An eight-year retrospective study with a median 6.4-year follow-up has associated long-term statin use with an increased risk of kidney disease.
Statin users, compared with case-matched controls who did not use statins, showed a 30 to 36 percent greater prevalence of kidney disease during follow-up averaging 4.5 years in an analysis of health insurance plan members, Medscape reports. The study was published on December 1, 2015 in the American Journal of Cardiology. The lead author is Dr. Tushar Acharya (University of California, San Francisco).
Statins lower the risk of cardiovascular disease and cardiovascular death, but “on the other hand, statins increase the risk of incident diabetes and possibly kidney diseases, both of which paradoxically increase long-term morbidity and mortality,” the researchers explain.
The researchers analyzed health care data from 30- to 85-year-olds in the San Antonio, Texas area who were members of Tricare Prime or Tricare Plus insurance plan for members of the military and their families from 2003 to 2012. All patients were continuously enrolled in the health care plan during the study, and there were no missing data, according to Medscape.
statin use was associated with a significantly increased risk
In the overall group, statin use was associated with a significantly increased risk of different types of kidney disease. In the healthy cohort, patients who received statins had a significantly higher risk of chronic kidney disease (odds ratio 1.53; 95% CI 1.27-1.85, P< <0.001). After adjustment for diseases (such as hypertension) that developed during follow-up, this association weakened, suggesting that these factors are implicated in the development of kidney disease.
The overall group consisted of 43,438 individuals: 13,626 statin users and 29,812 nonusers. The most commonly prescribed statin was simvastatin (Zocor), 73.5 percent; followed by atorvastatin (Lipitor), 17.4 percent; pravastatin (Pravachol), 7 percent; and rosuvastatin (Crestor), 1.7 percent. Thirty-eight percent of the statin users received high-intensity doses, and they took the drugs for a mean of 4.65 years, Medscape reports.
The researchers matched 6,342 statin users with 6,342 nonusers, according to baseline demographics, comorbidities, presence of renal disease, health care utilization, and medication use. In this matched cohort, patients had a mean age of 56, and 45 percent were women.
The researchers also identified a “healthy cohort” of 3,982 statin users and 21,988 nonusers. They matched 3,351 statin users with 3,351 nonusers. These individuals were free of diabetes, chronic kidney disease, cardiovascular disease, and conditions that might limit life expectancy or physical activity.
patients who are taking statins should not stop taking them
The study’s senior author, Dr. Ishak A. Mansi of the University of Texas Southwestern, Dallas said patients who are taking statins should not stop taking them based on this study, according to Medscape, but clinicians should carefully monitor creatinine levels in patients taking statins. Creatinine is an indicator of kidney health.
“[D]espite the use of statins for more than a quarter of a century, there are aspects about its long-term effects in noncardiac diseases that we do not know very well.” With new guidelines from the American College of Cardiology that will increase statin use to many more millions of healthy people, “we better make sure that we are not causing harm,” Mansi cautioned.
The researchers said randomized controlled trials for statins were sometimes prematurely terminated once the efficacy of reducing major acute cardiovascular events was achieved, and these trials rarely had total mortality as a primary outcome. The researchers say further studies are urgently needed “in which the long-term effects of statins on total mortality and total comorbidity indices (not only cardiovascular morbidity) are set as the primary outcomes,” according to Medscape.