Predictors of Abnormal Diffusing Capacity for Carbon Monoxide in Post-pneumonia Ugandans With and Without HIV

Abnormal diffusing capacity for carbon monoxide (DLco) is highly prevalent among people with HIV (PWH) and associated with increased mortality in both PWH and the general population. Because there are no DLco data from East Africa, we characterized the prevalence and risk factors for abnormal DLco in PWH and people without HIV (PWoH) in Uganda.

Kampala, Uganda.

We performed a cross-sectional analysis of adults with and without HIV, who were followed longitudinally for lung function change after pneumonia. We used the participants' first American Thoracic Society/European Respiratory Society-compliant DLco measurements post pneumonia. We built multivariable linear and logistic regression models to determine predictors of abnormal DLco. We then developed stratified multivariable models to determine whether the predictors of abnormal DLco differ by HIV serostatus.

Among 447 individuals, 47.9% were PWH, 17.2% were ever cigarette smokers, 71.4% had tuberculosis (TB) on enrollment, and 9.9% had self-reported past TB. The prevalence of abnormal DLco was 21.7%. In adjusted models, HIV was significantly associated with a lower %predicted DLco, as were past bacterial pneumonia, TB (past and on enrollment), and smoking. After stratification and adjustment, TB (past and on enrollment) was significantly associated with a lower %predicted DLco both among PWH and PWoH; smoking was associated with lower DLco among PWoH, and work fumes exposure was associated with higher odds of DLco < lower limit of normal among PWH only.

Abnormal DLco was common post pneumonia in Ugandan adults, and its predictors differed by HIV serostatus. Longitudinal follow-up can help understand the trajectory of and morbidity associated with DLco.