Carotid intima-media thickness and its associations with type 2 diabetes mellitus in South Africans

Abstract

OBJECTIVES: Carotid intima-media thickness (CIMT) is a surrogate marker of subclinical atherosclerosis and a predictor of cardiovascular events. Few studies in Africa have evaluated CIMT and its associations in people with type 2 diabetes mellitus. This study measured CIMT in a sample of mainly black South African patients with type 2 diabetes mellitus, and evaluated the association of demographic and clinical risk factors with CIMT. DESIGN: Cross-sectional study. SETTING: Kafalong Hospital, a large community hospital in Pretoria that mainly serves an urban black community. SUBJECTS: Patients with type 2 diabetes mellitus. OUTCOME MEASURES: We evaluated clinical, biochemical and CIMT ultrasound measurements in a standardised fashion. RESULTS: In 185 patients, the univariate significant predictors of mean far-wall CIMT were age [beta 0.007 (standard error 0.001)], systolic blood pressure [beta 0.001 (standard error 0.000)] and inverse serum creatinine [beta -8.15 (standard error 3.23)]. Low-density lipoprotein cholesterol, apolipoprotein A-1, apolipoprotein B:A-1 ratio and apolipoprotein B:A-1 ratio > 1.2 all had p-values below 0.1, but above 0.05. Age had the largest R-squared (20%). The multivariate models did not explain more of the variation in CIMT than did age alone. CONCLUSION: Lipid parameters were related to CIMT in our study population. However, this did not reach statistical significance in this relatively small sample, and lipids added very little to the variability of CIMT compared with age alone.