Sex and ethnic differences in subclinical cardiovascular dysfunction in adults with type 2 diabetes

Background

Type 2 diabetes (T2D) confers higher relative rate of cardiovascular complications in women than men. South Asians (SA) are at increased risk of developing T2D than white Europeans (WE). The sex- and ethnic-specific differences of the effect of T2D on cardiovascular structure and function is underexplored.

Objectives

To examine the differences in cardiovascular dysfunction between sexes and ethnicities in an asymptomatic population with T2D.

Methods

Adults with T2D (n = 479) and non-diabetic controls (n = 116) underwent comprehensive stress perfusion cardiovascular magnetic resonance, echocardiography, and cardiopulmonary exercise testing. Cardiovascular structure and function were compared between T2D and controls, separately by sex and ethnicity. Regression analyses were performed to determine the clinical risk factors associated with cardiovascular dysfunction.

Results

Men with T2D, but not women, demonstrated worse systolic function and myocardial fibrosis. Women with T2D had lower myocardial perfusion reserve than men and a greater proportion of women had coronary microvascular dysfunction. Coronary microvascular dysfunction was associated with body mass index (BMI) in women with a significant sex interaction. Both SA and WE with T2D had concentric left ventricular remodelling, worse diastolic dysfunction, lower MPR, and lower aerobic exercise capacity, compared to controls. Ethnicity did not influence the magnitude of cardiovascular abnormalities seen in T2D.

Conclusions

Coronary microvascular dysfunction is worse and more prevalent in women than men with T2D. Increased BMI had an inverse association with MPR only in females with a significant sex interaction. In the presence of matching risk factors, SA and WE had similar T2D-associated adverse cardiovascular alterations. SA were not at increased risk of cardiovascular changes by virtue of ethnicity alone.