Subclinical atherosclerosis among HIV-infected patients attending Mulago hospital HIV clinics in Uganda
Background: HIV-infected adults are at a higher risk of Cardiovascular Diseases (CVD) than the general population. This is as a result of an increased risk for atherosclerosis. Increased immune activation and inflammation in chronic HIV-infection may contribute to atherosclerosis and can be detected by elevated levels of inflammatory markers in the blood. The prevalence and factors associated with atherosclerosis have not been well studied in our HIV infected population. Objectives: To determine the prevalence and the factors associated with subclinical atherosclerosis among HIV-infected patients within the HIV care and treatment program at Mulago hospital, Uganda. Methods: This was a cross sectional study of consenting HIV infected adults attending MJAP and IDI clinics. HAART naïve patients and HAART experienced patients were consecutively selected from patients’ enrollment register at MJAP clinic and IDI respectively. These patients underwent an in-depth assessment, including a detailed structured questionnaire covering socio-demographic characteristics, co morbid conditions, health-related behaviors, medication exposure, and family history of CVD. Physical examination included measurement of blood pressure, weight and height from which we computed BMI, waist and hip circumference to get waist-to-hip ratio. Fasting blood samples were obtained to measure glucose, total cholesterol, HDL-c, LDL-c and triglycerides by use of immunoprecipitation analysis. We measured hsCRP using an enzyme-labeled immunosorbent sandwich assay. We measured CIMT as a marker of atherosclerosis using a linear probe of PHILIPS HD-7. Subclinical atherosclerosis was defined as CIMT ≥0.78mm. Data were analyzed using STATA 12, continuous variables were described using medians and inter quartile ranges (IQR), and nominal variables described as frequencies and percentages. We used bi-¬variate and multivariate regression to assess factors associated with subclinical atherosclerosis. A stepwise method was employed and included factors with a p-value of <0.2 in the final model. The level of significance for all pair-wise analyses was set at 0.05. Results We enrolled 245 patients of whom 145 (59%) were HAART-naïve and 100 (41%) patients on HAART for at least 7 years. The prevalence of subclinical atherosclerosis was 18% overall, 14% and 24% among HAART naïve and HAART treated patients respectively. The variables that were associated with subclinical atherosclerosis among HIV infected adults on bi-variate analysis included; older age, height, weight, BMI, increased waist and hip circumference, an increased blood pressure, increased LDL and triglyceride, use of anti hypertensive drugs, a family history of obesity and smoking. Majority of patients with subclinical atherosclerosis were on HAART, but this was not statistically significant (p=0.068). Factors independently associated with subclinical atherosclerosis included age [odds ratio (OR) 1.83; 95% confidence interval (CI) 1.24–2.69; P=0.002], BMI [OR 1.15; 95%CI 1.01-1.31; p=0.041] and high LDL-Cholesterol [OR 2.99; 95%CI 1.02-8.78; p=0.046]. High sensitive CRP was ≥3mg/L in 130 (54%) HIV patients of whom 56 (43%) were on HAART. HsCRP positively correlated with waist circumference, triglycerides, TC:HDL and negatively correlated with HDL. Conclusion The prevalence of subclinical atherosclerosis was 2 in every 10 HIV infected adults. Traditional risk factors of CVD (Age, BMI and HDL) were associated with subclinical atherosclerosis. Although there was no association between ESR or hsCRP with subclinical atherosclerosis, hsCRP correlated with traditional risk factors for CVD. We recommend routine assessment of CVD using traditional risk factors within HIV care and treatment programs.