Differences between HIV‐infected and uninfected adults in the contributions of smoking, diabetes and hypertension to acute coronary syndrome: two parallel case–control studies

Abstract

The aim of the study was to assess the separate contributions of smoking, diabetes and hypertension to acute coronary syndrome (ACS) in HIV-infected adults relative to uninfected adults. Two parallel case-control studies were carried out. In the first study, HIV-positive adults diagnosed with ACS between 1997 and 2009 (HIV+/ACS) were matched for age, gender and known duration of HIV infection with HIV-positive adults without ACS (HIV+/noACS), each individual in the HIV+/ACS group being matched with three individuals in the HIV+/noACS group. In the second study, each individual in the HIV+/ACS group in the first study was matched for age, gender and calendar date of ACS diagnosis with three HIV-negative individuals diagnosed with ACS between 1997 and 2009 (HIV-/ACS). Each individual in the HIV-/ACS group was then matched for age and gender with an HIV-negative adult without ACS (HIV-/noACS). After matching, the ratio of numbers of individuals in the HIV+/ACS, HIV+/noACS, HIV-/ACS and HIV-/noACS groups was therefore 1 : 3 : 3 : 3, respectively. We performed logistic regression analyses to identify risk factors for ACS in each case-control study and calculated population attributable risks (PARs) for smoking, diabetes and hypertension in HIV-positive and HIV-negative individuals. There were 57 subjects in the HIV+/ACS group, 173 in the HIV+/noACS group, 168 in the HIV-/ACS group, and 171 in the HIV-/noACS group. Independent risk factors for ACS were smoking [odds ratio (OR) 4.091; 95% confidence interval (CI) 2.086-8.438; P < 0.0001] and a family history of cardiovascular disease (OR 7.676; 95% CI 1.976-32.168; P = 0.0003) in HIV-positive subjects, and smoking (OR 4.310; 95% CI 2.425-7.853; P < 0.0001), diabetes (OR 5.778; 95% CI 2.393-15.422; P = 0.0002) and hypertension (OR 6.589; 95% CI 3.554-12.700; P < 0.0001) in HIV-negative subjects. PARs for smoking, diabetes and hypertension were 54.35 and 30.58, 6.57 and 17.24, and 9.07 and 38.81% in HIV-positive and HIV-negative individuals, respectively. The contribution of smoking to ACS in HIV-positive adults was generally greater than the contributions of diabetes and hypertension, and was almost twice as high as that in HIV-negative adults. Development of effective smoking cessation strategies should be prioritized to prevent cardiovascular disease in HIV-positive adults.