Left Ventricular Diastolic Function in Normotensive Type-2 Diabetic Subjects

Background Most previous studies on diastolic function in diabetics are confounded by coexisting ischemic heart disease, obesity and hypertension. Therefore, there may be advantages in studying patients with diabetes mellitus in developing nations where confounding variables are less prevalent. The aim of this study was to assess the effect of type-2 diabetes mellitus on left ventricular diastolic function in normotensive subjects in Nigeria. Methods One-hundred-twenty-two patients with type-2 diabetes mellitus aged 35–74 years with a mean age of 55.30 ± 8.53 years were studied. Patients with blood pressure ≥ 140/90 mmHg or on treatment for hypertension were excluded from the study. Ninety-one healthy volunteers aged 40–75 years with a mean age of 55.30 ± 8.56 years were recruited as normal controls. Transthoracic echocardiography was performed in all subjects to assess their left ventricular diastolic filling pattern by analyzing mitral and pulmonary flow velocities. Results Seventy-one (58%) of the type-2 diabetic subjects had evidence of impaired relaxation, 9 (7%) had pseudonormal filling and 7 (6%) had a restrictive filling pattern. Only 29% of the diabetics had a normal filling profile compared to 58% of the normal controls (c2 = 19.4, p=0.0002). Conclusions The result of the study shows that Nigerian type-2 diabetics have impaired left ventricular filling compared with normal subjects independent of confounding factors such as obesity and blood pressure. Therefore, not only Caucasians, African Americans and Asians but also African diabetic subjects suffered from diastolic dysfunction.