Pulmonary function in an international sample of HIV-positive, treatment-naïve adults with CD4 counts >500 cells/μL: A substudy of the INSIGHT Strategic Timing of AntiRetroviral Treatment (START) trial

Objectives: The aim of the study was to describe the prevalence and correlates of chronic obstructive pulmonary disease (COPD) in a multicentre international cohort of persons living with HIV (PLWH). Methods: We performed a cross-sectional analysis of adult PLWH, naïve to HIV treatment, with baseline CD4 cell count >500 cells/μL enrolled in the Pulmonary Substudy of the Strategic Timing of AntiRetroviral Treatment (START) trial. We collected standardized, quality-controlled spirometry. COPD was defined as forced expiratory volume in 1s:forced vital capacity (FEV₁:FVC) ratio less than the lower limit of normal. Results: Among 1026 participants from 80 sites and 20 countries, the median age was 36 [interquartile range (IQR) 30, 44] years, 29% were female, and the median time since HIV diagnosis was 1.2 (IQR 0.4, 3.5) years. Baseline median CD4 cell count was 648 (IQR 583, 767) cells/μL, median viral load was 4.2 (IQR 3.5, 4.7) log₁₀ HIV-1 RNA copies/mL, and 10% had a viral load ≤400 copies/mL despite lack of HIV treatment. Current/former/never smokers comprised 28%/11%/61% of the cohort, respectively. COPD was present in 6.8% of participants, and varied by age, smoking status and region. Forty-eight per cent of those with COPD reported lifelong nonsmoking. In multivariable regression, age and pack-years of smoking had the strongest associations with FEV₁:FVC ratio (P<0.0001). There was a significant effect of region on FEV₁:FVC ratio (P=0.010). Conclusions: Our data suggest that, among PLWH who were naïve to HIV treatment and had CD4 cell counts >500 cells/μL, smoking and age were important factors related to COPD. Smoking cessation should remain a high global priority for clinical care and research in PLWH.