Increased relative wall thickness is a marker of subclinical cardiac target-organ damage in African diabetic patients

Objective

To assess the prevalence and covariates of abnormal left ventricular (LV) geometry in diabetic outpatients attending Muhimbili National Hospital in Dar es Salaam, Tanzania.

Methods

Echocardiography was performed in 61 type 1 and 123 type 2 diabetes patients. LV hypertrophy was taken as LV mass/height^2.7 > 49.2 g/m^2.7 in men and > 46.7 g/m^2.7 in women. Relative wall thickness (RWT) was calculated as the ratio of LV posterior wall thickness to end-diastolic radius and considered increased if ≥ 0.43. LV geometry was defined from LV mass index and RWT in combination.

Results

The most common abnormal LV geometries were concentric remodelling in type 1 (30%) and concentric hypertrophy in type 2 (36.7%) diabetes patients. Overall, increased RWT was present in 58% of the patients. In multivariate analyses, higher RWT was independently associated with hypertension, longer isovolumic relaxation time, lower stress-corrected midwall shortening and circumferential end-systolic stress, both in type 1 (multiple R² = 0.73) and type 2 diabetes patients (multiple R² = 0.66), both p < 0.001. These associations were independent of gender, LV hypertrophy or renal dysfunction.

Conclusion

Increased RWT is common among diabetic sub-Saharan Africans and is associated with hypertension and LV dysfunction.