Mechanisms of estrogen protection in diabetes and metabolic disease

Sex-Specific Cardiovascular Risk Factors and Treatment in Females With T2DM and CVD: Developments and Knowledge Gaps

PURPOSE

There are large disparities in the impact of diabetes on cardiovascular disease (CVD) risk and outcomes by sex and gender. Achieving health equity requires understanding risks and medication efficacy in female patients, especially now, as novel pharmacologic treatments are transforming the diabetes and CVD treatment landscape. This review examines 2 bodies of research that can inform sex differences in CVD in patients with diabetes: female-specific risk factors for CVD and sex-related limitations of clinical trial research in evaluating novel diabetes and CVD treatments.

METHODS

Two literature searches were performed using Ovid Medline(R) All. The first retrieved manuscripts covering sex and gender differences related to CVD risk and therapies and diabetes. The second focused on randomized controlled trial data on sex/gender differences and GLP-1/SGLT-2/DPP-4 drugs.

RESULTS

Female-specific risk factors for CVD include early menarche, premature or early menopause, irregular cycles and polycystic ovary syndrome; pregnancy; adverse pregnancy outcomes; history of breast cancer; and autoimmune diseases. Clinical trials of novel pharmacological treatments for diabetes and CVD have undersampled female populations, and clinical characteristics of male and female participants have differed significantly. Thus, evidence to evaluate potential sex differences in treatment efficacy and side effects has been lacking.

CONCLUSION

To improve health of female patients with diabetes, sex-specific cardiovascular risk factors should be taken into account in screening and treatment decisions. Further, studies of cardiovascular and diabetes medications must ensure adequate representation by sex and report participant characteristics and outcomes by sex.

The association between parity and type 2 diabetes mellitus: a cross-sectional, community-based study

BACKGROUND

Limited published data exist on the association between parity (number of deliveries) and diabetes mellitus (DM). This study was conducted to evaluate the association between parity and type 2 DM (T2DM) among Sudanese women.

METHOD

A multistage sampling survey was conducted in four villages in the River Nile State, Sudan, between July and September 2022. The World Health Organization's three-level stepwise questionnaire was adopted to collect women's sociodemographic characteristics (age, sex, height, weight, marital status, parity, education level, occupation, detailed obstetric history, and family history of T2DM). Multivariate analyses were performed.

RESULTS

A total of 397 women were recruited. Their median (interquartile range) age was 45.0 (33.0‒55.7) years. A total of 154 women (38.8%) were nulliparous, whereas 93 (23.4%), 70 (17.6%), and 80 (20.2%) had para 1‒3, 4 or 5, and more than 5, respectively. A total of 112 (28.2%) women had T2DM. In multivariate analysis, older age (adjusted odds ratio, AOR, 1.04, 95%, confidence interval, CI, 1.02‒1.06), high parity (AOR, 1.1, 95% C, 1.01‒1.20), and a family history of DM (AOR, 3.26, 95% CI, 1.98‒5.38) were associated with T2DM. Compared with the nulliparity, para 1‒3 (AOR, 2.33; 95% CI, 1.17‒4.61), para 4 or 5 (AOR, 2.12; 95% CI, 1.04‒4.30), and para > 5 (AOR, 2.16; 95% CI, 1.09‒4.27) were at higher risk of T2DM. In women aged < 50 years, high parity (AOR, 1.22; 95% CI, 1.06‒1.44) was associated with T2DM. Compared with the nulliparous women, para 4 or 5 (AOR, 3.47; 95% CI, 1.16‒10.34) and para > 5 (AOR, 4.63; 95% CI, 1.54‒13.87) were associated with T2DM, whereas para 1‒3 was not associated with T2DM. In the women aged ≥ 50 years, parity and parity groups were not associated with T2DM.

CONCLUSION

There is a high prevalence of T2DM among Sudanese women. Parity and high parity are significant predictors of T2DM among these women in this part of Sudan.

Sex Differences in Kidney Health and Disease

BACKGROUND

Sex differences exist in kidney physiology and disease which are underpinned by the biological actions of the sex hormones estrogen, progesterone and testosterone. In this review, we present an up-to-date discussion of the hormonal and molecular signalling pathways implicated in sex differences in kidney health and disease.

SUMMARY

Estrogen and progesterone have protective effects on renal blood flow, glomerular filtration rate and nephron ion and water reabsorptive processes, whereas testosterone tends to compromise these functions. The biological effects of estrogen appear to be the most important in reinforcing kidney function and protecting against kidney diseases in females. The actions of estrogen are myriad but all tend to bolster kidney physiology to maintain a steady-state and adaptable extracellular fluid volume (ECFV) and blood pressure. Estrogen safeguards ECFV homeostasis by stimulating renal epithelial sodium channel (ENaC) and water channel (AQP2) expression and transport function. Renal maintenance of ECFV within narrow physiological limits is a first-line of defense against hypertension and lowers the risk of cardiovascular disease in women. The estrogenic and XX chromosome basis for a female advantage are evident in a wide range of kidney diseases including acute kidney injury, chronic kidney disease, end-stage kidney disease, diabetic kidney disease, and polycystic kidney disease. The molecular mechanisms involve estrogen regulation of nephron ion and water transport, genetic immunogenic responses, activation of the protective arm of the renin angiotensin-aldosterone system and XX chromosome reinforcement of immune responses. Kidney disease can also predispose patients to cancer and women are protected in renal cancer with lower incidence, morbidity, and mortality than age-matched men with the disease.

KEY MESSAGES

This review underscores the importance of incorporating sex-specific considerations into clinical practice and basic research to bridge the gap in understanding and addressing biological sex disparities in kidney disease and renal cancer.

Reproductive risk factors across the female lifecourse and later metabolic health

Metabolic health is characterized by optimal blood glucose, lipids, cholesterol, blood pressure, and adiposity. Alterations in these characteristics may lead to the development of type 2 diabetes mellitus or dyslipidemia. Recent evidence suggests that female reproductive characteristics may be overlooked as risk factors that contribute to later metabolic dysfunction. These reproductive traits include the age at menarche, menstrual irregularity, the development of polycystic ovary syndrome, gestational weight change, gestational dysglycemia and dyslipidemia, and the severity and timing of menopausal symptoms. These risk factors may themselves be markers of future dysfunction or may be explained by shared underlying etiologies that promote long-term disease development. Disentangling underlying relationships and identifying potentially modifiable characteristics have an important bearing on therapeutic lifestyle modifications that could ease long-term metabolic burden. Further research that better characterizes associations between reproductive characteristics and metabolic health, clarifies underlying etiologies, and identifies indicators for clinical application is warranted in the prevention and management of metabolic dysfunction.

Comparison of Heart Rate Variability, QTc, and JT Interval Between Diabetic Patients and Healthy Controls: Role of Gender and Phases of Menstrual Cycle

Background and objectives

Type 2 Diabetes mellitus (T2DM) is a heterogeneous group of metabolic disorders with variable degrees of insulin resistance and altered glucose metabolism. Increased attention in studying the role of gonadal hormones in diabetes is not only due to their relation to insulin sensitivity, and glucose tolerance but also to the gender-specific nature of the prevalence of various diabetic complications. The cyclical change in the hormone level in females will make it necessary to consider the menstrual cycle while analyzing the risk factors for diabetes. Hence, the role of gender and menstrual cycle in T2DM are analyzed here using the simple non-invasive cardiovascular risk indices like heart rate variability (HRV), QT interval corrected for heart rate (QTc), and JT interval.

Materials and methods

In this analytical study, T2DM patients in the age group of 18-45 years with less than five years duration from diagnosis and taking not more than two anti-hyperglycemic drugs were included. Time and frequency domains of HRV analysis, QTc, and JT intervals were compared with age and BMI matched control group. The comparison of these parameters was also made between two genders in the diabetic group and they were analyzed across different phases of the menstrual cycle in female diabetic patients when physiological variation in the gonadal hormones occurred as a natural phenomenon.

Results

HRV parameters were reduced and the QTc and JT intervals were prolonged in diabetic patients of both genders. Reduction in low-frequency (LF) band power and high-frequency (HF) band power of HRV analysis in diabetic females were statistically significant in the luteal phase of the menstrual cycle in comparison with age and BMI-matched healthy controls. There was no significant difference in the HRV parameters, QTc, and JT interval between the male and female diabetic groups. HF band power is significantly reduced in the menstrual phase and relatively higher in the follicular phase when compared to the luteal phase among female diabetic patients.

Conclusion

The reduced sympathetic and parasympathetic activity were observed in diabetic patients of both genders and they were significant in the luteal phase of diabetic females compared to the healthy control group. Vagal activity is relatively higher in the follicular phase of the menstrual cycle in female diabetic patients.

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.

Short-Term Effects of Early Menopause on Adiposity, Fatty Acids Profile and Insulin Sensitivity of a Swine Model of Female Obesity

Menopause strongly increases incidence and consequences of obesity and non-communicable diseases in women, with recent research suggesting a very early onset of changes in lipid accumulation, dyslipidemia, and insulin resistance. However, there is a lack of adequate preclinical models for its study. The present trial evaluated the usefulness of an alternative method to surgical ovariectomy, the administration of two doses of a GnRH analogue-protein conjugate (Vacsincel^®), for inducing ovarian inactivity in sows used as preclinical models of obesity and menopause. All the sows treated with the compound developed ovarian stoppage after the second dose and, when exposed to obesogenic diets during the following three months, showed changes in the patterns of fat deposition, in the fatty acids profiles at the different tissues and in the plasma concentrations of fructosamine, urea, β-hydroxibutirate, and haptoglobin when compared to obese fed with the same diet but maintaining ovarian activity. Altogether, these results indicate that menopause early augments the deleterious effects induced by overfeeding and obesity on metabolic traits, paving the way for future research on physiopathology of these conditions and possible therapeutic targets using the swine model.

The interactions of diet-induced obesity and organophosphate flame retardant exposure on energy homeostasis in adult male and female mice

Previously, sex-dependent alterations in energy homeostasis were reported in adult mice fed a standard chow attributed to exposure to a mixture of organophosphate flame retardants (OPFRs) via estrogen receptors (ERα). In this study, adult male and female mice (C57BL/6J; Taconic) were treated with the same mixture of OPFRs (1 mg/kg each of tricresyl phosphate (TCP), triphenyl phosphate (TPP), and tris(1-3-dichloro-2propyl)phosphate (TDCPP)) for 7 weeks on a low-fat diet (LFD, 10% kcal fat) or a high fat (HFD, 45% kcal fat) in a diet-induced obesity model. Consistent with our previous observations, OPFRs altered weight gain in males, differentially with diet, while females remained unaffected. OPFR treatment also revealed sex-dependent perturbations in metabolic activity. During the night (approximately 0100-0400 hr), males exhibited elevated activity and oxygen consumption, while in females these parameters were decreased, irrespective of diet. OPFR disrupted feeding behavior and abolished diurnal water intake patterns in females while increasing nighttime fluid consumption in males. Despite no marked effect of OPFRs on glucose or insulin tolerance, OPFR treatment altered circulating insulin and leptin in females and ghrelin in males. Data indicate that adult OPFR exposure might influence, and perhaps exacerbate, the effects of diet-induced obesity in adult mice by altering activity, ingestive behavior, and metabolism.

Estradiol/GPER affects the integrity of mammary duct-like structures in vitro

High estrogen concentration leads to an inflammatory reaction in the mammary gland tissue in vivo; however, the detailed mechanism underlying its specific effects on the breast duct has not been fully clarified. We used 3D-cultured MCF-10A acini as a breast duct model and demonstrated various deleterious effects of 17-β estradiol (E2), including the destruction of the basement membrane surrounding the acini, abnormal adhesion between cells, and cell death via apoptosis and pyroptosis. Moreover, we clarified the mechanism underlying these phenomena: E2 binds to GPER in MCF-10A cells and stimulates matrix metalloproteinase 3 (MMP-3) and interleukin-1β (IL-1β) secretion via JNK and p38 MAPK signaling pathways. IL-1β activates the IL-1R1 signaling pathway and induces continuous MMP-3 and IL-1β secretion. Collectively, our novel findings reveal an important molecular mechanism underlying the effects of E2 on the integrity of duct-like structures in vitro. Thus, E2 may act as a trigger for ductal carcinoma transition in situ.

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

OBJECTIVE

The aim of the study was to understand the association between women's reproductive history and their risk of developing type 2 diabetes. We hypothesized that characteristics signifying lower cumulative endogenous estrogen exposure would be associated with increased risk.

METHODS

Prospective cohort analysis of 124,379 postmenopausal women aged 50 to 79 years from the Women's Health Initiative (WHI). We determined age of menarche and final menstrual period, and history of irregular menses from questionnaires at baseline, and calculated reproductive length from age of menarche and final menstrual period. Presence of new onset type 2 diabetes was from self-report. Using multivariable Cox proportional hazards models, we assessed associations between reproductive variables and incidence of type 2 diabetes.

RESULTS

In age-adjusted models, women with the shortest (<30 y) reproductive periods had a 37% (95% CI, 30-45) greater risk of developing type 2 diabetes than women with medium-length reproductive periods (36-40 y). Women with the longest (45+ y) reproductive periods had a 23% (95% CI, 12-37) higher risk than women with medium-length periods. These associations were attenuated after full adjustment (HR 1.07 [1.01, 1.14] for shortest and HR 1.09 [0.99, 1.22] for longest, compared with medium duration). Those with a final menstrual period before age 45 and after age 55 had an increased risk of diabetes (HR 1.04; 95% CI, 0.99-1.09 and HR 1.08; 95% CI, 1.01-1.14, respectively) compared to those with age of final menstrual period between 46 and 55 years. Timing of menarche and cycle regularity was not associated with risk after full adjustment.

CONCLUSIONS

Reproductive history may be associated with type 2 diabetes risk. Women with shorter and longer reproductive periods may benefit from lifestyle counseling to prevent type 2 diabetes.

Menopausal Hormone Therapy, Age, and Chronic Diseases: Perspectives on Statistical Trends

The release of the Women's Health Initiative (WHI) study in 2002 was a shock to the medical community. Hormone therapy (HT) had generally been considered to be highly beneficial for postmenopausal women since it was the gold standard for relief of menopausal symptoms (hot flashes, night sweats, vaginal atrophy) and it was thought to protect women from osteoporosis, heart disease, and cognitive decline and to generally improve quality of life. However, WHI showed a statistically significant increase in a number of disease states, including breast cancer, cardiovascular disease, and stroke. One problem with the WHI study was that the average age of women in the study was 63, which is considerably older than the age at which most women enter menopause (about 51). The timing hypothesis attempts to rationalize the effect of age on response to HT and risk of various diseases. The data suggests that younger women (50-60) may be protected from heart disease with only a slight increase in breast cancer risk. In contrast, older women (>65) are more susceptible to breast cancer and heart disease and should avoid HT. This Perspective on Statistical Trends evaluates the current data on HT and risk for chronic diseases as a function of age.

Reproductive factors and risk of type 2 diabetes in an occupational cohort of Chinese women

AIMS

Hormonal milieu has long been known to play an important role in the development of type 2 diabetes (T2D). The aims of this study are to investigate the roles of menstrual and reproductive factors in relation to T2D risk in an occupational cohort of Chinese women; and to explore the role of endogenous estrogen in T2D development.

METHODS

We conducted a cross-sectional analysis of baseline data from 16114 women (11051 premenopausal and 5063 postmenopausal) aged ≥20years who participated in the ongoing prospective occupational cohort study. Multivariable logistic regressions were modeled to evaluate the associations of reproductive factors with T2D risk.

RESULTS

Early menarche at age (≤12 versus 15-16 years) was associated with increased T2D risk (odds ratio [OR]: 1.60, 95% confidence interval [CI]: 1.16-2.22). After multiple adjustment including age, BMI and occupation, postmenopausal status was positively associated with T2D risk (OR: 1.54, 95% CI: 1.10-2.14). Reproductive life span was significantly associated with T2D risk (P=0.02), albeit displaying a U-shape relationship. Similarly, age at menopause was also associated with T2D risk in the same U-shaped as with reproductive life span (P=0.03). Further, years since menopause (P=0.003), but not history of cycle regularity and hormone use, was associated with increased T2D risk.

CONCLUSION

Reproductive factors were associated with T2D supporting the notion that either a short or prolonged exposure to endogenous estrogen affects T2D risk in Chinese women. Reproductive factors should be added to risk stratification when counseling women about their risk of developing diabetes.

Diabetes and Menopause

During menopause, women's body composition, sex hormone profile, and metabolic profile may change dramatically. In this review, we summarize studies examining whether the menopausal transition and physiologic factors characterizing the transition are associated with increased risk of diabetes. We review the evidence for estrogen therapy and diabetes risk and studies examining the relationship between diabetes and menarche, which represents an extension of the reproductive life span at the opposite end of the age spectrum. Although studied less extensively, the presence of type 1 or type 2 diabetes may increase the risk of ovarian failure, and we review this literature. In conclusion, we note that the evidence linking menopausal sex hormone changes with increased diabetes risk is weak, although rapid changes as observed with oophorectomy may increase risk. Further studies should investigate the contradictory effects of estrogen therapy upon hepatic and glucose metabolism in mid-life women.