Cigarette Smoking Leads to More Rapid Lung Function Decline in Patients With HIV

Results of a study published in Thorax suggest individuals with HIV infection have more rapid lung function decline and a higher risk for chronic obstructive pulmonary disease (COPD) than the general population, particularly those who are current smokers.

Investigators from the Copenhagen Comorbidity in HIV Infection (COCOMO), INSIGHT Strategic Timing of Antiretroviral Treatment (START) Pulmonary Substudy, and Copenhagen General Population Study (CGPS) study groups used pooled data for this analysis. All study participants had undergone spirometry testing twice within the past 2 years. The risk for smoking-associated lung function decline was compared among participants with HIV infection (n=1130) and a cohort of matched control participants (n=2895).

Among participants in the HIV and control cohorts, the mean (SD) age was 46.6 (12.2) and 49.2 (11.2) years (P <.001), 81.9% and 79.8% were men, 70.1% and 99.9% were White (P <.001), and 28.2% and 18.5% were current smokers (P <.001), respectively.

Due to study designs, the follow-up duration was shorter among participants in the HIV vs control cohorts (median, 2.5 vs 10.4 years).

At baseline, the mean measurement of forced expiratory volume in one second (FEV₁) was 3.4 L among participants in the HIV cohort and 3.7 L for those in the control cohort (P <.001).

Further comparisons between participants in the HIV vs control cohorts were made after adjustments for age, sex, ethnicity, and smoking status. Results showed the annual rate of FEV₁ decline was more rapid among participants with HIV infection (36.4 vs 27.9 mL; adjusted mean difference [aMD], -8.5 mL; P <.001). This more rapid rate of annual FEV₁ decline among HIV-positive participants was most pronounced among those who were current smokers (aMD, -16.8 mL; P <.001), with smaller differences noted among those who were former smokers (aMD, -7.2 mL; P =.008), never smokers (aMD, -5.0 mL; P =.023), and White (aMD, -11.9 mL; P <.001).

Similar results were observed in regard to the annual decline in forced vital capacity (FVC).  Compared with control participants, a more rapid rate of FVC decline was observed in HIV-positive participants overall (aMD, -17.7 mL/year; P <.001), as well as among those who were current smokers (aMD, -29.6 mL/year; P <.001), former smokers (aMD, -16.2 mL/year; P <.001), never smokers (aMD, -12.9 mL/year; P <.001), and White (aMD, -21.4 mL/year; P <.001).

Among HIV-positive participants, lower CD4⁺ nadir count and longer duration of HIV positivity were both significant risk factors for more rapid FEV₁ and FVC decline.

The major limitation of this analysis was the difference in follow-up durations between the cohorts.

“These data provide further support that HIV infection is a unique risk factor for COPD, even in never-smoking PLWH [people living with HIV],” the investigators concluded.

Disclosure: Multiple authors declared affiliations with industry. Please see the original reference for a full list of disclosures.

This article originally appeared on Infectious Disease Advisor