ABSTRACT
Early determination of myocardial manifestations of diabetes mellitus [DM] is of a major importance, since myocardial involvement considerably influence the prognosis of diabetic patients. Microalbuminuria [MA] and hyperinsulinemia [HI] have been shown to predict cardiovascular [CV] disease in patients with DM. However the relationship between these risk factors and both cardiac structure and function is still unclear. To assess the Echocardiographic evidence of cardiomyopathy in asymptomatic patients with type 2 DM; to relate these findings to MA and fasting plasma insulin level [FI]; and to investigate whether these observations are independent of glycemic control and other clinical CV risk factors. 63 type 2 diabetic patients without known cardiac diseases, duration of DM [mean 52.4 +/- 51.4 month], age [47.4 +/- 807 year], body mass index [BMI] [26.6 +/- 3.2], men [41/63], in addition to 20 healthy subjects matched for age, sex and BMI served as control were enrolled in the present study. Based on MA and FI, patients were subgrouped into [microalbuminuric and normoalbuminuric] and [hyperinsulinemic and normoinsulinemic] respectively. We compared Echo- derived indices of left ventricular [LV] structure and LV systolic and diastolic functions in patients versus control subjects and between the different patient subgroups. Diabetic patients had greater LV posterior wall thickness [PWT], interventricular septal thickness [IVST], and LV mass index [LVMI] [p<0.0001 for each]. LV diastolic dysfunction, manifested as reduction in E velocity and E/A ratio and prolongation in isovolumic relaxation time [IVRT] [p<0.001 for each], was documented in diabetic patients as compared with control subjects. MA was diagnosed in 15/63 [24%] patients. As compared with normoalbuminuric patients, MA was associated with higher fasting blood glucose [FBG] and FI [p<0.05 for each], greater LVPWT [p<0.05], and LVMI [p=0.02], and lower fractional shortening [FS], ejection fraction [EF], and E/A ratio [p<0.001, p=0.006 and p<0.05 respectively]. Patients with HI had lower FS [p=0.02] and lower E velocity [p=0.04] than in patients with normal FI. In multi-variate analysis, the associated findings either with MA or FI has been unchanged after adjusting for the duration of DM, glycemic control, age, gender, BMI, and BP. Type 2 diabetic patients without overt heart disease have increased LV wall thickness and LVMI and LV diastolic dysfunction suggesting subclinical diabetic cardiomyopathy [DCM]. MA and HI are independently associated with these changes, which may contribute to the relation of albuminuria and HI with increased rate of CV event among diabetics. Thus, screening of either MA or HI may identify patients at CV high risk