (β = 0.28; 95% CI = 0.08 to 0.48). No associations were found between ANM and other CVRFs.

CONCLUSIONS

Early menopause may be associated with changes in glucose metabolism, while it may have little to no impact on other CVRFs. Larger longitudinal studies are needed to replicate our findings.

Menopausal hormone therapy and the risk of type 2 diabetes mellitus: Health Insurance Database in South Korea-based retrospective cohort study

OBJECTIVE

Menopausal hormone therapy (MHT) is known to reduce the incidence of type 2 diabetes mellitus (T2DM); however, since the Women's Health Initiative study, the types and doses of female hormones used for MHT have changed considerably. Therefore, this study was conducted to determine whether MHT, which is currently widely prescribed, increases the risk of T2DM.

METHOD

We performed a retrospective cohort study based on national health insurance data and cancer screening data from 2002 to 2019. We included the MHT group as postmenopausal women older than 40 years who used at least one MHT for at least 6 months between 2003 and 2011. We subclassified the MHT group into five categories; tibolone, combined estrogen plus progestin by the manufacturer (CEPM), oral estrogen, combined estrogen plus progestin by the physician (CEPP), and transdermal estrogen. We selected the non-MHT group as postmenopausal women who had never been prescribed MHT from 2002 to 2019. We compared the incidence of T2DM between the MHT group and the non-MHT group.

RESULTS

We enrolled 330,771 women in the MHT group and 798,550 women in the control group. T2DM was diagnosed in 15.2% of the non-MHT group, 16.6% of the tibolone group, 12.1% of the CEPM group, 16.6% of the oral estrogen group, 15.4% of the CEPP group, and 17% of the transdermal estrogen group. In Cox proportional hazard analysis adjusted for variable factors, tibolone, oral estrogen, CEPP, and transdermal estrogen increased the incidence of T2DM. In contrast, there was no change in the risk of T2DM in the CEPM group.

CONCLUSIONS

MHT, including tibolone, which is currently the most prescribed agent, increased the risk of T2DM; however, CEPM did not increase the risk of T2DM. Only tibolone increased the risk of T2DM in participants older than 70 years.

Menopause and diabetes

In the last 20 years, the prevalence of type 2 diabetes mellitus (T2DM) has tripled in adults aged 20-79 years, affecting more than 25% of people over 50 years of age and especially women during menopause. After the menopause transition, women gain weight, increasing abdominal fat and decreasing lean body mass, with a significant reduction in energy expenditure. Increased insulin resistance and hyperinsulinism characterize this period, aggravated by an increase in plasma proinflammatory cytokines and free fatty acids, and a state of relative hyperandrogenism. Previous recommendations systematically excluded women with T2DM from menopause hormone therapy (MHT); new evidence confirms that MHT significantly reduces the diagnosis of new-onset T2DM and may be beneficial in terms of glycemic control when used for menopause symptom management in patients with pre-existing T2DM. A comprehensive and individualized approach is considered the first line of management for women during this period, especially in T2DM patients or in women at risk of developing the disease. The objectives of this presentation are to review the etiopathogenic factors involved in the increased incidence of new cases of T2DM during menopause, the impact of menopause on T2DM and the role of MHT.

Genetic prediction of age at menarche, age at natural menopause and type 2 diabetes: A Mendelian randomization study

BACKGROUND AND AIMS

The relationship between reproductive factors and type 2 diabetes (T2D) is controversial; therefore, we explored the causal relationship of age at menarche (AAM), age at natural menopause (ANM), with the risk of T2D and glycemic traits using two-sample Mendelian randomization.

METHODS AND RESULTS

We used publicly available data at the summary level of genome-wide association studies, where AAM (N = 329,345), ANM (N = 69,360), T2D (N = 464,389). The inverse variance weighting (IVW) method was employed as the primary method. To demonstrate the robustness of the results, we also conducted various sensitivity analysis methods including the MR-Egger regression, the weighted median (WM) and the MR Pleiotropy RESidual Sum and Outlier (MR-PRESSO) test. After excluding IVs associated with confounders, we found a causal association between later AAM and reduced risk of T2D (OR 0.81 [95% CI 0.75, 0.87]; P = 2.20 × 10^-8), lower levels of FI (β -0.04 [95% CI -0.06, -0.01]; P = 2.19 × 10^-3), FPG (β -0.03 [95% CI -0.05, -0.007]; P = 9.67 × 10^-5) and HOMA-IR (β -0.04 [95% CI -0.06, -0.01]; P = 4,95 × 10^-3). As for ANM, we only found a causal effect with HOMA-IR (β -0.01 [95% CI -0.02, -0.005]; P = 1.77 × 10^-3), but not with T2D.

CONCLUSIONS

Our MR study showed a causal relationship between later AAM and lower risk of developing T2D, lower FI, FPG and HOMA-IR levels. This may provide new insights into the prevention of T2D in women.

Obesity-Related Factors in Adult Women with Early Menarche

The average menarche age among South Korean women has decreased over time. Early menarche in women causes a higher incidence of obesity owing to the continuous fat accumulation induced by prolonged exposure to estrogen and adrenal steroids. Identifying the factors affecting obesity in women who experience early menarche is essential for managing obesity in adult women. This study aimed to analyze the factors associated with obesity in adult women who experienced early menarche and to provide basic data for obesity management. This study was a cross-sectional and descriptive survey from the seventh Korea National Health and Nutrition Examination. A total of 371 women aged ≥ 19 years experienced early menarche, and the propensity matching method was used to analyze the obesity-related factors identified in previous studies. The results showed that obesity in adult women with early menarche was negatively associated with the level of aerobic exercise (OR = 0.53, 95% CI = 0.30-0.93, p = 0.028) and muscle-strengthening exercise (OR = 0.33, 95% CI = 0.17-0.64, p = 0.001). Future longitudinal studies on girls who experience early menarche are needed to address female obesity prevention at every stage of life, and, based on these findings, obesity management programs can be developed and applied and their effectiveness determined.

The Associations between Upper and Lower Body Muscle Strength and Diabetes among Midlife Women

We hypothesized that a combined index of upper and lower body muscle strength would be more strongly associated with diabetes than either measure alone. Women recruited into the Integrated Women's Health Program had their handgrip strength (HGS) measured using a dynamometer and underwent a timed 5-repetition chair stand (RCS) test. HGS < 18 kg and RCS performance ≥ 12 s assessed upper and lower body strength, respectively, both individually and combined in a muscle strength index (MSI). Diabetes was defined as physician-diagnosed, use of anti-diabetic medication, or fasting blood glucose ≥ 7.0 mmol/L. Binary logistic regression examined the associations between muscle strength and diabetes. Of 1170 midlife women, 12.1% had diabetes. A low HGS was independently associated with diabetes (aOR: 1.59, 95% CI: 1.03, 2.44). Prolonged RCS was also associated with diabetes (aOR: 1.59, 95% CI: 1.09, 2.30), but this was not independent of visceral adiposity and muscle mass. A poor MSI had higher odds of diabetes (aOR: 2.37, 95% CI: 1.40, 4.03), independent of age, ethnicity, education level, menopausal status, smoking, alcohol consumption, physical activity, height, visceral adiposity, and muscle mass. The combination of both upper and lower body muscle strength into a composite MSI was more strongly associated with diabetes than either weak HGS or prolonged RCS alone in midlife women.

The interplay between diabetes mellitus and menopause: clinical implications

The menopausal transition is an impactful period in women's lives, when the risk of cardiovascular disease is accelerated. Similarly, diabetes mellitus profoundly impacts cardiovascular risk. However, the interplay between menopause and diabetes mellitus has not been adequately studied. The menopausal transition is accompanied by metabolic changes that predispose to diabetes mellitus, particularly type 2 diabetes mellitus (T2DM), as menopause results in increased risk of upper body adipose tissue accumulation and increased incidence of insulin resistance. Equally, diabetes mellitus can affect ovarian ageing, potentially causing women with type 1 diabetes mellitus and early-onset T2DM to experience menopause earlier than women without diabetes mellitus. Earlier age at menopause has been associated with a higher risk of T2DM later in life. Menopausal hormone therapy can reduce the risk of T2DM and improve glycaemic control in women with pre-existing diabetes mellitus; however, there is not enough evidence to support the administration of menopausal hormone therapy for diabetes mellitus prevention or control. This Review critically appraises studies published within the past few years on the interaction between diabetes mellitus and menopause and addresses all clinically relevant issues, such as the effect of menopause on the development of T2DM, and the management of both menopause and diabetes mellitus.

Cumulative Endogenous Estrogen Exposure Is Associated With Postmenopausal Fracture Risk: The Women's Health Initiative Study

We aimed to evaluate the relationship between cumulative endogenous estrogen exposure and fracture risk in 150,682 postmenopausal women (aged 50 to 79 years at baseline) who participated in the Women's Health Initiative. We hypothesized that characteristics indicating lower cumulative endogenous estrogen exposure would be associated with increased fracture risk. We determined ages at menarche and menopause as well as history of irregular menses from baseline questionnaires and calculated years of endogenous estrogen exposure from ages at menarche and menopause. Incident clinical fractures were self-reported over an average 16.7 years of follow-up. We used multivariable proportional hazards models to assess the associations between the estrogen-related variables and incidence of any clinical fracture. In fully adjusted models, those with the fewest years of endogenous estrogen exposure (<30) had an 11% higher risk of developing central body fractures and a 9% higher risk of lower extremity fractures than women with 36 to 40 years of endogenous estrogen exposure (the reference category). In contrast, women with the most years of endogenous estrogen exposure (more than 45 years) had a 9% lower risk of lower extremity fractures than the reference category. Women with irregular (not monthly) menstrual cycles were 7% to 8% more likely to experience lower extremity fractures than women with regular monthly cycles. Our findings support the hypothesis that characteristics signifying lower cumulative endogenous estrogen exposure are associated with higher fracture risk. © 2022 American Society for Bone and Mineral Research (ASBMR).

Number of Births and Risk of Diabetes in China's Older Women

As an important life event in individuals' life, childbirth will affect the health of women to different degrees. More and more attention has been paid to whether the number of births will affect the incident diabetes in elderly women, but there are few related studies. Based on the data of the Chinese Longitudinal Healthy Longevity Survey in 2018, 6,159 older women are selected as the study population. Logistic regression analyses are used to estimate the relationship between the number of births and diabetes risk. For each additional birth, the odds ratio of maternal diabetes will decrease by 6.9% and the result is significant at the 1% level, especially among mothers having four children or less. The conclusion is equally applicable in the sample of fathers and urban mothers, but the increase in the number of births will increase the risk of diabetes in rural mothers, although this result is not statistically significant. Later age at first birth, later age at last birth, the longer childbearing period, and birth interval will significantly reduce the risk of diabetes.

The Association between Menstrual Irregularities and the Risk of Diabetes in Premenopausal and Postmenopausal Women: A Cross-Sectional Study of a Nationally Representative Sample

Background: Studies have assessed the effects of menstrual irregularities and menopause on diabetes, but no definitive conclusion has been reached. This study investigated for the first time the relationship between menstrual irregularity and diabetes before and after menopause. Methods: This population-based cross-sectional study included 9043 participants from the Korea National Health and Nutrition Examination Survey (KNHANES) V (2010–2012). Multivariate logistic regression was used to assess the effect of menstrual irregularities on impaired fasting glucose (IFG) and diabetes incidence in women before and after menopause. Results: After adjustment for age and other diabetes-related factors, both menopause (OR = 1.51, 95% CI = 1.101–2.27, p = 0.047) and menstrual irregularities (OR = 1.51, 95% CI = 1.1–2.07, p = 0.011) were found to increase the risk of diabetes. Menstrual irregularities were significantly related to diabetes in the postmenopausal group (OR = 1.65, 95% CI  =  1.12–2.42, p = 0.012) but not in the premenopausal group (OR = 1.22, 95% CI  =  0.64–2.32, p = 0.555). Conclusions: In this study, menopausal status appeared to independently affect diabetes risk; menstrual irregularities were found to be a risk factor for postmenopausal diabetes. This study emphasizes the need for monitoring and early prevention, along with medical advice on menstrual irregularities, to reduce the prevalence of diabetes and improve the quality of life of postmenopausal women.

Hepatic Adropin is Regulated by Estrogen and Contributes to Adverse Metabolic Phenotypes in Ovariectomized Mice

Objective

Menopause is associated with visceral adiposity, hepatic steatosis and increased risk for cardiovascular disease. As estrogen replacement therapy is not suitable for all postmenopausal women, a need for alternative therapeutics and biomarkers has emerged.

Methods

9-week-old C57BL/6 J female mice were subjected to ovariectomy (OVX) or SHAM surgery (n = 10 per group), fed a standard diet and sacrificed 6- & 12 weeks post-surgery.

Results

Increased weight gain, hepatic triglyceride content and changes in hepatic gene expression of Cyp17a1, Rgs16, Fitm1 as well as Il18, Rares2, Retn, Rbp4 in mesenteric visceral adipose tissue (VAT) were observed in OVX vs. SHAM. Liver RNA-sequencing 6-weeks post-surgery revealed changes in genes and microRNAs involved in fat metabolism in OVX vs. SHAM mice. Energy Homeostasis Associated gene (Enho) coding for the hepatokine adropin was significantly reduced in OVX mice livers and strongly inversely correlated with weight gain (r = −0.7 p < 0.001) and liver triglyceride content (r = −0.4, p = 0.04), with a similar trend for serum adropin. In vitro, Enho expression was tripled by 17β-estradiol in BNL 1 ME liver cells with increased adropin in supernatant. Analysis of open-access datasets revealed increased hepatic Enho expression in estrogen treated OVX mice and estrogen dependent ERα binding to Enho. Treatment of 5-month-old OVX mice with Adropin (i.p. 450 nmol/kg/twice daily, n = 4,5 per group) for 6-weeks reversed adverse adipokine gene expression signature in VAT, with a trended increase in lean body mass and decreased liver TG content with upregulation of Rgs16.

Conclusions

OVX is sufficient to induce deranged metabolism in adult female mice. Hepatic adropin is regulated by estrogen, negatively correlated with adverse OVX-induced metabolic phenotypes, which were partially reversed with adropin treatment. Adropin should be further explored as a potential therapeutic target and biomarker for menopause-related metabolic derangement.

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OVX increased body weight, liver fat & adverse visceral fat adipokine signature.

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OVX altered liver transcriptome & miRNA profile including fat metabolism pathways.

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Enho was downregulated by OVX & inversely correlated with weight gain & liver fat.

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Hepatic adropin expression was upregulated by estrogen in-vitro & in-vivo.

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Adropin treatment partially reversed OVX induced adverse metabolic phenotypes.

Menopausal status, age at natural menopause and risk of diabetes in China: a 10-year prospective study of 300,000 women

BACKGROUND

Menopause characteristics have been implicated in future health consequences, yet little is known about its relevance to diabetes. We examined the associations of menopausal status and age at natural menopause with diabetes risk in Chinese women.

METHODS

We used prospective data of the China Kadoorie Biobank study that recruited 302,522 women aged 30-79 years in 2004-2008 from 10 areas across China. During average 10.8 years of follow-up, 11,459 incident diabetes cases were recorded among 281,319 women without prior diabetes diagnosis at baseline. Cox proportional hazards models were used to estimate adjusted hazard ratios (HRs) with 95% confidence intervals (CIs) for incident diabetes associated with menopausal status and age at natural menopause.

RESULTS

Overall, the mean (SD) age at natural menopause was 48.2 (4.4) years among 141,789 post-menopausal women. Naturally peri-, or post-menopausal women were at higher risk of diabetes, with HRs of 1.17 (95% CI 1.06-1.29) and 1.15 (1.06-1.25) compared with pre-menopausal women, adjusting for several potential confounders. Among women who had natural menopause, the HR of diabetes was 1.14 (1.01-1.30), 1.01 (0.93-1.09), 1.10 (1.04-1.16), and 1.10 (1.01-1.20) for menopause at ages less than 40, 40-44, 50-53, and 54 years or older, respectively, relative to 45-49 years.

CONCLUSIONS

In this study, we found that women with naturally peri-, or post-menopausal status had higher risk of developing diabetes. Besides, among the post-menopausal women, both earlier and later age at natural menopause were associated with increased risk of diabetes.

Association of severity of menstrual dysfunction with hyperinsulinemia and dysglycemia in polycystic ovary syndrome

STUDY QUESTION

Is the severity of menstrual cyclicity related to hyperinsulinemia and dysglycemia in women with hyperandrogenic polycystic ovary syndrome (PCOS)?

SUMMARY ANSWER

Hyperandrogenic PCOS women with amenorrhea, compared to those with oligomenorrhea or eumenorrhea, had a greater risk of post-challenge hyperinsulinemia, which may explain their higher prevalence of dysglycemia.

WHAT IS KNOWN ALREADY

PCOS is associated with metabolic dysregulation including insulin resistance (IR) and hyperinsulinemia, risk factors for type 2 diabetes mellitus (T2DM) and other vascular-metabolic morbidities. Although the severity of menstrual cyclicity is associated with IR in PCOS, it is unclear whether, and to what extent, it is related to hyperinsulinemia and glycemic abnormalities.

STUDY DESIGN, SIZE, DURATION

We prospectively compared the degree of menstrual cyclicity with the presence of dysglycemia (elevated 1-h plasma glucose ≥155 mg/dl; abnormal glucose tolerance [AGT], including prediabetes and T2DM; and AUC for glucose [G-AUC]) or dynamic state hyperinsulinemia (peak insulin levels either at 1 or 2 h of the oral glucose tolerance test (oGTT) and AUC for insulin [I-AUC]) in 333 hyperandrogenic PCOS women.

PARTICIPANTS/MATERIALS, SETTING, METHODS

In a tertiary care setting, hyperandrogenic PCOS participants with ovulatory eumenorrhea (Ov-Eumeno, n = 25), anovulatory eumenorrhea (Anov-Eumeno, n = 33), oligomenorrhea (Oligo, n = 150) and amenorrhea (Ameno, n = 125) underwent comprehensive phenotyping and a 2-h 75 g oGTT.

MAIN RESULTS AND THE ROLE OF CHANCE

Mean BMI was greater among Ameno women than among Oligo, Anov-Eumeno or Ov-Eumeno women. Adjusting for BMI, the Ameno group demonstrated higher mean 1- and 2-h insulin and glucose, peak insulin and I-AUC and G-AUC, and either had a higher, or tended toward having a higher, prevalence of elevated 1-h glucose level and prevalence of AGT than the Oligo, Anov-Eumeno or Ov-Eumeno groups. In logistic regression, adjusting for BMI, Ameno women were more likely to have: AGT than Oligo women (odds ratio [OR]: 2.3; 95% CI: 1.3 to 4.2); elevated 1-h glucose (OR: 10.2; CI: 1.3-79.7) than those with Ov-Eumeno; and both AGT (OR: 1.7; CI: 1.1-2.6) and elevated 1-h glucose (OR: 1.8; CI: 1.1-2.8) than those with Anov-Eumeno or Ov-Eumeno when combined. Race/ethnicity, age, waist-to-hip ratio, fasting insulin and glucose, and biochemical or clinical measures of hyperandrogenism were similar across the four menstrual categories.

LIMITATIONS, REASONS FOR CAUTION

Our study was limited by its cross-sectional nature and by studying women affected by PCOS as defined by the Androgen Excess & PCOS Society criteria (i.e. Rotterdam Phenotypes A, B and C) who were identified in the clinical setting. Consequently, extrapolation of the present data to other PCOS phenotypes (e.g. PCOS Phenotype D) should be made with caution.

WIDER IMPLICATIONS OF THE FINDINGS

In hyperandrogenic PCOS phenotypes, a history of amenorrhea, compared to oligomenorrhea or eumenorrhea, suggests a more severe cardiometabolic risk, including a higher degree of hyperinsulinemia and greater prevalence of glycemic abnormalities. These findings may assist in refining the treatment and screening guidelines for glycemic abnormalities in PCOS.

STUDY FUNDING/COMPETING INTEREST(S)

This work was supported in part by grants R01-DK073632 and R01-HD29364 from the NIH and an endowment of the Helping Hand of Los Angeles, Inc. (to R.A.). M.D.P. has no competing interests to declare. U.E. is an investor in Concentric Analgesics, Inc. R.A. serves as a consultant for Spruce Biosciences and Fortress Biotech and an advisor for Aurora Forge.

TRIAL REGISTRATION NUMBER

N/A.

Change in metabolic parameters and reproductive hormones from baseline to 6-month hormone therapy

Adequate evidence showed hormone therapy (HT) reduces the risk of new-onset diabetes in midlife women by decreasing fasting glucose and insulin. However, the improvement of these diabetic biomarkers varied with each individual in clinical observations. The objective of our study was to investigate potential baseline factors associated with the change of fasting glucose and insulin during HT.A retrospective cohort study was performed among 263 midlife participants aged 40 to 60 years with menopausal symptoms who have received 6-month individualized HT. Demographic information and laboratory indicators including reproductive hormone, lipid profiles, diabetic indicators were collected and measured at baseline and were followed-up. A series of statistical analyses were performed to confirm the effectiveness of HT and compare the baseline factors between participants with different glycemic or insulinemic response. Multivariable linear regression model with stepwise variable selection was further used to identify the associated factor with the change of fasting glucose and insulin.Of all participants, fasting glucose (P = .001) and fasting insulin (P < .001) were significantly decreased after individualized HT. Significant differences in baseline reproductive hormones were observed in participants with different glycemic response to HT (P < .001 for both follicle stimulating hormone [FSH] and estradiol). Stepwise linear regression model showed that in addition to baseline fasting glucose levels, baseline FSH was also independently associated with the change of fasting glucose (β = -0.145, P = .019 for baseline FSH) but not fasting insulin. Greater reduction in fasting glucose in women with higher FSH levels was observed even though they have already been in better metabolic conditions (P = .037).Midlife women with higher baseline FSH levels have greater reduction in fasting glucose but not fasting insulin. FSH could be an independent predictor of glycemic response to HT in peri- and postmenopausal women.

The Diabetes-Cardiovascular Connection in Women: Understanding the Known Risks, Outcomes, and Implications for Care

PURPOSE OF REVIEW

Cardiovascular disease (CVD) complications constitute about 50-70% of mortality in people with diabetes. However, there remains a persistently greater relative increase in CVD morbidity and mortality in women with diabetes than in their male counterparts. This review presents recent evidence for the risks, outcomes, and management implications for women with diabetes.

RECENT FINDINGS

Compared to men, women have higher BMI and more adverse cardiovascular risk profile at time of diabetes diagnosis with greater risk for coronary heart disease, stroke, vascular dementia, and heart failure. Pregnancy-specific risk factors of gestational diabetes and pre-eclampsia are associated with future type 2 diabetes (T2D) and CVD. Women with T2D may experience greater benefits than men from GLP-1 receptor agonists. Women with diabetes are at greater relative risk for CVD complications than men, with poorer outcomes, superimposed on preexisting gender disparities in social determinants of health, lower likelihood of being offered cardioprotective interventions, and enrollment in trials. Further research and the utilization of SGLT-2 inhibitors, GLP-1 receptor agonists, and other CVD prevention strategies will help reduce morbidity and mortality.

Epidemiological studies of the association between reproductive lifespan characteristics and risk of Type 2 diabetes and hypertension: A systematic review

Some reproductive factors are found to be associated with metabolic outcomes in women; however, little is known about reproductive lifespan characteristics and the mutual effect of age at menarche and age at menopause on cardiovascular risk. This systematic review evaluated reproductive lifespan characteristics and describes the mutual effect of age at menarche and age at menopause on the risk of type 2 diabetes (T2DM) and hypertension at midlife. PubMed, EMBASE, and Web of Science were screened for studies published up to September 1, 2020. The individual effect estimates were reviewed and synthesized without meta-analysis due to methodological and clinical or conceptual diversity in reported studies. Of the 3033 identified studies, 20 were included in the final synthesis: 6 reported reproductive life span; 12 reported age at menarche, and 7 reported age at menopause. Synthesis of two cohorts, with a median follow-up of 9-11 years, showed that a shorter reproductive lifespan was positively associated with T2DM, yielding 6-15% higher risk of T2DM for a one-year decrease in reproductive lifespan. A few studies also demonstrated that women who experienced early menarche (four of six studies) and early menopause (two of five studies) were positively associated with risk of T2DM. The association between reproductive lifespan and hypertension was unclear due to the limited availability of studies. Our findings suggest that a shorter reproductive lifespan is associated with T2DM risk in postmenopausal women, especially those with early menarche and early menopause. Large cohort studies are needed to assess the association between reproductive lifespan and incident hypertension in midlife.

Mediation model with a categorical exposure and a censored mediator with application to a genetic study

Mediation analysis is a statistical method for evaluating the direct and indirect effects of an exposure on an outcome in the presence of a mediator. Mediation models have been widely used to determine direct and indirect contributions of genetic variants in clinical phenotypes. In genetic studies, the additive genetic model is the most commonly used model because it can detect effects from either recessive or dominant models (or any model in between). However, the existing approaches for mediation model cannot be directly applied when the genetic model is additive (e.g. the most commonly used model for SNPs) or categorical (e.g. polymorphic loci), and thus modification to measures of indirect and direct effects is warranted. In this study, we proposed overall measures of indirect, direct, and total effects for a mediation model with a categorical exposure and a censored mediator, which accounts for the frequency of different values of the categorical exposure. The proposed approach provides the overall contribution of the categorical exposure to the outcome variable. We assessed the empirical performance of the proposed overall measures via simulation studies and applied the measures to evaluate the mediating effect of a women’s age at menopause on the association between genetic variants and type 2 diabetes.

Natural menopausal age and cardiovascular disease risk factors in older Chinese women: Guangzhou Biobank Cohort Study

OBJECTIVE

To examine the associations of natural menopausal age with cardiovascular disease risk factors and whether the associations varied by parity in older Chinese women.

METHODS

Information of demographic characteristics, lifestyles, and reproductive factors was collected by face-to-face interview. Framingham Risk Score was used as an indicator of cardiovascular disease risk, with a score ≥ 10% considered as high cardiovascular disease risk (vs low, dichotomous). Multivariable logistic and linear regressions were used to examine the associations of menopausal age with cardiovascular disease risk factors.

RESULTS

Of 18,339 women aged 50+ years, the average (standard deviation) age was 61.8 (6.9) years. Compared with women with menopausal age of 45 to 54 years, after adjustment for multiple potential confounders, women with menopausal age <45 years or ≥55 years had higher Framingham Risk Score (0.93%, 95% confidence interval: 0.40-1.46, and 0.69%, 95% confidence interval: 0.18-1.20, respectively). Women with menopausal age <45 or ≥55 years had higher odds of high cardiovascular disease risk (vs low) (odds ratio [95% confidence interval]:1.26 (1.10-1.44) and 1.17 (1.02-1.33), respectively). The associations of menopausal age with the Framingham Risk Score varied by parity (P for interaction ≤0.001). The Framingham Risk Score was higher in those with one to three parity (<45 y: 1.01 [0.43-1.59]; ≥55 y: 1.14 [0.60-1.68]) and lower for parity ≥4 (<45 y: -0.33 [-1.84 to 1.18]; ≥55 y: -2.02 [-3.82 to -0.22]). In nulliparous women, the Framingham Risk Score was highest in menopausal age <45 years (3.97 [1.67-6.26]), but the differences were nonsignificant in menopausal age ≥55 years (0.66 [-1.38 to 2.71]).

CONCLUSIONS

Both early and late natural menopausal ages were associated with a higher cardiovascular disease risk, and the associations were stronger in those with lower parity.

Cardiometabolic health in premature ovarian insufficiency

Premature ovarian insufficiency (POI) is an increasing public health problem with a prevalence now approaching 4%. POI results in adverse effects on the skeleton and central nervous system as well as disturbances of metabolic and cardiological factors that predispose to a major increased risk of cardiovascular disease (CVD). This article reviews the effects of the premature loss of ovarian function on lipids and lipoproteins, glucose and insulin metabolism, body composition, hemostasis and blood pressure, together with effects on the development of metabolic syndrome and diabetes mellitus. The article examines the effects of POI on vascular endothelial function and inflammation that result in arterial disease, and reviews the effects of hormone replacement therapy (HRT) on these various metabolic processes and on cardiovascular outcomes. It is essential that women with POI receive hormonal treatment to help prevent the development of CVD, and that this treatment is continued at least until the normal age of menopause. It appears that HRT has a more favorable effect than the combined oral contraceptive, but larger clinical trials are needed to establish the optimal treatment. Other therapeutic measures may need to be added to correct existing metabolic abnormalities and, in particular, attention to lifestyle factors such as diet and exercise must be encouraged.

Relationship between age at menarche and risk of glucose metabolism disorder: a systematic review and dose-response meta-analysis

OBJECTIVE

Studies investigating the impact of age at menarche on glucose metabolism disorder have reached inconsistent conclusions, and a quantitative comprehensive assessment of the dose-response association between age at menarche and glucose metabolism disorder has not been reported. We performed a systematic review and meta-analysis of studies assessing the risk of glucose metabolism disorder by age at menarche.

METHODS

MEDLINE via PubMed and EMBASE databases were searched up to March 13, 2019. Restricted cubic splines were used to model the dose-response association.

RESULTS

Twenty-five publications (including 34 studies) were included in the meta-analysis. The summary risk ratios (RRs) and 95% confidence limit (CL) per 1-year increase in age at menarche were 0.98 (95% CL 0.98, 0.99) for type 2 diabetes mellitus (T2DM), 0.97 (95% CL 0.96, 0.99) for impaired fasting glucose (IFG), and 0.98 (95% CL 0.97, 0.99) for gestational diabetes mellitus (GDM). We identified linear negative correlations between age at menarche and T2DM (Pnonlinearity = 0.052) and IFG (Pnonlinearity = 0.145), a nonlinear dose-response between age at menarche and GDM (Pnonlinearity = 0.038).

CONCLUSIONS

Older age at menarche (range 8-18 years old) is associated with reduced risk of glucose metabolism disorder. The strongest reduction in risk of GDM is observed at menarche age of 14.5 years.

Perils of prolonged ovarian suppression and hypoestrogenism in the treatment of breast cancer: Is the risk of treatment worse than the risk of recurrence?

Premenopausal breast cancer is usually estrogen receptor positive, and hence, prolonged ovarian suppression by medical or surgical means to prevent recurrence has become standard of management to improve disease-free survival. Ten-year adjuvant tamoxifen therapy is associated with 3.5% fewer recurrences compared to five years. The SOFT trial demonstrated small but statistically significant incremental improvements in long-term disease-free survival by the addition of gonadotropin-releasing hormone analog treatment (triptorelin) to an aromatase inhibitor (exemestane). Profound hypoestrogenism in the premenopausal age group may not be well tolerated due to a host of bothersome side effects (primarily vasomotor symptoms, musculoskeletal complaints, genitourinary syndrome of menopause, and mood disorders). Prolonged hypoestrogenism in younger women is associated with premature development of cardiovascular disease, bone loss, cognitive decline, and all-cause mortality. This paper explores multi-system consequences of prolonged hypoestrogenism in premenopausal women derived from studies of women with and without breast cancer. Pretreatment counseling in estrogen receptor positive breast cancer should emphasize the benefit of prolonged estrogen suppression on breast cancer recurrence and established risks of lifelong hypoestrogenism on quality of life and all-cause mortality. Future genomic research may help identify the best candidates for extended ovarian suppression to avoid treating many women when only a minority benefit.

Gonadal hormonal factors before menopause and incident type 2 diabetes in women: A 22-year follow-up of 83 799 women from the E3N cohort study

BACKGROUND

In many populations the incidence of type 2 diabetes is higher in men than in women. This may be explained by exposure to female gonadal hormones, but so far, there is no consensus on their role over the life course in type 2 diabetes etiology.

METHODS

Data are from 83 799 French women from the E3N (Etude Épidémiologique de Femmes de la Mutuelle Générale de l'Education Nationale) cohort study, followed for 22 years. Multivariable Cox models including classical risk factors were used to estimate hazard ratios (HR) and 95% confidence intervals (CI) between gonadal hormonal factors and incident type 2 diabetes.

RESULTS

Older age at menarche, more menstrual cycles, older age at menopause, longer duration of exposure to gonadal hormones and breastfeeding were inversely associated with incident type 2 diabetes cases (n = 4806). While a longer duration of menstrual cycles (HR = 1.23 [95% CI: 1.07-1.41] comparing ≥32 vs ≤24 days) and use of contraceptive pills (HR = 1.33 [1.25-1.42]) were associated with a greater risk of type 2 diabetes.

CONCLUSIONS

In women, a longer exposure to endogenous gonadal hormones with a later menopause as well as breastfeeding were associated with a lower risk of developing type 2 diabetes, independently of classical diabetes risk factors. In contrast, the use of contraceptive agents was associated with incident diabetes, but the influence of each type of contraception and of exposure duration remain to be investigated.

The midlife transition and the risk of cardiovascular disease and cancer Part I: magnitude and mechanisms

Heart disease and cancer are the leading causes of death in the United States. In women, the clinical appearance of both entities-coronary heart disease and cancer (breast, endometrium, and ovary)-escalate during the decades of the midlife transition encompassing the menopause. In addition to the impact of aging, during the interval between the age of 40 and 65 years, the pathophysiologic components of metabolic syndrome also emerge and accelerate. These include visceral adiposity (measured as waist circumference), hypertension, diabetes, and dyslipidemia. Osteoporosis, osteoarthritis, sarcopenia, depression, and even cognitive decline and dementia appear, and most, if not all, are considered functionally related. Two clinical reports confirm the interaction linking the emergence of disease: endometrial cancer and metabolic syndrome. One describes the discovery of unsuspected endometrial cancer in a large series of elective hysterectomies performed in aged and metabolically susceptible populations. The other is from the Women's Health Initiative Observational Study, which found a positive interaction between endometrial cancer and metabolic syndrome regardless of the presence or absence of visceral adiposity. Both provide additional statistical support for the long-suspected causal interaction among the parallel but variable occurrence of these common entities-visceral obesity, heart disease, diabetes, cancer, and the prevalence of metabolic syndrome. Therefore, 2 critical clinical questions require analysis and answers: 1: Why do chronic diseases of adulthood-metabolic, cardiovascular, endocrine-and, in women, cancers of the breast and endometrium (tissues and tumors replete with estrogen receptors) emerge and their incidence trajectories accelerate during the postmenopausal period when little or no endogenous estradiol is available, and yet the therapeutic application of estrogen stimulates their appearance? 2: To what extent should identification of these etiologic driving forces require modification of the gynecologist's responsibilities in the care of our patients in the postreproductive decades of the female life cycle? Part l of this 2-part set of "expert reviews" defines the dimensions, gravity, and interactive synergy of each clinical challenge gynecologists face while caring for their midlife (primarily postmenopausal) patients. It describes the clinically identifiable, potentially treatable, pathogenic mechanisms driving these threats to quality of life and longevity. Part 2 (accepted, American Journal of Obstetrics & Gynecology) identifies 7 objectives of successful clinical care, offers "triage" prioritization targets, and provides feasible opportunities for insertion of primary preventive care initiatives. To implement these goals, a reprogrammed, repurposed office visit is described.

Associations of Menstrual Cycle Characteristics Across the Reproductive Life Span and Lifestyle Factors With Risk of Type 2 Diabetes

IMPORTANCE

Menstrual cycle dysfunction is associated with insulin resistance, a key feature early in the pathogenesis of type 2 diabetes. However, the evidence linking irregular and long menstrual cycles with type 2 diabetes is scarce and inconsistent.

OBJECTIVES

To evaluate the associations between menstrual cycle characteristics at different points throughout a woman's reproductive life span and risk of type 2 diabetes and the extent to which this association is modified by lifestyle factors.

DESIGN, SETTING, AND PARTICIPANTS

This prospective cohort study included 75 546 premenopausal US female nurses participating in the Nurses' Health Study II from 1993 to June 30, 2017. Data analysis was performed from February 1 to December 30, 2019.

EXPOSURES

Self-reported usual length and regularity of menstrual cycles at the age ranges of 14 to 17 years, 18 to 22 years, and 29 to 46 years.

MAIN OUTCOMES AND MEASURES

Incident type 2 diabetes identified through self-report and confirmed by validated supplemental questionnaires.

RESULTS

Among the 75 546 women in the study at baseline, the mean (SD) age was 37.9 (4.6) years (range, 29.0-46.0 years). A total of 5608 participants (7.4%) had documented new cases of type 2 diabetes during 1 639 485 person-years of follow-up. After adjustment for potential confounders, women reporting always having irregular menstrual cycles between the age ranges of 14 to 17 years, 18 to 22 years, and 29 to 46 years were, respectively, 32% (95% CI, 22%-44%), 41% (95% CI, 23%-62%), and 66% (95% CI, 49%-84%) more likely to develop type 2 diabetes than women reporting very regular cycles (within 3-4 days of expected period) in the same age range. Similarly, women reporting a usual cycle length of 40 days or more between the age ranges of 18 to 22 years and 29 to 46 years were, respectively, 37% (95% CI, 19%-57%) and 50% (95% CI, 36%-65%) more likely to develop type 2 diabetes during follow-up compared with women reporting a usual cycle length of 26 to 31 days in the same age ranges. These associations appeared to be stronger among women with overweight or obesity, a low-quality diet, and low levels of physical activity. The relative excess risk of type 2 diabetes due to the interaction between irregular and long menstrual cycles and the overall unhealthy lifestyle score was 0.73 (95% CI, 0.57-0.89) and 0.68 (95% CI, 0.54-0.83), respectively.

CONCLUSIONS AND RELEVANCE

In this cohort study of US female nurses participating in the Nurses' Health Study II, irregular and long menstrual cycles throughout life were associated with a greater risk of type 2 diabetes, particularly among women with overweight or obesity, a low-quality diet, and low levels of physical activity.

Reproductive health in women with type 2 diabetes mellitus

As type 2 diabetes mellitus (T2DM) reaches epidemic proportions in the developed world and the age at diagnosis decreases, more women of reproductive age are being affected. In this article, we provide a synoptic view on potential mechanisms and relevant factors underlying menstrual cycle disorders and fertility issues in women with T2DM. The article discusses the function of the hypothalamic-pituitary-ovarian (HPO) axis, the central role of the hypothalamus in the homeostasis of this system, the central modulators of the axis, and the peripheral metabolic signals involved in neuroendocrine control of reproduction. The available literature on the relationship between T2DM and the female reproductive lifespan, menstrual cycle disorders, fertility issues, and gestational health in women with T2DM are also discussed. The data so far indicate that there is a "U-shaped" relationship between menarche, menopause, and T2DM, both early and late menarche/menopause being risk factors for T2DM. Hyperglycemia and its consequences may be responsible for the effects of T2DM on reproductive health in women, but the exact mechanisms are not as yet fully understood; thus, more studies are needed in order to identify factors causing disruption of the HPO axis.

Prolonged bisphenol-A exposure decreases endocrine pancreatic proliferation in response to obesogenic diet in ovariectomized mice

Research on the deleterious actions of bisphenol (BP)-A have focused on its effects on insulin secretion during pre/perinatal periods or adulthood. Estrogens also modulate endocrine pancreas physiology in females during aging; however, the effects of BPA on islet morphophysiology after menopause have not been investigated. We evaluated the effects of BPA exposure on glucose homeostasis and islet morphofunction in ovariectomized (OVX) mice fed on a high-fat diet (HFD). Adult Swiss female mice were underwent to bilateral ovariectomy, and with the confirmation of the establishment of surgical menopause, the females were then submitted, or not,to a normolipidic diet or HFD [control (CTL) and HFD groups, respectively] without or with 1 μg/mL BPA in their drinking water (CBPA and HBPA groups) for 90 days. HFD females displayed obesity, hyperglycemia, hyperinsulinemia, glucose intolerance and insulin resistance. BPA did not modulate HFD-induced obesity or body glucose impairments in HBPA females, and islets isolated from both the HFD and HBPA groups exhibited insulin hypersecretion. The HBPA islets, however, displayed enlarged islet cells and reduced proliferation, in association with the downregulation of mRNAs encoding PDX-1, NGN3 and CCND2 and upregulation of mRNAs encoding ER-β, GPR30, TNF-α and IL-1β in HBPA islets. BPA consumption in OVX mice impaired the islet-cell hyperplasia response to the HFD, partly mediated by increased expression of ER-β and GPR30, which impaired the expression of major genes involved in islet-cell survival and functionality. Together with higher pro-inflammatory cytokines expression in the islet milieu, these alterations may accelerate β-cell failure in postmenopause.

Association between reproductive years and insulin resistance in middle-aged and older women: A 10-year prospective cohort study

OBJECTIVES

We hypothesized that reproductive years, a marker of total estrogen exposure, may play an important role in insulin resistance.

STUDY DESIGN

A total of 3327 middle-aged and older women (age range 40-69 years) from the Korean Genome and Epidemiology Study were included in this large prospective cohort study with a mean follow-up of 10.8 years.

MAIN OUTCOME MEASURES

Insulin resistance and sensitivity were calculated using the homeostatic model assessment of insulin resistance (HOMA-IR) and quantitative insulin sensitivity check index (QUICKI). A linear mixed model for a repeated-measures covariance pattern with unstructured covariance within participants was used to assess longitudinal associations between baseline reproductive years and subsequent changes in HOMA-IR and QUICKI. Cox proportional hazards regression was used to estimate hazard ratios (HRs) and 95 % confidence intervals (CIs) for new-onset insulin resistance according to quartiles of reproductive years.

RESULTS

Changes in HOMA-IR were significantly greater in Q1 (fewest reproductive years) than in Q4 (most reproductive years) (beta[SE] = 0.038[0.016]; p-value = 0.022), while changes in QUICKI were significantly smaller in Q1 than in Q4 (beta[SE] = -0.001[0.000]; p-value = 0.048) after adjusting for possible confounders over time. Compared with Q1, HRs (95 % CIs) for the incidence of new-onset insulin resistance were 0.807 (0.654-0.994) for Q2, 0.793 (0.645-0.974) for Q3, and 0.770 (0.622-0.953) for Q4 after adjusting for possible confounders.

CONCLUSION

A short reproductive period is associated with elevated levels on the HOMA-IR and decreased levels on the QUICKI over time. The lowest quartile of reproductive years was significantly associated with a higher risk of new-onset insulin resistance.

Diabetes in Menopause: Risks and Management

The aim of this review is to present, critically appraise and qualitatively synthesize current evidence on the risk of type 2 diabetes mellitus (T2DM) development during menopause, the management of climacteric symptoms in women with T2DM and the management of T2DM in postmenopausal women. Menopause represents the end of reproductive life in women, as a result of ovarian aging. It is characterized by substantial decrease in the endogenous oestrogen concentrations and it is accompanied by alterations in body weight, adipose tissue distribution and energy expenditure, as well as insulin secretion, insulin sensitivity and activity that can predispose to the development of T2DM, independently of, and additively to, aging. Many women in midlife experience climacteric symptoms, including hot flushes and night sweats, resulting in an indication to receive Hormone Replacement Treatment (HRT). HRT has a favourable effect on glucose homeostasis both in women without and with T2DM. The latter was considered in the past as a cardiovascular disease (CVD) equivalent, which would suggest that women with the disease should not receive HRT. However, nowadays evidence exists to support an individualized approach of women based on their CVD risk, as some women with T2DM may be excellent candidates for HRT. Regarding T2DM management for women in menopause, lifestyle intervention, including diet and exercise, constitutes its cornerstone. However, most of these women will eventually require pharmacologic therapy. The most suitable agents should be selected according to their metabolic, cardiovascular and bone effects, taking into consideration the specific characteristics and comorbidities of each postmenopausal woman.

Cardiovascular Risk in Perimenopausal Women

Cardiovascular disease, and particularly coronary heart disease (CHD), has a low incidence in premenopausal women. Loss of ovarian hormones during the perimenopause and menopause leads to a sharp increase in incidence. Although most CHD risk factors are common to both men and women, the menopause is a unique additional risk factor for women. Sex steroids have profound effects on many CHD risk factors. Their loss leads to adverse changes in lipids and lipoproteins, with increases being seen in low density lipoprotein (LDL) cholesterol and triglycerides, and decreases in high density lipoprotein (HDL) cholesterol. There is a reduction in insulin secretion and elimination, but increases in insulin resistance eventually result in increasing circulating insulin levels. There are changes in body fat distribution with accumulation in central and visceral fat which links to the other adverse metabolic changes. There is an increase in the incidence of hypertension and of type 2 diabetes mellitus, both major risk factors for CHD. Oestrogens have potent effects on blood vessels and their loss leads to dysfunction of the vascular endothelium. All of these changes result from loss of ovarian function contributing to the increased development of CHD. Risk factor assessment in perimenopausal women is recommended, thereby permitting the timely introduction of lifestyle, hormonal and therapeutic interventions to modify or reverse these adverse changes.

Metabolic Syndrome During Menopause

The metabolic syndrome (MetS) comprises individual components including central obesity, insulin resistance, dyslipidaemia and hypertension and it is associated with an increased risk of cardiovascular disease (CVD) and type 2 diabetes mellitus (T2DM). The menopause per se increases the incidence of MetS in aging women. The effect(s) of menopause on individual components of MetS include: i) increasing central obesity with changes in the fat tissue distribution, ii) potential increase in insulin resistance, iii) changes in serum lipid concentrations, which seem to be associated with increasing weight rather than menopause itself, and, iv) an association between menopause and hypertension, although available data are inconclusive. With regard to the consequences of MetS during menopause, there is no consistent data supporting a causal relationship between menopause and CVD. However, concomitant MetS during menopause appears to increase the risk of CVD. Furthermore, despite the data supporting the association between early menopause and increased risk of T2DM, the association between natural menopause itself and risk of T2DM is not evident. However, the presence and the severity of MetS appears to be associated with an increased risk of T2DM. Although the mechanism is not clear, surgical menopause is strongly linked with a higher incidence of MetS. Interestingly, women with polycystic ovary syndrome (PCOS) have an increased risk of MetS during their reproductive years; however, with menopausal transition, the risk of MetS becomes similar to that of non-PCOS women.

Diabetes: a metabolic and reproductive disorder in women

Reproductive dysfunction is a common but little studied complication of diabetes. The spectrum of reproductive health problems in diabetes is broad, and encompasses delayed puberty and menarche, menstrual cycle abnormalities, subfertility, adverse pregnancy outcomes, and potentially early menopause. Depending on the age at diagnosis of diabetes, reproductive problems can manifest early on in puberty, emerge later when fertility is desired, or occur during the climacteric period. Historically, women with type 1 diabetes have frequently had amenorrhoea and infertility, due to central hypogonadism. With the intensification of insulin therapy and improved metabolic control, these problems have declined, but do persist. Additional reproductive implications of contemporary diabetes management are now emerging, including polycystic ovary syndrome and hyperandrogenism, which are underpinned by insulin action on the ovary. The sharp rise in type 2 diabetes incidence in youth suggests that more women of reproductive age will encounter diabetes-related reproductive problems in their lifetimes. With an ever increasing number of young women living with diabetes, clinicians need to be aware of and equipped for the challenges of navigating reproductive health concerns across the lifespan.

Association of puberty timing with type 2 diabetes: A systematic review and meta-analysis

BACKGROUND

Emerging studies have investigated the association between puberty timing, particularly age at menarche (AAM), and type 2 diabetes. However, whether this association is independent of adiposity is unclear. We aimed to systematically review published evidence on the association between puberty timing and type 2 diabetes (T2D) or impaired glucose tolerance (IGT), with and without adjustment for adiposity, and to estimate the potential contribution of puberty timing to the burden of T2D in the United Kingdom (UK).

METHODS AND FINDINGS

We searched PubMed, Medline, and Embase databases for publications until February 2019 on the timing of any secondary sexual characteristic in boys or girls in relation to T2D/IGT. Inverse-variance-weighted random-effects meta-analysis was used to pool reported estimates, and meta-regression was used to explore sources of heterogeneity. Twenty-eight observational studies were identified. All assessed AAM in women (combined N = 1,228,306); only 1 study additionally included men. In models without adjustment for adult adiposity, T2D/IGT risk was lower per year later AAM (relative risk [RR] = 0.91, 95% CI 0.89-0.93, p < 0.001, 11 estimates, n = 833,529, I2 = 85.4%) and higher for early versus later menarche (RR = 1.39, 95% CI 1.25-1.55, p < 0.001, 23 estimates, n = 1,185,444, I2 = 87.8%). Associations were weaker but still evident in models adjusted for adiposity (AAM: RR = 0.97 per year, 95% CI 0.95-0.98, p < 0.001, 12 estimates, n = 852,268, I2 = 51.8%; early menarche: RR = 1.19, 95% CI 1.11-1.28, p < 0.001, 21 estimates, n = 890,583, I2 = 68.1%). Associations were stronger among white than Asian women, and in populations with earlier average AAM. The estimated population attributable risk of T2D in white UK women due to early menarche unadjusted and adjusted for adiposity was 12.6% (95% CI 11.0-14.3) and 5.1% (95% CI 3.6-6.7), respectively. Findings in this study are limited by residual and unmeasured confounding, and self-reported AAM.

CONCLUSIONS

Earlier AAM is consistently associated with higher T2D/IGT risk, independent of adiposity. More importantly, this research has identified that a substantial proportion of T2D in women is related to early menarche, which would be expected to increase in light of global secular trends towards earlier puberty timing. These findings highlight the need to identify the underlying mechanisms linking early menarche to T2D/IGT risk.

Type 2 Diabetes Mellitus and Menopausal Hormone Therapy: An Update

During menopausal transition, various phenotypical and metabolic changes occur, affecting body weight, adipose tissue distribution and energy expenditure as well as insulin secretion and sensitivity. Taken together, these can predispose women to the development of type 2 diabetes mellitus (T2DM). Many women in midlife experience climacteric symptoms, including hot flashes and night sweats. Menopausal hormone therapy (MHT) is then indicated. MHT has a favourable effect on glucose homeostasis in both women without and with T2DM. T2DM was considered in the past as a cardiovascular disease (CVD) equivalent, which would suggest that women with T2DM should not receive MHT. This notion may still deter many clinicians from prescribing MHT to these patients. However, nowadays there is strong evidence to support an individualised approach after careful evaluation of CVD risk. In older women with T2DM (> 60 years old or > 10 years in menopause), MHT should not be initiated, because it may destabilise mature atherosclerotic plaques, resulting in thrombotic episodes. In obese women with T2DM or in women with moderate CVD risk, transdermal 17β-oestradiol could be used. This route of delivery presents beneficial effects regarding triglyceride concentrations and coagulation factors. In peri- or recently post-menopausal diabetic women with low risk for CVD, oral oestrogens can be used, since they exhibit stronger beneficial effects on glucose and lipid profiles. In any case, a progestogen with neutral effects on glucose metabolism should be used, such as natural progesterone, dydrogesterone or transdermal norethisterone. The goal is to maximise benefits and minimise adverse effects.

Sex and Gender Driven Modifiers of Alzheimer's: The Role for Estrogenic Control Across Age, Race, Medical, and Lifestyle Risks

Research indicates that after advanced age, the major risk factor for late-onset Alzheimer’s disease (AD) is female sex. Out of every three AD patients, two are females with postmenopausal women contributing to over 60% of all those affected. Sex- and gender-related differences in AD have been widely researched and several emerging lines of evidence point to different vulnerabilities that contribute to dementia risk. Among those being considered, it is becoming widely accepted that gonadal steroids contribute to the gender disparity in AD, as evidenced by the “estrogen hypothesis.” This posits that sex hormones, 17β-estradiol in particular, exert a neuroprotective effect by shielding females’ brains from disease development. This theory is further supported by recent findings that the onset of menopause is associated with the emergence of AD-related brain changes in women in contrast to men of the same age. In this review, we discuss genetic, medical, societal, and lifestyle risk factors known to increase AD risk differently between the genders, with a focus on the role of hormonal changes, particularly declines in 17β-estradiol during the menopause transition (MT) as key underlying mechanisms.

Premature ovarian failure and tissue engineering

Premature ovarian failure (POF) usually happens former to the age of 40 and affects the female physiological state premenopausal period. In this condition, ovaries stop working long before the expected menopausal time. Of diagnostic symptoms of the disease, one can mention amenorrhea and hypoestrogenism. The cause of POF in most cases is idiopathic; however, cancer therapy may also cause POF. Commonly utilized therapies such as hormone therapy, in-vitro activation, and regenerative medicine are the most well-known treatments for POF. Hence, these therapies may be associated with some complications. The aim of the present study is to discuss the beneficial effects of tissue engineering for fertility rehabilitation in patients with POF as a newly emerging therapy.

Multiple pregnancies and the risk of diabetes mellitus in postmenopausal women

OBJECTIVE

We aimed to investigate whether the number of pregnancies during childbearing age was associated with diabetes in postmenopausal women with no history of gestational diabetes.

METHODS

Our data source was the continuous National Health and Nutrition Examination Survey 1999 to 2014. We selected 9,138 postmenopausal women over 40 years old who did not have a history of gestational diabetes during pregnancy. Logistic regression analyses were applied for the association of the number of pregnancies with diabetes.

RESULTS

We found women with ≥4 pregnancies had significantly greater fasting plasma glucose (FPG), glycated hemoglobin (HbA1c), 2-hour plasma glucose, and the Homeostatic Model Assessment of Insulin Resistance than those with two to three pregnancies (all P < 0.01). These women also had a significantly higher prevalence of diabetes (28.4% vs 20.7%; P < 0.001). Using the two to three pregnancies group as the reference, we observed a positive association of log-FPG and log-HbA1c with 4 or more pregnancies after adjustment for sociodemographic, lifestyle, and reproductive factors, and body mass index (both P < 0.05). Compared to women with two to three pregnancies, the odds ratios for diabetes were 1.31 (95% confidence interval [CI] 1.01-1.71) for women who never got pregnant and 1.28 (95% CI 1.10-1.48) for those with at least 4 pregnancies after multivariate adjustment.

CONCLUSIONS

At least 4 pregnancies through childbearing age may be a potential risk factor for diabetes in postmenopausal women without a history of gestational diabetes.

Association of age at menopause and type 2 diabetes: A systematic review and dose-response meta-analysis of cohort studies

AIMS

Early age at menopause has been associated with increased incidence of type 2 diabetes mellitus (T2DM), but the quantitative association between age at menopause and T2DM was unclear. We performed a meta-analysis to assess the dose-response association between age at menopause and T2DM.

METHODS

PubMed, Embase and Web of Science were searched up to January 5, 2019 for cohort studies that evaluated the association of age at menopause and risk of T2DM. Relative risks (RRs) and 95% confidence intervals (95% CIs) were pooled by using the random-effects models. Restricted cubic spline model was used to evaluate the liner or nonlinear relation.

RESULTS

We identified 6 studies for the meta-analysis (267,284 women and 19,654 cases of T2DM). The pooled RR was 0.64 (95% CI 0.44-0.94) comparing the latest with the earliest category of age at menopause. The risk of T2DM was reduced by 10% (RR=0.90, 95% CI, 0.84-0.98) with each 5-year increment in age at menopause. We found an inverse linear association between age at menopause and T2DM.

CONCLUSIONS

Our results suggest that later age at menopause was associated with lower risk of T2DM.

Association Between Age at Natural Menopause and Risk of Type 2 Diabetes in Postmenopausal Women With and Without Obesity

OBJECTIVE

The relationship between age at natural menopause and type 2 diabetes mellitus (T2DM) has yielded conflicting results, particularly when confounded by the presence of obesity. We therefore aimed to examine the association between age at natural menopause and development of T2DM and the influence of postmenopausal obesity status on this association.

DESIGN

The data for this study was derived from one center (Beijing) of the REACTION study. After screening through our inclusion and exclusion criteria, 2689 postmenopausal women who completed a 3-year follow-up were included. Logistic regression analysis was conducted to clarify the association of the age at natural menopause with the development of T2DM.

RESULTS

After adjustment for potential confounders, there was no significant association between the age at natural menopause and development of T2DM for all subjects. However, when subjects were stratified along the postmenopausal obesity status at baseline, in the presence or absence of obesity, we found a surprising contradictory association in two subgroups: late menopause (age >50 years) was associated with an increased risk (OR, 1.45; 95% CI, 1.02 to 2.05) of developing T2DM in the postmenopausal group without obesity, whereas we found a reduced risk (OR, 0.43; 95% CI, 0.27 to 0.71) in the postmenopausal group with obesity. Moreover, we found that early menopausal women (age ≤45 years) with postmenopausal obesity had the highest risk (OR, 2.10; 95% CI, 1.11 to 4.00) of developing T2DM compared with all other postmenopausal women.

CONCLUSIONS

Postmenopausal obesity status may influence the association of age at natural menopause and the development of T2DM.

Mediation analysis in a case-control study when the mediator is a censored variable

Mediation analysis is an approach for assessing the direct and indirect effects of an initial variable on an outcome through a mediator. In practice, mediation models can involve a censored mediator (eg, a woman's age at menopause). The current research for mediation analysis with a censored mediator focuses on scenarios where outcomes are continuous. However, the outcomes can be binary (eg, type 2 diabetes). Another challenge when analyzing such a mediation model is to use data from a case-control study, which results in biased estimations for the initial variable-mediator association if a standard approach is directly applied. In this study, we propose an approach (denoted as MAC-CC) to analyze the mediation model with a censored mediator given data from a case-control study, based on the semiparametric accelerated failure time model along with a pseudo-likelihood function. We adapted the measures for assessing the indirect and direct effects using counterfactual definitions. We conducted simulation studies to investigate the performance of MAC-CC and compared it to those of the naïve approach and the complete-case approach. MAC-CC accurately estimates the coefficients of different paths, the indirect effects, and the proportions of the total effects mediated. We applied the proposed and existing approaches to the mediation study of genetic variants, a woman's age at menopause, and type 2 diabetes based on a case-control study of type 2 diabetes. Our results indicate that there is no mediating effect from the age at menopause on the association between the genetic variants and type 2 diabetes.

Menstrual and reproductive factors and type 2 diabetes risk: The Japan Public Health Center-based Prospective Study

AIMS/INTRODUCTION

Menstrual and reproductive factors, including age at menarche, parity and breast-feeding, have been linked to type 2 diabetes risk. We prospectively investigated the association between these factors and type 2 diabetes risk in a large Japanese cohort.

MATERIALS AND METHODS

Participants were 37,511 women aged 45-75 years who participated in the baseline (1990-1993), second (1995-1998) and third surveys (2000-2003) of the Japan Public Health Center-based Prospective Study, and who had no history of diabetes at the second survey. Menstrual and reproductive history was ascertained using questionnaires at the baseline and second surveys. Odds ratios of self-reported, physician-diagnosed type 2 diabetes over the 5-year period from the second survey were estimated using logistic regression.

RESULTS

At the third survey, 513 new cases of type 2 diabetes were self-reported. The odds ratios of type 2 diabetes tended to increase with the number of parity, after adjustment for covariates other than body mass index (P for trend = 0.029). The multivariable-adjusted odds ratios of type 2 diabetes for women with three or more births was 1.56 (95% confidence interval 0.96-2.53) compared with those who were nulliparous. The association between parity and type 2 diabetes risk was attenuated after additional adjustment for body mass index (P for trend = 0.12). No factors other than parity were significantly associated with type 2 diabetes risk.

CONCLUSIONS

Higher parity might be associated with an increased risk of type 2 diabetes among Japanese women, partly through increasing bodyweight.