ALBUQUERQUE, N.M., April 10 -- The moderate use of statins is associated with a sharply reduced risk of death from chronic obstructive pulmonary disease, researchers here found.
In a large matched cohort study of 76,232 patients, moderate use of statins was associated with an 83% reduction in the risk of death from COPD, they reported in the April issue of CHEST.
Use of statins also was linked to a 40% reduced risk of death from pneumonia or flu, according to Floyd Frost, Ph.D., of the Lovelace Respiratory Research Institute here, and colleagues.
The findings were confirmed in two separate case-control studies -- one each for COPD and for pneumonia and flu -- which yielded similar risk reductions, Dr. Frost and colleagues said.
The study provided additional evidence that statins, in addition as lowering LDL levels, also can modulate the immune system -- a property that may be important in the event of a new flu pandemic, Dr. Frost and colleagues said.
The Lovelace study is "extremely valuable because it suggests that statin therapy may well be efficacious in real-world application to COPD patients and possibly for acute influenza," said John Mancini, M.D., of the University of British Columbia in Vancouver, in an accompanying editorial.
The findings provide a "compelling rationale for executing randomized clinical trials that will more clearly define the magnitude of effect and the characteristics of patients that will benefit the most," Dr. Mancini said.
The current findings come from the medical records of several health management organizations in the Albuquerque area, Dr. Frost and colleagues said.
The researchers identified 19,058 patients who each had at least 90 days of statin use from Jan. 1, 1992, to Dec. 31, 2003 -- the cases -- and matched each of them with three HMO patients who did not use statins.
Statin use was stratified into low-dose (less than 4 mg/day) and moderate-dose (4 mg/day or more).
For patients using a moderate dose of statins, a logistic regression analysis of causes of death showed that:
- The risk of death from pneumonia was reduced 51%. The odds ratio was 0.49, with a 95% confidence interval from 0.26 to 0.76, which was significant at P<0.05.
- The risk of death from unspecified pneumonia or flu was reduced 40%. The odds ratio was 0.60, with a 95% confidence interval from 0.26 to 0.82, which was significant at P<0.05.
- The risk of death from COPD was reduced 83%. The odds ratio was 0.17, with a 95% confidence interval from 0.07 to 0.42, which was significant at P<0.05.
For the case-control studies, the researchers identified 397 HMO members who died in a hospital with a diagnosis of unspecified pneumonia or flu, as well as 54,136 people with the same diagnosis who survived. They also found 207 who died of COPD, as well as 9,622 with COPD who survived.
Patients were grouped into three age cohorts -- those born in or before 1920, from 1921 to 1945, and from 1946 to 1955 -- with the youngest group serving as a reference.
For moderate statin users analysis found that:
- The risk of death from unspecified pneumonia or flu was again reduced. The odds ratio was 0.62, with a 95% confidence interval from 0.43 to 0.91, which was significant at P<0.05.
- The risk of death from COPD was similarly reduced. The odds ratio was 0.19, with a 95% confidence interval from 0.08 to 0.47, which was significant at P<0.05.
Although the three studies cannot show cause and effect, Dr. Frost and colleagues said, the results "are in general agreement with prior studies" and are unlikely to be artifacts of study design.