Prevalence and covariates of electrocardiographic left ventricular hypertrophy in diabetic patients in Tanzania.

Background: Left ventricular hypertrophy (LVH) has been demonstrated to be a powerful predictor of cardiovascular (CV) morbidity and mortality in diabetic as well as hypertensive patients. However, less is known about the prevalence of electrocardiographic LVH (ECG-LVH) and its relation to other CV risk factors in diabetic patients in sub-Saharan Africa. Therefore, the aim was to assess the prevalence of ECG-LVH in diabetic patients in Dares Salaam, Tanzania, and its relation to other cardiovascular risk factors.

Methods: Two hundred and thirty-seven consecutive patients attending the Muhimbili diabetic clinic were studied. ECG-LVH was diagnosed by Sokolow-Lyon voltage and Cornell voltage-duration product criteria. Q waves, ST-segment deviation, T-wave abnormalities and intraventricular conduction defects were classified by the Minnesota codes. Blood pressure (BP), serum creatinine, cholesterol and triglyceride levels, and HbA 1c and urinary albumin and creatinine concentrations were determined.

Results: The prevalence of LVH in patients was 16% by either ECG criteria; 12.2% by Sokolow-Lyon and 5.1% by Cornell product criteria. Patients with LVH had significantly higher systolic and mean BP and pulse pressure, and a higher prevalence of ST-segment abnormalities, T-wave inversion and albuminuria than those without LVH (all p < 0.05). In multivariate logistic regression analysis, systolic BP was the only independent predictor of ECG-LVH. The prevalence of ECG-LVH increased by 15% per 10 mmHg higher systolic BP [OR 1.151 (95% CI 1.009-1.314), p < 0.05]. Clustering of cardiovascular risk factors differed significantly between type 1 and type 2 diabetes patients. On average, type 1 patients had 0.8 and type 2 had 2.2 additional CV risk factors.

Conclusion: ECG-LVH was present in 16% of diabetic patients in Tanzania. Systolic BP was the most important predictor of ECG-LVH. Clustering of CV risks was significantly higher in type 2 than in type 1 diabetics, demonstrating the need for systematic multiple risk-factor assessment in these patients.