Abstract
Background: Diabetes mellitus [DM) is a fast-increasing non-communicable disease in South Africa, with a prevalence of 11.3%. The present study aimed to longitudinally investigate the association of carotid intima-media thickness [CIMT) progression and cardiovascular risk factors in the T2DM and non-DM rural black population of South Africa. Methods: This population-based retrospective cohort study was conducted in the Dikgale Mamabolo Mothiba Surveillance area between 2014 and 2023 by the Africa Wits INDEPTH Partnership for Genomic Research (AWI-Gen). The IBM Statistical Package for the Social Sciences version 27 was used to analyze data. The paired T-test was used to determine the mean differences between baseline and follow-up. Longitudinal estimates of the association of CIMT with CVD risk factors in the T2DM and non-DM groups were analyzed using linear mixed models. Results: The baseline mean age was 51.64 years. There was a significant increase in CIMT (left and mean CIMT), low-density lipoprotein-cholesterol (LDL-C), systolic blood pressure (SBP), diastolic blood pressure (DBP), and pulse rate in the T2DM and non-DM groups. In the T2DM group, there was a strong significant association between age (2.20 mm), LDL-C (4.30 mm), SBP (4.57 mm), and waist/hip ratio (0.24 mm) with CIMT progression. The non-DM group revealed a significant association between LDL-C (0.001 mm), SBP (1.41 mm), and CIMT progression. Conclusion: CIMT was associated with other main CVD-related risk factors (age, LDL-C, LDL-C/HDL-C ratio, TC/HDL-C ratio, waist/hip ratio, and SBP). CIMT progression was more pronounced in the T2DM group than non-DM, suggesting a higher risk of atherosclerosis and cardiovascular complications in T2DM individuals.