Effects of sex and hormone replacement therapy use on the prevalence of isolated impaired fasting glucose and isolated impaired glucose tolerance in subjects with a family history of type 2 diabetes

Impact of Physiological Fluctuations of Sex Hormones During the Menstrual Cycle on Glucose Metabolism and the Gut Microbiota

Diabetes mellitus is one of the most prevalent chronic diseases. Previous studies have shown differences in glucose metabolism between males and females. Moreover, difficulties in medication adherence have been reported in females with type 2 diabetes. These observations are believed to be caused by fluctuations in sex hormone concentrations during the menstrual cycle. Furthermore, gut microbiota is linked to female host metabolism and sex hormone production. Understanding the interactions between fluctuating hormone concentrations during the menstrual cycle, gut microbiota, and glucose metabolism in humans is significant because of the increasing prevalence of diabetes and the consequent need to expand preventive efforts. A literature search was performed to determine and summarize the existing evidence, deduce future research needs to maintain female health, and investigate the relationship between the physiological menstrual cycle and glucose metabolism. Studies from 1967 to 2020 have already examined the relationship between variations during the menstrual cycle and glucose metabolism in healthy female subjects using an oral-glucose tolerance test or intravenous glucose tolerance test. However, the overall number of studies is rather small and the results are contradictory, as some studies detected differences in glucose concentrations depending on the different cycle phases, whereas others did not. Some studies reported lower glucose levels in the follicular phase than in the luteal phase, whereas another study detected the opposite. Data on gut microbiota in relation to the menstrual cycle are limited. Conflicting results exist when examining the effect of hormonal contraceptives on the gut microbiota and changes in the course of the menstrual cycle. The results indicate that the menstrual cycle, especially fluctuating sex hormones, might impact the gut microbiota composition.The menstrual cycle may affect the gut microbiota composition and glucose metabolism. These results indicate that glucose tolerance may be the greatest in the follicular phase; however, further well-conducted studies are needed to support this assumption.

Prevalence, risk factors and clinical correlates of glucose disturbances in a large sample of Han Chinese patients with first-episode drug-naïve major depressive disorder

Glucose disturbances are a common comorbidity of major depressive disorder (MDD) patients and have been extensively studied in the past. However, few studies have explored glucose disturbances in first-episode drug-naïve (FEDN) MDD patients. The purpose of this study was to examine the prevalence and risk factors of glucose disturbances in FEDN MDD patients to understand the relationship between MDD and glucose disturbances in the acute early phase and provide important implications for therapeutic interventions. Using a cross-sectional design, we recruited a total of 1718 MDD patients. We collected their socio-demographic information, clinical data, and blood glucose indicators.17-item Hamilton Depression Rating Scale (HAMD), 14-item Hamilton Anxiety Rating Scale (HAMA), and the positive symptom subscale of the Positive and Negative Syndrome Scale (PANSS) were used to assess their depression, anxiety, psychotic symptoms, respectively. The prevalence of glucose disturbances in FEDN MDD patients was 13.6%. Depression, anxiety and psychotic symptoms, body mass index (BMI) levels and suicide attempts rates were higher in the group with glucose disorders than in the group without glucose disorders among patients with first-episode drug-naive MDD. Correlation analysis showed that glucose disturbances were associated with HAMD score, HAMA score, BMI, psychotic symptoms and suicide attempts. Furthermore, binary logistic regression showed that HAMD score and suicide attempts were independently associated with glucose disturbances in MDD patients. Our findings suggest that the prevalence of comorbid glucose disturbances is very high in FEDN MDD patients. Moreover, more severe depressive symptoms and higher suicide attempts are correlated with glucose disturbances in MDD FEDN patients in the early stage.

Sex differences in energy metabolism: natural selection, mechanisms and consequences

Metabolic homeostasis operates differently in men and women. This sex asymmetry is the result of evolutionary adaptations that enable women to resist loss of energy stores and protein mass while remaining fertile in times of energy deficit. During starvation or prolonged exercise, women rely on oxidation of lipids, which are a more efficient energy source than carbohydrates, to preserve glucose for neuronal and placental function and spare proteins necessary for organ function. Carbohydrate reliance in men could be an evolutionary adaptation related to defence and hunting, as glucose, unlike lipids, can be used as a fuel for anaerobic high-exertion muscle activity. The larger subcutaneous adipose tissue depots in healthy women than in healthy men provide a mechanism for lipid storage. As female mitochondria have higher functional capacity and greater resistance to oxidative damage than male mitochondria, uniparental inheritance of female mitochondria may reduce the transmission of metabolic disorders. However, in women, starvation resistance and propensity to obesity have evolved in tandem, and the current prevalence of obesity is greater in women than in men. The combination of genetic sex, programming by developmental testosterone in males, and pubertal sex hormones defines sex-specific biological systems in adults that produce phenotypic sex differences in energy homeostasis, metabolic disease and drug responses.

Aging Affects Insulin Resistance, Insulin Secretion, and Glucose Effectiveness in Subjects with Normal Blood Glucose and Body Weight

AIM

Several studies have demonstrated that factors including diabetes, including insulin resistance (IR), glucose effectiveness (GE), and the first and second phase of insulin secretion (FPIS, SPIS) could easily be calculated using basic characteristics and biochemistry profiles. Aging is accompanied by deteriorations of insulin resistance (IR) and insulin secretion. However, little is known about the roles of aging in the different phases of insulin secretion (ISEC), i.e., the first and second phase of insulin secretion (FPIS, SPIS), and glucose effectiveness (GE).

METHODS

In total, 169 individuals (43 men and 126 women) recruited from the data bank of the Meei-Jaw (MJ) Health Screening Center and Cardinal Tien Hospital Data Access Center between 1999 and 2008, with a similar fasting plasma glucose (FPG: 90 mg/dL) and BMI (men: 23 kg/m², women 22 kg/m²) were enrolled. The IR, FPIS, SPIS, and GE were estimated using our previously developed equations shown below. Pearson correlation analysis was conducted to assess the correlations between age and four diabetes factors (DFs: IR, FPIS, SPIS, and GE). The equations that are used to calculate the DF in the present study were built and published by our group.

RESULTS

The age of the participants ranged from 18 to 78 years. Men had higher FPIS but lower HDL-C levels than women (2.067 ± 0.159, 1.950 ± 0.186 μU/min and 1.130 ± 0.306, 1.348 ± 0.357 mmol/dl, accordingly). The results of the Pearson correlation revealed that age was negatively related to the IR and GE in both genders (IR: r = -0.39, p < 0.001 for men, r = -0.24, p < 0.003 for women; GE: r = 0.66, p < 0.001 for men, r = 0.78, p < 0.001 for women). At the same time, the FPIS was also only found to be negatively correlated with age in females (r = -0.238, p = 0.003), but there was no difference in the SPIS and age among both genders.

CONCLUSIONS

We have found that in Chinese subjects with a normal FPG level (90 mg/dL) and body mass index (men: 23 kg/m², women: 22: kg/m²), age is negatively related to the IR and GE among both genders. Only the FPIS was found to be negatively related to age in women. The tightness of their relationships, from the highest to the lowest, are GE, FPIS, and IR. These results should be interpreted with caution because of the small sample size.

Sex differences in the nonlinear association of triglyceride glucose index with all-cause and cardiovascular mortality in the general population

BACKGROUND

The evidence on the association between the triglyceride glucose (TyG) index and the risk of death in the general population remains controversial. This study aims to investigate the relationship between the TyG index and all-cause and cardiovascular mortality in the general population, with a focus on sex differences.

METHODS

This prospective cohort study analyzed data from the National Health and Nutrition Examination Survey (1999-2002), comprising 7,851 US adults. The study employed multivariate Cox proportional hazards regression and two-segment Cox hazard regression models to evaluate the sex-specific differences in the relationship between the TyG index and all-cause and cardiovascular mortality.

RESULTS

After 11,623 person-years of follow-up, there were 539 deaths, with 10.56% due to all-cause mortality and 2.87% due to cardiovascular mortality. After adjusting for multiple variables, our study found a U-shaped association of the TyG index with all-cause and cardiovascular mortality, with inflection points at 9.36 and 9.52. A significant sex difference was observed in the association between the TyG index and mortality. Below the inflection point, the relationship between the TyG index and mortality was consistent in males and females. However, above the inflection point, only males exhibited a positive association between the TyG index and all-cause mortality (adjusted hazard risk [HR], 1.62, 95% confidence interval [CI], 1.24-2.12) and cardiovascular mortality (adjusted HR, 2.28, 95% CI, 1.32-3.92).

CONCLUSIONS

Our study showed a U-shaped association between the TyG index and all-cause and cardiovascular mortality in the general population. Furthermore, sex differences were observed in the association between the TyG index and mortality once it exceeded a certain threshold.

Loss of Brain Angiogenesis Inhibitor-3 (BAI3) G-Protein Coupled Receptor in Mice Regulates Adaptive Thermogenesis by Enhancing Energy Expenditure

Effective energy expenditure is critical for maintaining body weight (BW). However, underlying mechanisms contributing to increased BW remain unknown. We characterized the role of brain angiogenesis inhibitor-3 (BAI3/ADGRB3), an adhesion G-protein coupled receptor (aGPCR), in regulating BW. A CRISPR/Cas9 gene editing approach was utilized to generate a whole-body deletion of the BAI3 gene (BAI3-/-). In both BAI3-/- male and female mice, a significant reduction in BW was observed compared to BAI3+/+ control mice. Quantitative magnetic imaging analysis showed that lean and fat masses were reduced in male and female mice with BAI3 deficiency. Total activity, food intake, energy expenditure (EE), and respiratory exchange ratio (RER) were assessed in mice housed at room temperature using a Comprehensive Lab Animal Monitoring System (CLAMS). While no differences were observed in the activity between the two genotypes in male or female mice, energy expenditure was increased in both sexes with BAI3 deficiency. However, at thermoneutrality (30 °C), no differences in energy expenditure were observed between the two genotypes for either sex, suggesting a role for BAI3 in adaptive thermogenesis. Notably, in male BAI3-/- mice, food intake was reduced, and RER was increased, but these attributes remained unchanged in the female mice upon BAI3 loss. Gene expression analysis showed increased mRNA abundance of thermogenic genes Ucp1, Pgc1α, Prdm16, and Elov3 in brown adipose tissue (BAT). These outcomes suggest that adaptive thermogenesis due to enhanced BAT activity contributes to increased energy expenditure and reduced BW with BAI3 deficiency. Additionally, sex-dependent differences were observed in food intake and RER. These studies identify BAI3 as a novel regulator of BW that can be potentially targeted to improve whole-body energy expenditure.

Interaction between gut microbiota and sex hormones and their relation to sexual dimorphism in metabolic diseases

Metabolic diseases, such as obesity, metabolic syndrome (MetS) and type 2 diabetes (T2D), are now a widespread pandemic in the developed world. These pathologies show sex differences in their development and prevalence, and sex steroids, mainly estrogen and testosterone, are thought to play a prominent role in this sexual dimorphism. The influence of sex hormones on these pathologies is not only reflected in differences between men and women, but also between women themselves, depending on the hormonal changes associated with the menopause. The observed sex differences in gut microbiota composition have led to multiple studies highlighting the interaction between steroid hormones and the gut microbiota and its influence on metabolic diseases, ultimately pointing to a new therapy for these diseases based on the manipulation of the gut microbiota. This review aims to shed light on the role of sexual hormones in sex differences in the development and prevalence of metabolic diseases, focusing on obesity, MetS and T2D. We focus also the interaction between sex hormones and the gut microbiota, and in particular the role of microbiota in aspects such as gut barrier integrity, inflammatory status, and the gut-brain axis, given the relevance of these factors in the development of metabolic diseases.

Involvement of inflammatory lipoproteinemia with idiopathic adhesive capsulitis accompanying subclinical hypothyroidism

BACKGROUND

Thyroid functional abnormalities are considered risk factors for idiopathic adhesive capsulitis (IAC) though that relationship remains uncertain. Although dyslipidemias are associated with IAC, no readily accessible study has reported associations between dyslipidemias and IAC patients with subclinical hypothyroidism. The purposes of this study were to investigate whether subclinical hypothyroidism is an independently associated factor for IAC and to determine the differences in prevalence of dyslipidemias between two groups of persons with subclinical hypothyroidism: one composed of IAC patients and the other of individuals without IAC.

METHODS

This case-control study included a case group of 412 IAC patients without intrinsic shoulder lesions, extrinsic causes, or medication for thyroid dysfunction. The control group comprised 1236 age- and sex-matched persons seeking general checkups at the authors' health promotion center during the same period as the case group. Control subjects had normal shoulder function and no previously diagnosed adhesive capsulitis, no medication for thyroid dysfunction, and no history of trauma or of shoulder surgery. The studied variables were age, gender, obesity, diabetes, dyslipidemias, subclinical hypothyroidism, hypothyroidism, and hyperthyroidism. A conditional logistic regression analysis evaluated the matched sets of subjects to determine odds ratios and 95% confidence intervals for the studied variables. The differences in the prevalence of dyslipidemias between IAC patients with subclinical hypothyroidism and individuals with subclinical hypothyroidism but without IAC were determined with generalized estimating equations, using covariates of age, sex, and diabetes. The P values were set at < 0.05.

RESULTS

Subclinical hypothyroidism (odds ratio, 2.10; 95% confidence interval, 1.36-3.15; P = .001) was significantly associated with IAC. Patients with IAC and subclinical hypothyroidism had a significantly higher prevalence of hyper-low-density lipoproteinemia, an inflammatory lipoproteinemia, than individuals with subclinical hypothyroidism but without IAC (P = .002).

CONCLUSIONS

Subclinical hypothyroidism is significantly associated with IAC. Hyper-low-density lipoproteinemia, an inflammatory lipoproteinemia, is involved in IAC accompanied by subclinical hypothyroidism.

Sex as a Biological Variable in Nutrition Research: From Human Studies to Animal Models

Biological sex is a fundamental source of phenotypic variability across species. Males and females have different nutritional needs and exhibit differences in nutrient digestion and utilization, leading to different health outcomes throughout life. With personalized nutrition gaining popularity in scientific research and clinical practice, it is important to understand the fundamentals of sex differences in nutrition research. Here, we review key studies that investigate sex dimorphism in nutrition research: sex differences in nutrient intake and metabolism, sex-dimorphic response in nutrient-restricted conditions, and sex differences in diet and gut microbiome interactions. Within each area above, factors from sex chromosomes, sex hormones, and sex-specific loci are highlighted.

Real-world Benefits of Diabetes Management App Use and Self-monitoring of Blood Glucose on Glycemic Control: Retrospective Analyses

Background

Among self-care measures, the self-monitoring of blood glucose (SMBG) is a critical component for checking blood glucose levels. In addition, there is growing evidence suggesting that digital technologies are being adopted as an additional method for health care systems to increase patient contact. However, for patients with non–insulin-treated diabetes mellitus type 2 (DMT2), the value of SMBG was inconsistent among studies, and the evidence for digital technologies from real-world clinical practice is still limited.

Objective

Our study aimed to assess patients with non–insulin-treated DMT2 who were receiving care from a single clinic and analyze whether the use of a diabetes management app and SMBG behavior would affect glycemic control in a real-world clinical setting.

Methods

We collaborated with a large clinic focused on diabetes care in Taiwan that had been using the Health2Sync mobile app and web-based Patient Management Platform to collect the data. The patients were divided into 2 groups (app-engaged-user group and only-data-uploader group) according to different activities in the app, and blood glucose was recorded every month from 1 to 6 months after registration in the app. A sample of 420 patients was included in the analysis, and a linear mixed model was built to investigate which factors affected the patients’ blood glucose percentage change.

Results

Using the mixed model coefficient estimates, we found that the percentage change was significantly negative when the only-data-uploader group was set as the baseline (t=–3.873, df=1.81 × 10⁴; P<.001 for the patients of the app-engaged-user group). We found that for patients with shorter diabetes duration, their blood glucose decreased more than patients with longer diabetes duration (t=2.823, df=1.71 × 10⁴; P=.005 for the number of years of diabetes duration). In addition, we found that for younger patients, their blood glucose decreased more than older patients (t=2.652, df=1.71 × 10⁴; P=.008 for the age of the patients). Furthermore, the patients with an education level of junior high school or lower saw a significantly greater decrease in blood glucose percentage change than the patients with an education level of senior high school or higher (t=4.996, df=1.72 × 10⁴; P<.001 for the patients with an education level of senior high school or higher). We also found that the count of blood glucose measured enlarged the decrease along the interaction months (t=–8.266, df=1.97 × 10⁴; P<.001 for the nth month × the count of blood glucose in the nth month). Lastly, the gender of the patients did not significantly affect the percentage change (t=0.534, df=1.74 × 10⁴; P=.59 for female patients).

Conclusions

Our analysis showed the following: the blood glucose percentage change of the patients in the app-engaged-user group dropped more than that in the only-data-uploader group; shorter diabetes duration is associated with a steeper decrease in the patients’ blood glucose percentage change; the percentage decrease in blood glucose change in younger patients is greater than older patients; the blood glucose percentage change of the patients with an education level of junior high school or lower dropped more than those with an education level of senior high school or higher; and the more frequently the patients test SMBG each month, the greater the decrease in the patients’ blood glucose percentage. Further studies can be performed to consider the differences in daily behaviors such as exercise and diet across the patients and whether these factors could have vital effects on glycemic control.

The β Cell in Diabetes: Integrating Biomarkers With Functional Measures

The pathogenesis of hyperglycemia observed in most forms of diabetes is intimately tied to the islet β cell. Impairments in propeptide processing and secretory function, along with the loss of these vital cells, is demonstrable not only in those in whom the diagnosis is established but typically also in individuals who are at increased risk of developing the disease. Biomarkers are used to inform on the state of a biological process, pathological condition, or response to an intervention and are increasingly being used for predicting, diagnosing, and prognosticating disease. They are also proving to be of use in the different forms of diabetes in both research and clinical settings. This review focuses on the β cell, addressing the potential utility of genetic markers, circulating molecules, immune cell phenotyping, and imaging approaches as biomarkers of cellular function and loss of this critical cell. Further, we consider how these biomarkers complement the more long-established, dynamic, and often complex measurements of β-cell secretory function that themselves could be considered biomarkers.

Sex differences in the association between suicide attempts and glucose disturbances in first-episode and drug naive patients with major depressive disorder

BACKGROUND

Glucose metabolism is related to depression, but the relationship between blood glucose and suicide attempts in patients with major depressive disorder (MDD) remains unclear. This large-scale sample explores the relationship between suicide attempts and fasting blood glucose, in addition to sex differences in first-episode and drug naive (FEDN) MDD patients.

METHODS

1718 FEDN MDD patients diagnosed for the first time were recruited, and their demographic data, clinical data, and blood glucose indicators were collected. 17-item Hamilton Depression Rating Scale (HAMD), 14-item Hamilton Anxiety Rating Scale (HAMA), and positive subscale of the Positive and Negative Syndrome Scale (PANSS) were used to assess their depression, anxiety and psychotic symptoms, respectively.

RESULTS

The depression, anxiety, psychotic symptoms and blood sugar levels of the suicide attempt group were higher than those of the non-suicide attempt group. Correlation analysis showed that blood glucose was significantly associated with suicide attempts in male and female patients. While binary logistic regression showed that blood glucose levels were significantly associated with suicide attempts in male patients, it showed that suicide attempts were not significantly associated with blood glucose levels in female patients.

LIMITATIONS

The main limitations are cross-sectional design and inability to control selection bias.

CONCLUSIONS

In male MDD patients, fasting blood glucose level is a potential biomarker of suicide attempt, which deserves attention to avoid suicide risk. However, in female patients, fasting blood glucose has no significant correlation to suicide attempts.

Sexual dimorphism in the progression of type 2 diabetic kidney disease in T2DN rats

Diabetic kidney disease (DKD) is a common complication of diabetes, which frequently leads to end-stage renal failure and increases cardiovascular disease risk. Hyperglycemia promotes renal pathologies such as glomerulosclerosis, tubular hypertrophy, microalbuminuria, and a decline in glomerular filtration rate. Importantly, recent clinical data have demonstrated distinct sexual dimorphism in the pathogenesis of DKD in people with diabetes, which impacts both severity- and age-related risk factors. This study aimed to define sexual dimorphism and renal function in a nonobese type 2 diabetes model with the spontaneous development of advanced diabetic nephropathy (T2DN rats). T2DN rats at 12- and over 48-wk old were used to define disease progression and kidney injury development. We found impaired glucose tolerance and glomerular hyperfiltration in T2DN rats to compare with nondiabetic Wistar control. The T2DN rat displays a significant sexual dimorphism in insulin resistance, plasma cholesterol, renal and glomerular injury, urinary nephrin shedding, and albumin handling. Our results indicate that both male and female T2DN rats developed nonobese type 2 DKD phenotype, where the females had significant protection from the development of severe forms of DKD. Our findings provide further evidence for the T2DN rat strain's effectiveness for studying the multiple facets of DKD.

Chemokines in Prediabetes and Type 2 Diabetes: A Meta-Analysis

Background

A growing number of studies found inconsistent results on the role of chemokines in the progression of type 2 diabetes (T2DM) and prediabetes (PDM). The purpose of this meta-analysis was to summarize the results of previous studies on the association between the chemokines system and T2DM/PDM.

Methods

We searched in the databases, PubMed, Web of Science, Embase and Cochrane Library, for eligible studies published not later than March 1, 2020. Data extraction was performed independently by 2 reviewers, on a standardized, prepiloted form. Group differences in chemokines concentrations were summarized using the standardized mean difference (SMD) with a 95% confidence interval (CI), calculated by performing a meta-analysis using the random-effects model.

Results

We identified 98 relevant studies that investigated the association between 32 different chemokines and T2DM/PDM. Altogether, these studies involved 14,708 patients and 14,574 controls. Results showed that the concentrations of CCL1, CCL2, CCL4, CCL5, CCL11, CXCL8, CXCL10 and CX3CL1 in the T2DM patients were significantly higher than that in the controls, while no difference in these concentrations was found between the PDM patients and controls.

Conclusion

Progression of T2DM may be associated with elevated concentrations of chemokines.

Meta-Analysis Registration

PROSPERO, identifier CRD42019148305.

Incidence of diabetes in South Asian young adults compared to Pima Indians

INTRODUCTION

South Asians (SA) and Pima Indians have high prevalence of diabetes but differ markedly in body size. We hypothesize that young SA will have higher diabetes incidence than Pima Indians at comparable body mass index (BMI) levels.

RESEARCH DESIGN AND METHODS

We used prospective cohort data to estimate age-specific, sex, and BMI-specific diabetes incidence in SA aged 20-44 years living in India and Pakistan from the Center for Cardiometabolic Risk Reduction in South Asia Study (n=6676), and compared with Pima Indians, from Pima Indian Study (n=1852).

RESULTS

At baseline, SA were considerably less obese than Pima Indians (BMI (kg/m²): 24.4 vs 33.8; waist circumference (cm): 82.5 vs 107.0). Age-standardized diabetes incidence (cases/1000 person-years, 95% CI) was lower in SA than in Pima Indians (men: 14.2, 12.2-16.2 vs 37.3, 31.8-42.8; women: 14.8, 13.0-16.5 vs 46.1, 41.2-51.1). Risk of incident diabetes among 20-24-year-old Pima men and women was six times (relative risk (RR), 95% CI: 6.04, 3.30 to 12.0) and seven times (RR, 95% CI: 7.64, 3.73 to 18.2) higher as compared with SA men and women, respectively. In those with BMI <25 kg/m², however, the risk of diabetes was over five times in SA men than in Pima Indian men. Among those with BMI ≥30 kg/m², diabetes incidence in SA men was nearly as high as in Pima men. SA and Pima Indians had similar magnitude of association between age, sex, BMI, and insulin secretion with diabetes. The effect of family history was larger in SA, whereas that of insulin resistance was larger in Pima Indians CONCLUSIONS: In the background of relatively low insulin resistance, higher diabetes incidence in SA is driven by poor insulin secretion in SA men. The findings call for research to improve insulin secretion in early natural history of diabetes.

Sexual dimorphism in adipose tissue mitochondrial function and metabolic flexibility in obesity

OBJECTIVE

The prevalence of obesity is growing globally. Adiposity increases the risk for metabolic syndrome, type 2 diabetes and cardiovascular disease. Adipose tissue distribution influences systemic metabolism and impacts metabolic disease risk. The link between sexual dimorphisms of adiposity and metabolism is poorly defined. We hypothesise that depot-specific adipose tissue mitochondrial function contributes to the sexual dimorphism of metabolic flexibility in obesity.

METHODS

Male and female mice fed high fat diet (HFD) or standard diet (STD) from 8-18 weeks of age underwent whole animal calorimetry and high-resolution mitochondrial respirometry analysis on adipose tissue depots. To determine translatability we used RT-qPCR to examine key brown adipocyte-associated gene expression: peroxisome proliferator-activated receptor co-activator 1α, Uncoupling protein 1 and cell death inducing DFFA like effector a in brown adipose tissue (BAT) and subcutaneous adipose tissue (sWAT) of 18-week-old mice and sWAT from human volunteers.

RESULTS

Male mice exhibited greater weight gain compared to female mice when challenged with HFD. Relative to increased body mass, the adipose to body weight ratio for BAT and sWAT depots was increased in HFD-fed males compared to female HFD-fed mice. Oxygen consumption, energy expenditure, respiratory exchange ratio and food consumption did not differ between males and females fed HFD. BAT mitochondria from obese females showed increased Complex I & II respiration and maximal respiration compared to lean females whereas obese males did not exhibit adaptive mitochondrial BAT respiration. Sexual dimorphism in BAT-associated gene expression in sWAT was also associated with Body Mass Index in humans.

CONCLUSIONS

We show that sexual dimorphism of weight gain is reflected in mitochondrial respiration analysis. Female mice have increased metabolic flexibility to adapt to changes in energy intake by regulating energy expenditure through increased complex II and maximal mitochondrial respiration within BAT when HFD challenged and increased proton leak in sWAT mitochondria.

Association between fasting glucose levels and adhesive capsulitis in a normoglycemic population: a case-control study

BACKGROUND

Hyperglycemia is the most commonly cited risk factor for adhesive capsulitis. However, no study has established whether fasting glucose levels within the normoglycemic range are associated with idiopathic adhesive capsulitis (IAC). This study hypothesized that increments of fasting glucose levels within the normoglycemic range would be linked to IAC. This study investigated any association between normoglycemic fasting glucose levels and IAC.

METHODS

This case-control study comprised a group of 151 patients with IAC without intrinsic shoulder lesions, extrinsic causes, or known metabolic risk factors such as diabetes, dyslipidemia, and thyroid dysfunction. The control group comprised 453 age- and sex-matched persons seeking general check-ups at the authors' health promotion center during the same period as the case group. Control subjects had normal shoulder function, no previous diagnosis of adhesive capsulitis or of metabolic disease, and no history of trauma or of shoulder surgery. The studied variables were body mass index, serum lipid profiles, thyroid hormone levels, fasting glucose levels, glycosylated hemoglobin A1c, and high-sensitivity C-reactive protein. Fasting glucose levels were studied as scale data and categorical data (<85, 85-89, 90-94, and 95-99 mg/dL). Multivariable conditional logistic regression analysis evaluated the matched sets of subjects. Odds ratios and 95% confidence intervals were determined for various potentially associated factors.

RESULTS

Fasting glucose level, hypercholesterolemia, and high-sensitivity C-reactive protein were significantly associated with IAC (P ≤ .030). Fasting glucose levels in the <85 mg/dL quartile were significantly negatively associated with IAC (P ≤ .001). In contrast, fasting glucose levels in the 90-94 mg/dL quartile or higher were significantly positively associated with IAC (P ≤ .034).

CONCLUSION

IAC is positively associated with fasting glucose levels of 90-99 mg/dL, which are currently considered normoglycemic.

Diet quality and its association with glycemic parameters in different diabetes progression stages. A cross-sectional questionnaire study at a primary care clinic

BACKGROUND

Diabetes mellitus is a leading cause of preventable deaths and becomes a major public health concern in Malaysia. Multiple studies have reported the association between diet quality and glycemic parameters among known diabetic subjects. Its influence in individuals with borderline diabetes (i.e. pre-diabetes) or unknown diabetes is still unclear.

OBJECTIVE

The objective of this study was to assess the association between diet quality evaluated by healthy eating index (HEI) with the glucose outcome in individuals with distinct diabetes progression stages, as well as to identify causal factors in relation to their diabetes status.

METHOD

A cross-sectional study was conducted at clinical care setting in Universiti Sains Malaysia (USM) between October 2018-March 2019. Normoglycemic controls (n = 47), at-risk of pre-diabetes (n = 58), pre-diabetes (n = 24) as well as individuals with undiagnosed diabetes (n = 18) were queried about their habitual diet by using Food Frequency Questionnaire (FFQ). Correlation analyses were performed to examine the relationship between HEI score and 1) Fasting plasma glucose (FPG) 2) postprandial blood glucose (2-HPP) and glycosylated hemoglobin (HbA1c). Multinomial regression was performed to identify predictors associated with diabetes status of study participants.

RESULT

Overall, diet quality of study participants was unsatisfactory with the mean score of 58.05 ± 9.07 that need improvement. Total HEI score was negatively correlated with the 2-HPP levels in pre-diabetic patients (r = - 0.45, p = 0.05). No significant association was revealed between glycemic parameters and total HEI score among other groups. Age, body mass index (BMI), triglycerides and female gender were positively correlated with the risk of pre-diabetes, at-risk of pre-diabetes and undiagnosed diabetes (p < 0.01).

CONCLUSION

Diet quality was not strongly associated with glycemic parameters among study participants. Age, BMI, triglycerides and female gender are crucial factors, that needed to be prioritized by primary care providers when managing pre-diabetes/diabetes to achieve possible reversion. Further in-depth investigations with large sample are warranted to confirm study findings.

Association Between High-Sensitivity C-Reactive Protein and Idiopathic Adhesive Capsulitis

BACKGROUND

Chronic inflammation is implicated in the development of idiopathic adhesive capsulitis (IAC), whose association with high-sensitivity C-reactive protein (CRP), an inflammation marker, is undetermined. This study's purposes were to investigate the association between high-sensitivity CRP levels and IAC and to determine the metabolic factors associated with high-sensitivity CRP.

METHODS

This case-control study examined a group of 202 patients with IAC and without intrinsic shoulder lesions or extrinsic causes and a control group of 606 age and sex-matched persons seeking general check-ups at our health promotion center during the same period as the case group. Control subjects had normal shoulder function and no previously diagnosed adhesive capsulitis; no medication for diabetes, dyslipidemia, and thyroid abnormalities; and no history of trauma or of shoulder surgery. The studied variables were body mass index; diabetes; thyroid abnormalities; dyslipidemias; triglyceride/high-density lipoprotein (TG/HDL) >3.5; serum levels of thyroid hormone, fasting glucose, and glycosylated hemoglobin A1c (HbA1c); and high-sensitivity CRP >1.0 mg/L. Multivariable conditional logistic regression analysis evaluated the matched sets of subjects. Odds ratios (ORs) and 95% confidence intervals (CIs) were determined for the studied variables possibly affecting IAC.

RESULTS

Serum high-sensitivity CRP >1.0 mg/L was significantly associated with IAC (OR, 2.47 [95% CI, 1.65 to 3.70]) after adjusting for diabetes, fasting glucose level, HbA1c, dyslipidemia, TG/HDL >3.5, and thyroid-stimulating hormone (p ≤ 0.031). Diabetes (OR, 1.71 [95% CI, 1.09 to 3.33]), fasting glucose level (OR, 1.54 [95% CI, 1.12 to 2.12]), HbA1c (OR, 2.00 [95% CI, 1.25 to 3.22]), hypertriglyceridemia (OR, 1.70 [95% CI, 1.03 to 3.41]), hypo-high-density lipoproteinemia (OR, 1.98 [95% CI, 1.04 to 3.79]), and TG/HDL >3.5 (OR, 1.37 [95% CI, 1.06 to 1.88]) were significantly associated with high-sensitivity CRP >1.0 mg/L in patients with IAC (p ≤ 0.039).

CONCLUSIONS

Serum high-sensitivity CRP >1.0 mg/L is an independent associated marker for IAC. Dyslipidemia, insulin resistance, and hyperglycemia, which are recognized factors associated with IAC, are also associated with high-sensitivity CRP >1.0 mg/L in these patients, supporting the interaction of chronic systemic inflammation in IAC.

LEVEL OF EVIDENCE

Prognostic Level III. See Instructions for Authors for a complete description of levels of evidence.

Lipid peroxidation mediated the association of urinary 1-bromopropane metabolites with plasma glucose and the risk of diabetes: A cross-sectional study of urban adults in China

Exposure to 1-bromopropane (1-BP) has been reported to cause glutathione depletion and increase the level of oxidative damage, which play critical roles in diabetes. However, the possible associations or mechanisms of the exposure of 1-BP with the plasma glucose level and the risk of diabetes are unclear. In this study, we explored the relationships of the urinary 1-BP metabolite N-Acetyl-S-(n-propyl)-l-cysteine (BPMA) with fasting plasma glucose (FPG) levels and the risk of diabetes, and the mediating role of oxidative damage in the above relationships in 3678 urban adults from the Wuhan-Zhuhai cohort in China. We found a significant dose-response relationship between BPMA and FPG levels with a β of 0.09 (95 % CI: 0.04, 0.14). In addition, mediating effect of urinary BPMA on FPG levels was observed depending on elevated 8-isoprostane level, with a median proportion of 32.06 %. Furthermore, we observed a significant association between urinary BPMA and the risk of diabetes, with an adjusted odds ratio of 1.34 (1.18, 1.52) for all participants. These results indicated that urinary 1-BP metabolites were positively associated with FPG levels and the risk of diabetes among urban adults in this cross-sectional study. Lipid peroxidation partially mediated the association between urinary 1-BP metabolites and FPG levels.

The Effects of Postprandial Resistance Exercise on Blood Glucose and Lipids in Prediabetic, Beta-Thalassemia Major Patients

Insulin resistance and diabetes mellitus are common consequences of iron overload in the pancreas of beta-thalassemia major (BTM) patients. Moreover, postprandial blood glucose elevations are linked to major vascular complications. The purpose of this study was to investigate the effects of a bout of acute resistance exercise following breakfast consumption of glucose and fat on the metabolism in prediabetic, BTM patients. Six patients underwent two trials (exercise and control) following breakfast consumption (consisting of approximately 50% carbohydrates, 15% proteins, 35% fat), in a counterbalanced order, separated by at least three days. In an exercise trial, patients performed chest and leg presses (3 sets of 10 repetitions maximum/exercise), while in the control trial they rested. Blood samples were obtained in both trials at: pre-meal, 45 min post-meal (pre-exercise/control), post-exercise/control, 1 h post-exercise/control, 2 h post-exercise/control and 24 h post-exercise/control. Blood was analysed for glucose and lipids (total cholesterol, High Density Lipoprotein-cholesterol, Low Density Lipoprotein-cholesterol, triglycerides). Blood glucose levels increased significantly 45 min following breakfast consumption. Blood glucose and lipids did not differ between trials at the same time points. It seems that a single bout of resistance training is not sufficient to improve blood glucose and fat levels for the subsequent 24-h post-exercise period in prediabetic, BTM patients.

Prevalence of Prediabetes Among Adolescents and Young Adults in the United States, 2005-2016

IMPORTANCE

Individuals with prediabetes are at increased risk of developing type 2 diabetes, chronic kidney disease, and cardiovascular disease. The incidence and prevalence of type 2 diabetes in the US adolescent population have increased in the last decade. Therefore, it is important to monitor the prevalence of prediabetes and varying levels of glucose tolerance to assess the future risk of type 2 diabetes in the youngest segment of the population.

OBJECTIVE

To examine the prevalence of impaired fasting glucose (IFG), impaired glucose tolerance (IGT), and increased glycated hemoglobin A1c (HbA1c) levels in US adolescents (aged 12-18 years) and young adults (aged 19-34 years) without diabetes.

DESIGN, SETTING, AND PARTICIPANTS

This cross-sectional analyses of the 2005-2016 National Health and Nutrition Examination Survey assessed a population-based sample of adolescents and young adults who were not pregnant, did not have diabetes, and had measured fasting plasma glucose, 2-hour plasma glucose after a 75-g oral glucose tolerance test, and HbA1c levels. Analysis began in April 2017.

MAIN OUTCOMES AND MEASURES

Impaired fasting glucose was defined as fasting plasma glucose of 100 mg/dL to less than 126 mg/dL, IGT as 2-hour plasma glucose of 140 mg/dL to less than 200 mg/dL, and increased HbA1c level as HbA1c level between 5.7% and 6.4%. The prevalence of IFG, isolated IFG, IGT, isolated IGT, increased HbA1c level, isolated increased HbA1c level, and prediabetes (defined as having IFG, IGT, or increased HbA1c level) were estimated. Fasting insulin levels and cardiometabolic risk factors across glycemic abnormality phenotypes were also compared. Obesity was defined as having age- and sex-specific body mass index (calculated as weight in kilograms divided by height in meters squared) in the 95th percentile or higher in adolescents or 30 or higher in young adults.

RESULTS

Of 5786 individuals, 2606 (45%) were adolescents and 3180 (55%) were young adults. Of adolescents, 50.6% (95% CI, 47.6%-53.6%) were boys, and 50.6% (95% CI, 48.8%-52.4%) of young adults were men. Among adolescents, the prevalence of prediabetes was 18.0% (95% CI, 16.0%-20.1%) and among young adults was 24.0% (95% CI, 22.0%-26.1%). Impaired fasting glucose constituted the largest proportion of prediabetes, with prevalence of 11.1% (95% CI, 9.5%-13.0%) in adolescents and 15.8% (95% CI, 14.0%-17.9%) in young adults. In multivariable logistic models including age, sex, race/ethnicity, and body mass index, the predictive marginal prevalence of prediabetes was significantly higher in male than in female individuals (22.5% [95% CI, 19.5%-25.4%] vs 13.4% [95% CI, 10.8%-16.5%] in adolescents and 29.1% [95% CI, 26.4%-32.1%] vs 18.8% [95% CI, 16.5%-21.3%] in young adults). Prediabetes prevalence was significantly higher in individuals with obesity than in those with normal weight (25.7% [95% CI, 20.0%-32.4%] vs 16.4% [95% CI, 14.3%-18.7%] in adolescents and 36.9% [95% CI, 32.9%-41.1%] vs 16.6% [95% CI, 14.2%-19.4%] in young adults). Compared with persons with normal glucose tolerance, adolescents and young adults with prediabetes had significantly higher non-high-density lipoprotein cholesterol levels, systolic blood pressure, central adiposity, and lower insulin sensitivity (P < .05 for all).

CONCLUSIONS AND RELEVANCE

In the United States, about 1 of 5 adolescents and 1 of 4 young adults have prediabetes. The adjusted prevalence of prediabetes is higher in male individuals and in people with obesity. Adolescents and young adults with prediabetes also present an unfavorable cardiometabolic risk profile, putting them both at increased risk of type 2 diabetes and cardiovascular diseases.

Activation of brown adipose tissue in diet-induced thermogenesis is GC-C dependent

Uroguanylin (UGN) is released from the intestine after a meal. When applied in brain ventricles, UGN increases expression of markers of thermogenesis in brown adipose tissue (BAT). Therefore, we determine the effects of its receptor, guanylate cyclase C (GC-C), on mouse interscapular BAT (iBAT) activity during diet-induced thermogenesis (DIT). The activation of iBAT after a meal is diminished in GC-C KO mice, decreased in female wild type (WT) mice, and abolished in old WT animals. The activation of iBAT after a meal is the highest in male WT animals which leads to an increase in GC-C expression in the hypothalamus, an increase in iBAT volume by aging, and induction of iBAT markers of thermogenesis. In contrast to iBAT activation after a meal, iBAT activation after a cold exposure could still exist in GC-C KO mice and it is significantly higher in female WT mice. The expression of GC-C in the proopiomelanocortin neurons of the arcuate nucleus of the hypothalamus but not in iBAT suggests central regulation of iBAT function. The iBAT activity during DIT has significantly reduced in old mice but an intranasal application of UGN leads to an increase in iBAT activity in a dose-dependent manner which is in strong negative correlation to glucose concentration in blood. This activation was not present in GC-C KO mice. Our results suggest the physiological role of GC-C on the BAT regulation and its importance in the regulation of glucose homeostasis and the development of new therapy for obesity and insulin resistance.

Sex Differences in Age-Associated Type 2 Diabetes in Rats-Role of Estrogens and Oxidative Stress

Females live longer than males, and the estrogens are one of the reasons for this difference. We reported some years ago that estrogens are able to protect rats against oxidative stress, by inducing antioxidant genes. Type 2 diabetes is an age-associated disease in which oxidative stress is involved, and moreover, some studies show that the prevalence is higher in men than in women, and therefore there are sex-associated differences. Thus, the aim of this study was to evaluate the role of estrogens in protecting against oxidative stress in type 2 diabetic males and females. For this purpose, we used Goto-Kakizaki rats, which develop type 2 diabetes with age. We found that female diabetic rats showed lower glycaemia levels with age than did diabetic males and that estrogens enhanced insulin sensitivity in diabetic females. Moreover, glucose uptake, measured by positron emission tomography, was higher in the female brain, cerebellum, and heart than in those from male diabetic rats. There were also sex-associated differences in the plasma metabolic profile as determined by metabolomics. The metabolic profile was similar between estrogen-replaced and control diabetic rats and different from ovariectomized diabetic rats. Oxidative stress is involved in these differences. We showed that hepatic mitochondria from females produced less hydrogen peroxide levels and exhibited lower xanthine oxidase activity. We also found that hepatic mitochondrial glutathione oxidation and lipid oxidation levels were lower in diabetic females when compared with diabetic males. Ovariectomy induced oxidative stress, and estrogen replacement therapy prevented it. These findings provide evidence for estrogen beneficial effects in type 2 diabetes and should be considered when prescribing estrogen replacement therapy to menopausal women.

Lower Plasma Magnesium, Measured by Nuclear Magnetic Resonance Spectroscopy, is Associated with Increased Risk of Developing Type 2 Diabetes Mellitus in Women: Results from a Dutch Prospective Cohort Study

Background: Low circulating magnesium (Mg) is associated with an increased risk of developing type 2 diabetes mellitus (T2DM). We aimed to study the performance of a nuclear magnetic resonance (NMR)-based assay that quantifies ionized Mg in EDTA plasma samples and prospectively investigate the association of Mg with the risk of T2DM. Methods: The analytic performance of an NMR-based assay for measuring plasma Mg was evaluated. We studied 5747 subjects free of T2DM at baseline in the Prevention of Renal and Vascular End-stage Disease (PREVEND) study. Results: Passing–Bablok regression analysis, comparing NMR-measured ionized Mg with total Mg measured by the Roche colorimetric assay, produced a correlation of r = 0.90, with a slope of 1.08 (95% CI: 1.00–1.13) and an intercept of 0.02 (95% CI: −0.02–0.08). During a median follow-up period of 11.2 (IQR: 7.7–12.0) years, 289 (5.0%) participants developed T2DM. The association of NMR-measured ionized Mg with T2DM risk was modified by sex (P_interaction = 0.007). In women, we found an inverse association between Mg and the risk of developing T2DM, independent of adjustment for potential confounders (HR: 1.80; 95% CI: 1.20–2.70). In men, we found no association between Mg and the risk of developing T2DM (HR: 0.90; 95%: 0.67–1.21). Conclusion: Lower NMR-measured plasma ionized Mg was independently associated with a higher risk of developing T2DM in women, but not in men.

Sex differences in metabolism and cardiometabolic disorders

PURPOSE OF REVIEW

Sex differences are pervasive in metabolic and cardiovascular traits, yet they have often been ignored in human and animal model research. Sex differences can arise from reversible hormonal effects, from irreversible organizational (developmental) processes, and from gene expression differences from the X and Y chromosomes. We briefly review our current understanding of the impact of these factors in metabolic traits and disorders, with an emphasis on the recent literature.

RECENT FINDINGS

Novel sex differences continue to be identified for metabolic and cardiovascular traits. For example, it is now clear that gut microbiota tend to differ between men and women, with potentially large implications for disease susceptibility. Also, tissue-specific gene regulation differs between men and women, contributing to differential metabolism. These new insights will open up personalized therapeutic avenues for cardiometabolic diseases.

SUMMARY

Sex differences in body fat distribution, glucose homeostasis, insulin signaling, ectopic fat accumulation, and lipid metabolism during normal growth and in response to hormonal or nutritional imbalance are mediated partly through sex hormones and the sex chromosome complement. Most of these differences are mediated in a tissue-specific manner. Important future goals are to better understand the interactions between genetic variation and sex differences, and to bring an understanding of sex differences into clinical practice.

Ideal cardiovascular health among Ghanaian populations in three European countries and rural and urban Ghana: the RODAM study

Cardiovascular health (CVH) is a construct defined by the American Heart Association (AHA) as part of its 2020 Impact Goal definition. CVH has, until now, not been evaluated in Sub-Saharan African populations. The aim of this study was to investigate differences in the prevalence of ideal CVH and its constituent metrics among Ghanaians living in rural and urban Ghana and Ghanaian migrants living in three European countries. The AHA definition of CVH is based on 7 metrics: smoking, body mass index, diet, physical activity, blood pressure, total cholesterol, and fasting plasma glucose. These were evaluated among 3510 Ghanaian adults (aged 25-70 years) residing in rural and urban Ghana and three European cities (Amsterdam, London and Berlin) in the multi-centre RODAM study. Differences between groups were assessed using logistic regression with adjustments for gender, age, and education. Only 0.3% of all participants met all 7 metrics of the AHA's definition of ideal CVH. Compared to rural Ghana (25.7%), the proportions and adjusted odds ratio (OR) of individuals who had 6-7 CVH metrics in the ideal category were substantially lower in urban Ghana, (7.5%; OR 0.204, 95% CI 0.15-0.29), Amsterdam (4.4%; 0.13, 0.08-0.19), Berlin (2.7%; 0.06, 0.03-0.11), and London (1.7%; 0.04, 0.02-0.09), respectively. The proportion of ideal CVH for the various metrics ranged from 96% for all sites in the smoking metric to below 6% in the diet metric. The proportion of ideal CVH is extremely low in Ghanaians, especially among those living in urban Ghana and Ghanaian migrants in Europe.

Gender differences in glucose homeostasis and diabetes

Some aspects of glucose homeostasis are regulated differently in males and females. This review discusses the most fundamental gender differences in glucose homeostasis and diabetes. These include the prevalence of impaired fasting glucose and impaired glucose tolerance, the prevalence and incidence of type 2 and type 1 diabetes, and the sex-specific effects of testosterone and estrogen deficiency and excess. These gender-specific differences in glucose homeostasis represent a source of factors that should be studied to develop gender-based therapeutic avenues for diabetes.

Association between Socioeconomic Status and Diabetes Mellitus: The National Socioeconomics Survey, 2010 and 2012

INTRODUCTION

The prevalence of Diabetes Mellitus (DM) is increasing, globally. However, studies on the association between Socioeconomic Status (SES) factors and DM have mostly been conducted in specific areas with rather small sample sizes or not with nationally representative samples. Their results have also been inconclusive regarding whether SES has any influence on DM or not.

AIM

To determine the association between SES and DM in Thailand.

MATERIALS AND METHODS

This study utilized the data from the National socioeconomics survey, a cross-sectional study conducted by the National Statistical Office (NSO) in 2010 and 2012. A total of 17,045 and 16,903 participants respectively who met the inclusion criteria were included in this study. The information was collected by face-to-face interview with structured questionnaires. Multilevel mixed-effects logistic regression analysis was performed to determine the potential socioeconomic factors associated with DM.

RESULTS

The prevalence of DM was 3.70% (95% CI: 3.36 to 4.05) and 8.11% (95%CI: 6.25 to 9.74) in 2010 and 2012 respectively and the prevalence of DM in 2012 was 1.36 times (95% CI: 1.25 to 1.48) when compared with 2010. The multilevel mixed-effects logistic regression observed that odds of having DM were significantly higher among those who aged 55-64 years old in 2010 and 65 years old or greater in 2012 (OR_adj = 18.13; 95%CI: 9.11 to 36.08, OR_adj 31.69; 95%CI: 20.78 to 48.33, respectively), females (OR_adj = 2.09; 95%CI: 1.66 to 2.62, OR_adj = 1.77; 95%CI: 1.54 to 2.05, respectively), and had lower education attainment (OR_adj = 5.87; 95%CI: 4.70 to 7.33, OR_adj= 1.22; 95%CI: 1.04 to 1.45, respectively) were also found to be associated with DM .

CONCLUSION

The study indicated that SES has been associated with DM. Those with female gender, old age and low educational attainment were vulnerable to DM.

Sex-gender-related therapeutic approaches for cardiovascular complications associated with diabetes

Diabetes is a chronic disease associated with micro- and macrovascular complications and is a well-established risk factor for cardiovascular disease. Cardiovascular complications associated with diabetes are among the most important causes of death in diabetic patients. Interestingly, several sex-gender differences have been reported to significantly impact in the pathophysiology of diabetes. In particular, sex-gender differences have been reported to affect diabetes epidemiology, risk factors, as well as cardiovascular complications associated with diabetes. This suggests that different therapeutic approaches are needed for managing diabetes-associated cardiovascular complications in men and women. In this review, we will discuss about the sex-gender differences that are known to impact on diabetes, mainly focusing on the cardiovascular complications associated with the disease. We will then discuss the therapeutic approaches for managing diabetes-associated cardiovascular complications and how differences in sex-gender can influence the existing therapeutic approaches.

Epidemiology of Gender Differences in Diabetes and Obesity

Some aspects of glucose homeostasis and energy balance are regulated differently in males and females. This review discusses the most fundamental gender differences in diabetes and obesity, including the prevalence of impaired fasting glucose and impaired glucose tolerance, the prevalence and incidence of type 2 and type 1 diabetes, as well as the prevalence of metabolic syndrome and obesity. These gender-specific differences in glucose homeostasis and energy balance represent a source of factors that should be studied to develop gender-based therapeutic avenues for diabetes.

Gender-specific differences in diabetic neuropathy in BTBR ob/ob mice

AIMS

To identify a female mouse model of diabetic peripheral neuropathy (DPN), we characterized DPN in female BTBR ob/ob mice and compared their phenotype to non-diabetic and gender-matched controls. We also identified dysregulated genes and pathways in sciatic nerve (SCN) and dorsal root ganglia (DRG) of female BTBR ob/ob mice to determine potential DPN mechanisms.

METHODS

Terminal neuropathy phenotyping consisted of examining latency to heat stimuli, sciatic motor and sural sensory nerve conduction velocities (NCV), and intraepidermal nerve fiber (IENF) density. For gene expression profiling, DRG and SCN were dissected, RNA was isolated and processed using microarray technology and differentially expressed genes were identified.

RESULTS

Similar motor and sensory NCV deficits were observed in male and female BTBR ob/ob mice at study termination; however, IENF density was greater in female ob/ob mice than their male counterparts. Male and female ob/ob mice exhibited similar weight gain, hyperglycemia, and hyperinsulinemia compared to non-diabetic controls, although triglycerides were elevated more so in males than in females. Transcriptional profiling of nerve tissue from female mice identified dysregulation of pathways related to inflammation.

CONCLUSIONS

Similar to males, female BTBR ob/ob mice display robust DPN, and pathways related to inflammation are dysregulated in peripheral nerve.

Steroid Sex Hormones, Sex Hormone-Binding Globulin, and Diabetes Incidence in the Diabetes Prevention Program

CONTEXT

Steroid sex hormones and SHBG may modify metabolism and diabetes risk, with implications for sex-specific diabetes risk and effects of prevention interventions.

OBJECTIVE

This study aimed to evaluate the relationships of steroid sex hormones, SHBG and SHBG single-nucleotide polymorphisms (SNPs) with diabetes risk factors and with progression to diabetes in the Diabetes Prevention Program (DPP).

DESIGN AND SETTING

This was a secondary analysis of a multicenter randomized clinical trial involving 27 U.S. academic institutions.

PARTICIPANTS

The study included 2898 DPP participants: 969 men, 948 premenopausal women not taking exogenous sex hormones, 550 postmenopausal women not taking exogenous sex hormones, and 431 postmenopausal women taking exogenous sex hormones.

INTERVENTIONS

Participants were randomized to receive intensive lifestyle intervention, metformin, or placebo.

MAIN OUTCOMES

Associations of steroid sex hormones, SHBG, and SHBG SNPs with glycemia and diabetes risk factors, and with incident diabetes over median 3.0 years (maximum, 5.0 y).

RESULTS

T and DHT were inversely associated with fasting glucose in men, and estrone sulfate was directly associated with 2-hour post-challenge glucose in men and premenopausal women. SHBG was associated with fasting glucose in premenopausal women not taking exogenous sex hormones, and in postmenopausal women taking exogenous sex hormones, but not in the other groups. Diabetes incidence was directly associated with estrone and estradiol and inversely with T in men; the association with T was lost after adjustment for waist circumference. Sex steroids were not associated with diabetes outcomes in women. SHBG and SHBG SNPs did not predict incident diabetes in the DPP population.

CONCLUSIONS

Estrogens and T predicted diabetes risk in men but not in women. SHBG and its polymorphisms did not predict risk in men or women. Diabetes risk is more potently determined by obesity and glycemia than by sex hormones.

Sex differences in metabolic homeostasis, diabetes, and obesity

There are fundamental aspects of the control of metabolic homeostasis that are regulated differently in males and females. This sex asymmetry represents an evolutionary paradigm for females to resist the loss of energy stores. This perspective discusses the most fundamental sex differences in metabolic homeostasis, diabetes, and obesity. Together, the role of genetic sex, the programming effect of testosterone in the prenatal period in males, and the activational role of sex hormones at puberty produce two different biological systems in males and females that need to be studied separately. These sex-specific differences in energy homeostasis and metabolic dysfunction represent an untested source of factors that can be harnessed to develop relevant sex-based therapeutic avenues for diabetes, metabolic syndrome, and obesity.

Differences by sex in the prevalence of diabetes mellitus, impaired fasting glycaemia and impaired glucose tolerance in sub-Saharan Africa: a systematic review and meta-analysis

OBJECTIVE

To assess differences between men and women in the prevalence of diabetes mellitus, impaired fasting glycaemia and impaired glucose tolerance in sub-Saharan Africa.

METHODS

In September 2011, the PubMed and Web of Science databases were searched for community-based, cross-sectional studies providing sex-specific prevalences of any of the three study conditions among adults living in parts of sub-Saharan Africa (i.e. in Eastern, Middle and Southern Africa according to the United Nations subregional classification for African countries). A random-effects model was then used to calculate and compare the odds of men and women having each condition.

FINDINGS

In a meta-analysis of the 36 relevant, cross-sectional data sets that were identified, impaired fasting glycaemia was found to be more common in men than in women (OR: 1.56; 95% confidence interval, CI: 1.20-2.03), whereas impaired glucose tolerance was found to be less common in men than in women (OR: 0.84; 95% CI: 0.72-0.98). The prevalence of diabetes mellitus - which was generally similar in both sexes (OR: 1.01; 95% CI: 0.91-1.11) - was higher among the women in Southern Africa than among the men from the same subregion and lower among the women from Eastern and Middle Africa and from low-income countries of sub-Saharan Africa than among the corresponding men.

CONCLUSION

Compared with women in the same subregions, men in Eastern, Middle and Southern Africa were found to have a similar overall prevalence of diabetes mellitus but were more likely to have impaired fasting glycaemia and less likely to have impaired glucose tolerance.

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

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

Toward integrated and sustainable prevention against diabetes in rural China: study rationale and protocol of eCROPS

BACKGROUND

Being an intermediate stage in the development of diabetes, pre-diabetics were estimated as high as 14% to 63% in China and one to three quarters of them will develop into diabetes within 10 years. It is well established that the risk of diabetes progression can be modified substantially and a whole range of proven guidelines, protocols and methodologies are available. Unfortunately, most proven interventions are seldom used in daily practice and this is especially true in resource poor rural China. This project aims at demonstrating that an evolutionary intervention package featuring low cost, integration with routine services, cultural sensitization and self-optimization, is effective and sustainable in preventing diabetes.

METHODS/DESIGN

This project utilizes a quasi cluster randomized controlled trial and a batched implementation strategy in which villages are recruited in 7 blocks within 7 consecutive years respectively. Block 0 involves 3 villages and provides an opportunity for piloting and refining primitive intervention methodologies and protocols. The following 6 blocks consist of 14 villages each and serve as intervention arm; while all the villages not yet started intervention form the control arm. For each block, measurement happens at baseline and every 12 months (for plasma glucose) or monthly (for body weight and blood pressure) after baseline. These arrangements enable documentation of up to 6 years of consecutive measures and detection of lower incidence of progression into diabetes, improved body max index and blood pressure, and increased service use and involvement in healthy dietary and physical activities among pre-diabetics receiving the experimental intervention compared to themselves at baseline or those in the delayed-intervention control condition.

DISCUSSION

China has a long history of separating disease prevention and treatment systems and there is a clear need to leverages key success factors in a synergetic way toward integrated and sustainable diabetes prevention. This project is owned and managed by local health authorities and utilizes available resources. It introduces a package of long-term incentives, establishes ongoing mechanisms for continuous capacity building and quality improvement, and builds up an operational cycle for catalyzing similar efforts in the local prefecture even throughout rural China.

TRIAL REGISTRATION

Current Controlled Trials: ISRCTN66772711.

Reductions in glucose among postmenopausal women who use and do not use estrogen therapy

OBJECTIVE

Among postmenopausal women who do not use estrogen therapy (ET), we have previously reported that intensive lifestyle modification (ILS) leads to increases in sex hormone-binding globulin (SHBG) and that such increases are associated with reductions in fasting plasma glucose (FPG) and 2-hour postchallenge glucose (2HG). Oral ET decreases FPG and increases 2HG while increasing both SHBG and estradiol (E2). It is unknown if ILS reduces glucose among ET users, if changes in SHBG and E2 might mediate any glucose decreases in ET users, and if these patterns differ from those in non-ET users.

METHODS

We conducted a secondary analysis of postmenopausal women in the Diabetes Prevention Program who used ET at baseline and 1-year follow-up (n = 324) and who did not use ET at either time point (n = 382). Participants were randomized to ILS, metformin, or placebo administered at 850 mg BID.

RESULTS

ET users were younger, more often white, and more likely to have had bilateral oophorectomy than non-ET users. Among ET users, ILS reduced FPG (P < 0.01) and 2HG (P < 0.01), and metformin reduced FPG (P < 0.01) but not 2HG (P = 0.56), compared with placebo. Associations between SHBG and total E2 with FPG and 2HG were not significant among women randomized to ILS or metformin. These patterns differed from those observed among women who did not use ET.

CONCLUSIONS

We conclude that among glucose-intolerant ET users, interventions to reduce glucose are effective but possibly mediated through different pathways than among women who do not use ET.

Diabetes mellitus in patients with schizophrenia in West-Bank, Palestine

AIMS

The main aims of the study were to investigate the prevalence of pre-diabetes and diabetes mellitus (DM) in patients with schizophrenia, to compare it with those published in the general population, and to assess significant associations with dysglycemia defined as having either pre-DM or DM.

METHODS

A cross-sectional study carried out in 4 governmental primary psychiatric healthcare centers in Northern West-Bank, Palestine. Fasting blood glucose (FBG) and glycated hemoglobin (HbA1c) were measured. The World Health Organization (WHO) criteria for defining pre-DM and DM were used. Dysglycemia was defined as FBG >110mg/dl.

RESULTS

Based on WHO criteria, 27 patients (10.8%) had diabetes and 34 (13.6%) had pre-diabetes. The prevalence of DM in patients with schizophrenia was not significantly higher than that reported in the general population of Palestine. However, the prevalence of pre-DM was significantly higher than that reported in the general population of Palestine. Regression analysis showed that advancing age and abnormal waist circumference were significant predictors of dysglycemia in patients with schizophrenia.

CONCLUSIONS

This study confirmed the high prevalence of dysglycemia in patients with schizophrenia, supporting the need for monitoring of blood glucose in this category of patients. The presence of primary risk factors is more important in the development of dysglycemia in patients with schizophrenia than exposure to antipsychotic drugs.

A Comparison between Revised NCEP ATP III and IDF Definitions in Diagnosing Metabolic Syndrome in an Urban Sri Lankan Population: The Ragama Health Study

Background. The prevalence of metabolic syndrome (MetS) within individual cohorts varies with the definition used. The aim of this study was to compare the prevalence of MetS between IDF and revised NCEP ATP III criteria in an urban Sri Lankan population and to investigate the characteristics of discrepant cases. Methods. 2985 individuals, aged 35-65 years, were recruited to the study. Anthropometric and blood pressure measurements and laboratory investigations were carried out following standard protocols. Results. Age and sex-adjusted prevalences of MetS were 46.1% and 38.9% by revised NCEP and IDF definitions, respectively. IDF criteria failed to identify 21% of men and 7% of women identified by the revised NCEP criteria. The discrepant group had more adverse metabolic profiles despite having a lower waist circumference than those diagnosed by both criteria. Conclusion. MetS is common in this urban Sri Lankan cohort regardless of the definition used. The revised NCEP definition was more appropriate in identifying the metabolically abnormal but nonobese individuals, especially among the males predisposed to type 2 diabetes or cardiovascular disease. Further research is needed to determine the suitability of the currently accepted Asian-specific cut-offs for waist circumference in Sri Lankan adults.

Gender differences in the prevalence of diabetes mellitus in chronic hospitalized patients with schizophrenia on long-term antipsychotics

Gender-specific relationships between diabetes mellitus (DM) and schizophrenia have previously received little systematic study. The results showed that the overall DM prevalence was 20% with rates of 17% (58/343) in males and 27% (46/172) in females (p<0.01). Furthermore, increased body mass index (BMI), abdominal obesity and antipsychotic types were predictors of diabetes in these chronic schizophrenic patients.

Altered intramuscular lipid metabolism relates to diminished insulin action in men, but not women, in progression to diabetes

Whether sex differences in intramuscular triglyceride (IMTG) metabolism underlie sex differences in the progression to diabetes are unknown. Therefore, the current study examined IMTG concentration and fractional synthesis rate (FSR) in obese men and women with normal glucose tolerance (NGT) vs. those with prediabetes (PD). PD (n = 13 men and 7 women) and NGT (n = 7 men and 12 women) groups were matched for age and anthropometry. Insulin action was quantified using a hyperinsulinemic-euglycemic clamp with infusion of [6,6-(2)H(2)]-glucose. IMTG concentration was measured by gas chromatography/mass spectrometry (GC/MS) and FSR by GC/combustion isotope ratio MS (C-IRMS), from muscle biopsies taken after infusion of [U-(13)C]palmitate during 4 h of rest. In PD men, the metabolic clearance rate (MCR) of glucose was lower during the clamp (4.71 ± 0.77 vs. 8.62 ± 1.26 ml/kg fat-free mass (FFM)/min, P = 0.04; with a trend for lower glucose rate of disappearance (Rd), P = 0.07), in addition to higher IMTG concentration (41.2 ± 5.0 vs. 21.2 ± 3.4 µg/mg dry weight, P ≤ 0.01), lower FSR (0.21 ± 0.03 vs. 0.42 ± 0.06 %/h, P ≤ 0.01), and lower oxidative capacity (P = 0.03) compared to NGT men. In contrast, no difference in Rd, IMTG concentration, or FSR was seen in PD vs. NGT women. Surprisingly, glucose Rd during the clamp was not different between NGT men and women (P = 0.25) despite IMTG concentration being higher (42.6 ± 6.1 vs. 21.2 ± 3.4 µg/mg dry weight, P = 0.03) and FSR being lower (0.23 ± 0.04 vs. 0.42 ± 0.06 %/h, P = 0.02) in women. Alterations in IMTG metabolism relate to diminished insulin action in men, but not women, in the progression toward diabetes.

Characteristics of insulin resistance and insulin secretory capacity in Korean subjects with IFG and IGT

Both IFG and IGT are prediabetic conditions that can progress to type 2 DM. However, previous studies have shown that these are not identical. This study was conducted on 307 drug naïve prediabetic adults who did not meet the diagnostic criteria for diabetes based on the OGTT. According to the OGTT, the subjects were divided into isolated IFG (i-IFG), isolated IGT (i-IGT), and combined glucose intolerance (CGI) group. We also measured insulin resistance indices (HOMA-IR, WBISI), an insulin secretion indices (insulinogenic index [IGI], AUC I/G(0-120), disposition index [DI]), and compared each of the three groups. The OGTT measurements showed that 87 subjects were diagnosed with i-IFG, 75 subjects had i-IGT, and 145 subjects had CGI. With respect to the insulin resistance indices, HOMA-IR and WBISI were not significantly different. However, insulin secretory capacity, the IGI and DI were significantly higher for the i-IFG group. Moreover, after confounders were adjusted, HOMA-IR, IGI, AUC I/G(0-120), and the DI were significantly higher for the i-IFG group and WBISI was significantly higher for the i-IGT group. These results demonstrate that the pathogenesis of IFG is more closely associated with insulin resistance, and the pathogenesis of IGT is more closely associated with impaired insulin secretion.

Effects of gender and height on the oral glucose tolerance test: the isfahan diabetes prevention study

BACKGROUND

Impaired fasting glucose (IFG) is more prevalent in men, whereas impaired glucose tolerance (IGT) is more prevalent in women.

AIM

To determine whether gender difference in the prevalence of glucose intolerance is related to height.

METHODS

A cross-sectional study of 2,368 first-degree relatives (FDR) of patients with type 2 diabetes was conducted between years 2003 to 2005. All participants (614 men and 1754 women) were in the age range 30-60 years, and were FDR of consecutive patients from outpatient clinics at Isfahan Endocrine and Metabolism Research Centre, Iran. All subjects underwent a standard 75 g 2-h oral glucose tolerance test (OGTT). Weight, height, waist and hip circumference, and glycated haemoglobin were also measured.

RESULTS

IGT was more common amongst women (OR 0.66; 95% CI 0.51, 0.87),whereas diabetes (OR 1.31; 95% CI 0.96, 1.78), and IFG (OR 1.41; 95% CI 1.10, 1.80) was more common amongst men. Women had a lower mean fasting plasma glucose (FPG) (p < 0.001), but showed higher 2hPG, and FPG-2hPG increase (p < 0.001). The gender difference in mean 2hPG and FPG-2hPG increase, was not evident after adjustment for height. Negative correlation to height was observed in 2hPG and FPG-2hPG increase, both in men and women (p < 0.001), but height showed little association with FPG.

CONCLUSIONS

Women had higher mean 2hPG and FPG-2hPG increase, but showed a lower FPG level than men. The inverse association between height and 2hPG and FPG-2hPG increase may be explained by gender difference.

Effect of low-dose oral contraceptives on metabolic risk factors in African-American women

CONTEXT

The effect of oral contraceptive pill (OCP) use on cardiovascular risk in African-American women is unknown.

OBJECTIVE

Our objective was to examine in African-American women the effect of OCP use on insulin resistance, glucose intolerance, and triglycerides (TGs).

DESIGN

This was a cross-sectional study.

SETTING

The study was conducted at the National Institutes of Health Clinical Research Center.

PARTICIPANTS

A total of 104 healthy nondiabetic African-American women [21 OCP users, 83 controls, age mean +/- sd, 34.7 +/- 7.6 yr, body mass index (BMI) 31 +/- 8.4 kg/m(2)] was included in the study.

INTERVENTIONS

Subjects had oral glucose tolerance tests, insulin-modified frequently sampled iv glucose tolerance tests, and fasting lipid profiles. Insulin resistance was determined by the insulin sensitivity index (S(I)).

MAIN OUTCOME MEASURES

Insulin resistance, glucose tolerance status, and TG levels were determined.

RESULTS

Fasting glucose did not differ between OCP users and controls (P = 0.27). In contrast, compared with controls, 2-h glucose (135 +/- 23 vs.120 +/- 25 mg/dl; P = 0.01) and fasting TGs (73 +/- 31 vs.57 +/- 27 mg/dl; P = 0.02) were higher in OCP users. OCP users tended to be more insulin resistant than controls (S(I): 2.51 +/- 2.01 vs. 3.46 +/- 2.09; P = 0.09). Multiple regression analysis revealed that BMI, age, and OCP use were significant determinants of 2-h glucose (adjusted R(2) = 0.37; P < 0.001) and TG levels (adjusted R(2) = 0.21; P < 0.001). As BMI was a determinant of both 2-h glucose and TGs, participants were divided into nonobese and obese groups, and the analyses repeated. Among the nonobese women, the OCP users were more insulin resistant (S(I): 2.91 +/- 1.58 vs. 4.35 +/- 1.88; P = 0.03) and had a higher prevalence of glucose intolerance than controls (odds ratio 5.7; 95% confidence interval 1.4-24; P = 0.01).

CONCLUSION

In African-American women, OCP use is associated with an increase in markers of cardiovascular risk manifested by increased insulin resistance, glucose intolerance, and elevated TGs.

Effect of ovarian suppression with gonadotropin-releasing hormone agonist on glucose disposal and insulin secretion

Several lines of evidence suggest that ovarian hormones influence glucose homeostasis, although their exact role in humans has not been clearly defined. In the present study, we sought to test the hypothesis that ovarian hormones regulate glucose homeostasis by examining the effect of pharmacologically induced ovarian hormone deficiency on glucose disposal and insulin secretion. Young, healthy women with regular menstrual patterns were studied during the follicular and luteal phases of their cycle at baseline and after 2 mo of treatment with gonadotropin-releasing hormone agonist (GnRHa; n = 7) or placebo (n = 6). Using hyperglycemic clamps, in combination with stable isotope-labeled (i.e., (13)C and (2)H) glucose tracers, we measured glucose disposal and insulin secretion. Additionally, we assessed body composition and regional fat distribution using radiologic imaging techniques as well as glucoregulatory hormones. Ovarian hormone suppression with GnRHa did not alter body composition, abdominal fat distribution, or thigh tissue composition. There was no effect of ovarian suppression on total, oxidative, or nonoxidative glucose disposal expressed relative to plasma insulin level. Similarly, no effect of ovarian hormone deficiency was observed on first- or second-phase insulin secretion or insulin clearance. Finally, ovarian hormone deficiency was associated with an increase in circulating adiponectin levels but no change in leptin concentration. Our findings suggest that a brief period of ovarian hormone deficiency in young, healthy, eugonadal women does not alter glucose disposal index or insulin secretion, supporting the conclusion that ovarian hormones play a minimal role in regulating glucose homeostasis. Our data do, however, support a role for ovarian hormones in the regulation of plasma adiponectin levels.