Statins Help Protect Lung Function in Smokers and Former Smokers

October 8, 2007 — Statin therapy was associated with a slower decline in pulmonary function in smokers and former smokers, independent of the underlying lung disease, according to the results of a study published in the October 1 Online First issue of Chest.

"Smokers are affected by a variety of inflammatory diseases, including COPD [chronic obstructive pulmonary disease]," write J.I. Keddissi, MD, FCCP, from The Oklahoma City Department of Veterans Affairs (VA) Medical Center and the University of Oklahoma Medical Center, and colleagues. "Statins, 3-hydroxy-3-methyl-glutaryl-coenzyme-A reductase inhibitors, are used for their lipid lowering characteristics, but also appear to have anti inflammatory and immunomodulatory activity.... Interestingly, all of these additional actions may counteract some of the harmful effects of cigarette smoking induced chronic inflammation."

The investigators categorized all smokers and former smokers seen at the Oklahoma City VA hospital in 2005, with abnormal baseline spirometry and 2 or more pulmonary function tests (PFTs) done 6 months apart, into obstructive or restrictive groups based on their initial PFT. Use of statins, annual decrease in forced expiratory volume at 1 second (FEV1) and forced vital capacity (FVC), and need for respiratory-related urgent care in the emergency department or in a hospital, were compared between groups.

Of 418 patients studied, 215 were receiving statin therapy; 319 had obstructive and 99 had restrictive disease. Decline in FEV1 was lower in statin users than in control subjects (–0.005 ± 0.20 vs 0.085 ± 0.17 L/year; P < .0001), as was decline in FVC (–0.046 ± 0.45 vs 0.135 ± 0.32 L/year; P < .0001). The apparent protective effect of statins was independent of the type of lung disease and of current smoking status.

Among patients with obstructive spirometric patterns, the statin group had a lower incidence of respiratory-related urgent care (0.12 ± 0.29 vs 0.19 ± 0.32/patient-year; P = .02).

"In smokers and former smokers, statins are associated with a slower decline in pulmonary function, independent of the underlying lung disease," the study authors write. "Prospective, randomized trials are needed to study the effect of statins on lung function."

Limitations of the study include inability to compare the effects of simvastatin with those of other statins, possible inclusion of some patients with an asthmatic component to their lung disease, smoking status not confirmed with laboratory analysis, retrospective design with possible selection bias, and lack of generalizability to women.

"Our study adds to a growing body of evidence suggesting that statins may have a beneficial effect in inflammatory lung diseases," the study authors conclude. "Our finding that statin use may have a protective effect on lung function in current and ex smokers is supported by numerous animal and in vitro studies. Due to its retrospective nature, it should only be considered as theory generating."

The study authors have disclosed no relevant financial relationships.

Chest. Published online October 1, 2007.

Source: http://www.medscape.com/viewarticle/563871?src=mpnews