Effect of postmenopausal status and age at menopause on type 2 diabetes and prediabetes in Japanese individuals: Toranomon Hospital Health Management Center Study 17 (TOPICS 17)

FKBP5 mediates glucocorticoid signaling in estrogen deficiency-associated endothelial dysfunction

BACKGROUND

Cardiovascular disease (CVD) is the leading cause of mortality among postmenopausal women, with atherosclerosis being a major underlying factor. Endothelial dysfunction, a key initiating event in atherosclerosis, can be triggered by hormonal and metabolic changes. While estrogen deficiency has been linked to increased cardiovascular risk, the molecular mechanisms by which it exacerbates endothelial dysfunction, particularly in the presence of elevated glucocorticoid levels, remain poorly understood. This study aims to explore the role of FK506-binding protein 5 (FKBP5) in mediating glucocorticoid-induced endothelial dysfunction in estrogen-deficient females.

METHODS

Estrogen deficiency was developed in female mice by ovariectomy (OVX). Female mice and human umbilical vein endothelial cells (HUVECs) were treated with dexamethasone (DEX) to mimic elevated cortisol levels in vivo and vitro. Endothelial function of the mice aorta was assessed using wire myography. Oxidative stress and inflammation were evaluated through reactive oxygen species (ROS) detection, immunofluorescence and mRNA expression analysis. The selective FKBP5 inhibitor SAFit2 was used to study the functional role of FKBP5 in these processes.

RESULTS

Estrogen deficiency contributed to endothelial dysfunction in female mice, an effect exacerbated by elevated glucocorticoid levels. FKBP5 expression was upregulated in both ovariectomized mice aortas and DEX-treated endothelial cells. Inhibition of FKBP5 reversed endothelial dysfunction, reduced ROS levels, and suppressed the expression of pro-inflammatory mediators, including ICAM-1, IL-1β, TNF-α, and NF-κB.

CONCLUSION

FKBP5 mediates glucocorticoid-induced endothelial dysfunction under estrogen-deficient conditions. Inhibition of FKBP5 represents a promising therapeutic strategy to ameliorate endothelial dysfunction and improve vascular health in estrogen-deficient women.

Low HDL cholesterol levels in women and hypertriglyceridemia in men: predictors of MASLD onset in individuals without steatosis

BACKGROUND

Individuals with metabolic-associated steatotic liver disease (MASLD) have a worse prognosis compared to patients without steatosis, and its prevalence is increasing. However, detailed risk factors based on obesity and sex remain unclear. We aimed to investigate the impact of cardiometabolic risk factors (CMRFs) on the risk of MASLD in individuals without pre-existing SLD.

METHODS

SLD was diagnosed by ultrasonography. Non-SLD individuals were followed 65,657 person-years. Incidence rates of MASLD were assessed by Kaplan-Meier analysis. Furthermore, independent factors associated with the development of MASLD were identified using Cox regression analysis, stratified by four groups: obese men, non-obese men, obese women, and non-obese women.

RESULTS

The overall incidence rate of MASLD was 39.3/1,000 person-years. The cumulative incidence was highest in obese men, followed by obese women, non-obese men, and non-obese women. Two or more CMRFs increased the risk of MASLD in all groups. Low HDL cholesterol level was the strongest independent risk factor in both obese and non-obese women and hypertriglyceridemia for both obese and non-obese men. The impact of these CMRFs was stronger in non-obese individuals. (HR [95% CI]: women non-obese 1.9 [1.5-2.4], obese 1.4 [1.1-1.8]; men non-obese 2.3 [1.9-2.9], obese 1.5 [1.2-2.0]).

CONCLUSIONS

Multiple CMRFs are important to MASLD development, regardless of sex and obesity. In this Japanese cohort, low HDL cholesterol in women and hypertriglyceridemia in men were the most significant risk factors, especially among the non-obese group. These findings suggest that sex-specific CMRFs may play a role in the development of MASLD.

Association of Parity with Type 2 Diabetes Mellitus in Japan

This study investigates the association between parity and type 2 diabetes mellitus (T2DM) in Japanese women, considering the clinical history of gestational diabetes mellitus (GDM) and menopausal status, which are known risk factors for T2DM. Overall, 30,116 Japanese women (6,588 premenopausal and 23,528 postmenopausal) were included in this cross-sectional study. They were divided into two groups according to menopausal status (premenopausal and postmenopausal women), and the association between parity and T2DM was evaluated using a multiple logistic regression model with possible confounders, including a clinical history of GDM. The association between parity and T2DM was not statistically significant in premenopausal women. In contrast, a linear graded association between parity and T2DM was found in postmenopausal women. Furthermore, the association between parity and T2DM in postmenopausal women was attenuated after adjusting for body weight gain after the age of 20 years. A clinical history of GDM was significantly associated with a high risk for T2DM, regardless of adjustment for body weight gain after the age of 20 years in both premenopausal and postmenopausal women. Parity is associated with an increased risk of T2DM in postmenopausal women but not in premenopausal women. Maintaining appropriate body weight would be beneficial in attenuating the risk of T2DM in postmenopausal women. A clinical history of GDM is a risk factor for T2DM in both pre- and postmenopausal women; therefore, women with a clinical history of GDM require continuous medical care to survey for T2DM.

Schistosoma mansoni antigen induced innate immune memory features mitochondrial biogenesis and can be inhibited by ovarian produced hormones

We have previously identified that S. mansoni infection induces a unique form of myeloid training that protects male but not female mice from high fat diet induced disease. Here we demonstrate that ovarian derived hormones account for this sex specific difference. Ovariectomy of females prior to infection permits metabolic reprogramming of the myeloid lineage, with BMDM exhibiting carbon source flexibility for cellular respiration, and mice protected from systemic metabolic disease. The innate training phenotype of infection can be replicated by in vivo injection of SEA, and by exposure of bone marrow to SEA in culture prior to macrophage differentiation (Day 0). This protective phenotype is linked to increased chromatin accessibility of lipid and mitochondrial pathways in BMDM including Nrf1 and Tfam, as well as mitochondrial biogenesis. This work provides evidence that S. mansoni antigens induce a unique form of innate training inhibited by ovarian-derived hormones in females.

Association of age at menopause with type 2 diabetes mellitus in postmenopausal women: a systematic review and meta-analysis

The onset of menopause usually occurs between the ages of 48 and 52, leading to diverse symptoms in various body systems due to a decrease in estrogen level. Visceral obesity and diminished estrogen level during the menopausal phase are associated with unfavorable metabolic changes, resulting in insulin resistance and increased risk of type 2 diabetes mellitus (T2DM). Owing to the increase in the incidence and prevalence of T2DM in recent decades, it is important to identify predisposing factor such as menopausal age to improve T2DM prevention and management. We searched PubMed, Scopus, and Google Scholar databases to find all studies related to menopause and type 2 diabetes up to August 4, 2023. Studies were reviewed for compliance with the inclusion criteria. Sample size and number of post-menopausal T2DM cases were extracted from studies. Effect sizes and related confidence intervals were calculated for them. The combined analysis of 17 studies demonstrated a significant association between menopausal age and risk of T2DM. The calculated odds ratio (OR) demonstrated that women with menopausal age > 45 had significantly decreased risk of developing T2DM with OR of 0.13 (95% CI: 0.04, 0.22). This effect changed to OR = 0.44 (95% CI: -1.12, 2.00) and 0.21 (95% CI: -1.39, 1.82) for menopausal age > 50 and > 55, respectively. In conclusion, this present meta-analysis emphasizes the importance of the complex relationship between earlier menopausal age and risk of T2DM development.

CTX-1 and TRACP-5b as biomarkers for osteoporosis risk in type 2 diabetes mellitus: a cross-sectional study

OBJECTIVE

Type 2 diabetes mellitus (T2DM) demonstrates a higher risk of fractures compared to the healthy population. Therefore, the aim of our study is to assess the risk of osteoporosis in T2DM patients.

METHODOLOGY

A cross-sectional observational study was conducted in T2DM patients. The serum levels of bone resorption markers- carboxy-terminal crosslinked telopeptide of type 1 collagen (CTX-1) and tartrate-resistant acid phosphatase 5b (TRACP-5b) were compared in the T2DM group (n = 43) and the control group (n = 43) and its association with duration of T2DM, HbA1c level, body mass index (BMI), oral hypoglycaemic agents (OHA), and level of functioning was evaluated.

RESULTS

CTX-1 and TRACP-5b were significantly lower in the T2DM group compared to the control group (p < 0.05). There was no significant correlation between the bone resorption markers and the duration of T2DM and HbA1c levels. However, a significant positive correlation was found between the level of functioning and TRACP-5b level, but no such correlation was observed in T2DM patients. The linear regression model revealed that none of the OHA affected the levels of CTX-1 and TRACP-5b.

CONCLUSION

The bone resorption markers are not influenced by the duration of T2DM and HbA1c level. However, they were significantly associated with BMI and the level of functionality. However, further research is needed to strengthen the evidence of the association between T2DM and osteoporosis.

APOE4 and Chronic Health Risk Factors are Associated with Sex-Specific Preclinical Alzheimer's Disease Neuroimaging Biomarkers

Introduction

Two thirds of Alzheimer's disease (AD) patients are female. Genetic and chronic health risk factors for AD affect females more negatively compared to males.

Objective

This exploratory multimodal neuroimaging study aimed to examine sex differences in cognitively unimpaired older adults on: (1) amyloid-β via 18F-AV-45 Florbetapir PET imaging, (2) neurodegeneration via T1 weighted MRI volumetrics, (3) cerebral blood flow via ASL-MRI. We identified AD risk factors including genetic (APOE genotype status) and health markers (fasting glucose, mean arterial pressure, waist-to-hip ratio, and android and gynoid body fat) associated with neuroimaging outcomes for which we observed sex differences.

Methods

Participants were sedentary, amyloid-β positive older adults (N = 112, ages 65-87 years) without evidence of cognitive impairment (CDR = 0).

Results

Multivariate analysis of covariance models adjusted for intracranial volume, age, and years of education demonstrated lower volume (F (7, 102) = 2.67, p = 0.014) and higher blood flow F (6, 102) = 4.25, p =<0.001) among females compared to males in regions of interest connected to AD pathology and the estrogen receptor network. We did not observe sex differences in amyloid-β levels. Higher than optimal waist to hip ratio was most strongly associated with lower volume, while higher android fat percentage and APOE ε4 carrier status were most strongly associated with higher blood flow among female participants.

Discussion

Findings suggest genetic and chronic health risk factors are associated with sex-specific AD neuroimaging biomarkers. Underlying sex-specific biological pathways may explain these findings. Our results highlight the importance of considering sex differences in neuroimaging studies and when developing effective interventions for AD prevention and risk reduction.

Estrogen counteracts age-related decline in beige adipogenesis through the NAMPT-regulated ER stress response

Thermogenic beige adipocytes are recognized as potential therapeutic targets for combating metabolic diseases. However, the metabolic advantages that they offer are compromised with aging. Here we show that treating mice with estrogen (E2), a hormone that decreases with age, can counteract the age-related decline in beige adipogenesis when exposed to cold temperature while concurrently enhancing energy expenditure and improving glucose tolerance in mice. Mechanistically, we found that nicotinamide phosphoribosyl transferase (NAMPT) plays a pivotal role in facilitating the formation of E2-induced beige adipocytes, which subsequently suppresses the onset of age-related endoplasmic reticulum (ER) stress. Furthermore, we found that targeting NAMPT signaling, either genetically or pharmacologically, can restore the formation of beige adipocytes by increasing the number of perivascular adipocyte progenitor cells. Conversely, the absence of NAMPT signaling prevents this process. Together, our findings shed light on the mechanisms regulating the age-dependent impairment of beige adipocyte formation and underscore the E2-NAMPT-controlled ER stress pathway as a key regulator of this process.

The effects of aerobic exercise on cardiometabolic health in postmenopausal females: A systematic review and meta-analysis of randomized controlled trials

BACKGROUND

After menopause, reductions in ovarian hormones increase the risk of cardiovascular disease. Aerobic exercise training has been shown to reduce cardiovascular risk in older adults, but its effectiveness in postmenopausal females is less definitive.

OBJECTIVES

The objectives of this study were to examine the: (1) effects of aerobic training, and (2) association between aerobic training intensity and cardiometabolic health outcomes in postmenopausal females.

DESIGN

Systematic review and meta-analysis of randomized controlled trials.

DATA SOURCES AND METHODS

Six electronic databases were searched from inception to July 21, 2023 for aerobic training interventions reporting cardiometabolic outcomes in postmenopausal females. Data were synthesized qualitatively and random-effects meta-analyses and subgroup analyses (light, moderate, and vigorous intensity) were performed. Grading of Recommendations, Assessment, Development and Evaluation was used to assess the certainty of evidence.

RESULTS

Fifty-nine studies (n = 4,225; 45-78 years old) were identified, 53 (n = 3,821) were included in the quantitative analyses. Aerobic training interventions varied in frequency (3-21×/week), intensity, type, time (8-60 min/session), and duration (3-52 weeks). Aerobic training improved systolic blood pressure (mean difference (MD) = -4.41 mmHg, 95% confidence interval (95%CI) [-7.29, -1.52], p = 0.01), resting heart rate (MD = -3.08 bpm, 95%CI [-5.11, -1.05], p < 0.01), body mass index (BMI, MD = -0.65 kg/m2, 95%CI [-0.99, -0.31], p < 0.01), waist circumference (MD = -2.03 cm, 95%CI [-2.65, -1.41], p < 0.01), body fat (MD = -2.57 kg, 95%CI [-3.65, -1.49], p < 0.01), low-density lipoprotein cholesterol (MD = -10.46 mg/dL, 95%CI [-16.31, -4.61], p < 0.01), high-density lipoprotein cholesterol (MD = 3.28 mg/dL, 95%CI [0.20, 6.36], p = 0.04) and cardiorespiratory fitness (standardized MD = 1.38, 95%CI [1.13, 1.64], p < 0.01). There was a very low certainty of evidence for all outcomes. In subgroup analyses, light- and vigorous intensities were beneficial for BMI with no effect for moderate-intensity exercise (p < 0.01). Light intensity showed a beneficial effect (p = 0.02) for glucose levels (p < 0.01) and triglycerides; there was no effect with moderate or vigorous intensities.

CONCLUSION

Aerobic training may improve cardiometabolic health outcomes in postmenopausal females. There may be differential effects of exercise intensity on BMI, blood triglycerides, and blood glucose; however, this warrants further investigation.

REGISTRATION

PROSPERO-CRD42022313350.

Changes in insulin resistance, glucose effectiveness, and first and second phases of insulin secretion in women aged 45-60 years old in Taiwan

BACKGROUND

In women after menopause, the incidence of diabetes mellitus increases. Increased insulin resistance (IR), decreased glucose effectiveness (GE), and the first and second phases of insulin secretion (FPIS and SPIS), are the four most important factors that trigger glucose intolerance and diabetes (diabetogenic factor [DF]). In the cross-sectional study, we enrolled nondiabetic women between the ages of 45 and 60 years to observe the changes in DFs during the perimenopausal period and to elucidate the underlying mechanisms of diabetes in menopausal women.

METHODS

We randomly enrolled 4194 women who underwent health checkups. Using demographic and biochemical data, IR, FPIS, SPIS, and GE were calculated using previously published equations. The relationship between the DFs and age was evaluated using a simple correlation.

RESULTS

Body mass index, blood pressure, fasting plasma glucose, low-density lipoprotein cholesterol, triglyceride, and SPIS were higher, and GE was lower in older women (≥52 years old). A significant decrease in GE and increased SPIS were observed with age. However, no changes were observed in IR or FPIS.

CONCLUSION

The IR and FPIS did not change during perimenopause. Increased SPIS may compensate for the decrease in GE, which is probably one of the reasons for the higher incidence of diabetes in menopausal women.

Estrogen prevents age-dependent beige adipogenesis failure through NAMPT-controlled ER stress pathway

Thermogenic beige adipocytes are recognized as potential therapeutic targets for combating metabolic diseases. However, the metabolic advantages they offer are compromised with aging. Here, we show that treating mice with estrogen (E2), a hormone that decreases with age, to mice can counteract the aging- related decline in beige adipocyte formation when subjected to cold, while concurrently enhancing energy expenditure and improving glucose tolerance. Mechanistically, we find that nicotinamide phosphoribosyltranferase (NAMPT) plays a pivotal role in facilitating the formation of E2-induced beige adipocytes, which subsequently suppresses the onset of age-related ER stress. Furthermore, we found that targeting NAMPT signaling, either genetically or pharmacologically, can restore the formation of beige adipocytes by increasing the number of perivascular adipocyte progenitor cells. Conversely, the absence of NAMPT signaling prevents this process. In conclusion, our findings shed light on the mechanisms governing the age-dependent impairment of beige adipocyte formation and underscore the E2-NAMPT controlled ER stress as a key regulator of this process.

Highlights

Estrogen restores beige adipocyte failure along with improved energy metabolism in old mice.Estrogen enhances the thermogenic gene program by mitigating age-induced ER stress.Estrogen enhances the beige adipogenesis derived from SMA+ APCs.Inhibiting the NAMPT signaling pathway abolishes estrogen-promoted beige adipogenesis.

Abdominal obesity, serum estradiol and cardiovascular risk among Nigerian postmenopausal women: a cross-sectional study

Background

Rates of cardiovascular (CV) disease mortality is usually higher in men but this equalizes with that of women following menopause.

Objectives

This was to determine the contribution of abdominal obesity and estradiol to cardiovascular risk in postmenopausal women (PMW) as well as estimate their CV risk profile.

Methods

271 consenting PMW were recruited consecutively into this cross-sectional hospital-based study. Data relating to their socio-demography, blood pressure and anthropometry was obtained and laboratory analysis of lipid profile and serum estradiol was done. Cardiovascular risk of participants was estimated using standardized calculators.

Results

Mean age of participants was 57.8±5.5 years. Significant correlation existed between each of triglyceride (Positive), High Density Lipoprotein (negative) and Waist-Hip-Ratio (WHR) (p=0.001 and 0.000 respectively). Hypertension and dyslipidaemia were significantly associated with WHR (p=0.01 and 0.031 respectively). Significant negative correlation existed between CV risk profile and serum estradiol (rs = -0.140, p = 0.028). Ten-unit increase in WHR was associated with two-fold risk of hypertension (OR> 1.73, C.I.= 1.13-2.66). A unit change in age was associated with 0.61 increase in TC.

Conclusion

Abdominal obesity and serum estradiol significantly influence cardio-metabolic risk. Newer risk calculator which incorporates factors peculiar to women such as serum E2 is hereby recommended.

Disparities in the Glycemic and Incretin Responses to Intraduodenal Glucose Infusion Between Healthy Young Men and Women

CONTEXT

Premenopausal women are at a lower risk of type 2 diabetes (T2D) compared to men, but the underlying mechanism(s) remain elusive. The secretion of the incretin hormones, glucose-dependent insulinotropic polypeptide (GIP) and glucagon-like peptide-1 (GLP-1), from the small intestine is a major determinant of glucose homeostasis and may be influenced by sex.

OBJECTIVES

This study compared blood glucose and plasma insulin and incretin responses to intraduodenal glucose infusions in healthy young males and females.

DESIGN

In Study 1, 9 women and 20 men received an intraduodenal glucose infusion at 2 kcal/min for 60 minutes. In Study 2, 10 women and 26 men received an intraduodenal glucose at 3 kcal/min for 60 minutes. Venous blood was sampled every 15 minutes for measurements of blood glucose and plasma insulin, GLP-1 and GIP.

RESULTS

In response to intraduodenal glucose at 2 kcal/min, the incremental area under the curve between t = 0-60 minutes (iAUC0-60min) for blood glucose and plasma GIP did not differ between the 2 groups. However, iAUC0-60min for plasma GLP-1 (P = 0.016) and insulin (P = 0.011) were ∼2-fold higher in women than men. In response to intraduodenal glucose at 3 kcal/min, iAUC0-60min for blood glucose, plasma GIP, and insulin did not differ between women and men, but GLP-1 iAUC0-60min was 2.5-fold higher in women (P = 0.012).

CONCLUSION

Healthy young women exhibit comparable GIP but a markedly greater GLP-1 response to intraduodenal glucose than men. This disparity warrants further investigations to delineate the underlying mechanisms and may be of relevance to the reduced risk of diabetes in premenopausal women when compared to men.

Endothelial ERα promotes glucose tolerance by enhancing endothelial insulin transport to skeletal muscle

The estrogen receptor (ER) designated ERα has actions in many cell and tissue types that impact glucose homeostasis. It is unknown if these include mechanisms in endothelial cells, which have the potential to influence relative obesity, and processes in adipose tissue and skeletal muscle that impact glucose control. Here we show that independent of impact on events in adipose tissue, endothelial ERα promotes glucose tolerance by enhancing endothelial insulin transport to skeletal muscle. Endothelial ERα-deficient male mice are glucose intolerant and insulin resistant, and in females the antidiabetogenic actions of estradiol (E2) are absent. The glucose dysregulation is due to impaired skeletal muscle glucose disposal that results from attenuated muscle insulin delivery. Endothelial ERα activation stimulates insulin transcytosis by skeletal muscle microvascular endothelial cells. Mechanistically this involves nuclear ERα-dependent upregulation of vesicular trafficking regulator sorting nexin 5 (SNX5) expression, and PI3 kinase activation that drives plasma membrane recruitment of SNX5. Thus, coupled nuclear and non-nuclear actions of ERα promote endothelial insulin transport to skeletal muscle to foster normal glucose homeostasis.

Rice Bran Supplementation Ameliorates Gut Dysbiosis and Muscle Atrophy in Ovariectomized Mice Fed with a High-Fat Diet

Rice bran, a byproduct of rice milling, is rich in fiber and phytochemicals and confers several health benefits. However, its effects on gut microbiota and obesity-related muscle atrophy in postmenopausal status remain unclear. In this study, we investigated the effects of rice bran on gut microbiota, muscle synthesis, and breakdown pathways in estrogen-deficient ovariectomized (OVX) mice receiving a high-fat diet (HFD). ICR female mice were divided into five groups: sham, OVX mice receiving control diet (OC); OVX mice receiving HFD (OH); OVX mice receiving control diet and rice bran (OR); and OVX mice receiving HFD and rice bran (OHR). After twelve weeks, relative muscle mass and grip strength were high in rice bran diet groups. IL-6, TNF-α, MuRf-1, and atrogin-1 expression levels were lower, and Myog and GLUT4 were higher in the OHR group. Rice bran upregulated the expression of occludin and ZO-1 (gut tight junction proteins). The abundance of Akkermansiaceae in the cecum was relatively high in the OHR group. Our finding revealed that rice bran supplementation ameliorated gut barrier dysfunction and gut dysbiosis and also maintained muscle mass by downregulating the expression of MuRf-1 and atrogin-1 (muscle atrophy-related factors) in HFD-fed OVX mice.

Association of urinary iodine concentration with prediabetes/diabetes in adults: Analysis of the NHANES 2005-2016

BACKGROUND & AIMS

Iodine is required for synthesizing thyroid hormones and regulating human metabolism. Iodine deficiency can lead to thyroid function abnormalities, which are closely associated with disturbances in glucose-insulin homeostasis. Research on the relationship between iodine and diabetes/prediabetes in adults was sparse and inconsistent. We assessed trends in urinary iodine concentration (UIC) and diabetes/prediabetes prevalence and focused on the association between iodine and diabetes/prediabetes among U.S. adults.

METHODS

We analyzed the National Health and Nutrition Examination Survey (NHANES) data from the 2005-2016 cycles. Linear regression was employed to evaluate UIC and prediabetes/diabetes prevalence trends over time. Both multiple logistic regression and restricted cubic splines (RCS) were performed to evaluate the association of UIC with diabetes/prediabetes.

RESULTS

A distinctly declining trend in median UIC and a significant increase in diabetes prevalence in U.S. adults from 2005 to 2016 were observed. The fourth quartile of UIC was associated with a 30% lower risk for prediabetes, compared with the first quartile (OR=0.70, 95% CI: 0.56-0.86, P_trend=0.001). However, UIC was not significantly associated with the prevalence of diabetes. The RCS model suggested a significant nonlinear relationship between UIC and the risk of diabetes (P for nonlinearity =0.0147). Stratification analysis showed that the negative associations of UIC with the risk of prediabetes were more pronounced in participants who were men, aged 46-65, overweight, light alcohol drinkers, and nonactive smokers.

CONCLUSIONS

Overall, the adults' median UIC in the U.S. population was a declining trend. However, diabetes prevalence increased significantly from 2005 to 2016. Higher UIC was associated with a lower risk of prediabetes.

The association between daytime napping and risk of type 2 diabetes is modulated by inflammation and adiposity: Evidence from 435 342 UK-Biobank participants

BACKGROUND

Existing evidence concerning the relationship between daytime napping and type 2 diabetes (T2D) is inconsistent, and whether the effects of napping differ by body fat percentage (BFP) and C-reactive protein (CRP) is unclear. We aimed to investigate the association between daytime napping frequency and T2D risk and whether such an association was modified by BFP and CRP.

METHODS

We included 435 342 participants free of diabetes from the UK Biobank. Participants were categorized as nonnappers, occasional nappers, and frequent nappers based on napping frequency, and BFP/CRP was divided into quartiles. Cox proportional hazards models were used.

RESULTS

During a median follow-up of 9.2 years, 17 592 T2D cases occurred. Higher frequency of daytime napping was significantly associated with an increased risk of T2D. Compared with nonnappers, the adjusted hazard ratios (HRs) for occasional nappers and habitual nappers were 1.28 (95% confidence interval [CI]: 1.24-1.32) and 1.49 (95% CI: 1.41-1.57), respectively. There was a significant additive and multiplicative interaction (relative excess risk due to interaction [RERI] = 0.490, 95% CI 0.307-0.673; p for multiplicative interaction <.001) between napping and BFP, whereby a higher hazard of T2D associated with more frequent napping was greatest among participants in the highest BFP quartile (HR = 4.45, 95% CI: 3.92-5.06). The results for CRP were similar (RERI = 0.266, 95% CI: 0.094-0.439; p for multiplicative interaction <.001).

CONCLUSIONS

Higher daytime napping frequency is associated with an increased T2D risk, and such relationships are modified by BFP and CRP. These findings underscore the importance of adiposity and inflammation control to mitigate diabetes risk.

The effect of menopause on cardiovascular risk factors according to body mass index in middle-aged Korean women

BACKGROUND

Menopausal status and obesity are associated with an increased risk for cardiovascular diseases. However, there are few studies on the effect of menopause on cardiovascular risk factors according to the degree of obesity during the menopausal transition. We aimed to evaluate the effect of menopause on cardiovascular risk factors according to body mass index (BMI) in middle-aged Korean women.

METHODS

We analyzed 361 postmenopausal women and 758 premenopausal women (age: 45-55 years) without diabetes mellitus, hypertension, or dyslipidemia, using a cohort database released by the Korean National Health and Nutrition Examination Survey 2016-2018. Subjects were divided into two groups based on BMI. Women who underwent a hysterectomy or were pregnant were excluded from this study. Differences between groups adjusted for age and BMI were assessed.

RESULTS

Postmenopausal women (52 ± 2 years) were older than premenopausal women (48 ± 2 years), and BMI did not differ between the two groups (22.8 ± 2.9 vs. 23.0 ± 3.1 kg/m2). After adjustment for age and BMI in total and non-obese subjects (not obese subjects), postmenopausal women exhibited higher hemoglobin A1c and total cholesterol levels than premenopausal women. Subgroup analysis for 138 postmenopausal and 138 age- and BMI-matched premenopausal women showed that postmenopausal women had higher total cholesterol levels than premenopausal women with marginal significance (201 ± 25 vs. 196 ± 27 mg/dL).

CONCLUSION

Menopausal status was associated with increased glucose and cholesterol levels independent of age and BMI in middle-aged Korean women. Menopausal status showed a significant relationship with increased total cholesterol levels even after adjusting for age and BMI in non-obese women but not obese women. Therefore, intensive monitoring and treating of lipid status is necessary to prevent cardiovascular events during the menopausal transition, especially in non-obese subjects.

Sex-stratified RNA-seq analysis reveals traumatic brain injury-induced transcriptional changes in the female hippocampus conducive to dementia

Introduction

Traumatic brain injury (TBI), resulting from a violent force that causes functional changes in the brain, is the foremost environmental risk factor for developing dementia. While previous studies have identified specific candidate genes that may instigate worse outcomes following TBI when mutated, TBI-induced changes in gene expression conducive to dementia are critically understudied. Additionally, biological sex seemingly influences TBI outcomes, but the discrepancies in post-TBI gene expression leading to progressive neurodegeneration between the sexes have yet to be investigated.

Methods

We conducted a whole-genome RNA sequencing analysis of post-mortem brain tissue from the parietal neocortex, temporal neocortex, frontal white matter, and hippocampus of 107 donors characterized by the Aging, Dementia, and Traumatic Brain Injury Project. Our analysis was sex-stratified and compared gene expression patterns between TBI donors and controls, a subset of which presented with dementia.

Results

We report three candidate gene modules from the female hippocampus whose expression correlated with dementia in female TBI donors. Enrichment analyses revealed that the candidate modules were notably enriched in cardiac processes and the immune-inflammatory response, among other biological processes. In addition, multiple candidate module genes showed a significant positive correlation with hippocampal concentrations of monocyte chemoattractant protein-1 in females with post-TBI dementia, which has been previously described as a potential biomarker for TBI and susceptibility to post-injury dementia. We concurrently examined the expression profiles of these candidate modules in the hippocampus of males with TBI and found no apparent indicator that the identified candidate modules contribute to post-TBI dementia in males.

Discussion

Herein, we present the first sex-stratified RNA sequencing analysis of TBI-induced changes within the transcriptome that may be conducive to dementia. This work contributes to our current understanding of the pathophysiological link between TBI and dementia and emphasizes the growing interest in sex as a biological variable affecting TBI outcomes.

Does reproductive stage impact cardiovascular disease risk factors? Results from a population-based cohort in Lausanne (CoLaus study)

CONTEXT

Menopause has been associated with adverse cardiovascular disease (CVD) risk profile, yet it is unclear whether the changes in CVD risk factors differ by reproductive stage independently of underlying ageing trajectories.

DESIGN

The CoLaus study is a prospective population-based cohort study in Lausanne, Switzerland.

PATIENTS

We used data from women at baseline and follow-up (mean: 5.6 ± 0.5 years) from 2003 to 2012 who did not use hormone therapy. We classified women into (i) premenopausal, (ii) menopausal transition, (iii) early (≤5 years) and (iv) late (&gt;5 years) postmenopausal by comparing their menstruation status at baseline and follow-up.

MEASUREMENTS

We measured fasting lipids, glucose and cardiovascular inflammatory markers. We used repeated measures (linear mixed models) for longitudinal analysis, using premenopausal women as a reference category. We adjusted analyses for age, medications and lifestyle factors.

RESULTS

We used the data from 1710 women aged 35-75 years. Longitudinal analysis showed that the changes in CVD risk factors were not different in the other three menopausal categories compared to premenopausal women. When age was used as a predictor variable and adjusted for menopause status, most CVD risk factors increased, while interleukin-6 and interleukin-1β decreased with advancing age.

CONCLUSION

The current study suggests that women have a worsening cardiovascular risk profile as they age, and although menopausal women may have higher levels of cardiovascular risk factors compared to premenopausal women at any given time, the 5-year changes in cardiovascular risk factors may not depend on the reproductive stage.

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.

Associations between night-time sleep duration and fasting glucose and ratio of triglyceride to high-density lipoprotein cholesterol among adults free of type 2 diabetes or without diagnosed type 2 diabetes: a multicentre, cross-sectional study in China

OBJECTIVES

We aimed to assess the associations between night-time sleep duration and fasting glucose (FG), triglyceride (TG) to high-density lipoprotein cholesterol (HDL-C) ratio and body mass index (BMI) among adults free of type 2 diabetes (T2D) or without diagnosed T2D.

DESIGN

Cross-sectional study.

SETTING

Medical examination centres at six hospitals in Beijing-Tianjin-Hebei region, China.

PARTICIPANTS

Participants were recruited via multistage, stratified cluster sampling. We included adults free of T2D or without diagnosed T2D who attended for physical examination and completed the validated questionnaire. 32 497 participants were included in the study, of whom 52.50% were men.

PRIMARY AND SECONDARY OUTCOME MEASURES

FG, TG, HDL-C, height and weight were measured.

RESULTS

Overall, 12.80% and 9.67% reported night sleep duration <7 hours and ≥9 hours, respectively; 6.91% had elevated FG and 3.57% had undiagnosed T2D. Sleep duration had an independent, U-shaped associated with FG (β₁ (linear term)=-0.111, p=0.047; β₂ (quadratic term)=0.008, p=0.026) with 6.9 hours of sleep associated with the lowest FG and a negative association with BMI (β=-0.154, p<0.001). BMI mediated a U-shaped association of sleep duration with TG/HDL-C (β₁=-0.040, p=0.017; β₂=0.003, p=0.023).

CONCLUSIONS

Both short and long night-time sleep was associated with elevated FG, and short sleep duration was associated with increased BMI. BMI mediated a U-shaped association between sleep duration and TG/HDL-C.

Sex Differences in Cardiovascular Impact of Early Metabolic Impairment: Interplay between Dysbiosis and Adipose Inflammation

The evolving view of gut microbiota has shifted toward describing the colonic flora as a dynamic organ in continuous interaction with systemic physiologic processes. Alterations of the normal gut bacterial profile, known as dysbiosis, has been linked to a wide array of pathologies. Of particular interest is the cardiovascular-metabolic disease continuum originating from positive energy intake and high-fat diets. Accumulating evidence suggests a role for sex hormones in modulating the gut microbiome community. Such a role provides an additional layer of modulation of the early inflammatory changes culminating in negative metabolic and cardiovascular outcomes. In this review, we will shed the light on the role of sex hormones in cardiovascular dysfunction mediated by high-fat diet-induced dysbiosis, together with the possible involvement of insulin resistance and adipose tissue inflammation. Insights into novel therapeutic interventions will be discussed as well. SIGNIFICANCE STATEMENT: Increasing evidence implicates a role for dysbiosis in the cardiovascular complications of metabolic dysfunction. This minireview summarizes the available data on the sex-based differences in gut microbiota alterations associated with dietary patterns leading to metabolic impairment. A role for a differential impact of adipose tissue inflammation across sexes in mediating the cardiovascular detrimental phenotype following diet-induced dysbiosis is proposed. Better understanding of this pathway will help introduce early approaches to mitigate cardiovascular deterioration in metabolic disease.

Dietary regulations for microbiota dysbiosis among post-menopausal women with type 2 diabetes

Type 2 diabetes (T2D) and T2D-associated comorbidities, such as obesity, are serious universally prevalent health issues among post-menopausal women. Menopause is an unavoidable condition characterized by the depletion of estrogen, a gonadotropic hormone responsible for secondary sexual characteristics in women. In addition to sexual dimorphism, estrogen also participates in glucose-lipid homeostasis, and estrogen depletion is associated with insulin resistance in the female body. Estrogen level in the gut also regulates the microbiota composition, and even conjugated estrogen is actively metabolized by the estrobolome to maintain insulin levels. Moreover, post-menopausal gut microbiota is different from the pre-menopausal gut microbiota, as it is less diverse and lacks the mucolytic Akkermansia and short-chain fatty acid (SCFA) producers such as Faecalibacterium and Roseburia. Through various metabolites (SCFAs, secondary bile acid, and serotonin), the gut microbiota plays a significant role in regulating glucose homeostasis, oxidative stress, and T2D-associated pro-inflammatory cytokines (IL-1, IL-6). While gut dysbiosis is common among post-menopausal women, dietary interventions such as probiotics, prebiotics, and synbiotics can ease post-menopausal gut dysbiosis. The objective of this review is to understand the relationship between post-menopausal gut dysbiosis and T2D-associated factors. Additionally, the study also provided dietary recommendations to avoid T2D progression among post-menopausal women.

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.

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.

Impact of moderate dietary protein restriction on glucose homeostasis in a model of oestrogen deficiency

The need to consume adequate dietary protein to preserve physical function during ageing is well recognized. However, the effect of protein intakes on glucose metabolism is still intensively debated. During age-related oestrogen withdrawal at the time of the menopause, it is known that glucose homeostasis may be impaired but the influence of dietary protein levels in this context is unknown. The aim of the present study is to elucidate the individual and interactive effects of oestrogen deficiency and suboptimal protein intake on glucose homeostasis in a preclinical model involving ovariectomy (OVX) and a 13-week period of a moderately reduced protein intake in 7-month-old ageing rats. To investigate mechanisms of action acting via the pancreas-liver-muscle axis, fasting circulating levels of insulin, glucagon, IGF-1, FGF21 and glycemia were measured. The hepatic lipid infiltration and the protein expression of GLUT4 in the gastrocnemius were analyzed. The gene expression of some hepatokines, myokines and lipid storage/oxidation related transcription factors were quantified in the liver and the gastrocnemius. We show that, regardless of the oestrogen status, moderate dietary protein restriction increases fasting glycaemia without modifying insulinemia, body weight gain and composition. This fasting hyperglycaemia is associated with oestrogen status-specific metabolic alterations in the muscle and liver. In oestrogen-replete (SHAM) rats, GLUT4 was down-regulated in skeletal muscle while in oestrogen-deficient (OVX) rats, hepatic stress-associated hyperglucagonaemia and high serum FGF21 were observed. These findings highlight the importance of meeting dietary protein needs to avoid disturbances in glucose homeostasis in ageing female rats with or without oestrogen withdrawal.

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.

Menopause and cardiometabolic diseases: What we (don't) know and why it matters

This narrative review discusses the current understanding, knowledge gaps and challenges in expanding our knowledge of the association between menopause and the reproductive aging process and cardiometabolic disease (CMD) in women, with a focus on type 2 diabetes and cardiovascular disease. The physiological changes that occur at different stages of the reproductive life span, as well as type of menopause and timing, are factors widely associated with CMD risk; however, the underlying mechanisms remain either unclear or insufficiently studied. Decreased ovarian estrogen production and relative androgen excess around menopause onset are the most studied factors linking menopause and cardiometabolic health; nevertheless, the evidence is not persuasive and other hypotheses might explain the changes in CMD risk during menopausal transition. In this context, hormone therapy has been widely adopted in the treatment and prevention of CMD, although uncertainty regarding its cardiometabolic effects has raised the need to optimize therapeutic modalities. Mechanisms such as the "iron overload theory" and new "omics" platforms could provide new insights into potential pathways underlying the association between menopause and cardiometabolic health, such as the DNA damage response. Although it has been widely reported that environmental and lifestyle factors affect both menopause and cardiometabolic health, there is little evidence on the role of these exposures in menopause-associated CMD risk.

Gender-Dependent Characteristics of Serum 1,25-Dihydroxyvitamin D/25-Hydroxyvitamin D Ratio for the Assessment of Bone Metabolism

Objectives Vitamin D deficiency, which is common worldwide, increases the risks of falls and fractures and can lead to increased morbidity and mortality. However, the clinical utility and relevance of vitamin D activation remain unknown. The aim of the present study was to clarify the clinical usefulness of serum 1,25-dihydroxyvitamin D (1,25D)/25-hydroxyvitamin D (25D) ratio for assessment of the extent of bone metabolism. Methods We retrospectively screened data for 87 patients whose serum 1,25D and 25D levels were measured. Eight patients who were taking vitamin D preparations were excluded, and data for 79 patients (33 males and 46 females) were analyzed. Since menopausal status can be associated with serum vitamin D level, we divided the patients by gender and divided the female patients into two groups at the age of 50 years. Results The median serum 1,25D/25D ratio was significantly lower in males than in females, with the most considerable difference in all males [4.1 (interquartile range: 2.3-5.8) × 10-3] versus elderly females (aged ≧50 years) [7.9 (3.3-10.1) × 10-3). Main disorders were endocrine (30.6%), inflammatory (18.5%), and bone-related (16.7%) disorders. The ratios of serum 1,25D/25D had significant negative correlations with femoral dual-energy X-ray absorptiometry % young adult mean (DEXA %YAM) (R=-0.35) and lumbar DEXA %YAM (R=-0.32). Significant correlations were found between the 1,25D/25D ratio and serum levels of inorganic phosphate (iP), parathyroid hormone, and alkaline phosphatase (ALP). The 1,25D/25D ratio had gender-specific characteristics: the ratio was significantly correlated with age in males (R=-0.49), while it was significantly correlated with BMI in females (R=0.34). Conclusions The results of this study suggested that vitamin D activity is negatively correlated with bone mineral density, being reduced in aged males but enhanced in obese females.

The Impact of Pregnancy and Menopause on the Correlation Between Salivary Calcium Levels, Calcium Intake, and Bleeding on Probing (BOP)

Aims:

Evaluate the impact of pregnancy and menopause on the correlation between salivary calcium levels, calcium intake, and bleeding on probing (BOP), so it can be used as indicators to determine the oral health status of pregnant and menopausal women.

Materials and Methods:

This was a descriptive study using a cross-sectional approach. Participants included 26 menopausal women, 24 pregnant women, and 35 control subjects. Salivary calcium levels were measured using an atomic absorption spectrophotometer, and calcium intake was assessed using a semi-quantitative food frequency questionnaire. Other supporting data included height, weight, blood pressure, blood glucose level, salivary pH, and volume.

Results:

The mean salivary calcium levels of pregnant women (0.72 ± 0.61 mmol/L) were lower than those of control subjects (1.69 ± 0.81 mmol/L), but the mean salivary calcium levels of menopausal women were higher (1.99 ± 1.24 mmol/L). Most of the subjects in all three groups had inadequate calcium intake. The mean BOP values of pregnant and menopausal women were higher than those of the control subjects. This study found the only variable that correlated with the salivary calcium level was the menopausal group’s blood glucose level (P = 0.009).

Conclusions:

Pregnancy and menopause did not have an impact on the relationship between salivary calcium levels and BOP but had an impact on the relationship between salivary calcium levels and calcium intake. Calcium intake did not affect salivary calcium levels in both conditions when compared with the control group.

Trajectories of Body Weight and Fat Mass in Relation to Incident Prediabetes in a Biracial Cohort of Free-Living Adults

Objectives

Obesity is a risk factor for type 2 diabetes (T2D), but prospective data relating adiposity measures to incident prediabetes are scant.

Methods

The Pathobiology of Prediabetes in A Biracial Cohort study followed normoglycemic African Americans (AA) and European Americans (EA) with parental history of T2D for the primary outcome of incident prediabetes (impaired fasting glucose and/or impaired glucose tolerance) for 5.5 years. Serial assessments included anthropometry and body fat composition. We analyzed weight, body mass index (BMI), waist, total, and abdominal fat mass in relation to incident prediabetes risk.

Results

Of the 376 subjects enrolled (217 AA, 159 EA; mean age 44.2 years, BMI 31.4 kg/m²), 343 (192 AA, 151 EA) had evaluable follow-up data. A total of 101 (52 AA, 49 EA) developed prediabetes during follow-up. Progressors to prediabetes had a mean baseline weight of 90.0 ± 20.4 kg versus 82.9 ± 21.7 kg among nonprogressors (P = 0.0036). During 5.5 (mean 2.62) years of follow-up, the weight change among nonprogressors was 0.63 ± 6.11 kg compared with 2.54 ± 6.91 kg among progressors (ANOVA P = 0.0072). Progressors also showed greater increases in total fat (P = 0.0015) and trunk fat (P = 0.0005) mass than nonprogressors. Adjusted for age and sex, the significant predictors of incident prediabetes were BMI (P = 0.0013), waist (P < 0.0001), total fat (P = 0.0025), and trunk fat (P < 0.0001) mass.

Conclusions

Among obese free-living offspring of parents with T2D, long-term normoglycemic status was associated with a weight gain of ~0.2 kg/y, whereas progression to prediabetes was associated with a weight gain of ~1 kg/y.

Oxidative and Cellular Stress Markers in Postmenopause Women with Diabetes: The Impact of Years of Menopause

Women live approximately one-third of their lives in postmenopause. Among postmenopausal women, type 2 diabetes mellitus (DM2) is one of the most prevalent chronic diseases. These conditions promote alterations in the oxidative, metabolic, and immune-inflammatory profiles marked by higher extracellular 72 kDa-heat shock protein (eHSP72). Here, we investigated whether the time of menopause is associated with oxidative cellular stress marker levels in postmenopausal women with DM2. Sixty-four women were recruited (56.7 ± 12.6 years old) in the pre- (n = 22) and postmenopause (n = 42) period, with (n = 19) or without DM2 (n = 45), and a fasting blood collection was made for the evaluation of metabolic, oxidative, and inflammatory markers. We found that menopause and DM2 influenced metabolic and oxidative parameters and presented synergistic effects on the plasma lipoperoxidation levels. Also, postmenopausal women had the highest eHSP72 concentration levels associated with the years in postmenopause. We conclude that the time of menopause impacts the markers of cellular stress and increases the risk of oxidative stress, mainly when it is associated with DM2.

Normalized Hand Grip and Back Muscle Strength as Risk Factors for Incident Type 2 Diabetes Mellitus: 16 Years of Follow-Up in a Population-Based Cohort Study

PURPOSE

Muscle strength is associated with type 2 diabetes mellitus (T2DM). However, it is controversial whether muscle strength and normalized muscle strength is a risk factor for T2DM. Moreover, the relationship of back muscle strength (BMS) and incident T2DM has not been reported. In this study, we investigated the relationship between HGS, BMS, normalized HGS and BMS, and incident T2DM.

METHODS

A total of 2699 non-diabetes subjects aged 40-69 years (1313 women and 1386 men) in the Korean Genome and Epidemiology Study (KoGES) Ansan cohort were followed for 16 years. At the baseline and biennial follow-up visits, fasting glucose, postprandial 2-h glucose, clinical examinations, HGS, and BMS were measured by trained interviewers and examiners. HGS and BMS were measured at baseline. The relationships between incident T2DM, HGS, BMS, and normalized HGS and BMS were estimated using Cox proportional hazard regression models after adjusting for the confounding factors.

RESULTS

HGS and BMS were not associated with incident T2DM in multivariate analysis. However, the hazard ratio (HR) per one standard deviation (SD) increase in the body mass index (BMI), waist circumference (WC), waist-hip ratio (WHR)-normalized HGS, and BMS was associated with a lower risk for incident T2DM in both women and men after adjusting for the confounding factors (HR = 0.842-0.880-fold for women, p ≤ 0.015; HR = 0.887-0.903-fold for men, p ≤ 0.024). In the sub-analysis of menopause status, the HR per one SD increase in BMI, weight^2/3, WC, and WHR-normalized HGS was associated with a lower risk for incident T2DM in both pre- and post-menopausal women after adjusting for the confounding factors (HR = 0.860-0.820-fold for premenopausal, P ≤ 0.006; HR = 0.900-0.867-fold for postmenopausal, p ≤ 0.024). Additionally, we confirmed that the quartile group with higher muscle strength was associated with a lower risk for incident T2DM.

CONCLUSION

The present study suggested that normalized HGS and BMS were associated with a lower risk for the future development of T2DM. Moreover, weak muscle strength in premenopausal women may be the cause of T2DM. Further research is needed to determine whether efforts to improve muscle strength, such as exercise can reduce the risk of T2DM.

Increased blood glucose level following hysterectomy among reproductive women in India

BACKGROUND

In recent years, the hysterectomy, a surgical removal of the uterus, has received increased attention in health policy debates in India. The trigger for this was a series of media reports that highlighted an unusual surge in the number of women undergoing hysterectomies with a significant number of cases involving young and early menopausal women from low-income families. When menopause occurs as a result of hysterectomy, then the hormones such as estrogen and progesterone affect how the body cells respond to insulin. To date, we have not come across a national study following blood glucose levels among women who undergo a hysterectomy.

METHODS

The study used the Indian fourth round of National Family Health Survey data, which is a cross-sectional nationally representative sample of 699,686 women in the age group 15-49 years and conducted during 2015-16. Bivariate and multivariate logistic regressions were used to examine the effect of hysterectomy on blood glucose level of > 140 mg/dl among women of reproductive age groups.

RESULTS

The blood glucose level of > 140 mg/dl was much higher among women who had undergone a hysterectomy (12.2%) compared to non-hysterectomy women (5.7%). The pattern holds true among relevant background characteristics such as age, place of residence, education, caste, religion, wealth, marital status, body mass index (BMI), anaemia and consumption of tobacco. The adjusted odds after controlling for significant background factors, women who underwent hysterectomy experienced 15% higher odds of blood glucose level of > 140 mg/dl compared those who did not.

CONCLUSIONS

The results indicated increased blood glucose level among women post hysterectomy. Hence, the government of India should consider developing evidence-based policies and programming to provide effective targeted interventions for the better reproductive health of women.

Association between sleep duration and impaired fasting glucose according to work type in non-regular workers: data from the first and second year (2016, 2017) of the 7th Korean National Health and Nutrition Examination (KNHANE) (a cross-sectional study)

Background

We aimed to find the relationship between sleep duration and impaired fasting glucose according to working type in non-regular workers using the 2016 and 2017 Korean National Health And Nutrition Examination (KNHANE, 7th revision).

Method

In the 1st and 2nd year (2016, 2017) of the 7th KNHANE, 16,277 people participated. Minors were excluded because this study was intended for individuals aged 19 years and older. As this study was based on wage workers, unemployment, self-employed workers, employers, unpaid family workers, and those who have insufficient answers such as unknown or no response were excluded. Regular workers were excluded because this study was intended for non-regular workers. Finally, a total of 2,168 people were included in the survey, except those who had been diagnosed with diabetes, had a fasting blood glucose level of 126 mg/dL or higher, or taking hypoglycemic agents or receiving insulin injections. To find the relationship between sleep duration and impaired fasting glucose according to work type in non-regular workers, multiple logistic regression analysis was performed by adjusting the general and occupational characteristics after stratification according to work type. All statistical analyses were performed using the SPSS software (version 26.0; SPSS Inc., Chicago, IL, USA).

Results

In the case of insufficient sleep duration in irregular female workers, the odds ratio (OR) of impaired fasting glucose was statistically insignificant, but in the case of insufficient sleep duration in irregular male workers who have shift work, the odds ratio (OR) of impaired fasting glucose was significantly higher than that of sufficient sleep duration (Model 1, OR: 3.05, 95% confidence interval [CI]: 1.18–7.90; Model 2, OR: 2.81, 95% CI: 1.08–7.29).

Conclusions

Our findings demonstrate that insufficient sleep duration was associated with an increase in fasting blood glucose levels in non-regular male workers working shifts. This means that non-regular workers are in desperate need for adequate sleep and health care. We hope that our study will help improve the health of non-regular workers and more systematic and prospective follow-up studies will be conducted to further improve the health of non-regular workers.

Association between variations of physiological prolactin serum levels and the risk of type 2 diabetes: A systematic review and meta-analysis

AIM

To determine the pooled association between variations of prolactin serum levels within the physiological range and the risk of type 2 diabetes mellitus (T2D).

METHODS

Pubmed, Scopus, Web of Science, and grey literature were searched for studies investigating the association between variations of prolactin serum levels in the normal range and the risk of T2D in adults. The risk of prevalent and incident T2D was summarized as the odds ratio or relative risk according to the quartile of prolactin serum concentration, using random-effects meta-analysis.

RESULTS

Of 2,014 articles identified, 6 met the inclusion criteria. Data were pooled from cross-sectional studies including 6,670 subjects and longitudinal studies involving 13,203 subjects. Men with prolactin levels in the fourth quartile versus those in the first quartile had decreased risk of prevalent T2D (OR 0.52; 95%CI 0.35-077). The same association was seen in women (OR 0.46; 95%CI 0.30-0.73). Conversely, prolactin levels in the fourth versus first quartile were not associated with the risk of incident T2D in men (RR 1.21; 95%CI 0.79-1.87) or women (RR 0.77; 95%CI 0.48-1.22).

CONCLUSION

Higher prolactin serum levels within the normal range were associated with reduced risk of prevalent but not incident T2D. Further studies are necessary to address whether this association is causal, but these findings raise the discussion regarding the optimal level of prolactin suppression in subjects undergoing therapy with dopaminergic agonists.

Gender and age differences in the association between sleep characteristics and fasting glucose levels in Chinese adults

AIM

The present study examined the associations between night-time sleep duration, midday napping duration and bedtime, and fasting glucose levels, and whether or not such associations are dependent on gender and age.

METHODS

This study was a cross-sectional analysis of 172,901 adults aged≥40 years living in mainland China. Sleep duration was obtained by self-reports of bedtime at night, waking-up time the next morning and average napping duration at midday. Fasting plasma glucose (FPG)≥7.0mmol/L was defined as hyperglycaemia. Independent associations between night-time sleep duration, midday naptime duration and bedtime with hyperglycaemia were evaluated using regression models.

RESULTS

Compared with night-time sleep durations of 6-7.9h, both short (<6h) and long (≥8h) night-time sleep durations were significantly associated with an increased risk of hyperglycaemia in women [odds ratio (OR): 1.12, 95% confidence interval (CI): 1.01-1.29 and OR: 1.14, 95% CI: 1.08-1.21, respectively], and revealed a U-shaped distribution of risk in women and no significant association in men. Long midday nap durations (≥1h) were significantly but weakly associated with hyperglycaemia (OR: 1.04, 95% CI: 1.01-1.09) compared with no napping without interactions from gender or age, whereas the association between bedtime and fasting glucose levels did vary according to gender and age.

CONCLUSION

Night-time sleep duration, midday napping duration and bedtime were all independently associated with the risk of hyperglycaemia, and some of the associations between these sleep characteristics and hyperglycaemia were gender- and age-dependent.

Dietary Manganese, Plasma Markers of Inflammation, and the Development of Type 2 Diabetes in Postmenopausal Women: Findings From the Women's Health Initiative

OBJECTIVE

To examine the association between manganese intake and the risk of type 2 diabetes in postmenopausal women and determine whether this association is mediated by circulating markers of inflammation.

RESEARCH DESIGN AND METHODS

We included 84,285 postmenopausal women without a history of diabetes from the national Women's Health Initiative Observational Study (WHI-OS). Replication analysis was then conducted among 62,338 women who participated in the WHI-Clinical Trial (WHI-CT). Additionally, data from a case-control study of 3,749 women nested in the WHI-OS with information on biomarkers of inflammation and endothelial dysfunction were examined using mediation analysis to determine the relative contributions of these known biomarkers by which manganese affects type 2 diabetes risk.

RESULTS

Compared with the lowest quintile of energy-adjusted dietary manganese, WHI-OS participants in the highest quintile had a 30% lower risk of type 2 diabetes (hazard ratio [HR] 0.70 [95% CI 0.65, 0.76]). A consistent association was also confirmed in the WHI-CT (HR 0.79 [95% CI 0.73, 0.85]). In the nested case-control study, higher energy-adjusted dietary manganese was associated with lower circulating levels of inflammatory biomarkers that significantly mediated the association between dietary manganese and type 2 diabetes risk. Specifically, 19% and 12% of type 2 diabetes risk due to manganese were mediated through interleukin 6 and hs-CRP, respectively.

CONCLUSIONS

Higher intake of manganese was directly associated with a lower type 2 diabetes risk independent of known risk factors. This association may be partially mediated by inflammatory biomarkers.

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.

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.

Sleep-related symptoms of midlife women with and without type 2 diabetes mellitus

OBJECTIVES

The purpose of this study was to determine the associations between type 2 diabetes mellitus and sleep-related symptoms among midlife women from four major racial/ethnic groups in the United States.

METHODS

The data from 164 participants of two larger Internet survey studies (62 women diagnosed with type 2 diabetes and 102 women without diabetes) were included. In the original studies, multiple instruments including the questions on background characteristics, health status, and menopause status and the Sleep Index for Midlife Women were used. The data were analyzed using χ tests, independent t tests, Mann-Whitney U tests, and hierarchical multiple regression analyses.

RESULTS

The mean total number of sleep-related symptoms was significantly higher in those with type 2 diabetes (9.95 ± 5.83) than those without diabetes (7.25 ± 6.08) (t = 2.81, P = 0.006). The mean total severity score of sleep-related symptoms was also significantly higher in those with type 2 diabetes (33.42 ± 22.41) than those without diabetes (21.87 ± 21.40) (t = 3.29, P = 0.001). Among postmenopausal women and Asian women, there were significant differences in total numbers and total severity scores between those with type 2 diabetes and those without diabetes (all P < 0.05). When background characteristics, health status, and menopause status were controlled, having a diagnosis of type 2 diabetes was positively associated with total numbers (β=0.143, P = 0.047) and total severity scores (β=0.176, P = 0.014) of sleep-related symptoms.

CONCLUSIONS

This secondary analysis supported significant associations of type 2 diabetes to sleep-related symptoms of midlife women from four major racial/ethnic groups in the United States.

Epidemiological characteristics and risk factors of T2DM in Chinese premenopausal and postmenopausal women

Objective

This study was to analyse the prevalence of type 2 diabetes mellitus (T2DM) in premenopausal and postmenopausal women.

Methods

A total of 3227 women met the requirements from June to December in 2014, including 207 cases of premenopausal women and 3020 cases of postmenopausal women. The prevalence of T2DM and the associated risk factors in the two groups were analysed.

Results

The prevalence of premenopausal women with T2DM was 12.1%, while the prevalence in postmenopausal women was 19.4% (P < 0.05). Total serum protein (TP) (OR = 1.164 95% CI = 1.023–1.324) (P = 0.021) is a major risk factor for premenopausal women with T2DM. The prevalence of T2DM increased with the increase in TP. In postmenopausal groups, the prevalence of T2DM was associated with age (OR = 1.037 95% CI = 1.024–1.051) (P < 0.001), BMI (OR = 1.076 95% CI = 1.044–1.109) (P < 0.001), blood pressure (OR = 1.521 95% CI = 1.234–1.875) (P < 0.001), triglycerides (TG) (OR = 1.106 95% CI = 1.027–1.190) (P = 0.008), blood urea nitrogen (BUN) (OR = 1.065 95% CI = 1.004–1.129) (P = 0.036), alanine aminotransferase (ALT) (OR = 1.009 95% CI = 1.003–1.016) (P = 0.004) and TP (OR = 1.031 95% CI = 1.005–1.057) (P = 0.018).

Conclusions

Postmenopausal women have a higher rate of type 2 diabetes than premenopausal women. TP is a major risk factor for premenopausal women with T2DM. TP, ALT, and BUN are postmenopausal risk factors in addition to traditional risk factors such as obesity, lipidaemia and blood pressure. We should monitor risk factors and take early prevention and intervention measures to reduce the prevalence of diabetes and improve the quality of life of postmenopausal women.

Trial registration

ChiCTR, ChiCTR-TRC-14005029. Registered 29 July 2014,http://www.chictr.org.cn/showproj.aspx?proj=4545

Association Between Okinawan Vegetables Consumption and Risk of Type 2 Diabetes in Japanese Communities: The JPHC Study

Background

Some Okinawan vegetables have been reported to have anti-diabetic activity; however, no prospective cohort study has clarified whether consumption of Okinawan vegetables is associated with a risk of type 2 diabetes. This study aimed to determine the association between consumption of Okinawan vegetables and risk of type 2 diabetes through a large-scale, population-based, prospective study in Japan.

Methods

We examined 10,732 participants (4,714 men and 6,018 women) aged 45–74 years who resided in Okinawa. Participants were asked to answer a 147-item food frequency questionnaire. We calculated the overall amount of Okinawan vegetables consumed and the amount of seven specific kinds of Okinawan vegetables consumed. The odds ratios (ORs) for self-reported type 2 diabetes during 5 years of follow-up were estimated via multivariate logistic regression analysis.

Results

During the 5-year period, 216 new cases (123 men and 93 women) of type 2 diabetes were reported. Comparing the highest tertile to the lowest tertile of intake, the overall amount of Okinawan vegetables consumed was not associated with risk of type 2 diabetes in men (OR 1.22; 95% confidence interval [CI], 0.74–2.01, P-trend = 0.53) or in women (OR 0.96; 95% CI, 0.57–1.62, P-trend = 0.89). The consumption of seven specific kinds of Okinawan vegetables was also not associated with the risk of type 2 diabetes.

Conclusions

The consumption of total Okinawan vegetables was not associated with the risk of type 2 diabetes.

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.

Protective role of skeletal muscle mass against progression from metabolically healthy to unhealthy phenotype

OBJECTIVE

Metabolically healthy individuals are known to be resistant to cardiovascular disease development. However, a considerable fraction of those individuals shows deteriorated metabolic health over time. Although skeletal muscle is the primary insulin-responsive target organ, a longitudinal investigation of the skeletal muscle mass in relation to the development of metabolically unhealthy phenotype has not been performed. We aimed to evaluate whether greater skeletal muscle mass is an independent protective factor for the development of metabolically unhealthy phenotype.

DESIGN, PARTICIPANTS AND MEASUREMENTS

We conducted a retrospective cohort study with 9033 metabolically healthy volunteers who underwent routine health examinations in 2012 and a follow-up examination in 2016. Obesity was defined as Asian-Pacific body mass index criterion ≥25 kg/m² . Subjects with fewer than two risk factors (elevated blood pressure, triglyceride, glucose, high-sensitivity C-reactive protein, insulin resistance and decreased high-density lipoprotein cholesterol levels) were characterized as metabolically healthy using Wildman criteria.

RESULTS

At the 4-year follow-up, approximately one-fourth of the nonobese participants and half of the participants with obesity showed metabolic deterioration. In nonobese men and women, higher appendicular skeletal muscle mass (ASM)/weight at baseline was significantly associated with decreased risk of metabolic deterioration. Compared to the lowest quartile of ASM/weight, the adjusted odds ratios (95% confidence intervals) of the highest quartile were 0.68 (0.52-0.89) in nonobese men and 0.64 (0.46-0.90) in nonobese women. However, this association was not observed in obese subjects.

CONCLUSIONS

Greater skeletal muscle mass at baseline is significantly associated with maintenance of metabolically healthy status, especially in nonobese individuals.