Background
Pulmonary artery enlargement is a marker of pulmonary hypertension. We aimed to determine the proportion with pulmonary artery enlargement among well-treated persons with human immunodeficiency virus HIV (PWH) and uninfected controls.

Methods
PWH with a chest computed tomography were included from the ongoing Copenhagen Comorbidity in HIV Infection (COCOMO) study. Age and sex-matched uninfected controls were recruited from the Copenhagen General Population Study. Pulmonary artery enlargement was defined as a ratio of >1 between the diameter of the main pulmonary artery (at the level of its bifurcation) and the diameter of the ascending aorta.

Results
In total, 900 PWH were included, and 44 (5%) had a pulmonary artery–aorta ratio (PA:A) >1. After adjustment for age, sex, and body mass index, obesity (adjusted odds ratio, 4.33; 95% confidence interval, 1.76–10.65; P = .001) and injection drug use (IDU) (4.90; 1.00–18.46; P = .03) were associated with higher odds of having a PA:A >1, and pulmonary indices and smoking status were not. HIV seropositivity was borderline associated with a PA:A >1 (adjusted odds ratio, 1.89; 95% confidence interval, .92–3.85; P = .08).

Conclusions
A PA:A >1 was common in PWH. Obesity and IDU were independently associated with this finding and HIV serostatus was borderline associated with it, but HIV-related factors were not. Increased awareness may be appropriate in obese PWH and those with IDU.