A new study examining asymptomatic adults with type 2 diabetes found that coronary microvascular dysfunction was significantly more common in women than in men.
Researchers assessed 479 patients with type 2 diabetes (T2D) and 116 non-diabetic controls using cardiovascular magnetic resonance imaging to evaluate myocardial perfusion reserve (MPR), a marker of coronary microvascular function.
Patients with T2D had lower MPR than controls. Among patients with T2D, women had lower MPR than men (2.6 vs 3.1) and coronary microvascular dysfunction (CMD), defined as MPR less than2.5, was more common in women than in men (46% vs 26%).
The study excluded participants with known or silent coronary artery disease, to focus on early microvascular changes. All participants underwent standardized vasodilator stress testing and rest perfusion imaging to calculate MPR.
Sex-specific differences in risk factors associated with MPR were observed. In women, higher body mass index (BMI) was significantly linked to lower MPR, while in men, systolic blood pressure (SBP) was inversely associated with MPR. The interaction between sex and BMI was statistically significant, suggesting that BMI may have a stronger negative effect on MPR in women than in men.
Other variables, including HbA1c, low-density lipoprotein (LDL), and diabetes duration,were not significantly associated with MPR after adjustment. Measures of cardiac structure, such as left ventricular mass-to-volume ratio and extracellular volume fraction, were also not associated. However, lower MPR was associated with reduced global longitudinal strain and left ventricular ejection fraction.
“Our study has several strengths,” wrote Jian L. Yeo, corresponding author from the Department of Cardiovascular Sciences, University of Leicester and the National Institute for Health and Care Research (NIHR) Leicester Biomedical Research Centre, Glenfield Hospital. “Our T2D cohort is the largest to prospectively undertake detailed phenotyping with CMR including quantitative perfusion imaging.”
Yeo and colleagues concluded that “female sex and systolic blood pressure were independently and inversely associated with MPR,” noting that these associations may have implications for CMD prevention in T2D. The study further stated, “There was a significant interaction between sex and BMI for MPR.”
MPR measurements did not differ significantly across 1.5T and 3T MRI systems. The study sample was multi-ethnic and representative of both sexes, with a rigorous screening protocol to rule out participants with clinical or hidden ischemic disease.
The results indicate that CMD was more common in women with T2D, even in the absence of symptoms. These findings suggest the need for sex-specific strategies in identifying and addressing early coronary vascular impairment. Further research is needed to determine whether modifying factors such as body mass index in women or blood pressure in men can improve coronary microvascular function.
The study used pooled data from four prospective clinical investigations conducted in the UK and was supported by national health and cardiovascular research funding bodies.
Full disclosures can be found in the published study.
