Reduced Subendocardial Viability Ratio Is Associated With Unfavorable Cardiovascular Risk Profile in Women With Short Duration of Type 2 Diabetes

Abstract

Background: The pathophysiological perturbations underlying the unfavorable cardiovascular prognosis in women with type 2 diabetes (T2DM) remain elusive. Low subendocardial viability ratio (SEVR), an index of myocardial oxygen supply and demand, has been associated with intermediate cardiovascular risk markers and cardiovascular mortality in various populations. However, whether SEVR is associated with sex and cardiovascular risk markers in patients with T2DM remains to be clarified.

Methods: We examined 86 T2DM patients (mean age 59±10 years, 47% women, median diabetes duration 1.9 (range 0.2-5.0) years) and 86 sex- and age-matched control subjects in a cross-sectional study. SEVR was noninvasively assessed by tonometry and markers of cardiovascular risk by carotid-femoral pulse wave velocity (PWV), homeostasis model assessment of insulin resistance (HOMA2-IR), C-reactive protein, urinary albumin/creatinine ratio, and heart rate variability.

Results: Women with diabetes had significantly lower SEVR compared to both men with diabetes (161% ± 26% vs. 178% ± 32%, P < 0.01), women without diabetes (185% ± 24%, P < 0.001), and men without diabetes (188% ± 28%, P < 0.001). The differences remained significant after adjustment for age, systolic blood pressure, heart rate, diabetes, and smoking. SEVR was associated with PWV, HOMA2-IR, C-reactive protein, and reduced heart rate variability in patients and control subjects, but the associations became nonsignificant after adjustment for heart rate.

Conclusions: SEVR is reduced in women with short duration of T2DM and associated with cardiovascular risk markers. The latter association seems to be at least partly mediated via heart rate. We hypothesize that reduced SEVR may contribute to the unfavorable cardiovascular prognosis in women with diabetes.

Trial registration: ClinicalTrials.gov NCT00674271.

Keywords: HOMA index; arterial stiffness; blood pressure; heart rate variability; hypertension; low-grade inflammation; sex; subendocardial viability ratio; type 2 diabetes mellitus..