Sex-specific differential in risk of diabetes-related macrovascular outcomes

Molecular Mechanisms of Adenosine Stress T1 Mapping

BACKGROUND

Adenosine stress T1 mapping is an emerging magnetic resonance imaging method to investigate coronary vascular function and myocardial ischemia without application of a contrast agent. Using gene-modified mice and 2 vasodilators, we elucidated and compared the mechanisms of adenosine myocardial perfusion imaging and adenosine T1 mapping.

METHODS

Wild-type (WT), A_2AAR^-/- (adenosine A_2A receptor knockout), A_2BAR^-/- (adenosine A_2B receptor knockout), A₃AR^-/- (adenosine A₃ receptor knockout), and eNOS^-/- (endothelial nitric oxide synthase knockout) mice underwent rest and stress perfusion magnetic resonance imaging (n=8) and T1 mapping (n=10) using either adenosine, regadenoson (a selective A_2AAR agonist), or saline. Myocardial blood flow and T1 were computed from perfusion imaging and T1 mapping, respectively, at rest and stress to assess myocardial perfusion reserve and T1 reactivity (ΔT1). Changes in heart rate for each stress agent were also calculated. Two-way ANOVA was used to detect differences in each parameter between the different groups of mice.

RESULTS

Myocardial perfusion reserve was significantly reduced only in A_2AAR^-/- compared to WT mice using adenosine (1.06±0.16 versus 2.03±0.52, P<0.05) and regadenoson (0.98±026 versus 2.13±0.75, P<0.05). In contrast, adenosine ΔT1 was reduced compared with WT mice (3.88±1.58) in both A_2AAR^-/- (1.63±1.32, P<0.05) and A_2BAR^-/- (1.55±1.35, P<0.05). Furthermore, adenosine ΔT1 was halved in eNOS^-/- (1.76±1.46, P<0.05) versus WT mice. Regadenoson ΔT1 was approximately half of adenosine ΔT1 in WT mice (1.97±1.50, P<0.05), and additionally, it was significantly reduced in eNOS^-/- mice (-0.22±1.46, P<0.05). Lastly, changes in heart rate was 2× greater using regadenoson versus adenosine in all groups except A_2AAR^-/-, where heart rate remained constant.

CONCLUSIONS

The major findings are that (1) although adenosine myocardial perfusion reserve is mediated through the A_2A receptor, adenosine ΔT1 is mediated through the A_2A and A_2B receptors, (2) adenosine myocardial perfusion reserve is endothelial independent while adenosine ΔT1 is partially endothelial dependent, and (3) ΔT1 mediated through the A_2A receptor is endothelial dependent while ΔT1 mediated through the A_2B receptor is endothelial independent.

Phenotypic sexual dimorphism in response to dietary fat manipulation in C57BL/6J mice

BACKGROUND

Obesity and the metabolic syndrome are increasingly prevalent in society and their complications and response to treatment exhibit sexual dimorphism. Mouse models of high fat diet-induced obesity are commonly used for both mechanistic and therapeutic studies of metabolic disease and diabetes. However, the inclusion of female mammals in obesity research has not been a common practice, and has resulted in a paucity of data regarding the effect of sex on metabolic parameters and its applicability to humans.

METHODS

Here we analyzed male and female C57BL/6 J mice beginning at 4 weeks of age that were placed on a low-fat diet (LFD, 10% calories from fat), a Western Diet (WD, 45% calories from fat), or a high fat diet (HFD, 60% calories from fat). Assessments of body composition, glucose homeostasis, insulin production, and energy metabolism, as well as histological analyses of pancreata were performed.

RESULTS

Both male and female C57BL/6 J mice had similar increases in total percent body weight gain with both WD and HFD compared to LFD, however, male mice gained weight earlier upon HFD or WD feeding compared to female mice. Male mice maintained their caloric food intake while reducing their locomotor activity with either WD or HFD compared to LFD, whereas female mice increased their caloric food intake with WD feeding. Locomotor activity of female mice did not significantly change upon WD or HFD feeding, yet female mice exhibited increased energy expenditure compared to WD or HFD fed male mice. Glucose tolerance tests performed at 4, 12 and 20 weeks of dietary intervention revealed impaired glucose tolerance that was worse in male mice compared to females. Furthermore, male mice exhibited an increase in pancreatic β cell area as well as reduced insulin sensitivity after HFD feeding compared to WD or LFD, whereas female mice did not.

CONCLUSIONS

Male and female C57BL/6 J mice exhibited strikingly different responses in weight, food consumption, locomotor activity, energy expenditure and β cell adaptation upon dietary manipulation, with the latter exhibiting less striking phenotypic changes. We conclude that the nature of these responses emphasizes the need to contextualize studies of obesity pathophysiology and treatment with respect to sex.

Sex differences in cardiovascular risk factors before and after the development of type 2 diabetes and risk for incident cardiovascular disease

AIMS

To assess sex differences in cardiovascular (CVD) risk factor changes before and after the development of type 2 diabetes, and, the association between incident diabetes with incident CVD in mid-life.

METHODS

We included 4893 Coronary Artery Risk Development in Young Adults Study participants, age 18-30 years at enrollment (1985-86). We ascertained incident diabetes and assessed sex differences in annual change in body mass index, blood pressure, and lipids before and after the ascertainment of diabetes using piecewise linear regression. We examined sex differences in the association between incident diabetes with incident CVD over 31 years of median follow-up.

RESULTS

Progression in most CVD risk factors did not differ by sex before diabetes. Women had better CVD profiles at the time of diabetes compared to men, and after diabetes, women had worse annual changes in blood pressure and lipids. Incident diabetes was associated with a higher hazard for incident CVD (Hazard Ratio [HR]: 1.45, 95% confidence limits: 1.07, 1.96) and we did not observe effect modification by sex (p for interaction = 0.8).

CONCLUSIONS

CVD risk factors worsened more rapidly after the development of type 2 diabetes for women than men. However, diabetes was not a stronger risk factor for incident CVD for women than men.

Obesity and cardiovascular disease in women

As the prevalence of obesity continues to grow worldwide, the health and financial burden of obesity-related comorbidities grows too. Cardiovascular disease (CVD) is clearly associated with increased adiposity. Importantly, women are at higher risk of CVD when obese and insulin resistant, in particular at higher risk of developing heart failure with preserved ejection fraction and ischemic heart disease. Increased aldosterone and mineralocorticoid receptor activation, aberrant estrogenic signaling and elevated levels of androgens are among some of the proposed mechanisms explaining the heightened CVD risk. In addition to traditional cardiovascular risk factors, understanding nontraditional risk factors specific to women, like excess weight gain during pregnancy, preeclampsia, gestational diabetes, and menopause are central to designing personalized interventions aimed to curb the epidemic of CVD. In the present review, we examine the available evidence supporting a differential cardiovascular impact of increased adiposity in women compared with men and the proposed pathophysiological mechanisms behind these differences. We also discuss women-specific cardiovascular risk factors associated with obesity and insulin resistance.

Program completion and glycemic control in a remote patient monitoring program for diabetes management: Does gender matter?

AIMS

To examine gender differences in program completion and glycemic outcomes for patients with type 2 diabetes (T2D) in a remote patient monitoring (RPM) program for diabetes management.

METHODS

Based on data from an RPM program that enrolled post-discharge T2D patients (n = 1645) in 2014-2017, logistic regression models were estimated to assess gender difference in the likelihood of completing the three-month RPM program; whereas ordinary least squares (OLS) regression models were used to examine gender difference in post-RPM hemoglobin A1c (HbA1c), controlling for demographics, baseline health status, including HbA1c, patient activation scores, and physiological data upload frequency for patients who had completed the program.

RESULTS

Among enrolled participants, men had lower odds of completing the three-month RPM program than women (adjusted odds ratio, 0.61; 95% confidence interval [CI], 0.39-0.95). However, among those who completed the program, men had lower post-RPM HbA1c than women (-0.18; 95% CI, -0.33, -0.03) after controlling for baseline HbA1c and other covariates.

CONCLUSIONS

While female patients with T2D were more likely to complete the RPM program, they showed a higher glycemic level at the end of the program compared to male patients. To close gender disparities in health, interventions through telemedicine tailored towards women's diabetes outcomes and men's engagement level are warranted.

Assessment of Non-Adherence to Oral Metformin and Atorvastatin Therapies: A Cross-Sectional Survey in Piedmont (Italy)

INTRODUCTION

It is not possible to recover from chronic diseases; however, a healthy lifestyle and correct adherence to therapy can avoid complications and co-morbidities. The aim of this study was the cross-sectional evaluation, by means of a questionnaire, of real-world data on the prevalence of non-adherence to metformin and atorvastatin oral therapies in a sample of patients that attend community pharmacies in the Piedmont Region. The secondary aim was to evaluate the presence of correlations between non-adherence and a number of variables detected by the questionnaire.

MATERIALS AND METHODS

Data were gathered from face-to-face interviews in six community pharmacies in Piedmont. The questionnaire was divided into two sections: the first included the Morisky, Green and Levine Medication Adherence Questionnaire (MAQ) (to assess therapy adherence); the second included questions on gender, age, level of education and the pharmacy in which the questionnaire was administered. Comparisons between proportions and mean values were performed using the χ2 test. Modified Poisson regression with robust standard errors was used for multivariate analysis. The level of significance was fixed at 0.05, CI at 95%.

RESULTS

The sample analysed was composed of 408 subjects (receiving either metformin or atorvastatin). According to MAQ, 62 patients were non-adherent (15% of the total cohort). Crude and multivariate analysis did not show any statistically significant correlation between gender, age, level of education and non-adherence. It emerged that there was a correlation between non-adherence and being a customer of two of the pharmacies involved [PR = 3.31 (p=0.028) and PR = 3.11 (p=0.027)].

CONCLUSIONS

Community pharmacies can be an appropriate setting to identify non-adherent patients. Therefore, healthcare professionals could realize an integrated and structured intervention to improve adherence. However, MAQ could underestimate the number of non-adherent patients. Further studies to test the association between non-adherence prevalence and being the customer of a specific pharmacy should be performed.

Sex differences in cardiometabolic disorders

The prevalence of cardiometabolic disorders in both women and men has increased worldwide and is linked to a rise in obesity and obesity-associated associated clustering of other cardiometabolic risk factors such as hypertension, impaired glucose regulation and dyslipidemia. However, the predominance of common types of cardiometabolic disorders such as heart failure, atrial fibrillation and ischemic heart disease is sex specific, and our identification of these and the underlying mechanisms is only just emerging. New evidence suggests that sex hormones, sex-specific molecular mechanisms and gender influence glucose and lipid metabolisms, as well as cardiac energy metabolism, and function. Here we review sex differences in cardiometabolic risk factors, associated preclinical and clinical cardiac disorders and potential therapeutic avenues.

Sex Differences in Cardiovascular Risk Profile From Childhood to Midlife Between Individuals Who Did and Did Not Develop Diabetes at Follow-up: The Bogalusa Heart Study

OBJECTIVE

Childhood and young adulthood may represent time periods in which cardiovascular risk factors (CVRFs) and their cumulative exposure lay the foundation for future risk of chronic diseases. We examined the longitudinal burden of CVRFs since childhood in men and women in whom diabetes did and did not develop at follow-up.

RESEARCH DESIGN AND METHODS

We included 1,530 participants (mean [SD] follow-up time 33.1 [8.2] years), who participated in the Bogalusa Heart Study and had been examined at least four times starting in childhood (mean age [SD] at first examination 9.4 [3.1] years). The area under the growth curve was used as a measure of cumulative exposure to CVRFs since childhood.

RESULTS

In childhood, boys and girls in whom diabetes did and did not develop at follow-up had similar CVRFs. Yet, over time, women during the transition from normoglycemia to diabetes experienced greater adverse changes in total cholesterol (TC), LDL cholesterol, and fasting plasma glucose (FPG) (noted as early as 23.5 years old and persisting across adulthood up to the age of the diagnosis of diabetes); a higher burden of exposure to BMI, TC, LDL cholesterol, and FPG from childhood to midlife; and a greater change in rates of BMI, TC, LDL cholesterol, and FPG since childhood than men during the same transition (interaction P values <0.05).

CONCLUSIONS

The greater exposure of women to and burden of CVRFs associated with diagnosis of diabetes may help to explain the stronger impact of diabetes as a major risk factor for cardiovascular events in women compared with men.

Cardiovascular Disease in Type 2 Diabetes: A Review of Sex-Related Differences in Predisposition and Prevention

Type 2 diabetes mellitus is a major risk factor for cardiovascular disease. However, compiled data suggest that type 2 diabetes affects the risk of cardiovascular disease differentially according to sex. In recent years, large meta-analyses have confirmed that women with type 2 diabetes have a higher relative risk of incident coronary heart disease, fatal coronary heart disease, and stroke compared with their male counterparts. The reasons for these disparities are not completely elucidated. A greater burden of cardiometabolic risk in women was proposed as a partial explanation. Indeed, several studies suggest that women experience a larger deterioration in major cardiovascular risk factors and put on more weight than do men during their transition from normoglycemia to overt type 2 diabetes. This excess weight is associated with higher levels of biomarkers of endothelial dysfunction, inflammation, and procoagulant state. Moreover, sex differences in the prescription and use of some cardiovascular drugs may compound an "existing" disparity. We searched PubMed for articles published in English and French, by using the following terms: ("cardiovascular diseases") AND ("diabetes mellitus") AND ("sex disparity" OR "sex differences" OR "sex related differences" OR "sex-related differences" OR "sex disparities"). In this article, we review the available literature on the sex aspects of primary and secondary prevention of cardiovascular disease in people with type 2 diabetes, in the predisposition to cardiovascular disease in those people, and in the control of diabetes and associated cardiovascular risk factors.

Empagliflozin in women with type 2 diabetes and cardiovascular disease - an analysis of EMPA-REG OUTCOME®

AIMS/HYPOTHESIS

The global epidemic of type 2 diabetes affects women and men equally; however, the relative impact on the cardiovascular (CV) system appears greater for women than men when compared with peers without diabetes. Furthermore, women are often under-represented in CV outcome trials, resulting in less certainty about the impact of CV prevention therapies across the sexes. The EMPA-REG OUTCOME® trial, which included 28.5% women, found that empagliflozin, given in addition to standard of care, reduced the risk of CV death by 38%, heart failure (HF) hospitalisation by 35% and a composite endpoint for incident or worsening nephropathy by 39%. Here we report a secondary analysis of the trial to determine the relative effects of empagliflozin in women vs men.

METHODS

The population studied were individuals with type 2 diabetes (HbA_1c 53-86 mmol/mol [7-10%] and eGFR >30 ml min^-1 [1.73 m]^-2), with established atherosclerotic CV disease. Individuals were randomised to receive empagliflozin 10 mg or 25 mg, or placebo once daily in addition to standard of care, and followed. The trial continued until ≥691 individuals had experienced an adjudicated event included in the primary outcome. All CV outcome events, including HF hospitalisations and deaths were prospectively adjudicated by blinded clinical events committees.

RESULTS

At baseline, the demographic profile of the 2004 women (age ± standard deviation 63.6 ± 8.8 years) compared with the 5016 men (age 63.0 ± 8.6 years) in the trial was largely similar, with the exception that LDL-cholesterol was numerically higher in women (2.5 ± 1.0 vs 2.1 ± 0.9 mmol/l), consistent with lower rates of lipid-lowering therapies (75.4% vs 83.2%). Women were also less likely to have smoked (31.5% vs 69.9%). The annualised incidence rate for women in the placebo group was numerically lower than in men for CV death (1.58% vs 2.19%), numerically higher for HF hospitalisation (1.75% vs 1.33%) and similar for renal events (7.22% vs 7.75%). We did not detect any effect modification by sex within the statistical power restrictions of the analysis for CV death, HF hospitalisation and incident or worsening nephropathy (interaction p values 0.32, 0.20 and 0.85, respectively). Compared with placebo, empagliflozin increased the rates of genital infections in both women (2.5% vs 10.0%) and men (1.5% vs 2.6%).

CONCLUSIONS/INTERPRETATION

CV death, HF hospitalisation and incident or worsening nephropathy rate reductions induced by empagliflozin were not different between women and men.

Adherence to Guidelines for Screening and Medication Use: Mortality and Onset of Major Macrovascular Complications in Elderly Persons With Diabetes Mellitus

OBJECTIVE

The objective of this study is to investigate relationships between adherence to recommended screening and medication use and severe macrovascular complications and all-cause mortality among persons aged above 68 years with diabetes mellitus (DM).

METHOD

Data came from a 5% Medicare claims sample of beneficiaries initially diagnosed with DM during 2006-2008; follow-up was up to 7 years.

RESULTS

Adherence to screening guidelines led to reduced mortality-hazard ratio (HR) = 0.57, 95% confidence interval [CI] = [0.56, 0.58]; congestive heart failure [CHF], HR = 0.89, CI = [0.87, 0.91]; acute myocardial infarction [AMI], HR = 0.90, CI = [0.85, 0.95]; and stroke/transient ischemic attack [Stroke/TIA], HR = 0.92, CI = [0.87, 0.97]-during follow-up. Recommended medication use led to lower mortality: HR = 0.72, CI = [0.70, 0.73]; CHF, HR = 0.67, CI = [0.66, 0.69]; AMI, HR = 0.68, CI = [0.65, 0.71]; and Stroke/TIA, HR = 0.79, CI = [0.76, 0.83].

DISCUSSION

Elderly persons newly diagnosed with diabetes who adhered to recommended care experienced reduced risk of mortality and severe macrovascular complications.