ATS 2009, SAN DIEGO-- New HIV therapies have prolonged lives and improved health for patients with HIV, but the treatments have also brought the longer-term effects of the disease into sharper focus.
Patients with HIV are not only about twice as likely to smoke as HIV-negative individuals, they are also more susceptible to the detrimental effects of smoking and tend to suffer a swifter decline in lung function, according to new research. Syed Kadri, medical student at Ohio State University Medical Center will present new research documenting this decline among HIV-positive individuals on Sunday, May 17, at the 105th International Conference of the American Thoracic Society in San Diego.
"Early in the epidemic, HIV was a different disease--with few effective drugs, the best that an HIV- positive patient could hope for was a relatively painless death after a brief period," said Mr. Kadri. "The long-term effects of HIV were therefore fairly obvious: death. But with the advent of a new class of anti-retroviral drugs called 'highly active anti-retroviral therapy,' or HAART, the clinical picture of HIV has changed. The disease has gone from being an automatic death sentence to a chronic condition, and like all chronic conditions, it brings with it other complications that can seriously affect the lives of those who have it."
Mr. Kadri and colleagues are directing a prospective study to evaluate declines in lung function among HIV-positive patients. The patients, mostly men in their 40s, half of whom were smokers, were assessed at baseline for two measures of respiratory status, FEV1 and DLCO, and had been followed for two years at the time of reporting. FEV1 is a measure of expiratory flow in one second, a standard gauge of lung capacity, whereas DLCO is a measurement of diffusing capacity of the lungs and is decreased in patients with emphysema.
At the end of two years, the 63 patients displayed marked declines in lung function, going from an average FEV1 of 88% predicted to 83.2% and a DLCO of 77.6 to 70.0. "This is the type of decline you might expect to see in elderly individuals who have a long history of smoking," said Mr. Kadri. "These results indicate that HIV-positive patients are more susceptible to lung-related problems than HIV-negative individuals and that HIV-positive smokers are even more susceptible to developing early emphysema. We don't know when these differences begin to manifest in HIV-positive individuals who smoke, but the severity is likely a function of the time that they have lived with the disease."
The researchers have begun a new leg of the study, to analyze the effects of smoking cessation in the same cohort as those in the current study. "We hope this next phase will show us whether lung function improves with smoking cessation in HIV-positive individuals and what factors are associated with successful cessation," said Mr. Kadri. "Clinically, this study shows that HIV patients need to quit smoking, which could be a difficult task given their higher prevalence of smoking. Physicians treating patients with HIV should be aware that they are at much higher risk for emphysema, and counsel them more about smoking cessation."