Researchers from the University of Modena, Italy, say patients with HIV are twice as likely to smoke than is the general population (42% vs 21%) and are less likely to quit. These patients are also more likely to have lung cancer and COPD. Also, their risk of cardiovascular disease (CVD) rises by 76%.
Antiretroviral therapy, immune hyperactivation, and premature senescence have been implicated in the pathogenesis of lung cancer and CVD in patients with HIV, the researchers say. However, most studies have focused on current smoking status, and few have focused on cumulative cigarette exposure. Thus, the researchers decided to determine the relationship of lifetime smoking history and risk of heart and lung diseases in patients with HIV.
In their study of 903 clinic patients with HIV, 214 (24%) had never smoked, 259 (29%) were former smokers, and 430 (48%) were current smokers. The groups were divided further, according to number of years smoked and time since quitting smoking.
The data showed current smokers had a median of 22.5 pack-years of smoking, vs 14.0 pack-years for former smokers. Lifetime cumulative smoking exposure was a “significant and powerful predictor” of cardiopulmonary disease. The study found a trend toward higher prevalence of clinical and subclinical lung and heart diseases as well as multimorbidity (at least 2 lung and 1 heart abnormalities) with increasing pack-years. The highest prevalence was among current smokers.
Three patients developed lung cancer, and out of the 350 who had pulmonary function testing, 40 were diagnosed with COPD. Among patients without clinical COPD and/or lung cancer, computed tomography scanning identified emphysema, bronchiolitis, noncalcified lung nodules, significant bronchial wall thickening, and bronchiectasis. Nearly half of patients had multimorbidity lung disease. Forty-three patients had evidence of prior myocardial infarction (MI): Eight never-smokers, 22 former smokers, and 13 current smokers had MIs.
A smoking cessation time of ≤ 5 years among patients with ≥ 10 pack-years was a significant risk factor for multimorbidity heart and lung diseases. The researchers say current smoking status is a poor indicator of risk of heart and lung diseases among these patients. When assessing, they suggest estimating the pack-year history for both former and current smokers, which could help with cost-effective screening.
Guaraldi G, Raggi P, Gomes A, et al. PLoS ONE. 2015;10(12):1-14.