Influencing factors on cardiac structure and function beyond glycemic control in patients with type 2 diabetes mellitus

Background: We hypothesized that clinical factors other than glycemic control may influence abnormal cardiac function in patients with type 2 diabetes mellitus (T2DM). We aimed to investigate the independent factors for abnormal cardiac function among clinical factors in T2DM. Methods: We studied 148 asymptomatic patients with T2DM without overt heart disease. Echocardiographic findings were compared between diabetic patients and 68 age-matched healthy subjects. Early (E) and late (A) diastolic mitral flow velocity and early diastolic mitral annular velocity (e') were measured for assessing left ventricular (LV) diastolic function. We evaluated insulin resistance, non-esterified fatty acid, high-sensitive CRP, estimated glomerular filtration rate, waist/hip ratio, abdominal visceral adipose tissue (VAT), subcutaneous adipose tissue (SAT) and other clinical characteristics in addition to glycemic control. VAT and SAT were quantified by computed tomography. Results: In T2DM, E/A and e' were significantly lower, and E/e', left atrial volume and LV mass were significantly greater than in control subjects. In multivariate liner regression analysis, VAT was an independent determinant of left atrial volume (beta = 0.203, p = 0.011), E/A (beta = -0.208, p = 0.002), e' (beta = -0.354, p<0.001) and E/e' (beta = 0.220, p = 0.003). Age was also an independent determinant, whereas fasting plasma glucose and hemoglobin A1c levels were not. In addition to systolic blood pressure, waist-hip ratio (beta = 0.173, p = 0.024) and VAT/SAT ratio (beta = 0.162, p = 0.049) were independent determinants of LV mass. Conclusion: Excessive visceral fat accompanied by adipocyte dysfunction may play a greater role than glycemic control in the development of diastolic dysfunction and LV hypertrophy in T2DM.