Carotid Atherosclerosis and its Correlation with ApoB/ApoA-I and Non-HDL-c/HDL-c Ratios among Adults with Type 2 Diabetes: A Cross-Sectional Study in Southwestern Uganda

Abstract

Background: Type 2 diabetes mellitus (T2DM) poses an increased risk for cardiovascular disease (CVD) through atherosclerosis. The apolipoprotein B (apoB)/apolipoprotein A-I (apoA-I) (ApoB/ApoA-I) ratio is a powerful predictor of atherosclerotic CVD and is associated with carotid atherosclerosis (CA) in T2DM; however, this association had never been studied in our setting. This study set out to determine the prevalence of CA and its correlation with ApoB/ApoA-I and non-high-density lipoprotein cholesterol (non-HDL-c)/high-density lipoprotein cholesterol (non-HDL-c/HDL-c) ratios among patients with T2DM in Southwestern Uganda. Methods: A cross-sectional study conducted at Mbarara Regional Referral Hospital included 212 ambulatory patients with T2DM aged ≥40 years. Socio-demographic, clinical, and behavioral characteristics were determined. Fasting blood samples were collected for measuring serum glucose, Apo B, Apo A-I, and the routine lipid profile. The apoB/apoA-I ratio and the non-HDL-c/HDL-c ratio were calculated. Carotid intima-media thickness (CIMT) was measured bilaterally at three points by high-resolution B-mode ultrasound. A mean value of six measurements from the right and left carotid arteries was used as a measure of CIMT. Carotid atherosclerosis was defined as a mean CIMT≥1.0 mm. A stepwise multivariate regression analysis and Pearson’s correlation were used to assess the association and correlation of CIMT with clinical factors, apoB/apoA-I, and non-HDL/HDL-c ratios. Results: The prevalence of CA was 35.9%. Age ≥55 years (OR 3.1; 95% CI:1.4 – 7.1; p<007) and age ≥ 65 years (OR 10.2; 95% CI: 3.5–29.5; p-< 0.001), coinfection with HIV (OR 3.8; 95% CI: 1.1–12.5; p-value = 0.030), high waist circumference (OR 2.7; 95% CI: 1.2 – 6.5; p-value = 0.022) and non-HDL-c/HDL-c ratio ≥ 4 (OR 3.0; 95% CI 1.0–8.5; p = 0.045) were associated with CA. The apoB/apoA-I ratio was elevated among T2DM patients with CA, but was not significantly associated with CA (OR 1.0; 95% CI: 0.4 – 2.5, p= 0.25). The optimal non-HDL-c/HDL-c ratio cutoff value for detecting CA was 3.39 (a sensitivity of 60.53% and a specificity of 54.41%). Conclusion: There is a high prevalence of CA among patients with T2DM. The non-HDL-c/HDL-c ratio was significantly associated with high CIMT but not the apoB/apoA-I ratio.