Diabetes and Menopause

The complementary roles of iron and estrogen in menopausal differences in cardiometabolic outcomes

Biological hormonal changes are frequently cited as an explanatory factor of sex and menopause differences in cardiometabolic diseases (CMD) and its associated risk factors. However, iron metabolism which varies between sexes and among women of different reproductive stages could also play a role. Recent evidence suggest that iron may contribute to CMD risk by modulating oxidative stress pathways and inflammatory responses, offering insights into the mechanistic interplay between iron and CMD development. In the current review, we provide a critical appraisal of the existing evidence on sex and menopausal differences in CMD, discuss the pitfall of current estrogen hypothesis as sole explanation, and the emerging role of iron in CMD as complementary pathway. Prior to menopause, body iron stores are lower in females as compared to males, but the increase during and after menopause, is tandem with an increased CMD risk. Importantly, basic science experiments show that an increased iron status is related to the development of type 2 diabetes (T2D), and different cardiovascular diseases (CVD). While epidemiological studies have consistently reported associations between heme iron intake and some iron biomarkers such as ferritin and transferrin saturation with the risk of T2D, the evidence regarding their connection to CVD remains controversial. We delve into the factors contributing to this inconsistency, and the limitation of relying on observational evidence, as it does not necessarily imply causation. In conclusion, we provide recommendations for future studies on evaluating the potential role of iron in elucidating the sex and menopausal differences observed in CMD.

Effect of fasting glucose levels on carotid intima-media thickness in premenopausal versus postmenopausal women

Objective

To investigate the relationship between fasting blood glucose (FBG) and carotid intimamedia thickness (IMT) in premenopausal and postmenopausal women.

Subjects and methods

The study enrolled 2,959 women seen at the Maanshan People's Hospital of Anhui Province from December 2013 to December 2018. Carotid IMT was measured using Doppler ultrasound. Linear regression and R smoothing curves were used to analyze the relationship between blood glucose level and carotid IMT in the premenopausal and postmenopausal groups.

Results

Postmenopausal compared with premenopausal women had higher mean IMT (mIMT; 0.81 ± 0.23 mm versus 0.70 ± 0.14 mm, respectively, p < 0.001) and maximum IMT (maxIMT; 0.86 ± 0.35 mm versus 0.74 ± 0.16 mm, respectively, p < 0.001) values. On linear regression analysis, mIMT values increased with increasing FBG values when FBG level was ≤ 7 mmol/L, but no significance was found between FBG and maxIMT. After stratification by menopausal status, mIMT and maxIMT increased with increasing FBG when FBG was ≤ 7 mmol/L in the premenopausal group. In the postmenopausal group, mIMT and maxIMT increased with increasing FBG. After adjustment for covariate factors, the relationship between FBG and mIMT remained the same as before the adjustment, but when FBG was ≤ 11 mmol/L, the maxIMT increased with increasing FBG. In the stratification analysis, maxIMT increased with increasing FBG when FBG was ≤ 7 mmol/L in the premenopausal group, while both mIMT and maxIMT increased with increasing FBG when FBG was > 10 mmol/L in the postmenopausal group.

Conclusion

Levels of FBG contributed more to increased IMT in postmenopausal than premenopausal women. The influence of FBG was greater on maxIMT than mIMT. Additionally, FBG was helpful in assessing focal thickening of the carotid intima.

Sex Hormones and Diabetes in 45- to 74-year-old Men and Postmenopausal Women: The Hispanic Community Health Study

Previous studies demonstrated associations of endogenous sex hormones with diabetes. Less is known about their dynamic relationship with diabetes progression through different stages of the disease, independence of associations, and role of the hypothalamic-pituitary gonadal axis. The purpose of this analysis was to examine relationships of endogenous sex hormones with incident diabetes, prediabetes, and diabetes traits in 693 postmenopausal women and 1015 men aged 45 to 74 years without diabetes at baseline participating in the Hispanic Community Health Study/Study of Latinos and followed for 6 years. Baseline hormones included estradiol, luteinizing hormone (LH), follicle stimulating hormone (FSH), sex hormone-binding globulin (SHBG), dehydroepiandrosterone sulfate (DHEAS), and, in men, testosterone and bioavailable testosterone. Associations were analyzed using multivariable Poisson and linear regressions. In men, testosterone was inversely associated with conversion from prediabetes to diabetes (incidence rate ratio [IRR] for 1 SD increase in testosterone: 0.821; 95% CI, 0.676, 0.997; P = 0.046), but not conversion from normoglycemia to prediabetes. Estradiol was positively associated with increase in fasting insulin and homeostatic model assessment of insulin resistance. In women, SHBG was inversely associated with change in glycosylated hemoglobin, postload glucose, and conversion from prediabetes to diabetes (IRR = 0.62; 95% CI, 0.44, 0.86, P = 0.005) but not from normoglycemia to prediabetes. Relationships with other hormones varied across glycemic measures. Stronger associations of testosterone and SHBG with transition from prediabetes to diabetes than from normoglycemic to prediabetes suggest they are operative at later stages of diabetes development. Biologic pathways by which sex hormones affect glucose homeostasis await future studies.

Sex difference in the associations among risk factors with depression in a large Taiwanese population study

Background

Depression is a common psychiatric health issue affecting an estimated 5% of adults worldwide, and it can lead to disability and increased economic burden. Consequently, identifying the factors associated with depression as early as possible is a vital issue. The aim of this study was to explore these associations in a large cohort of 121,601 Taiwanese participants in the Taiwan Biobank, and also to identify sex differences in the associations.

Methods

The study cohort included 77,902 women and 43,699 men (mean age, 49.9 ± 11.0 years), who were further classified into those with depression (n = 4,362; 3.6%) and those without depression (n = 117,239; 96.4%).

Results

The results of multivariable analysis showed that female sex (vs. male sex; odds ratio = 2.578; 95% confidence interval = 2.319–2.866; p &lt; 0.001) was significantly associated with depression. Older age, diabetes mellitus (DM), hypertension, low systolic blood pressure (SBP), smoking history, living alone, low glycated hemoglobin (HbA1c), high triglycerides, and low uric acid were significantly associated with depression in the men. In the women, older age, DM, hypertension, low SBP, smoking history, alcohol history, education level of middle and high school (vs. lower than elementary school), living alone, high body mass index (BMI), menopause, low HbA1c, high triglycerides, high total cholesterol, low estimated glomerular filtration rate (eGFR), and low uric acid were significantly associated with depression. Further, there were significant interactions between sex and DM (p = 0.047), smoking history (p &lt; 0.001), alcohol use (p &lt; 0.001), BMI (p = 0.022), triglyceride (p = 0.033), eGFR (p = 0.001), and uric acid (p = 0.004) on depression.

Conclusion

In conclusion, our results showed sex differences in depression, and the women were significantly associated with depression compared to men. Furthermore, we also found sex differences among the risk factors associated with depression.

Chronotype and Sleep Quality in Obesity: How Do They Change After Menopause?

PURPOSE OF REVIEW

This review primarily provides an overview of the current evidence on chronotype (which reflects an individual's preference for the timing of sleeping, eating, and activity in a 24-h period) and sleep quality changes in obesity in postmenopausal women. It also explores possible nutritional strategies to manage these changes in this phase of a woman's life.

RECENT FINDINGS

Menopause is a life stage frequently associated with sleep disturbances and changes in circadian rhythms. Sleep disturbances are one of the main symptoms of menopause and are caused by several factors such as hormonal changes, obesity, and melatonin reduction. In addition, the chronotype also changes following menopause. Nutritional strategies are essential because they could help manage menopausal sleep disturbances and circadian misalignment, particularly by tackling obesity and overweight. In the management of postmenopausal women, especially those experiencing obesity, careful assessment of sleep disturbances and chronotype and subsequent development of the most appropriate treatment, including nutritional management, should be part of the treatment routine.

Association between Reproductive Factors and Type 2 Diabetes: A Cross-Sectional Study

(1) Introduction: The available studies on the association between type 2 diabetes mellitus (T2DM) and menopause report conflicting results. (2) Objective: This study aimed to investigate the association of menopausal status, age at menopause, and length of the reproductive period with T2DM. (3) Methods: This cross-sectional study is part of the ‘China Eastern Cohort Study’, which is a community-based cohort study. Multistage, stratified, clustered sampling was used to recruit the study participants in Shanghai, China. Age at menarche and menopause was recorded, and reproductive period was calculated. Weighted logistic regression was used to calculate the prevalence ratios (PRs) with 95% confidence intervals (CIs) of T2DM. Restricted cubic splines were used to assess the relationship between age at menopause, reproductive period, and T2DM. (4) Results: A total of 20,128 women were included. The prevalence of T2DM was 13.7%. Postmenopausal women exhibited a higher prevalence of T2DM than premenopausal women (p < 0.001) and an unfavorable metabolic profile, including higher body mass index, hypertension, and hyperlipidemia. A higher risk of T2DM was observed in postmenopausal women (PR2.12, 95%CI: 1.79–2.51, p < 0.001) compared with premenopausal women, independently of confounding factors. After adjustment for confounding factors, age at menopause and reproductive period were not significantly associated with T2DM. (5) Conclusions: Postmenopausal status is associated with T2DM, while menopausal age and reproductive period are not associated with T2DM. Menopausal status should be considered during T2DM screening.

Menopausal status, age and management among women living with HIV in the UK

BACKGROUND

There is currently little evidence exploring menopausal status, age at last menstrual period (LMP) and management of menopause among women living with HIV aged 45-60 years in England.

METHODS

Socio-demographic, lifestyle and clinical data were collected through a self-completed cross-sectional survey. Longitudinal CD4 count and viral load data were available from linkage to clinical records, if consent was provided. Women were categorised as pre-, peri- or post-menopausal. Factors associated with menopausal stage were examined using ordinal logistic regression adjusting for age. Age at LMP was estimated using Kaplan-Meier survival analysis.

RESULTS

The 847 women had a median age of 49 [interquartile range (IQR): 47-52] years. Most were of black ethnicity (81.3%), were born outside the UK (85.0%) and had completed secondary education (88.7%); 177 (20.4%), 373 (43.0%) and 297 (34.2%) were pre-, peri- or post-menopausal, respectively. After adjusting for age, associations of menopausal status with non-cohabiting relationship [adjusted odds ratio = 0.63 (95% confidence interval: 0.43-0.91)], baseline viral load ≥ 100 000 copies/mL [2.67 (1.20-5.94)] and unemployment [1.34 (0.97-1.84)] remained significant. Median (IQR) age at LMP was 54 (51-55) years in the group. In total, 27.9% (233/836) of women reported severe menopausal symptoms; 45.6% of those with somatic symptoms had heard of hormone replacement therapy and 8.7% had used it. Only 5.6% of women with urogenital symptoms had used topical oestrogen.

CONCLUSIONS

Our findings highlight the importance of educating both women and their healthcare providers about menopausal symptoms and management options.

Selective ER-β agonists alleviate neuronal deficits in insulin-resistant estrogen-deficient rats

OBJECTIVE

The present study aimed to determine the effect of estrogen receptor (ER) agonists on depression and memory impairment in insulin-resistant ovariectomized (OVX) rats.

METHODS

Rats underwent bilateral ovariectomy, and low-dose streptozotocin (STZ) and a high-fat diet (58% fat, 25% protein, and 17% carbohydrates as a percentage of kilocalories) were administered to induce an estrogen-deficient insulin-resistant state. After 1 week of STZ administration, rats were treated with 17β-estradiol (17βE2) and selective ER-α (propylpyrazoletriol) and ER-β (diarylpropionitrile) agonists (10 μg/kg subcutaneously). Memory was evaluated using the Morris water maze and depression using the forced swim test.

RESULTS

Treatment with selective ER-β agonist and 17βE2 but not with selective ER-α agonist significantly modulated the neurobehavioral deficits in insulin-resistant OVX rats. These neurobehavioral parameters were further correlated with brain-derived neurotrophic factor (BDNF) levels and acetylcholinesterase (AChE) activity. Selective ER-β agonist and 17βE2 significantly modulated BDNF levels and AChE activity in insulin-resistant OVX rats. Significant increases in estradiol and uterine weight were observed in 17βE2-treated rats, but selective ER agonists did not show any effect.

CONCLUSION

ER-β agonist can be an effective strategy for the mitigation of memory loss and depression in an estrogen-deficient insulin-resistant state without all of the deleterious feminizing effects that occur with the use of 17βE2.

Precision hormone therapy: identification of positive responders

Since the introduction of menopausal hormone therapy (MHT) in the 1940s, randomized clinical trials and observational studies have been performed to determine the benefits and risks of MHT. However, MHT therapeutic impact remains under debate as multiple factors including genetic biomarkers and medical history contribute to inter-individual variations in neurodegenerative diseases. Herein, we review the characteristics of women who participated in clinical studies and methodological approaches for study analyses to assess the critical variables influencing an association between MHT and risk of neurodegenerative diseases. Outcomes of the review indicated that: (1) observational studies assessed outcomes of MHT in symptomatic women whereas MHT clinical trials were conducted in asymptomatic postmenopausal women not treated for menopausal symptoms, (2) in asymptomatic postmenopausal women, late MHT intervention was of no benefit, (3) different MHT treatments and regimens between observational studies and clinical trials may impact outcomes, and (4) observational studies may provide greater predictive validity for long-term neurological health outcomes as MHT was introduced in symptomatic women and administered over a long period of time. Going forward, achieving precision hormone therapy will require a priori identification of symptomatic women appropriate for MHT and the type and dose of MHT appropriate for their genetic profile and health risks.

Diabetes mellitus risk after hysterectomy: A population-based retrospective cohort study

We explored whether hysterectomy with or without bilateral oophorectomy was associated with the increasing incidence of diabetes mellitus (DM) in an East Asian population. This was a retrospective population-based cohort study that analyzed DM risk in Taiwanese women, using a health insurance research database of 1998 to 2013 containing nearly 1 million people. We identified 7088 women aged 30 to 49 years who had undergone hysterectomy with or without oophorectomy. The comparison group included 27,845 women without a hysterectomy who were randomly selected from the population and matched to women in the hysterectomy group by age (exact year) and year of the surgery. DM comorbidities were identified. The incidence and hazard ratios for DM were calculated with Cox proportional hazard regression models. The median ages of patients in the hysterectomy and comparison groups were both approximately 44 years. After a median 7.1 years of follow-up, the incidence of DM was 40% higher in the hysterectomized women as compared with the comparisons (9.12 vs 6.78/1000 person-years, P < .001), with an adjusted hazard ratio (aHR) of 1.37 (95% confidence interval [CI] = 1.23 -1.52). However, the DM risk was not increased in the women with hysterectomy plus oophorectomy (aHR=1.28, 95% CI = 0.93-1.76). Furthermore, among women aged 30 to 39 years, 40 to 49 years, the risk in hysterectomized women was higher than the comparisons (aHR = 1.75, 95% CI = 1.27-2.41; aHR = 1.33, 95% CI = 1.19-1.49, respectively). Our study provides essential and novel evidence for the association between hysterectomy and DM risk in women aged 30 to 49 years, which is relevant to these women and their physicians. Physicians should be aware of the increased DM risk associated with hysterectomy and take this into consideration when evaluating a patient for a hysterectomy. The current results might help gynecologists prevent DM and encourage diagnostic and preventive interventions in appropriate patients.

An Appraisal of the Role of Previously Reported Risk Factors in the Age at Menopause Using Mendelian Randomization

Objective

Menopause at a young age is associated with many health problems in women, including osteoporosis, depressive symptoms, coronary disease, and stroke. Many traditional observational studies have reported some potential risk factors for early menopause but have drawn different conclusions. This inconsistency can be attributed mainly to unmodified confounding factors. Identifying the factors causally associated with age at menopause is important for early intervention in women with abnormal menopause timing, and for improving the quality of life for postmenopausal women. This study aims to appraise whether the previously reported risk factors are causally associated with early age at natural menopause (ANM) susceptibility.

Methods

We used Mendelian randomization, a statistical method wherein genetic variants are used to determine whether an observational association between a risk factor and an outcome is consistent with a causal effect.

Results

Women with earlier age at menarche (β = 0.34, se = 0.16, p = 0.035), lower education level (β = 1.19, se = 0.41, p = 0.004) and higher body mass index (β = −0.05, se = 0.02, p = 0.027) had greater risk for early ANM. The causal link between early age at menarche and early ANM was replicated using ReproGen consortium data (β = 0.23, se = 0.07, p = 0.001). However, a current smoking habit, one of previously reported risk factors, was less likely to be correlated causally with early ANM, suggesting that previous observational studies may not have sufficiently adjusted for confounders.

Conclusion

Our results help to identify the risk factors of ANM via a genetics approach and future research into the biological mechanism could further help with targeted prevention for early menopause.

Differential ESR1 Promoter Methylation in the Peripheral Blood-Findings from the Women 40+ Healthy Aging Study

Background Estrogen receptor α (ERα) contributes to maintaining biological processes preserving health during aging. DNA methylation changes of ERα gene (ESR1) were established as playing a direct role in the regulation of ERα levels. In this study, we hypothesized decreased DNA methylation of ESR1 associated with postmenopause, lower estradiol (E2) levels, and increased age among healthy middle-aged and older women. Methods We assessed DNA methylation of ESR1 promoter region from dried blood spots (DBSs) and E2 from saliva samples in 130 healthy women aged 40-73 years. Results We found that postmenopause and lower E2 levels were associated with lower DNA methylation of a distal regulatory region, but not with DNA methylation of proximal promoters. Conclusion Our results indicate that decreased methylation of ESR1 cytosine-phosphate-guanine island (CpGI) shore may be associated with conditions of lower E2 in older healthy women.

Estrogen regulates sex-specific localization of regulatory T cells in adipose tissue of obese female mice

Regulatory T cells (Treg) play essential roles in maintaining immune homeostasis. Resident Treg in visceral adipose tissue (VAT-Treg) decrease in male obese mice, which leads to the development of obesity-associated chronic inflammations and insulin resistance. Although gender differences in immune responses have been reported, the effects of the difference in metabolic environment on VAT-Treg are unclear. We investigated the localization of VAT-Treg in female mice in comparison with that in male mice. On a high-fat diet (HFD), VAT-Treg decreased in male mice but increased in female mice. The increase was abolished in ovariectomized and HFD-fed mice, but was restored by estrogen supplementation. The IL33 receptor ST2, which is important for the localization and maturation of VAT-Treg in males, was reduced in CD4⁺CD25⁺ T cells isolated from gonadal fat of obese mice of both genders, suggesting that a different system exists for VAT-Treg localization in females. Extensive analysis of chemokine expression in gonadal fat and adipose CD4⁺CD25⁺T cells revealed several chemokine signals related to female-specific VAT-Treg accumulation such as CCL24, CCR6, and CXCR3. Taken together, the current study demonstrated sexual dimorphism in VAT-Treg localization in obese mice. Estrogen may attenuate obesity-associated chronic inflammation partly through altering chemokine-related VAT-Treg localization in females.

Infertility, Gravidity, and Risk Of Diabetes among High-Risk Women in the Diabetes Prevention Program Outcomes Study

OBJECTIVE

The extent to which infertility and pregnancy independently increase risk of diabetes and subclinical atherosclerosis is not known.

RESEARCH DESIGN AND METHODS

We conducted a secondary analysis of Diabetes Prevention Program (DPP) and the DPP Outcomes Study over a 15-year period. We included women who answered questions about gravidity and infertility at baseline (n = 2085). Infertility was defined as > 1 year of unsuccessful attempts to conceive; thus, women could have histories of infertility as well as pregnancy. Risk of diabetes associated with gravidity and infertility was calculated using Cox proportional hazards models adjusting for age, race/ethnicity, treatment arm, body mass index, and pregnancy during the study. Among women who underwent assessment of coronary artery calcification (CAC) (n = 1337), odds of CAC were calculated using logistic regression models with similar covariates.

RESULTS

Among premenopausal women (n = 1075), women with histories of pregnancy and infertility (n = 147; hazard ratio [HR] 1.80; 95% confidence interval [CI] 1.30, 2.49) and women with histories of pregnancy without infertility (n = 736; HR 1.49; 95% CI 1.15, 1.93) had greater diabetes risk than nulligravid women without infertility (n = 173). Premenopausal nulligravid women with histories of infertility had a non-significant elevation in risk, although the number of these women was small (n = 19; HR 1.63; 95% CI 0.88, 3.03). Associations were not observed among postmenopausal women (n = 1010). No associations were observed between infertility or pregnancy with CAC.

CONCLUSIONS

Pregnancy, particularly combined with a history of infertility, confers increased risk of diabetes but not CAC among glucose-intolerant premenopausal women.

Daily watermelon consumption decreases plasma sVCAM-1 levels in overweight and obese postmenopausal women

Postmenopausal status is associated with an increase in total and abdominal body fat as well as increased incidence of insulin resistance and cardiovascular disease. The purpose of this study was to determine if watermelon supplementation affects select systemic markers of atherosclerosis and measures of insulin resistance in overweight and obese postmenopausal women. We hypothesized that overweight and obese postmenopausal women consuming 100% watermelon puree daily for 6 weeks would have improved levels of select systemic markers connected with cardiovascular disease without changing markers of insulin resistance. To test this hypothesis, overweight and obese postmenopausal women were recruited to participate in this study. Participants were randomly assigned to either the control group (no intervention) or the watermelon puree group (WM) for 6 weeks. Plasma concentration of markers connected with atherosclerosis and glycemic control were measured pre- and poststudy. A significant 6% decrease in soluble vascular cell adhesion molecule-1 occurred pre- to poststudy in WM, P = .003. The pattern of change in fasting blood glucose (P = .633), insulin (P = .158), and homeostatic model assessment-estimated insulin resistance (P = .174) did not differ between groups. Pre- to poststudy increases were measured in the fasting plasma concentration of l-arginine (8%, P = .005), cis-lycopene (32%, P = .003), and trans-lycopene (42%, P = .003) in WM. We conclude that 6 weeks of watermelon supplementation improved soluble vascular cell adhesion molecule-1 levels, a marker connected to atherogenesis, independent of changes in body composition or glycemic control.

Inverse association between physical activity and blood glucose is independent of sex, menopause status and first-degree family history of diabetes

AIMS/INTRODUCTION

Exercise training is a recognized strategy central to the prevention, treatment, and management of diabetes and prediabetes. The aim of the present study was to investigate the association between physical activity and blood glucose, as well as the influence of sex, menopause status and family history of diabetes.

MATERIALS AND METHODS

Participants with normal weight were selected from Risk Evaluation of Cancers in Chinese Diabetic Individuals: A Longitudinal Study, and divided into inactive (moderate-to-vigorous-intensity physical activity [MVPA] <30 min/week), low-degree (MVPA ≥30 and ≤420 min/week) and high-degree (MVPA >420 min/week) activity groups.

RESULTS

A total of 2,601 individuals with an average age of 57.85 ± 8.39 years were enrolled. Multivariate anova uncovered that after adjustment for sex and menopause status, and family history of diabetes, respectively, fasting plasma glucose, 2-h plasma glucose and glycated hemoglobin A1c decreased through inactive, low-degree and high-degree activity groups (all P for trend <0.05). The association of blood glucose indexes with physical activity was independent of this association with sex and menopause status, and first-degree family history of diabetes, respectively. Multivariate linear regression analyses showed that MVPA was an independent factor associated negatively with fasting plasma glucose, 2-h plasma glucose and glycated hemoglobin A1c, respectively (all P < 0.01).

CONCLUSIONS

A higher degree of physical activity was associated with lower blood glucose regardless of sex, menopause status and first-degree family history of diabetes. MVPA is a negative factor associated with blood glucose independently. Physical activity of adequate duration and intensity is strongly recommended to individuals with susceptibility to diabetes as a result of sex and family history, but without overweight/obesity.

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.

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.

Sleep, Health, and Metabolism in Midlife Women and Menopause: Food for Thought

Sleep and metabolism are essential components of health. Metabolic health depends largely on individual's lifestyle. Disturbances in sleep health, such as changes in sleep patterns that are associated with menopause/reproductive aging and chronologic aging, may have metabolic health consequences. Sleep restriction and age-related changes in sleep and circadian rhythms may influence changes in appetite and reproductive hormones, energy expenditure, and body adiposity. In this article, the authors describe how menopause-related sleep disturbance may affect eating behavior patterns, immunometabolism, immunometabolic dysfunction, and associations between sleep and metabolic outcomes.

Low grip strength predicts incident diabetes among mid-life women: the Michigan Study of Women's Health Across the Nation

Background

skeletal muscle is the primary site of glucose uptake, yet the impact of age-related changes in muscle strength on diabetes risk is unknown.

Methods

four hundred and twenty-four participants (60% Black, 40% White) from the Michigan site of the Study of Women's Health Across the Nation contributed annual grip strength measures and were followed from 1996 to 2012 to identify incident cases of diabetes. Diabetes was defined as self-reported physician-diagnosed diabetes, use of anti-diabetic medications or measured fasting glucose ≥126 mg/dl or haemoglobin A1c > 6.5%.

Results

the 16-year diabetes incidence was 37%. The average baseline weight-normalised grip strength (NGS, kg per kg body weight) was 0.41 ± 0.12 and a mean of 0.29 ± 0.14 kg of absolute grip strength was lost per year. Each 0.1 higher NGS was associated with a 19% lower hazard of incident diabetes (P = 0.006) after adjustment for age, race/ethnicity, economic strain, smoking, menopause status, hormone use, physical activity and waist-hip ratio. In race/ethnic-stratified models, each 0.10 increase in NGS was associated with a 54% lower hazard of incident diabetes (P < 0.0001) among White women but the association among Black women was not statistically significant. In models without adjustment for waist-hip ratio or restricted to women <48 years of age at baseline, there was a statistically significant association between baseline NGS and incident diabetes among Black women. The rate of change in grip strength was not associated with diabetes incidence.

Conclusion

the mid-life is an important risk period for diabetes onset. Improving muscle strength. during mid-life may contribute to preventing diabetes among women.

Effects of soy isoflavones on the concentration of hyaluronic acid in the vagina of type 1 diabetic rats

OBJECTIVE

To assess the effects of isoflavones and 17β-estradiol on the vaginal epithelium extracellular matrix and hyaluronic acid (HA) in the diabetic rat model.

METHODS

Sixty adult, virgin, female rats underwent ovariectomy, then randomization into six groups of ten animals each: GI, sham ovariectomized control animals; GII, sham ovariectomized control diabetic animals; GIII, control ovariectomized rats receiving propylene glycol vehicle; GIV, control ovariectomized diabetic animals receiving propylene glycol vehicle; GV, diabetic ovariectomized animals treated with soy isoflavones (150 mg/kg by gavage); GVI, ovariectomized diabetic rats treated with estrogen (17β-estradiol, 10 mg/kg, subcutaneously). Treatment took place over 30 consecutive days. After euthanasia, a portion of the vagina was immersed in liquid nitrogen for RT-qPCR and Western blotting. Another portion was processed for paraffin embedding. Sections were stained with hematoxylin & eosin for histomorphometry and Picro Sirius Red for collagen quantification.

RESULTS

Vaginal epithelium histomorphometry in GIII (15.3 ± 1.1 µm) and GIV (14.5 ± 1.8 µm) was thinner than in GV (41.3 ± 1.5 µm) and GVI (74.3 ± 1.6 µm). There was an increase in collagen content in GV (84.1 ± 1.2 µm) and GVI (88.2 ± 1.7 µm). HA quantification was higher in GV (0.38 ± 1.1 μg/mg) and GVI (0.49 ± 1.4 μg/mg) when compared with GIII (0.12 ± 1.1 μg/mg) and GIV (0.10 ± 1.2 μg/mg), p < 0.05.

CONCLUSIONS

Soy isoflavones increase hyaluronic acid concentration in the vagina of diabetic ovariectomized rats. Such findings might help to attenuate the effects of vulvovaginal atrophy in women.

Association between muscle function and body composition, vitamin D status, and blood glucose in postmenopausal women with type 2 diabetes

AIMS

The aim of this study was to examine the association between muscle function, and body composition, vitamin D status, and blood glucose in post-menopausal women with type 2 diabetes (T2D).

METHODS

Forty post-menopausal women (62.48±7.67years; 154.6±5.11cm; 73.93±15.43kg; 31.13±5.82 BMI kg/m²) with a diagnosis of T2D participated in this cross-sectional study. The patients performed fasting blood sample exams, anthropometrics assessments, body composition, and clinical exams. Subjects performed physical tests including handgrip, timed up and go, 30-s chair stand, arm curl, and sit-to-stand. The correlation between the parameters of physical tests, age, body composition, vitamin D, and blood glucose was assessed by Pearson correlation.

RESULTS

The results showed there were significant correlations between blood glucose and relative strength (R=-0.398, p=0.011), arm curl test (R=-0.367 and p=0.020), and hip flexion (R=0.427, p=0.006).

CONCLUSIONS

These findings are important because they highlight the importance of resistance training in individuals with T2D and the relationship with a fat increase during a dicrease process. Furthermore, the concentration of serum glucose might be associated with decreases in muscle strength and muscle function in older adults. Thus, T2D patients should be involved with strength training to improve the strength and the muscle hypertrophy.

Menopausal Hormone Therapy and Type 2 Diabetes Prevention: Evidence, Mechanisms, and Clinical Implications

Type 2 diabetes has reached epidemic proportions in the United States. Large, randomized controlled trials suggest that menopausal hormone therapy (MHT) delays the onset of type 2 diabetes in women. However, the mechanisms and clinical implications of this association are still a matter of controversy. This review provides an up-to-date analysis and integration of epidemiological, clinical, and basic studies, and proposes a mechanistic explanation for the effect of menopause and MHT on type 2 diabetes development and prevention. We discuss the beneficial effects of endogenous estradiol with respect to insulin secretion, insulin sensitivity, and glucose effectiveness; we also discuss energy expenditure and adipose distribution, both of which are affected by menopause and improved by MHT, which thereby decreases the incidence of type 2 diabetes. We reconcile differences among studies that investigated the effect of menopause and MHT formulations on type 2 diabetes. We argue that discrepancies arise from physiological differences in methods used to assess glucose homeostasis, ranging from clinical indices of insulin sensitivity to steady-state methods to assess insulin action. We also discuss the influence of the route of estrogen administration and the addition of progestogens. We conclude that, although MHT is neither approved nor appropriate for the prevention of type 2 diabetes due to its complex balance of risks and benefits, it should not be withheld from women with increased risk of type 2 diabetes who seek treatment for menopausal symptoms.

Sex Hormones and Cardiometabolic Health: Role of Estrogen and Estrogen Receptors

With increased life expectancy, women will spend over three decades of life postmenopause. The menopausal transition increases susceptibility to metabolic diseases such as obesity, diabetes, cardiovascular disease, and cancer. Thus, it is more important than ever to develop effective hormonal treatment strategies to protect aging women. Understanding the role of estrogens, and their biological actions mediated by estrogen receptors (ERs), in the regulation of cardiometabolic health is of paramount importance to discover novel targeted therapeutics. In this brief review, we provide a detailed overview of the literature, from basic science findings to human clinical trial evidence, supporting a protective role of estrogens and their receptors, specifically ERα, in maintenance of cardiometabolic health. In so doing, we provide a concise mechanistic discussion of some of the major tissue-specific roles of estrogens signaling through ERα. Taken together, evidence suggests that targeted, perhaps receptor-specific, hormonal therapies can and should be used to optimize the health of women as they transition through menopause, while reducing the undesired complications that have limited the efficacy and use of traditional hormone replacement interventions.

Mapping the association between back pain and type 2 diabetes: A cross-sectional and longitudinal study of adult Spanish twins

BACKGROUND

Back pain and type 2 diabetes often co-occur, resulting in greater impact on people's health and complexity in their care. Plausible causal mechanisms for this association have been proposed, yet the nature of the link remains unclear. We therefore explored the direction of the association between type 2 diabetes and chronic back pain in twins, controlling for genetics and early environmental confounding.

METHODS

2,096 and 1,098 twins were included in the cross-sectional and longitudinal analyses, respectively. Any or severe (≥ 9) low back pain (LBP), neck pain (NP), and spinal pain (concurrent LBP and NP) and type 2 diabetes were investigated. Sequential analyses were performed using logistic regression. Firstly, twins were analysed unpaired (adjusted age and gender): total sample analyses. Then, to control for genetic and shared environmental factors, a co-twin case-control analysis was performed including monozygotic and dizygotic twin pairs discordant for back pain (cross-sectional only).

RESULTS

In the cross-sectional total sample analyses, type 2 diabetes was associated with chronic spinal pain (OR 1.61; 95%CI 1.12 to 2.31), severe chronic spinal pain (OR 3.33; 95%CI 1.47 to 7.53), chronic NP (OR 1.37; 95%CI 1.01 to 1.85), severe chronic NP (OR 2.28; 95%CI 1.24 to 4.21), and severe chronic LBP (OR 1.63; 95%CI 1.00 to 2.64). After further adjustment for genetic and shared environmental factors, none of the associations remained significant. The longitudinal analyses indicated that the presence of type 2 diabetes did not increase the risk of future back pain, or vice-versa, after two to four years.

CONCLUSIONS

Chronic back pain (spinal pain, NP, or LBP) was associated with the prevalence of type 2 diabetes. Associations are stronger for severe cases of pain. Future research should investigate the temporal relationships between these conditions with longer follow up in twins.

Effects of 17β-estradiol on leptin signaling in anterior pituitary of ovariectomized rats

Leptin is secreted predominantly by adipocytes and exerts its role mainly by interaction with the long form of leptin receptor (LEPR_V2). It has been identified that LEPR_V2 is widely distributed in various tissues, including the anterior pituitary. Cross-talk between leptin and estrogens has been indentified. Estrogen is known to modulate the tissue-specific expression of LEPR_V2 and leptin in ovariectomized (OVX) rats, a model of postmenopausal condition. Our previous data showed that 17β-estradiol (E₂) up-regulated the expression of LEPR_V2 protein and mRNA in rat dorsal root ganglion (DRG) in an estrogen receptor alpha (ERα)-dependent manner. But it is still unclear whether estrogen can regulate leptin signalling in the pituitary of OVX rats. In the present study, we found that ovariectomy decreased the expressions of LEPR_V2. Administration of E₂ increased the expressions of LEPR_V2 in a dose-dependent manner. In addition, E₂ improved LEPR_V2, STAT3, and SOCS3 protein levels in OVX rats. The effects of exogenous E₂ were attenuated by ICI 182,780, a specific estrogen receptors antagonist. However, E₂ did not change the Lepr_v1, a type of short form of leptin receptor (LEPR), or leptin mRNA levels. Thus, E₂ plays a crucial role in regulating pituitary sensitivity to leptin in OVX rats. Our findings implied that exogenous E₂ had potential roles in modification of the function of pituitary in postmenopausal women.

Western-style diet, sex steroids and metabolism

The evolutionary transition from hunting to farming was associated with introduction of carbohydrate-rich diets. Today, the increased consumption of simple sugars and high-fat food brought about by Western-style diet and physical inactivity are leading causes of the growing obesity epidemic in the Western society. The extension of human lifespan far beyond reproductive age increased the burden of metabolic disorders associated with overnutrition and age-related hypogonadism. Sex steroids are essential regulators of both reproductive function and energy metabolism, whereas their imbalance causes infertility, obesity, glucose intolerance, dyslipidemia, and increased appetite. Clinical and translational studies suggest that dietary restriction and weight control can improve metabolic and reproductive outcomes of sex hormone-related pathologies, including testosterone deficiency in men and natural menopause and hyperandrogenemia in women. Minimizing metabolic and reproductive decline through rationally designed diet and exercise can help extend human reproductive age and promote healthy aging. This article is part of a Special Issue entitled: Oxidative Stress and Mitochondrial Quality in Diabetes/Obesity and Critical Illness Spectrum of Diseases - edited by P. Hemachandra Reddy.