Sex Differences in the Cardiovascular Consequences of Diabetes Mellitus: A Scientific Statement From the American Heart Association

Diabetes as a risk factor for heart failure in women and men: a systematic review and meta-analysis of 47 cohorts including 12 million individuals

AIMS/HYPOTHESIS

The prevalence of diabetes and heart failure is increasing, and diabetes has been associated with an increased risk of heart failure. However, whether diabetes confers the same excess risk of heart failure in women and men is unknown. The aim of this study was to conduct a comprehensive systematic review with meta-analysis of possible sex differences in the excess risk of heart failure consequent to diabetes. Our null hypothesis was that there is no such sex difference.

METHODS

A systematic search was conducted in PubMed for population-based cohort studies published between January 1966 and November 2018. Studies were selected if they reported sex-specific estimates of RRs for heart failure associated with diabetes, and its associated variability, which were adjusted at least for age. Random-effects meta-analyses with inverse variance weighting were used to obtain pooled sex-specific RRs and women-to-men ratio of RRs (RRRs) for heart failure associated with diabetes.

RESULTS

Data from 47 cohorts, involving 12,142,998 individuals and 253,260 heart failure events, were included. The pooled multiple-adjusted RR for heart failure associated with type 1 diabetes was 5.15 (95% CI 3.43, 7.74) in women and 3.47 (2.57, 4.69) in men, leading to an RRR of 1.47 (1.44, 1.90). Corresponding pooled RRs for heart failure associated with type 2 diabetes were 1.95 (1.70, 2.22) in women and 1.74 (1.55, 1.95) in men, with a pooled RRR of 1.09 (1.05, 1.13).

CONCLUSIONS/INTERPRETATION

The excess risk of heart failure associated with diabetes is significantly greater in women with diabetes than in men with diabetes. PROSPERO registration: CRD42019135246.

Low-density lipoprotein receptor gene mutation at Exon 2 and 4 in premature coronary artery disease in our population

Objective

To determine the frequency of mutations in Low density lipoprotein receptor gene at exon 2 and 4 and its association with premature coronary artery disease (PCAD).

Methods

A case-control study was conducted at Armed Forces Institute of Cardiology and Chemical Pathology department of Army Medical College Rawalpindi for a period of six months from June 2017 to December 2017. A sample size of 50 (40 patients, 10 controls) with 5% significance and 95% confidence interval was calculated with 4:1 case to control ratio. Consecutive sampling was used for distribution of participants into both groups. .Diagnosed patients of premature coronary artery disease that is any cardiac event before the age of 45 in males and 50 in females were taken as cases. Controls were healthy males less than 45 years of age and females less than 50 years. Patients with diabetes mellitus, thyroid illnesses, any acute infection, low white blood cells count and kidney disorders were excluded. A total of fasting 10ml blood was withdrawn from each patient. 5ml was utilized for the routine blood tests and the rest 5ml was used for further genetic analysis.

Results

Total 50 participants were included in study. Mean age of participants in years was 42.48 ± 4.02 SD. Mean total cholesterol (TC) (mmol/l) were higher among cases (4.91±0.64 SD) than controls (4.22±0.66 SD). Serum triglyceride(Tg) (mmol/l) and low-density lipoprotein(LDL) (mmol/l) was also high among cases (2.07±0.58; 2.84±0.46) than controls (1.99±0.24; 1.98±0.32). One synonymous mutation in exon 2 of low-density lipoprotein receptor gene (LDLR) and one non-synonymous mutation in exon 4 (LDLR gene) were identified in our population in four patients among the forty cases. Data was analyzed by Statistical Package for the Social Science (SPSS) 21 version and a p-value of less than 0.05 was taken as significant.

Conclusion

Glutamic acid (E) is replaced by Lysine (K) at position number 207 (E207K) mutation at exon 4 of low-density lipoprotein receptor (LDLR) gene may be the causative genetic basis of premature coronary artery disease among Pakistani population. The identified synonymous mutation at exon 2 was not causative as there is no change in the amino acid.

Subclinical atherosclerosis burden predicts cardiovascular events in individuals with diabetes and chronic kidney disease

BACKGROUND

Individuals with diabetes have remarkably high rates of cardiovascular morbidity and mortality. However, the incremental cardiovascular risk in diabetes is heterogeneous and has often been related to renal involvement. The purpose of this study was to analyse the prognostic value of subclinical atherosclerosis in determining the incidence of first cardiovascular events (CVEs) in individuals with diabetes and chronic kidney disease (CKD) compared to CKD individuals without diabetes.

METHODS

We included data from individuals with CKD with and without diabetes, free from pre-existing cardiovascular disease, from the NEFRONA cohort. Participants underwent baseline carotid and femoral ultrasound and were followed up for 4 years. All CVEs during follow-up were registered. Bivariate analysis and Fine-Gray competing risk models were used to perform the statistical analysis.

RESULTS

During the mean follow-up time of 48 months, a total of 203 CVE was registered. 107 CVE occurred among participants without diabetes (19.58 per 1000 person-years) and 96 CVE occurred among participants with diabetes (44.44 per 1000 person-years). Following the competing risk analysis, the variables predicting CVEs in CKD individuals without diabetes were the number of territories with plaque at baseline (HR 1.862, 95% CI [1.432;2.240]), age (HR 1.026, 95% CI [1.003;1.049]) and serum concentrations of 25-OH vitamin D (HR 0.963, 95% CI [0.933;0.094]). The only variable predicting CVEs among CKD participants with diabetes was the number of territories with plaque at baseline (HR 1.782, 95% CI [1.393, 2.278]). For both models, concordance (C) index yielded was over 0.7.

CONCLUSIONS

The burden of subclinical atherosclerosis is the strongest predictor of future CVEs in diabetic individuals with CKD. Early detection of subclinical atherosclerotic burden by multiterritorial vascular ultrasound could improve CVE prediction in this population.

Sex differences in the association between diabetes and risk of cardiovascular disease, cancer, and all-cause and cause-specific mortality: a systematic review and meta-analysis of 5,162,654 participants

BACKGROUND

Studies have suggested sex differences in the mortality rate associated with diabetes. We conducted a meta-analysis to estimate the relative effect of diabetes on the risk of all-cause, cancer, cardiovascular disease (CVD), infectious disease, and respiratory disease mortality in women compared with men.

METHODS

Studies published from their inception to April 1, 2018, identified through a systematic search of PubMed and EMBASE and review of references. We used the sex-specific RRs to derive the women-to-men ratio of RRs (RRR) and 95% CIs from each study. Subsequently, the RRR for each outcome was pooled with random-effects meta-analysis weighted by the inverse of the variances of the log RRRs.

RESULTS

Forty-nine studies with 86 prospective cohorts met the inclusion criteria and were eligible for analysis. The pooled women-to-men RRR showed a 13% greater risk of all-cause mortality associated with diabetes in women than in men (RRR 1.13, 95% CI 1.07 to 1.19; P < 0.001). The pooled multiple-adjusted RRR indicated a 30% significantly greater excess risk of CVD mortality in women with diabetes compared with men (RRR 1.30, 95% CI 1.13 to 1.49; P < 0.001). Compared with men with diabetes, women with diabetes had a 58% greater risk of coronary heart disease (CHD) mortality, but only an 8% greater risk of stroke mortality (RRR_CHD 1.58, 95% CI 1.32 to 1.90; P < 0.001; RRR_stroke 1.08, 95% CI 1.01 to 1.15; P < 0.001). However, no sex differences were observed in pooled results of populations with or without diabetes for all-cancer (RRR 1.02, 95% CI 0.98 to 1.06; P = 0.21), infectious (RRR 1.13, 95% CI 0.90 to 1.38; P = 0.33), and respiratory mortality (RRR 1.08, 95% CI 0.95 to 1.23; P = 0.26).

CONCLUSIONS

Compared with men with the same condition, women with diabetes have a 58% and 13% greater risk of CHD and all-cause mortality, respectively, although there was a significant heterogeneity between studies. This points to an urgent need to develop sex- and gender-specific risk assessment strategies and therapeutic interventions that target diabetes management in the context of CHD prevention.

Current advances in the study of diabetic cardiomyopathy: From clinicopathological features to molecular therapeutics (Review)

The incidence of diabetes mellitus has become a major public health concern due to lifestyle alterations. Moreover, the complications associated with diabetes mellitus deeply influence the quality of life of patients. Diabetic cardiomyopathy (DC) is a type of diabetes mellitus complication characterized by functional and structural damage in the myocardium but not accompanied by coronary arterial disease. Currently, diagnosing and preventing DC is still a challenge for physicians due to its atypical symptoms. For this reason, it is necessary to summarize the current knowledge on DC, especially in regards to the underlying molecular mechanisms toward the goal of developing useful diagnostic approaches and effective drugs based on these mechanisms. There exist several review articles which have focused on these points, but there still remains a lot to learn from published studies. In this review, the features, diagnosis and molecular mechanisms of DC are reviewed. Furthermore, potential therapeutic and prophylactic drugs are discussed.

Cardiovascular safety and lower severe hypoglycaemia of insulin degludec versus insulin glargine U100 in patients with type 2 diabetes aged 65 years or older: Results from DEVOTE (DEVOTE 7)

AIMS

The aim of this study was to describe the risks of cardiovascular (CV) events and severe hypoglycaemia with insulin degludec (degludec) vs insulin glargine 100 units/mL (glargine U100) in patients with type 2 diabetes (T2D) aged 65 years or older.

MATERIALS AND METHODS

A total of 7637 patients in the DEVOTE trial, a treat-to-target, randomized, double-blind trial evaluating the CV safety of degludec vs glargine U100, were divided into three age groups (50-64 years, n = 3682; 65-74 years, n = 3136; ≥75 years, n = 819). Outcomes by overall age group and randomized treatment differences were analysed for major adverse cardiovascular events (MACE), all-cause mortality, severe hypoglycaemia and serious adverse events (SAEs).

RESULTS

Patients with increasing age had higher risks of CV death, all-cause mortality and SAEs, and there were non-significant trends towards higher risks of MACE and severe hypoglycaemia. Treatment effects on the risk of MACE, all-cause mortality, severe hypoglycaemia and SAEs were consistent across age groups, based on the non-significant interactions between treatment and age with regard to these outcomes.

CONCLUSIONS

There were higher risks of CV death, all-cause mortality and SAEs, and trends towards higher risks of MACE and severe hypoglycaemia with increasing age after adjusting for baseline differences. The effects across age groups of degludec vs glargine U100 on MACE, all-cause mortality and severe hypoglycaemia were comparable, suggesting that the risk of MACE, as well as all-cause mortality, is similar and the risk of severe hypoglycaemia is lower with degludec regardless of age. Evidence is conclusive only until 74 years of age.

Sex differences in diabetes and kidney disease: mechanisms and consequences

Type 1 and type 2 diabetes, along with their accompanying hyperglycemia, are associated with a multitude of comorbidities including the development of diabetic kidney disease. Although the hallmarks of these metabolic disorders have been well characterized in population and animal studies, it is becoming increasingly apparent that diabetes manifests itself differently in men and women. This review summarizes the recent diabetic literature with a focus on known sex differences in clinical and preclinical studies. It explores the physiological differences of glucose handling and the development of diabetes between men and women. This review also uncovers potential mechanisms for these differences, honing in on the vital role that sex hormone signaling plays in the progression of diabetes and renal complications.

Cardiovascular Risk and Risk Factor Management in Type 2 Diabetes Mellitus: A Population-Based Cohort Study Assessing Sex Disparities

BACKGROUND

With recent changes in the United Kingdom's clinical practice for diabetes mellitus care, contemporary estimates of sex disparities in cardiovascular risk and risk factor management are needed.

METHODS

In this retrospective cohort study, using the Clinical Practice Research Datalink linked to hospital and death records for people in England, we identified 79 985 patients with incident type 2 diabetes mellitus (T2DM) between 2006 to 2013 matched to 386 547 patients without diabetes mellitus. Sex-stratified Cox models were used to assess cardiovascular risk.

RESULTS

Compared with women without T2DM, women with T2DM had a higher cardiovascular event risk (adjusted hazard ratio, 1.20 [95% confidence interval, 1.12-1.28]) with similar corresponding data in men (hazard ratio, 1.12 [1.06-1.19]), leading to a nonsignificant higher relative risk in women (risk ratio, 1.07 [0.98-1.17]). However, some important sex differences in the management of risk factors were observed. Compared with men with T2DM, women with T2DM were more likely to be obese, hypertensive, and have hypercholesterolemia, but were less likely to be prescribed lipid-lowering medication and angiotensin-converting enzyme inhibitors, especially if they had cardiovascular disease.

CONCLUSIONS

Compared with men developing T2DM, women with T2DM do not have a significantly higher relative increase in cardiovascular risk, but ongoing sex disparities in prescribing should prompt heightened efforts to improve the standard and equity of diabetes mellitus care in women and men.

Social inequality and diabetes mellitus - developments over time among the adult population in Germany

The connection between social disadvantage and the presence of known diabetes and specific risk factors is well documented. This article summarises the results from the Robert Koch Institute examination surveys that were conducted between 1997 and 1999 as well as 2008 and 2011 to address social inequality - operationalised by level of education - with regard to prevalences of known and unknown diabetes, risk of diabetes and care of diabetes as well as their development over time. Both survey periods showed that the low education group has higher prevalences of known and unkown diabetes as well as a higher risk of developing diabetes within the next five years compared to the medium and high education group. Over time, prevalence tended to increase for known diabetes and to decrease for unknown diabetes for all education groups. For the 5-year diabetes risk, only the high education group showed a clear decrease over time. The chosen indicators of diabetes care indicated no clear differences between education groups and an improvement of diabetes care over time. For some indicators of care (foot examination, statins), improvements were only seen in the low education group. In conclusion, social inequalities in the prevalence of known and unknown diabetes as well as in diabetes risk remain in Germany; for the indicators of care, however, no clear education gradient is evident. Over time, inequality regarding the prevalence of diabetes has not increased further. However, with regard to diabetes risk, inequality has become slightly more evident. For individual care indicators, improvements are limited to specific education groups.

The impact of sex on risk of cardiovascular disease and all-cause mortality in adults with or without diabetes mellitus: A comparison between the U.S. and Japan

AIMS

To test a hypothesis that women with diabetes mellitus (DM) versus those without DM had a significantly higher risk of heart disease (HD), stroke and all-cause mortality than their male counterparts in the U.S. as well as in Japan.

METHODS

We analyzed two nationally representative datasets, one from the U.S. NHANES III cohort (n = 13,169), and the other from the Japan NIPPON DATA90 cohort (n = 7445). Hazard ratios (HRs) of DM for risk of mortality and sex-DM interaction effect on mortality were analyzed prospectively using Cox's proportional hazards regression models.

RESULTS

Patients with DM had significantly higher mortality from HD, stroke and all-cause mortality in the U.S. and in Japan. However, the HRs of DM versus non-DM for HD and all-cause mortality were significantly higher in women compared to men in the U.S. (sex-DM interaction: HR = 1.59, p = 0.01, and 1.24, p = 0.045 for HD and all-cause mortality), but the sex-DM interaction effect was not statistically significant in the Japanese cohort.

DISCUSSION

Patients with DM had a significantly higher risk of mortality than those without DM in the U.S. and Japan. However, women with DM versus those without DM had a higher relative risk of HD and all-cause mortality than their counterparts in men in the U.S, but this sex difference by DM status was not observed in the Japanese cohort. Whether the sex-difference effect of DM on HD and all-cause mortality is due to a difference in metabolic disorders between the two populations warrants consideration and further studies.

Sex differences in mechanisms of arterial stiffness

Arterial stiffness progressively increases with aging and is an independent predictor of cardiovascular disease (CVD) risk. Evidence supports that there are sex differences in the time course of aging-related arterial stiffness and the associated CVD risk, which increases disproportionately in postmenopausal women. The association between arterial stiffness and mortality is almost twofold higher in women versus men. The differential clinical characteristics of the development of arterial stiffness between men and women indicate the involvement of sex-specific mechanisms. This review summarizes the current literature on sex differences in vascular stiffness induced by aging, obesity, hypertension, and sex-specific risk factors as well as the impact of hormonal status, diet, and exercise on vascular stiffness in males and females. An understanding of the mechanisms driving sex differences in vascular stiffness has the potential to identify novel sex-specific therapies to lessen CVD risk, the leading cause of death in males and females. LINKED ARTICLES: This article is part of a themed section on The Importance of Sex Differences in Pharmacology Research. To view the other articles in this section visit http://onlinelibrary.wiley.com/doi/10.1111/bph.v176.21/issuetoc.

Gender difference in the risk for cardiovascular events or mortality of patients with diabetic foot syndrome

AIMS

Diabetic foot syndrome (DFS) increases the risk for atherosclerotic cardiovascular disease (ASCVD), chronic kidney disease (CKD), or mortality. The present study aims at ascertaining whether such DFS-related excess risk differs between genders, retrospectively investigating a population with diabetes from Tuscany, Italy, followed-up for 6 years (2011-2016).

METHODS

People with diabetes living in Tuscany on January 1st 2011 identified by administrative databases, were divided by baseline history of prior DFS hospitalizations, stratified by presence/absence of peripheral vascular disease and evaluating, by Cox regression analysis, whether adjusted DFS-related excess risk of incident ASCVD, CKD or mortality differed between genders.

RESULTS

In an overall population of 165,650 subjects with diabetes (81,829M/83,821F), basal prevalence of DFS was twice higher among males, who were moreover at a significantly greater risk of all considered outcomes along the 6-year period. On the contrary, baseline DFS significantly increased the hospitalization risk for ASCVD, CKD and mortality equally or at a slightly greater extent in females, while the risk for stroke was significantly associated with DFS only among females (HR: 1.622 (1.314-1.980); p = 0.0001 vs. HR: 1.132 (0.955-1.332); p = NS). This finding was even reinforced in non-vascular DFS, which was associated with a significant raised risk for stroke, heart failure or mortality exclusively in females.

CONCLUSIONS

In this population, DFS prevalence and overall risk for ASCVD, CKD or mortality were significantly higher among males. Baseline co-presence of DFS, however, conferred a similar adjusted risk for all these outcomes between genders, and in case of non-vascular DFS the risk was significantly increased only among females.

Blood pressure variability in individuals with and without (pre)diabetes: The Maastricht Study

OBJECTIVE

The mechanisms associating (pre)diabetes and cardiovascular disease (CVD) are incompletely understood. We hypothesize that greater blood pressure variability (BPV) may underlie this association, due to its association with (incident) CVD. Therefore, we investigated the association between (pre)diabetes and very short-term to mid-term BPV, that is within-visit, 24-h and 7-day BPV.

METHODS

Cross-sectional data from The Maastricht Study [normal glucose metabolism (NGM), n = 1924; prediabetes, n = 511; type 2 diabetes mellitus (T2DM), n = 975; 51% men, aged 60 ± 8 years]. We determined SD for within-visit BPV (n = 3244), average real variability for 24-h BPV (n = 2699) day (0900-2100 h) and night (0100-0600 h) separately, and SD for 7-day BPV (n = 2259). Differences in BPV as compared with NGM were assessed by multiple linear regressions with adjustment for potential confounders.

RESULTS

In T2DM, the average systolic/diastolic values of within-visit, 24-h and 7-day BPV were 4.8/2.6, 10.5/7.3 and 10.4/6.5 mmHg, respectively, and in prediabetes 4.9/2.6, 10.3/7.0 and 9.4/5.9 mmHg, respectively. T2DM was associated with greater nocturnal systolic BPV [0.42 mmHg (95% confidence interval: 0.05-0.80)], and greater 7-day systolic [0.76 mmHg (0.32-1.19)] and diastolic BPV [0.65 mmHg (0.29-1.01)], whereas prediabetes was associated with greater within-visit systolic BPV only [0.35 mmHg (0.06-0.65)], as compared with NGM.

CONCLUSION

Both T2DM and prediabetes are associated with slightly greater very short-term to mid-term BPV, which may, according to previous literature, explain a small part of the increased CVD risk seen in (pre)diabetes. Nevertheless, these findings do not detract from the fact that very short-term to mid-term BPV is substantial and important in individuals with and without (pre)diabetes.

Metabolic Predictors of Incident Coronary Heart Disease in Women

BACKGROUND

Although metabolomic profiling offers promise for the prediction of coronary heart disease (CHD), and metabolic risk factors are more strongly associated with CHD in women than men, limited data are available for women.

METHODS

We applied a liquid chromatography-tandem mass spectrometry metabolomics platform to measure 371 metabolites in a discovery set of postmenopausal women (472 incident CHD cases, 472 controls) with validation in an independent set of postmenopausal women (312 incident CHD cases, 315 controls).

RESULTS

Eight metabolites, primarily oxidized lipids, were significantly dysregulated in cases after the adjustment for matching and CHD risk factors in both the discovery and validation data sets. One oxidized phospholipid, C34:2 hydroxy-phosphatidylcholine, remained associated with CHD after further adjustment for other validated metabolites. Subjects with C34:2 hydroxy-phosphatidylcholine levels in the highest quartile had a 4.7-fold increase in CHD odds in comparison with the lowest quartile; C34:2 hydroxy-phosphatidylcholine also significantly improved the area under the curve (P<0.01) for CHD. The C34:2 hydroxy-phosphatidylcholine findings were replicated in a third replication data set of 980 men and women (230 cardiovascular events) with a stronger association observed in women.

CONCLUSIONS

These data replicate known metabolite predictors, identify novel markers, and support the relationship between lipid oxidation and subsequent CHD.

Sex Differences in Coronary Microvascular Function in Individuals With Type 2 Diabetes

Cardiovascular (CV) disease fatality rates are higher for women compared with men with diabetes despite lower rates of obstructive coronary artery disease (CAD). Impaired coronary flow reserve (CFR), the ratio of adenosine-stimulated to rest myocardial blood flow (MBF), is an indicator of coronary microvascular dysfunction and predicts major adverse CV events. We performed a post hoc analysis to determine whether there was a sex disparity in coronary microvascular dysfunction among 46 men and 27 women with well-controlled type 2 diabetes and without clinical evidence of obstructive CAD. We found that women had a higher rest MBF, lower CFR, and worse diastolic function compared with men. In addition, rest MBF was positively correlated with worse diastolic function in women. We previously showed that mineralocorticoid blockade improved CFR in men and women with type 2 diabetes, implicating aldosterone in the pathophysiology of coronary microvascular dysfunction. We therefore examined aldosterone levels and found that women had larger increases in aldosterone in response to an angiotensin-II infusion than did men. In conclusion, among individuals with type 2 diabetes and good cardiometabolic control, women had worse myocardial perfusion and diastolic function compared with men. The greater aldosterone responsivity in women may be a mechanism for this sex effect.

Estrogen-Dependent Disruption of Adiponectin-Connexin43 Signaling Underlies Exacerbated Myocardial Dysfunction in Diabetic Female Rats

The reasons for the higher severity of type 2 diabetes (T2DM)-associated cardiomyopathy in women, despite their inherent estrogen (E2)-dependent cardioprotection, remain unknown. We hypothesized that the reliance of the healthy females' hearts on augmented adiponectin (APN)-connexin 43 (Cx43) signaling becomes paradoxically detrimental when disrupted by T2DM in an E2-dependent manner. We tested this hypothesis in high-fat, low- dose streptozotocin diabetic rats and their controls with the following designations: 1) sham-operated (SO), 2) ovariectomized (OVX), 3) ovariectomized with E2 supplementation (OVX + E2), and 4) male. E2-replete (SO or OVX + E2) diabetic rats exhibited higher mortality and greater increases in left ventricular (LV) mass and reduced LV developed pressure, LV contractility, and fractional shortening but preserved ejection fraction. Further, compared with respective nondiabetic counterparts, the hearts of these E2-replete diabetic rats exhibited greater upregulation of cardiac estrogen receptor α and reductions in Cx43 expression and in the phosphorylation levels of the survival molecules extracellular regulating kinases 1/2 and phosphorylated AKT (pAKT). Whereas serum APN was reduced, independent of sex and ovarian hormone status in all DM rats, cardiac APN was most drastically reduced in DM SO rats. The present translational findings are the first to implicate ovarian hormones/E2 in the exacerbated myocardial dysfunction in female diabetic subjects and to suggest a pivotal role for malfunctioning cardiac APN-Cx43 signaling in this sex/E2-specific clinical problem.

Mortality risk in adults according to categories of impaired glucose metabolism after 18 years of follow-up in the North of Spain: The Asturias Study

People who develop type 2 diabetes (T2D) are known to have a higher mortality risk. We estimated all-cause, cardiovascular, and cancer mortality-risks in our patient cohort according to categories of impaired glucose metabolism. This 18-year retrospective analysis included a region-wide, representative sample of a population aged 30-75 years. Age- and sex-stratified hazard ratios (HRs) were calculated for 48 participants with diagnosed T2D, 83 with undiagnosed T2D (HbA1c ≥6.5%, fasting glycemia ≥126 mg/dL, or glycemia after 75 g glucose load ≥200 mg/dL); 296 with prediabetes (HbA1c 5.7%-6.4%, fasting glycemia 100-125 mg/dL, or glycemia after 75 g glucose load 140-199 mg/dL), and 607 with normoglycemia. Over 18,612 person-years, 32 individuals with undiagnosed T2D, 30 with diagnosed T2D, 62 with prediabetes, and 80 with normoglycemia died. Total sample crude mortality rate (MR) was 10.96 deaths per 1,000 person-years of follow-up. MR of the diagnosed T2D group was more than 3-times higher and that of newly diagnosed T2D was 2-times higher (34.72 and 21.42, respectively) than total sample MR. Adjusted HR for all-cause mortality was 2.02 (95% confidence interval 1.29-3.16) and 1.57 (95% CI 1.00-2.28) in the diagnosed T2D group and the newly diagnosed T2D group, respectively. Adjusted HR for cardiovascular mortality in the T2D group was 2.79 (95% CI 1.35-5.75); this risk was greatly increased in women with T2D: 6.72 (95% CI 2.50-18.07). In Asturias, age- and sex-standardized all-cause mortality is more than 2-times higher for adults with T2D than for adults without T2D. The HR for cardiovascular mortality is considerably higher in T2D women than in normoglycemic women.

SMARTWOMAN™: Feasibility assessment of a smartphone app to control cardiovascular risk factors in vulnerable diabetic women

BACKGROUND/HYPOTHESIS

SMARTWOMAN™ was designed to develop and assess the feasibility of a smartphone app to control cardiovascular risk factors in vulnerable diabetic women.

METHODS

Fourteen African-American women with diabetes and without known cardiovascular disease were enrolled. A weight-scale, glucometer, sphygmomanometer, and FitBit were synchronized to the smartphone, and text messaging was provided. Follow-up was 6 months.

RESULTS

Patients were able to follow instructions for app use and device prompts. Weekly device reporting was 85% for blood glucose, 82.5% for daily steps, and 77% for systolic blood pressure. Patient engagement levels were 85% to 100% at 1 month and 50% to 78% at month 6. The majority reported text messages to be useful, easy to understand, and appropriate in frequency. The women indicated on the exit questionnaire that study participation increased their motivation and ability to take charge of their health.

CONCLUSIONS

Use of a smartphone app to control cardiovascular risk factors appears feasible in a population of vulnerable indigent African-American diabetic women, resulted in increased patient satisfaction and positive reinforcement to healthy behaviors, and warrants a larger clinical outcome trial.

Protective Effect of Resveratrol against Ischemia-Reperfusion Injury via Enhanced High Energy Compounds and eNOS-SIRT1 Expression in Type 2 Diabetic Female Rat Heart

Type 2 diabetic women have a high risk of mortality via myocardial infarction even with anti-diabetic treatments. Resveratrol (RSV) is a natural polyphenol, well-known for its antioxidant property, which has also shown interesting positive effects on mitochondrial function. Therefore, we aim to investigate the potential protective effect of 1 mg/kg/day of RSV on high energy compounds, during myocardial ischemia-reperfusion in type 2 diabetic female Goto-Kakizaki (GK) rats. For this purpose, we used 31P magnetic resonance spectroscopy in isolated perfused heart experiments, with a simultaneous measurement of myocardial function and coronary flow. RSV enhanced adenosine triphosphate (ATP) and phosphocreatine (PCr) contents in type 2 diabetic hearts during reperfusion, in combination with better functional recovery. Complementary biochemical analyses showed that RSV increased creatine, total adenine nucleotide heart contents and citrate synthase activity, which could be involved in better mitochondrial functioning. Moreover, improved coronary flow during reperfusion by RSV was associated with increased eNOS, SIRT1, and P-Akt protein expression in GK rat hearts. In conclusion, RSV induced cardioprotection against ischemia-reperfusion injury in type 2 diabetic female rats via increased high energy compound contents and expression of protein involved in NO pathway. Thus, RSV presents high potential to protect the heart of type 2 diabetic women from myocardial infarction.

Adverse differences in cardiometabolic risk factor levels between individuals with pre-diabetes and normal glucose metabolism are more pronounced in women than in men: the Maastricht Study

OBJECTIVE

To investigate whether adverse differences in levels of cardiovascular risk factors in women than men, already established when comparing individuals with and without diabetes, are also present before type 2 diabetes onset.

RESEARCH DESIGN AND METHODS

In a population-based cohort study of individuals aged 40-75 years (n=3410; 49% women, 29% type 2 diabetes (oversampled by design)), we estimated associations with cardiometabolic and lifestyle risk factors of (1) pre-diabetes and type 2 diabetes (reference category: normal glucose metabolism) and (2) among non-diabetic individuals, of continuous levels of hemoglobin A1c (HbA1c). Age-adjusted sex differences were analyzed using linear and logistic regression models with sex interaction terms.

RESULTS

In pre-diabetes, adverse differences in cardiometabolic risk factors were greater in women than men for systolic blood pressure (difference, 3.02 mm Hg; 95% CI:-0.26 to 6.30), high-density lipoprotein (HDL) cholesterol (difference, -0.10 mmol/L; 95% CI: -0.18 to -0.02), total-to-HDL cholesterol ratio (difference, 0.22; 95% CI: -0.01 to 0.44), triglycerides (ratio: 1.11; 95% CI: 1.01 to 1.22), and inflammation markers Z-score (ratio: 1.18; 95% CI: 0.98 to 1.41). In type 2 diabetes, these sex differences were similar in direction, and of greater magnitude. Additionally, HbA1c among non-diabetic individuals was more strongly associated with several cardiometabolic risk factors in women than men: per one per cent point increase, systolic blood pressure (difference, 3.58 mm Hg; 95% CI: -0.03 to 7.19), diastolic blood pressure (difference, 2.10 mm Hg; 95% CI: -0.02 to 4.23), HDL cholesterol (difference, -0.09 mmol/L; 95% CI: -0.19 to 0.00), and low-density lipoprotein cholesterol (difference, 0.26 mmol/L; 95% CI: 0.05 to 0.47). With regard to lifestyle risk factors, no consistent pattern was observed.

CONCLUSION

Our results are consistent with the concept that the more adverse changes in cardiometabolic risk factors in women (than men) arise as a continuous process before the onset of type 2 diabetes.

The Sex-Specific Detrimental Effect of Diabetes and Gender-Related Factors on Pre-admission Medication Adherence Among Patients Hospitalized for Ischemic Heart Disease: Insights From EVA Study

Background: Sex and gender-related factors have been under-investigated as relevant determinants of health outcomes across non-communicable chronic diseases. Poor medication adherence results in adverse clinical outcomes and sex differences have been reported among patients at high cardiovascular risk, such as diabetics. The effect of diabetes and gender-related factors on medication adherence among women and men at high risk for ischemic heart disease (IHD) has not yet been fully investigated. Aim: To explore the role of sex, gender-related factors, and diabetes in pre-admission medication adherence among patients hospitalized for IHD. Materials and Methods: Data were obtained from the Endocrine Vascular disease Approach (EVA) (ClinicalTrials.gov Identifier: NCT02737982), a prospective cohort of patients admitted for IHD. We selected patients with baseline information regarding the presence of diabetes, cardiovascular risk factors, and gender-related variables (i.e., gender identity, gender role, gender relations, institutionalized gender). Our primary outcome was the proportion of pre-admission medication adherence defined through a self-reported questionnaire. We performed a sex-stratified analysis of clinical and gender-related factors associated with pre-admission medication adherence. Results: Two-hundred eighty patients admitted for IHD (35% women, mean age 70), were included. Around one-fourth of the patients were low-adherent to therapy before hospitalization, regardless of sex. Low-adherent patients were more likely diabetic (40%) and employed (40%). Sex-stratified analysis showed that low-adherent men were more likely to be employed (58 vs. 33%) and not primary earners (73 vs. 54%), with more masculine traits of personality, as compared with medium-high adherent men. Interestingly, women reporting medication low-adherence were similar for clinical and gender-related factors to those with medium-high adherence, except for diabetes (42 vs. 20%, p = 0.004). In a multivariate adjusted model only employed status was associated with poor medication adherence (OR 0.55, 95%CI 0.31-0.97). However, in the sex-stratified analysis, diabetes was independently associated with medication adherence only in women (OR 0.36; 95%CI 0.13-0.96), whereas a higher masculine BSRI was the only factor associated with medication adherence in men (OR 0.59, 95%CI 0.35-0.99). Conclusion: Pre-admission medication adherence is common in patients hospitalized for IHD, regardless of sex. However, patient-related factors such as diabetes, employment, and personality traits are associated with adherence in a sex-specific manner.

Risk of coronary artery disease and stroke according to sex and presence of diabetic nephropathy in type 1 diabetes

AIMS

To determine the effect of different stages of diabetic nephropathy (DN) and sex on the excess and absolute morbidity of coronary artery disease (CAD) and stroke in people with type 1 diabetes (T1D) in order to distinguish different cardiovascular disease (CVD) risk profiles in people with T1D.

MATERIALS AND METHODS

The study included 4410 people with T1D from the Finnish Diabetic Nephropathy Study (FinnDiane), divided by DN status, and a control population of 12 434 people without diabetes. CVD events were identified from the Finnish nationwide health registries. Cumulative incidences for CAD and stroke were calculated and standardized incidence ratios (SIRs) were estimated between participants with T1D and the control group, stratified by DN status and sex.

RESULTS

There were 487 incident CADs and 290 strokes at the end of 2014 (median follow-up 12.9 years). The cumulative incidence rates of CAD and stroke were similar in men and women within different nephropathy groups. The SIR for CAD was 7.5 (95% confidence interval [CI] 6.9-8.2), 17.2 (95% CI 14.9-19.5) in women and 5.3 (95% CI 4.7-5.9) in men. The women-to-men ratio of SIR increased by nephropathy group: 3.3, 3.7, 5.3 and 6.8 in the normo-, micro- and macroalbuminuria and end-stage renal disease (ESRD) groups, respectively. The SIR for stroke was 5.0 (95% CI 4.3-5.5), similar in men and women. The women-to-men ratio of SIR for stroke was 0.8, 1.3, 1.6 and 1.7, in the normo-, micro- and macroalbuminuria and ESRD groups, respectively. The SIR in participants with normoalbuminuria and an estimated glomerular filtration rate ≥90 mL/min/1.73 m² was 3.5 (95% CI 2.5-4.5) for CAD and 1.6 (95% CI 1.0-2.3) for stroke.

CONCLUSIONS

Although the excess CVD risk is several-fold greater in women compared to men, the absolute CVD risk in men and women was equal when nephropathy was taken into account. Even participants with normoalbuminuria and normal kidney function were found to have an excess CVD risk compared with the control group without diabetes.

Sex-specific trajectories of measures of cardiovascular health during childhood and adolescence: A prospective cohort study

BACKGROUND AND AIMS

Sex differences in measures of cardiovascular health in adults are well documented. However, the sex-specific aetiology of cardiovascular health across childhood and adolescence is poorly understood.

METHODS

We examined sex differences in trajectories of 11 measures of cardiovascular health from birth to 18 years, in a contemporary birth cohort study in England (N participants per outcomes: 662-13,985, N repeated measures per outcome: 1,831-112,768). Outcomes were measured over varying time spans from birth or mid-childhood to age 18 and with different numbers of repeated measures per outcome. Analyses were performed using fractional polynomial and linear spline multilevel models.

RESULTS

Females had higher mean BMI, height-adjusted fat mass, pulse rate, insulin, triglycerides, and non-high-density lipoprotein cholesterol (HDL-c) and lower mean height-adjusted lean mass from birth or from mid-childhood to age 18. For example, mean non-HDL-c was 0.07 mmol/l (95% confidence interval (CI), 0.04, 0.10) higher in females compared with males at birth. By age 18, this difference persisted and widened to 0.19 mmol/l (95% CI, 0.16, 0.23) higher non-HDL-c in females compared with males. Females had lower levels of glucose from mid-childhood and developed lower systolic blood pressure and higher HDL-c from mid-adolescence onward. For example, females had 0.08 mmol/l (95% CI, 0.05, 0.10) lower mean glucose compared with males at age seven which widened to a difference of 0.22 mmol/l (95% CI, 0.25, 0.19) at age 18.

CONCLUSIONS

Sex differences in measures of cardiovascular health are apparent from birth or mid-childhood and change during early life. These differences may have implications for sex-specific disease risk in future adult populations.

Increased susceptibility to OVX-associated metabolic dysfunction in UCP1-null mice

Premenopausal females are protected against adipose tissue inflammation and insulin resistance, until loss of ovarian hormone production (e.g., menopause). There is some evidence that females have greater brown adipose tissue (BAT) thermogenic capacity. Because BAT mass correlates inversely with insulin resistance, we hypothesized that increased uncoupling protein 1 (UCP1) expression contributes to the superior metabolic health of females. Given that UCP1 transiently increases in BAT following ovariectomy (OVX), we hypothesized that UCP1 may 'buffer' OVX-mediated metabolic dysfunction. Accordingly, female UCP1-knockout (KO) and WT mice received OVX or sham (SHM) surgeries at 12 weeks of age creating four groups (n = 10/group), which were followed for 14 weeks and compared for body weight and adiposity, food intake, energy expenditure and spontaneous physical activity (metabolic chambers), insulin resistance (HOMA-IR, ADIPO-IR and glucose tolerance testing) and adipose tissue phenotype (histology, gene and protein expression). Two-way ANOVA was used to assess the main effects of genotype (G), OVX treatment (O) and genotype by treatment (GxO) interactions, which were considered significant when P ≤ 0.05. UCP1KO mice experienced a more adverse metabolic response to OVX than WT. Whereas OVX-induced weight gain was not synergistically greater for KO compared to WT (GxO, NS), OVX-induced insulin resistance was significantly exacerbated in KO compared to WT (GxO for HOMA-IR, P < 0.05). These results suggest UCP1 is protective against metabolic dysfunction associated with loss of ovarian hormones and support the need for more research into therapeutics to selectively target UCP1 for prevention and treatment of metabolic dysfunction following ovarian hormone loss.

Sex differences in management and outcomes of patients with type 2 diabetes and cardiovascular disease: A report from TECOS

AIM

To examine sex differences in baseline characteristics and outcomes in patients with type 2 diabetes and atherosclerotic vascular disease.

MATERIALS AND METHODS

Cox models were used to analyse the association between sex and outcomes in the Trial Evaluating Cardiovascular Outcomes with Sitagliptin (TECOS), a randomized, placebo-controlled trial assessing the impact of sitagliptin on cardiovascular (CV) outcomes in patients with type 2 diabetes and atherosclerotic vascular disease.

RESULTS

A total of 4297 women and 10 374 men were followed for a median of 3.0 years. Women were slightly older and more often had cerebrovascular disease and peripheral arterial disease but less often coronary heart disease than men. At baseline, women were less likely to use aspirin or statins. The primary composite outcome of CV death, myocardial infarction, stroke, or hospitalization for unstable angina occurred in 418 women (9.7%) and 1272 men (12.3%; 3.48 vs 4.38 events/100 participant-years, crude hazard ratio [HR] 0.79, 95% confidence interval [CI] 0.71-0.89, adjusted HR 0.64, 95% CI 0.55-0.74; P < .0001). Women also had a significantly lower risk of secondary CV outcomes and all-cause death.

CONCLUSIONS

In this large prospective study of people with type 2 diabetes and CV disease, women had different CV disease burden, worse CV risk factor profiles, and less use of indicated medications than men. Despite this, women had significantly lower risk of CV events, suggesting that the cardioprotective effects of female sex extend to populations with type 2 diabetes.

A Population-Based Study of the Bidirectional Association Between Obstructive Sleep Apnea and Type 2 Diabetes in Three Prospective U.S. Cohorts

OBJECTIVE

Multiple lines of evidence support a complex relationship between obstructive sleep apnea (OSA) and diabetes. However, no population-based study has evaluated the potential bidirectional association between these two highly prevalent disorders.

RESEARCH DESIGN AND METHODS

We followed 146,519 participants from the Nurses' Health Study (NHS; 2002-2012), Nurses' Health Study II (NHSII; 1995-2013), and Health Professionals Follow-up Study (HPFS; 1996-2012) who were free of diabetes, cardiovascular disease, and cancer at baseline. Cox proportional hazards models were used to estimate hazard ratios (HRs) for developing diabetes according to OSA status. In parallel, we used similar approaches to estimate risk of developing OSA according to diabetes status among 151,194 participants free of OSA, cardiovascular disease, and cancer at baseline. In all three cohorts, diagnoses of diabetes and OSA were identified by validated self-reports.

RESULTS

Similar results were observed across the three cohorts. In the pooled analysis, 9,029 incident diabetes cases were identified during follow-up. After accounting for potential confounders, the HR (95% CI) for diabetes was 2.06 (1.86, 2.28) comparing those with versus without OSA. The association was attenuated but remained statistically significant after further adjusting for waist circumference and BMI (HR 1.37 [95% CI 1.24, 1.53]), with the highest diabetes risk observed for OSA concomitant with sleepiness (1.78 [1.13, 2.82]). In the second analysis, we documented 9,364 incident OSA cases during follow-up. Compared with those without diabetes, the multivariable HR (95% CI) for OSA was 1.53 (1.32, 1.77) in individuals with diabetes. Adjustment for BMI and waist circumference attenuated the association (1.08 [1.00, 1.16]); however, an increased risk was observed among those with diabetes who used insulin compared with those without diabetes (1.43 [1.11, 1.83]), particularly among women (1.60 [1.34, 1.89]).

CONCLUSIONS

OSA is independently associated with an increased risk of diabetes, whereas insulin-treated diabetes is independently associated with a higher risk of OSA, particularly in women. Clinical awareness of this bidirectional association may improve prevention and treatment of both diseases. Future research aimed at elucidating the mechanisms that underlie each association may identify novel intervention targets.

Sex differences in lipid and lipoprotein metabolism

BACKGROUND

Endogenous sex hormones are important for metabolic health in men and women. Before menopause, women are protected from atherosclerotic cardiovascular disease (ASCVD) relative to men. Women have fewer cardiovascular complications of obesity compared to men with obesity. Endogenous estrogens have been proposed as a mechanism that lessens ASCVD risk, as risk of glucose and lipid abnormalities increases when endogenous estrogens decline with menopause. While baseline risk is higher in males than females, endogenously produced androgens are also protective against fatty liver, diabetes and ASCVD, as risk goes up with androgen deprivation and with the decline in androgens with age.

SCOPE OF REVIEW

In this review, we discuss evidence of how endogenous sex hormones and hormone treatment approaches impact fatty acid, triglyceride, and cholesterol metabolism to influence metabolic and cardiovascular risk. We also discuss potential reasons for why treatment strategies with estrogens and androgens in older individuals fail to fully recapitulate the effects of endogenous sex hormones.

MAJOR CONCLUSIONS

The pathways that confer ASCVD protection for women are of potential therapeutic relevance. Despite protection relative to men, ASCVD is still the major cause of mortality in women. Additionally, diabetic women have similar ASCVD risk as diabetic men, suggesting that the presence of diabetes may offset the protective cardiovascular effects of being female through unknown mechanisms.

Reversing the Trends toward Shorter Lives and Poorer Health for U.S. Women: A Call for Innovative Interdisciplinary Research

The United States (U.S.) is a leader and innovator in biomedicine, yet trails behind for many key health indicators, especially for women. This paper highlights key evidence indicating that not only is the state of women's health in the U.S. lagging, but it is at risk for falling off the curve. Women's health care remains fragmented; research in the field can be disconnected and difficult to integrate across disciplines-silos prevail. Structural obstacles contribute to this lack of cohesion, and innovative, interdisciplinary research approaches which integrate the multidimensional aspects of sex and gender, and race and ethnicity, with a life course perspective are sorely needed. Such synergistic, scientific strategies have the potential to reverse the trend towards shorter life expectancy and poorer health for women in the U.S. The National Institute for Health (NIH) seeks to raise the bar for the health of all women by tackling these issues through enhancing the relevance of biomedical research to the health of women and driving the sustained advancement of women in biomedical careers.

Usefulness of Proneurotensin to Predict Cardiovascular and All-Cause Mortality in a United States Population (from the Reasons for Geographic and Racial Differences in Stroke Study)

Cardiovascular disease is a leading cause of death. Proneurotensin is a biomarker associated with the development of cardiovascular disease, cardiovascular mortality, and all-cause mortality. We assessed the association of fasting proneurotensin with mortal events by gender and race (black-white) in a US population. Using a case-cohort subpopulation of the Reasons for Geographic and Racial Differences in Stroke study, fasting proneurotensin was measured on a 1,046-person subcohort and in 651 participants with incident coronary heart disease. Higher proneurotensin was associated with all-cause mortality (hazard ratio [HR] 1.6 per interquartile range, 95% confidence interval [CI] 1.3 to 1.9) and cardiovascular mortality (HR 1.8, 95% CI 1.2 to 2.6). For all-cause and cardiovascular mortality, association was stronger in women (HR 1.9, 95% CI 1.4 to 2.6 and HR 2.5, 95% CI 1.4 to 4.7, respectively) than men (HR 1.4, 95% CI 1.0 to 1.8 and HR 1.4, 95% CI 0.9 to 2.3, respectively), although this difference was not significant. Proneurotensin predicted all-cause mortality in both races and was not predictive of cardiovascular mortality in whites but was in blacks. Proneurotensin was not associated with incident coronary heart disease events. Elevated proneurotensin levels predicted all-cause and cardiovascular mortality in both genders, with a trend toward stronger association in women. Associations were similar in blacks and whites. In conclusion, proneurotensin may be a useful biomarker for all-cause and cardiovascular mortality regardless of race, and it is potentially specific in women.

Sex-specific relevance of diabetes to occlusive vascular and other mortality: a collaborative meta-analysis of individual data from 980 793 adults from 68 prospective studies

BACKGROUND

Several studies have shown that diabetes confers a higher relative risk of vascular mortality among women than among men, but whether this increased relative risk in women exists across age groups and within defined levels of other risk factors is uncertain. We aimed to determine whether differences in established risk factors, such as blood pressure, BMI, smoking, and cholesterol, explain the higher relative risks of vascular mortality among women than among men.

METHODS

In our meta-analysis, we obtained individual participant-level data from studies included in the Prospective Studies Collaboration and the Asia Pacific Cohort Studies Collaboration that had obtained baseline information on age, sex, diabetes, total cholesterol, blood pressure, tobacco use, height, and weight. Data on causes of death were obtained from medical death certificates. We used Cox regression models to assess the relevance of diabetes (any type) to occlusive vascular mortality (ischaemic heart disease, ischaemic stroke, or other atherosclerotic deaths) by age, sex, and other major vascular risk factors, and to assess whether the associations of blood pressure, total cholesterol, and body-mass index (BMI) to occlusive vascular mortality are modified by diabetes.

RESULTS

Individual participant-level data were analysed from 980 793 adults. During 9·8 million person-years of follow-up, among participants aged between 35 and 89 years, 19 686 (25·6%) of 76 965 deaths were attributed to occlusive vascular disease. After controlling for major vascular risk factors, diabetes roughly doubled occlusive vascular mortality risk among men (death rate ratio [RR] 2·10, 95% CI 1·97-2·24) and tripled risk among women (3·00, 2·71-3·33; χ2 test for heterogeneity p<0·0001). For both sexes combined, the occlusive vascular death RRs were higher in younger individuals (aged 35-59 years: 2·60, 2·30-2·94) than in older individuals (aged 70-89 years: 2·01, 1·85-2·19; p=0·0001 for trend across age groups), and, across age groups, the death RRs were higher among women than among men. Therefore, women aged 35-59 years had the highest death RR across all age and sex groups (5·55, 4·15-7·44). However, since underlying confounder-adjusted occlusive vascular mortality rates at any age were higher in men than in women, the adjusted absolute excess occlusive vascular mortality associated with diabetes was similar for men and women. At ages 35-59 years, the excess absolute risk was 0·05% (95% CI 0·03-0·07) per year in women compared with 0·08% (0·05-0·10) per year in men; the corresponding excess at ages 70-89 years was 1·08% (0·84-1·32) per year in women and 0·91% (0·77-1·05) per year in men. Total cholesterol, blood pressure, and BMI each showed continuous log-linear associations with occlusive vascular mortality that were similar among individuals with and without diabetes across both sexes.

INTERPRETATION

Independent of other major vascular risk factors, diabetes substantially increased vascular risk in both men and women. Lifestyle changes to reduce smoking and obesity and use of cost-effective drugs that target major vascular risks (eg, statins and antihypertensive drugs) are important in both men and women with diabetes, but might not reduce the relative excess risk of occlusive vascular disease in women with diabetes, which remains unexplained.

FUNDING

UK Medical Research Council, British Heart Foundation, Cancer Research UK, European Union BIOMED programme, and National Institute on Aging (US National Institutes of Health).

Differential sex effects of systolic blood pressure and low-density lipoprotein cholesterol on type 2 diabetes: Life course data from the Bogalusa Heart Study

BACKGROUND

There may be sex-specific cardiometabolic mechanisms early in life that affect the development of type 2 diabetes mellitus (T2DM) through mid-adulthood. However, few studies have examined whether early life course interactions between cardiometabolic risk factors and sex are associated with incident T2DM.

METHODS

This study followed 7725 children (3834 [49.6%] females, 3891 [50.4%] males) from the Bogalusa Heart Study through mid-adulthood to examine whether low-density lipoprotein cholesterol (LDL-C), high-density lipoprotein cholesterol (HDL-C), body mass index (BMI), or systolic blood pressure (SBP) differentially affect the risk of T2DM for females versus males. Potential sex interactions were tested after adjusting for age, race, triglycerides, smoking, follow-up time, puberty stage, use of birth control, and enrollment year.

RESULTS

Mean (± SD) age at baseline was 9.4 ± 3.5 years. There were 176 cases of T2DM (cumulative incidence = 2.3%) during a median follow-up of 9.1 years. In females versus males, LDL-C and SBP were differentially associated with T2DM (P ≤ 0.001 and P = 0.017, respectively). The relationships of BMI and HDL-C with T2DM were non-differential between females and males (P = 0.79 and P = 0.27, respectively).

CONCLUSIONS

This study is the first to show evidence of sex-specific differential effects of LDL-C and SBP on the risk of T2DM from childhood to adulthood. Greater LDL-C places girls at disproportionally higher risk of T2DM as women, whereas greater SBP differentially exposes boys to a greater risk of T2DM as men. Additional studies within existing child cohorts are needed to confirm and investigate the mechanisms underlying these differential effects.

Sex differences in the effect of diabetes mellitus on platelet reactivity and coronary thrombosis: From the Assessment of Dual Antiplatelet Therapy with Drug-Eluting Stents (ADAPT-DES) study

BACKGROUND

Whether the consequences of diabetes mellitus (DM) are worse for women than for men treated with drug-eluting stents (DES) and antiplatelet therapy remain unclear.

METHODS

Patients from the Assessment of Dual Antiplatelet Therapy With Drug-Eluting Stents study were stratified according to sex and DM status. We investigated the sex-specific effect of DM on high on-clopidogrel platelet reactivity (HPR), defined as a P2Y₁₂ reaction units ≥208, and the adjusted association of DM on the 2-year risk for coronary thrombotic events (CTE), defined as spontaneous myocardial infarction or definite or probable stent thrombosis.

RESULTS

Out of 8582 patients included in the study, 829 were women with DM (9.6%) and 1954 were men with DM (16.2%). The prevalence of insulin-treated DM (ITDM) was greater in women (p<0.0001). By multivariable logistic regression, DM was associated with a greater likelihood of HPR that was uniform between sexes (p_int=0.88). Following adjustment for baseline variables and HPR, in women a stepwise increase in risk for CTEs was observed in the transition from no DM to non-ITDM (NITDM) (adjusted hazard ratio [adjHR]: 1.31; 95% CI: 0.78-2.18) to ITDM (adjHR: 2.69; 95% CI: 1.23-3.45). This increase in risk associated with subtypes of DM was of smaller magnitude in men (for NITDM, adjHR: 1.04; 95% CI: 0.77-1.39; for ITDM, adjHR: 1.46; 95% CI: 1.05-2.03; p_int=0.016).

CONCLUSIONS

In a population treated with DES and antiplatelet therapy, the risk for CTE associated with DM seems to be greater in women and was independent of HPR.

Sex Differences in the Burden and Complications of Diabetes

PURPOSE OF THE REVIEW

To review the latest evidence on sex differences in the burden and complications of diabetes and discuss the potential explanations for the sex differences described.

RECENT FINDINGS

Diabetes is a strong risk factor for vascular disease, with compelling evidence that the relative risks of vascular diseases conferred by diabetes are considerably greater in women than men. The mechanisms underpinning women's excess relative risk of vascular disease from diabetes are unknown. Sex differences in the health care provided for the prevention, management, and treatment of diabetes and its complications could contribute to women's greater excess relative risks of diabetes complications. However, since the excess risk of vascular disease is not seen for other major vascular risk factors, inherent biological factors may be more likely to be involved. In addition to other cardiometabolic pathways, the sex dimorphism in body composition and fat distribution may be particularly important in explaining women's greater excess risk of the vascular complications of diabetes. There is strong evidence to suggest that diabetes is a stronger risk factor for vascular disease in women than men. Although several mechanisms may be involved, further research is needed to provide new and deeper insights into the mechanisms underpinning sex differences in the association between diabetes and vascular diseases. Such research will inform patients, health care professionals, and policy makers to ensure that women are not disproportionately affected by diabetes, and will help to reduce the burden in both sexes.

Sex differences in the associations of obstructive sleep apnoea with epidemiological factors

Despite the well-known male predominance in the prevalence of obstructive sleep apnoea (OSA), sex differences in the associations between OSA and a comprehensive range of epidemiological factors remain less clear.We examined the prevalence of self-reported OSA in 143 326 females (age 48-93 years) from the Nurses' Health Study (NHS) and NHS-II and 22 896 males from the Health Professionals Follow-up Study (age 65-101 years) in 2012-2013. Multivariable logistic regression was used to estimate the sex-specific prevalence odds ratios (pOR) and 95% confidence intervals of OSA by demographic, anthropometric, lifestyle and comorbidity factors.The overall prevalence of self-reported OSA was 6.4% in females and 13.8% in males. After mutual adjustment, the associations of OSA with physical inactivity, hypertension and daytime sleepiness were stronger in females, whereas the associations with waist circumference and witnessed apnoea were stronger in males (p-heterogeneity <0.01). There were qualitative sex differences in the associations with age (pOR per 5-year increment in females 0.95, 95% CI 0.94-0.96, and males 1.04, 1.01-1.08; p-heterogeneity <0.0001) and marital status (pOR for married versus other in females 0.85, 95% CI 0.81-0.89, and males 1.11, 0.99-1.25; p-heterogeneity <0.0001).Substantial sex differences exist in the associations with various factors, suggesting sex-specific mechanisms in OSA.

Invited Commentary: Sex and Race Differences in Diabetes and Cardiovascular Disease-Achieving the Promise of Sex and Race Subgroup Analyses in Epidemiologic Research

Diabetes confers a higher risk of cardiovascular disease on women than on men. The reasons for these sex differences, such as poorer cardiovascular risk factor profiles, have received considerable attention. However, a recent report on sex × diabetes interactions on cardiovascular disease identified that few if any prior studies have confirmed these sex differences in black individuals, despite known diabetes-related disparities. In this issue of the Journal, George et al. (Am J Epidemiol. 2018;187(3):403-410.) found marginally significant multiplicative sex × diabetes interactions in black but not white study participants after adjustments for traditional and behavioral risk factors, competing risk, and change in diabetes status over time. This study is notable for its attempt to fill an important literature gap, and it elegantly addressed multiple statistical considerations in assessing sex × diabetes interactions according to race strata. The findings also highlighted several important considerations for conducting race and sex subgroup analyses.

Sex Differences in the Association of Diabetes With Cardiovascular Disease Outcomes Among African-American and White Participants in the Atherosclerosis Risk in Communities Study

A sex × diabetes interaction in cardiovascular disease (CVD) has been established among white persons; however, it is unknown whether this interaction occurs among African Americans. We hypothesized that there was a multiplicative sex × diabetes interaction for CVD among African Americans participating in the Atherosclerosis Risk in Communities Study (1987-2013). Race-specific Cox models were run in three stages: Stage 1 examined baseline diabetes status; stage 2 examined baseline diabetes status with the competing risk of non-CVD death; and stage 3 examined time-varying diabetes status with a competing risk of non-CVD death. There were 1,073 incident CVD events among 3,767 African Americans and 2,475 among 10,291 white persons. Among African Americans, in stage 1 analysis, the hazard ratio for women with diabetes was 2.3 (95% confidence interval (CI): 2.0, 2.7) compared with women without diabetes after adjustment for age, and the corresponding hazard ratio for men was 1.8 (95% CI: 1.5, 2.1) (P for interaction = 0.014). After full adjustment, the diabetes hazard ratio was attenuated to 2.0 (95% CI: 1.8, 2.3) among women and remained 1.8 (95% CI: 1.5, 2.1) for men (P for interaction = 0.058). A synergistic influence on CVD risk between being a black woman and having diabetes was consistent across stage 2 and stage 3 analyses, with marginally significant interaction, mirroring sex differences seen in whites.

Global aetiology and epidemiology of type 2 diabetes mellitus and its complications

Globally, the number of people with diabetes mellitus has quadrupled in the past three decades, and diabetes mellitus is the ninth major cause of death. About 1 in 11 adults worldwide now have diabetes mellitus, 90% of whom have type 2 diabetes mellitus (T2DM). Asia is a major area of the rapidly emerging T2DM global epidemic, with China and India the top two epicentres. Although genetic predisposition partly determines individual susceptibility to T2DM, an unhealthy diet and a sedentary lifestyle are important drivers of the current global epidemic; early developmental factors (such as intrauterine exposures) also have a role in susceptibility to T2DM later in life. Many cases of T2DM could be prevented with lifestyle changes, including maintaining a healthy body weight, consuming a healthy diet, staying physically active, not smoking and drinking alcohol in moderation. Most patients with T2DM have at least one complication, and cardiovascular complications are the leading cause of morbidity and mortality in these patients. This Review provides an updated view of the global epidemiology of T2DM, as well as dietary, lifestyle and other risk factors for T2DM and its complications.

Taking cardiology clinical trials to the next level: A call to action

Physicians previously perceived heart disease to be a man's disease; yet, since 1984, more women have died of ischemic heart disease. Because women who develop obstructive coronary heart disease and heart failure tend to do so 10 years later than men, cardiology clinical trials that use arbitrary age cutoffs or exclusion criteria based on comorbidities and polypharmacy often limit the pool of potential participants to a greater extent for women. Issues related to trial design and insufficient accounting for female-predominant disease patterns have contributed to low rates of enrollment of women in certain domains of cardiology research. Accordingly, women do not benefit from as rich an evidence base for cardiology as men. Here, we review major sex differences in heart disease and discuss areas of cardiology research in which women have been underrepresented. Considering the widespread sex differences in cardiovascular structure and function, it is important to include balanced numbers of women and men in cardiovascular clinical trials. Beyond inclusion, sex-specific reporting is also essential. Moreover, with ongoing developments of clinical-trial methodology, it is imperative to seek innovative ways to learn as much as possible about how interventions behave in women and men. Adaptive trials are specifically identified as promising opportunities to consider sex-based analyses at interim stages, allowing sex-specific flexibility as these trials unfold. Finally, we emphasize the importance of factoring sex as a biological variable into the design, analysis, and reporting of preclinical research, because this research critically informs the design and execution of clinical trials.

Pregestational diabetes increases fetoplacental vascular resistance in rats

INTRODUCTION

Diabetes is a well-known risk factor in pregnancy. Because maternal diabetes involves oxidative stress that is also induced by chronic hypoxia and can alter vascular function, we sought to determine the effects of chronic maternal hyperglycemia on the fetoplacental vasculature in rats and to compare it with the effects of chronic hypoxia.

METHODS

Diabetes was induced in female rats by a streptozotocin injection at a neonatal age. When these animals reached adulthood, their hyperglycemia was confirmed and they were inseminated. Half of them were exposed to hypoxia (10% O₂) for the last week before the delivery. One day before the expected date of delivery, one of their placentae was isolated and perfused.

RESULTS

Fetoplacental vascular resistance was increased equally by experimental diabetes, chronic hypoxia, and their combination. Fetoplacental perfusion pressure-flow analysis suggested increased resistance in the small vessels in chronic hypoxia and in larger vessels in diabetes. Fetal plasma nitrotyrosine levels, measured as a marker of peroxynitrite (reaction product of superoxide and nitric oxide), mirrored the differences in fetoplacental resistance, suggesting a causative role. Fetoplacental vasoconstrictor reactivity to acute hypoxic stimuli was reduced similarly in all groups. Fasudil, a strong vasodilator agent, reduced fetoplacental vascular resistance similarly in all groups, suggesting that for the observed differences among the groups, the changes in vascular morphology were more important than variances in vascular tone.

DISCUSSION

Maternal diabetes increases fetoplacental vascular resistance to a similar extent as chronic hypoxia. These stimuli are not additive. Changes in vascular tone are not responsible for these effects.

Sex Differences in Outcomes after Stroke in Patients with Diabetes in Ontario, Canada

BACKGROUND

Outcomes after stroke in those with diabetes are not well characterized, especially by sex and age. We sought to calculate the sex- and age-specific risk of cardiovascular outcomes after ischemic stroke among those with diabetes.

METHODS

Using population-based demographic and administrative health-care databases in Ontario, Canada, all patients with diabetes hospitalized with index ischemic stroke between April 1, 2002, and March 31, 2012, were followed for death, stroke, and myocardial infarction (MI). The Kaplan-Meier survival analysis and Fine-Gray competing risk models estimated hazards of outcomes by sex and age, unadjusted and adjusted for demographics and vascular risk factors.

RESULTS

Among 25,495 diabetic patients with index ischemic stroke, the incidence of death was higher in women than in men (14.08 per 100 person-years [95% confidence interval [CI], 13.73-14.44] versus 11.89 [11.60-12.19]) but was lower after adjustment for age and other risk factors (adjusted hazard ratio [HR], .95 [.92-.99]). Recurrent stroke incidence was similar by sex, but men were more likely to be readmitted for MI (1.99 per 100 person-years [1.89-2.10] versus 1.58 [1.49-1.68] among females). In multivariable models, females had a lower risk of readmission for any event (HR, .96 [95% CI, .93-.99]).

CONCLUSIONS

In this large, population-based, retrospective study among diabetic patients with index stroke, women had a higher unadjusted death rate but lower unadjusted incidence of MI. In adjusted models, females had a lower death rate compared with males, although the increased risk of MI among males persisted. These findings confirm and quantify sex differences in outcomes after stroke in patients with diabetes.

Identifying the Critical Gaps in Research on Sex Differences in Metabolism Across the Life Span

The National Institutes of Health (NIH) Office of Research in Women's Health now functions under a mandate calling for the systematic inclusion of both female and male cells, animals, and human subjects in all types of research, so that sex as a biological variable is understood in health and disease. Sex-specific data can improve disease prevention, diagnosis, and treatment as well as reduce inequities. Inclusion of women in research studies has modestly improved over the last 20 years, yet preclinical research is still primarily done using male animal models and male-derived cells, with the result that many conclusions are made based on incomplete and sex-biased data. There are important, yet poorly studied, sex differences in cardiometabolic disease. To begin to address these sex differences, the Center for Women's Health Research at the University of Colorado held its inaugural National Conference, "Sex Differences Across the Lifespan: A Focus on Metabolism," in September 2016 (cwhr@ucdenver.edu). Research to address the important goal of understanding key sex differences in cardiometabolic disease across the life span is lacking. The goal of this article is to discuss the current state of research addressing sex differences in cardiometabolic health across the life span, to outline critical research gaps that must be addressed in response to NIH mandates, and, importantly, to develop strategies to address sex as a biological variable to understand disease mechanisms as well as develop diagnostic and therapeutic modalities.

Incident ischaemic stroke and Type 2 diabetes: trends in incidence and case fatality in Scotland 2004-2013

AIM

To describe trends in first ischaemic stroke incidence and case fatality in adults with and without a diagnosis of Type 2 diabetes prior to their ischaemic stroke event in Scotland between 2004 and 2013.

METHODS

Using population-wide hospital admission, death and diabetes datasets, we conducted a retrospective cohort study. Negative binomial and logistic regression models were used to calculate year-specific incidence and case-fatality rates for people with Type 2 diabetes and for people without diabetes.

RESULTS

During 41.0 million person-years of follow-up there were 69 757 ischaemic stroke events. Type 2 diabetes prevalence among patients who experienced ischaemic stroke increased from 13.5% to 20.3% between 2004 and 2013. Stroke incidence rates declined by 2.7% (95% CI 2.4, 3.0) annually for people with and without diabetes [diabetes/year interaction: rate ratio 0.99 (95% CI 0.98, 1.01)]. Type 2 diabetes was associated with an increased risk of ischaemic stroke in men [rate ratio 1.23 (95% CI 1.17, 1.30)] and women [rate ratio 1.41 (95% CI 1.35, 1.48)]. Case-fatality rates were 14.2% and 12.7% in people with Type 2 diabetes and without diabetes, respectively. Case fatality declined by 3.5% (95% CI 2.7, 4.5) annually [diabetes/year interaction: odds ratio 1.01 (95% CI 0.98, 1.02)].

CONCLUSIONS

Ischaemic stroke incidence declined no faster in people with a diagnosis of Type 2 diabetes than in people without diabetes. Increasing prevalence of Type 2 diabetes among stroke patients may mean that declines in case fatality over time will be less marked in the future.

All-cause mortality in adults with and without type 2 diabetes: findings from the national health monitoring in Germany

OBJECTIVE

To estimate age-specific and sex-specific all-cause mortality among adults with and without type 2 diabetes (T2D) in Germany.

RESEARCH DESIGN AND METHODS

The German National Health Interview and Examination Survey 1998 (GNHIES98) included a mortality follow-up (median follow-up time 12.0 years) of its nationwide sample representative of the population aged 18-79 years. After exclusion of participants with type 1 diabetes, age- and sex-stratified mortality rates (MR) were calculated for 330 GNHIES98 participants with diagnosed T2D (self-reported diagnosis or antidiabetic medication), 245 with undiagnosed T2D (no diagnosed T2D, glycated hemoglobin A1c ≥6.5% (≥48 mmol/mol)), and 5975 without T2D. Mortality rate ratios (MRR) comparing MR of persons with and without T2D were estimated. Age-/sex-standardized MR and MRR were calculated including persons aged 45 years or older. MRR were used to estimate the number of years of life lost (YLL) due to diagnosed diabetes in 2010.

RESULTS

Over 75 994 person-years, 73 persons with undiagnosed T2D, 103 with diagnosed T2D, and 425 persons without T2D died. MRR were significantly higher in younger age groups, except for analyses limited to women or diagnosed T2D. Age- and sex-standardized MRR (95% CI) among persons aged 45 years or older were 1.96 (1.41 to 2.71) for undiagnosed, 1.68 (1.26 to 2.23) for diagnosed, and 1.82 (1.45 to 2.28) for total (undiagnosed or diagnosed) T2D. Sex-stratified analysis revealed similar age-standardized MRR for undiagnosed (1.56 (0.79 to 3.06)) and diagnosed T2D (1.56 (1.03 to 2.37)) among women, and a higher age-standardized MRR for undiagnosed (2.06 (1.43 to 2.97)) than diagnosed T2D (1.70 (1.10 to 2.63)) among men. YLL due to diagnosed diabetes in Germany in 2010 were 164 600 (35 000 to 279 300) among women and 169 900 (28 300 to 328 300) among men.

CONCLUSIONS

In Germany, age- and sex-standardized all-cause mortality is almost twice as high for adults with T2D as for adults without T2D. The T2D-associated excess risk of mortality appears to be most pronounced in younger adults and among men unaware of their T2D.

Comparison of Machine Learning Approaches Toward Assessing the Risk of Developing Cardiovascular Disease as a Long-Term Diabetes Complication

The estimation of long-term diabetes complications risk is essential in the process of medical decision making. Guidelines for the management of Type 2 Diabetes Mellitus (T2DM) advocate calculating the Cardiovascular Disease (CVD) risk to initiate appropriate treatment. The objective of this study is to investigate the use of sophisticated machine learning techniques toward the development of personalized models able to predict the risk of fatal or nonfatal CVD incidence in T2DM patients. The important challenge of handling the unbalanced nature of the available dataset is addressed by applying novel ensemble strategies. Hybrid Wavelet Neural Networks (HWNNs) and Self-Organizing Maps (SOMs) constitute the primary models for building ensembles following a subsampling approach. Different methods for combining the decisions of the primary models are applied and comparatively assessed. Data from the 5-year follow up of 560 patients with T2DM are used for development and evaluation purposes. The highest discrimination performance (Area Under the Curve (AUC): 71.48%) is achieved by taking into account both the HWNN- and SOM- based primary models' outputs. The proposed method is superior to the Binomial Linear Regression (BLR) model justifying the need to apply more sophisticated techniques in order to produce reliable CVD risk scores.