Objective: To determine whether older people who use nonsteroidal anti-inflammatory agents (NSAIDs) have increased levels of blood urea nitrogen (BUN), serum creatinine, and BUN:serum creatinine ratio.
Design: Cross-sectional, secondary data analysis.
Setting: Older people living in the communities of East Boston, MA, New Haven, CT, and Washington and Iowa Counties, Iowa.
Participants: A total of 4099 people aged 70 years or older who were participants in the National Institute on Aging's Established Populations for Epidemiologic Studies of the Elderly project, had survived to the 6-year follow-up interview and had consented to the blood drawing.
Measurements: We assessed use of the NSAIDs at the 3- and 6-year interviews through a drug inventory and visual review of medication containers. Markers of renal function assessed through analysis of blood samples drawn at the time of the interview included BUN and creatinine.
Results: Fifteen percent of the cohort reported use of NSAIDs during the 2 weeks preceding the 6-year interview. Controlling for age, sex, and a range of potential confounding variables, NSAID users had significant prevalence odds ratios of 1.9 (95% confidence interval (CI), 1.5-2.3) for being in the highest quartile of BUN (>23), 1.3 (CI 1.1-1.7) for the highest quartile of serum creatinine (> or =1.4), and 1.7 (CI 1.4-2.1) for the highest quartile of the BUN:creatinine ratio (> or = 19.4). Chronic NSAID users (those who reported NSAID use at both the 3-year and 6-year interviews) accounted for the increased risk of high serum creatinine levels.
Conclusion: Community-dwelling older people who use NSAIDs tend to have higher levels of common laboratory markers of renal dysfunction. This hypothesis requires further testing in prospective cohort studies designed a priori to evaluate these issues.