Statin use linked to reduced mortality from influenza
MedWire News: Hospitalized patients with laboratory-confirmed influenza who receive statins are significantly less likely to die than those who do not receive statins, show study findings.
"Our findings suggest that statins are a promising area of exploration and could provide a useful adjunct to antiviral medications and vaccine, particularly in settings where circulating influenza virus strains are not susceptible to antiviral medications, or vaccine is in short supply or not well-matched to circulating viruses," say Ann Thomas (Oregon Public Health Division, Portland, USA) and co-authors.
Using data from the Centers for Disease Control and Prevention's Emerging Infections Program, the researchers identified 3043 hospitalized adults (aged 70.4 years on average) with laboratory-confirmed influenza during the 2007-2008 influenza season.
Of these, 57.1% had received the influenza vaccine and 33.3% had received statin medication prior to or during hospitalization. The majority (76%) of patients who were on statins had been taking their medication both prior to and during hospitalization.
Compared with patients who did not receive statins, those who did were significantly more likely to be older (75.9 vs 63.5 years), male (49.2 vs 41.4%), and White (68.8% vs 59.6%); to have cardiovascular (66.0 vs 32.9%), metabolic (51.9 vs 27.4%), lung (30.4 vs 21.6%), or renal disease (22.8 vs 12.3%); and to have been vaccinated against influenza (62.1 vs 43.6%).
The researchers suggest that the finding of more mortality among Whites is most likely due to confounding or misclassification through incomplete race data. In addition, the finding that the vaccine appeared to not be effective against influenza was most likely due to poor viral matching during the chosen year and that over half of the patients were over the age of 70 years - an age group in which influenza vaccine is known to be less effective.
Among hospitalized patients with laboratory-confirmed influenza, 5% died within 30 days of their influenza test, with 39% of deaths occurring after discharge from the hospital. The researchers found that patients died a median of 7 days after discharge.
Multivariate regression analysis showed that administration of statins prior to or during hospitalization significantly reduced the likelihood of death (odds ratio=0.59) after adjusting for age, race, cardiovascular, lung, and renal disease, influenza vaccination, and antiviral administration.
Randomized controlled trials would best address the potential benefits of statins for influenza treatment, the researchers concluded in The Journal of Infectious Diseases, and "would allow for examination of such issues as dose-response, use in younger age groups, and identifying the most effective class of statins."
By Ingrid Grasmo