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High Rates of Airflow Obstruction, Emphysema in Heavy-Smoking Spanish Group: average age 45...37% emphysema...marijuana doubled risk
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6th IAS Conference on HIV Pathogenesis, Treatment and Prevention, July 17-20, 2011, Rome
Mark Mascolini
While 20% of HIV-positive men in a 275-person Spanish group had airflow obstruction, half of both men and women studied had emphysema [1]. Almost all study participants were responding well to antiretroviral therapy, and almost all were current or former smokers.
Researchers in several Spanish centers undertook this study because earlier work found high rates of pulmonary problems in people with HIV [2-7], yet most multicenter studies and individual HIV clinics do not routinely assess lung function. This cross-sectional study involved 275 people with HIV, 263 of them (95.6%) taking combination antiretroviral therapy, and 253 (92%) with an undetectable viral load. Study participants had been diagnosed with HIV for a median of 12 years, and median CD4 count at recruitment stood at 541 (interquartile range [IQR] 392 to 813).
Of the 275 people recruited between July 2008 and March 2010, 78.2% were men, 61.5% were active smokers, and 25.1% were former smokers. Active smokers averaged 32.3 +/- 16.6 pack-years, while former smokers averaged 24.2 +/- 18.1 pack-years. (A pack-year equals 20 cigarettes smoked every day for 1 year, so someone who smoked 63 cigarettes a day for 10 years would have a 32 pack-year history [8].)
Age averaged 48.5 years. Almost half of the study group, 47%, complained of chronic cough and sputum production, and 30% had grade 1 breathlessness on exertion. About 10% had an earlier diagnosis of TB or Pneumocystis pneumonia, 31% had been diagnosed with bacterial pneumonia, 5% with asthma, and 5% with chronic obstructive pulmonary disease (COPD).
The investigators used CT scans to diagnose emphysema and completed a series of pulmonary tests to assess static lung volume, lung diffusing capacity, pulmonary gas exchange, and exercise tolerance.
Testing determined that 17.2% of study participants had airflow obstruction (FEV1/FEV less than 0.7), including 19.7% of men and 8.3% of women (P = 0.051 for gender difference). The investigators judged airflow obstruction mild in 63% and moderate in 37%. Nearly one third of patients with airflow obstruction (30.1%) had an earlier diagnosis of COPD, and half of that group was being treated for COPD.
Among all patients, multivariate analysis determined that every year of age raised the risk of airflow obstruction 6% (odds ratio [OR] 1.06, 95% confidence interval [CI] 1.01 to 1.11). Current versus never smokers had more than a 6 times higher risk of airflow obstruction (OR 6.38, 95% CI 1.37 to 29.73), and a TB history more than doubled the risk (OR 2.23, 95% CI 0.86 to 5.78). Among smokers, current versus former smokers ran a tripled risk of airflow obstruction (OR 2.94, 95% CI 1.01 to 7.92), and a TB history tripled the risk (OR 3.03, 95% CI 1.13 to 8.09).
Emphysema prevalence (tES greater than 5%) stood at 37.7% overall, 39.9% in men, and 30.0% in women (gender difference not significant, P = 0.177). The researchers graded emphysema as mild in 87.2% of study participants and moderate in 12.8%. Two thirds of people with an emphysema tES above 5% had airflow obstruction.
Among all study participants, current smokers had a 13 times higher risk of emphysema than people who never smoked (OR 13.04, 95% CI 2.29 to 74.1). Heavy versus mild alcohol drinking quadrupled the risk of emphysema (OR 3.97, 95% CI 1.01 to 15.73), marijuana use almost doubled the risk (OR 1.91, 95% CI 1.11 to 3.32), heroin use more than doubled the risk (OR 2.36, 95% CI 1.40 to 3.99), and hepatitis C virus infection tripled the risk (OR 2.96, 95% CI 1.19 to 7.36). Among smokers, HCV infection almost doubled the risk of emphysema (OR 1.86, 95% CI 1.05 to 3.31) and evidence of Pneumocystis pneumonia more than tripled the risk (OR 3.47, 95% CI 1.43 to 8.40).
The investigators advised a high level of suspicion for airflow obstruction and emphysema in people with HIV, particularly those who smoke, have respiratory symptoms, or have a TB history. Because of the relatively young age of these patients, the researchers proposed findings like these may signal "a significant health problem in the next few years," as people responding to antiretroviral therapy continue to age.
References
1. Samperiz G, Guerrero D, Lopez M, et al. Prevalence and risk factors of pulmonary abnormalities in HIV patients treated with anti-retroviral therapy. 6th IAS Conference on HIV Pathogenesis, Treatment and Prevention. July 17-20, 2011. Rome. Abstract TUPE135.
2. Diaz PT, Clanton TL, Pacht ER. Emphysema-like pulmonary disease associated with human immunodeficiency virus infection. Ann Intern Med. 1992;116:124-128.
3. Diaz PT, King MA, Pacht ER, et al. Increased susceptibility to pulmonary emphysema among HIV-seropositive smokers. Ann Intern Med. 2000;132:369-372.
4. Crothers K, Butt AA, Gibert CL, Rodriguez-Barradas MC, Crystal S, Justice AC. Increased COPD among HIV-positive compared to HIV-negative veterans. Chest. 2006;130:1326-1333.
5. Crothers K, Huang L, Goulet JL, et al. HIV infection and risk for incident pulmonary diseases in the combination antiretroviral therapy era. Am J Respir Crit Care Med. 2011;183:388-395.
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6. Gingo MR, George MP, Kessinger CJ, et al. Pulmonary function abnormalities in HIV-infected patients during the current antiretroviral therapy era. Am J Respir Crit Care Med. 2010;182:790-796.
7. Miravitlles M, Soriano JB, Garcia-Rio F, et al. Prevalence of COPD in Spain: impact of undiagnosed COPD on quality of life and daily life activities. Thorax. 2009;64:863-868.
8. Smoking pack year calculator. http://smokingpackyears.com/.
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