Association between obstructive lung disease and markers of HIV infection in a high-risk cohort.

BACKGROUND: Evidence suggests an association between HIV infection and the presence of obstructive lung disease (OLD). However, the associations between specific markers of HIV infection and OLD remain unclear. A study was undertaken to determine the independent associations of HIV infection, CD4 cell count and plasma HIV viral load with the presence of OLD in an urban cohort. METHODS: Clinical, laboratory and spirometric data from the AIDS Linked to the Intravenous Experience (ALIVE) study, an observational study of current and former injection drug users in Baltimore, Maryland, were analysed. Multivariable logistic regression models were generated to identify HIV infection indices independently associated with OLD. RESULTS: Of 1077 participants (mean±SD age 48±8 years), 89% were African-American, 65% were men and 86% were current smokers. A total of 303 (28%) were HIV infected and 176 (16%) had spirometry-defined OLD. Higher viral load was independently associated with OLD. HIV-infected individuals with viral load >200,000 copies/ml had a 3.4-fold increase in the odds of OLD compared with HIV-negative participants (95% CI 1.24 to 9.39; p=0.02). The association between higher HIV viral load and OLD persisted after accounting for antiretroviral therapy use (OR 4.06, 95% CI 1.41 to 11.7; p=0.01). No association was observed between HIV serostatus or CD4 cell count and the presence of OLD. CONCLUSION: In a cohort at risk for OLD and HIV infection, high viral load but not CD4 cell count was associated with an increased prevalence of spirometry-defined OLD. These findings suggest that higher viral load may contribute mechanistically to the increased risk of OLD in patients with HIV infection.

Prevalence and risk factors for unrecognized obstructive lung disease among urban drug users.

BACKGROUND: Obstructive lung disease (OLD) is frequently unrecognized and undertreated. Urban drug users are at higher risk for OLD due to race, behavioral, and socioeconomic characteristics, yet little data exist on prevalence and risk factors associated with unrecognized OLD in this population. OBJECTIVE: The objective of this study is to determine the prevalence of unrecognized OLD in an urban population and identify the characteristics associated with lack of physician-diagnosed OLD. DESIGN: Cross-sectional analysis from the Acquired Immunodeficiency Syndrome Linked to the Intravenous Experience (ALIVE) study, an observational study of current and former injection drug users in Baltimore, Maryland, USA. PARTICIPANTS: All participants with spirometry-defined airflow obstruction were stratified by the presence or absence of physician diagnosis of OLD. MAIN MEASURES: Using cross-sectional demographic, clinical, and spirometric measurements, multivariable regression models were generated to identify factors independently associated with unrecognized OLD. KEY RESULTS: Of the 1083 participants evaluated in the ALIVE lung substudy, 176 (16.3%) met spirometric criteria for OLD. Of those, only 88 (50%) had a physician diagnosis of OLD. The prevalence of unrecognized OLD decreased as severity of airflow obstruction increased. Factors independently associated with unrecognized OLD were absence of respiratory symptoms (prevalence ratio [PR], 1.70; 95% confidence interval [CI]: 1.29-2.23; P < 0.01) and less severe dyspnea (PR, 0.83; 95% CI: 0.72-0.96, per point increase in dyspnea scale; P = 0.01). In the subset of human immunodeficiency virus (HIV)-infected participants, the use of antiretroviral therapy (ART) was independently associated with an increased prevalence of unrecognized OLD (PR, 1.93; 95% CI: 1.05-3.56; P = 0.03). CONCLUSIONS: In a cohort of current and former urban drug users, OLD is substantially underrecognized and associated with lack of respiratory symptoms. Relying on the presence of respiratory symptoms as a trigger to perform spirometry may result in a substantial underdiagnosis of OLD in this population. HIV-infected individuals receiving ART are a population particularly vulnerable to unrecognized OLD.

Tobacco use and nicotine dependence among HIV-infected and uninfected injection drug users.

INTRODUCTION: Urban U.S. populations are burdened by intersecting epidemics of HIV infection, injection drug use, and cigarette smoking. Given the substantial morbidity attributable to tobacco in these populations, we characterized smoking behaviors, nicotine addiction, and tobacco exposure among HIV-infected and HIV-uninfected injection drug users (IDUs) in Baltimore, Maryland. METHODS: Smoking behaviors among participants in the ALIVE Study were assessed using interviewer-administered questionnaires. Smoking history and nicotine dependence (Fagerstrom Index scores) were compared by HIV and drug injecting status. Serum cotinine (a nicotine metabolite) was measured for a sample of participants by enzyme immunoassay. RESULTS: Among 1052 participants (29.7% HIV-infected, 39.8% active injectors), 85.2% were current smokers and 9.3% were former smokers. Smoking prevalence, age at smoking initiation, and cumulative tobacco exposure were similar by HIV status. Median Fagerstrom scores of 4 for HIV-infected and HIV-uninfected smokers indicated moderate nicotine dependence. Daily cigarette consumption was identical by HIV status (median 10 cigarettes), although HIV-infected participants were less likely to smoke 1+ pack daily compared to HIV-uninfected participants (18.0% vs. 26.9%, p=0.001). Compared to former injectors, active injectors had higher smoking prevalence (90.5% vs. 81.7%, p=0.0001), greater daily cigarette consumption (30.7% vs. 19.6% smoked 1+ pack daily, p=0.0001), and slightly higher Fagerstrom scores (median 5 vs. 4). Cotinine levels paralleled self-reported cigarette consumption. DISCUSSION: Tobacco use is extremely common among inner-city IDUs. Smoking behavior and nicotine dependence did not materially differ by HIV status but were associated with active drug injection. Cessation efforts should target the dual dependence of cigarettes and drugs experienced among this population.

HIV and COPD: impact of risk behaviors and diseases on quality of life.

PURPOSE: Smoking worsens quality of life among HIV-infected individuals, but it remains unclear if this association is related simply to smoking or to chronic obstructive pulmonary disease (COPD), the end-organ disease caused by smoking. METHODS: Using cross-sectional data from the AIDS Linked to the Intravenous Experience study, we determined the independent effects of smoking, HIV and COPD assessed using the Medical Outcome Studies-HIV questionnaire. RESULTS: Of 973 participants, 287 (29.5%) were HIV infected and 151 (15.5%) had spirometry-defined obstruction. Eight hundred and thirty-four (85.7%) were current smokers with 23.3 mean pack-years history. HIV infection was independently associated with reduced physical and mental health. COPD was associated with a trend toward worse physical health (-1.48 units; 95%CI -3.33 to 0.38; p = 0.12) and was independently associated with worse mental health (-2.43 units; 95%CI -4.22 to -0.64; p < 0.01). After accounting for COPD and other covariates, smoking was not associated with changes in physical or mental health. CONCLUSIONS: The presence of COPD, rather than smoking, is associated with worse quality of life independent of HIV infection. Diagnosis and management of COPD in former or current smokers with or at risk for HIV may further improve quality of life.

Effect of cigarette smoking on HIV acquisition, progression, and mortality.

Cigarette smoking is more common among those with HIV compared with the general population. However, it remains unclear whether smoking alters the natural history of HIV infection or if unique health consequences related to smoking occur in the context of HIV. In this article, we review the literature on the effect of smoking on acquisition of HIV, progression of HIV to AIDS, and mortality. Although there was significant heterogeneity in the study populations evaluated, we found little evidence that cigarette smoking increases the risk for acquiring HIV. Two studies observed that smoking was associated with more rapid CD4 cell count declines, but most data suggest that smoking does not accelerate progression to clinical AIDS. The most consistent finding was an increased risk for respiratory infections in smokers. Although no effect of smoking was seen with AIDS-related mortality, findings related to all-cause mortality were inconclusive. Owing to an increase in chronic non-AIDS outcomes in the post-highly active antiretroviral therapy (HAART) era, smoking is likely an increasingly important contributor to morbidity and mortality in HIV-infected populations. Future investigation of the biological and clinical effects of smoking, and of preventive approaches to reduce the heavy burden among individuals with HIV is warranted.