ABSTRACT: BACKGROUND AND OBJECTIVES:Nonsteroidal anti-inflammatory drugs (NSAIDs) have been associated with AKI. Their association with nephrotic syndrome has not been systematically studied. This study aimed to assess the risk of nephrotic syndrome associated with NSAID use. DESIGN, SETTING, PARTICIPANTS, & MEASUREMENTS:A matched case-control study was performed in the UK primary care database. Cases were patients with a first diagnosis of nephrotic syndrome and controls were those without nephrotic syndrome. NSAID exposure (grouped either based on cyclooxygenase enzyme selectivity and chemical groups) was classified as either current (use at the nephrotic syndrome diagnosis date and corresponding date in the control group), recent, or past use. Odds ratios (ORs) and 95% confidence intervals (95% CIs) were calculated using unconditional logistic regression analysis. RESULTS:We included 2620 cases and 10,454 controls. Compared with non-use, current use of 15-28 days and >28 days of conventional NSAIDs was associated with a higher relative risk of nephrotic syndrome: adjusted OR, 1.34; 95% CI, 1.06 to 1.70, and OR, 1.42; 95% CI, 0.79 to 2.55, respectively. Also, recent use (discontinuation 1-2 months before nephrotic syndrome diagnosis date; OR, 1.55; 95% CI, 1.11 to 2.15) and past use (discontinuation 2 months-2 years; OR, 1.24; 95% CI, 1.07 to 1.43), but not current use of <15 days (OR, 0.78; 95% CI, 0.46 to 1.31) nor past use (discontinuation >2 years; OR, 0.96; 95% CI, 0.85 to 1.09) were associated with a higher relative risk of nephrotic syndrome as well as past use of selective COX-2 inhibitors (discontinuation 2-24 months; OR, 1.24; 95% CI, 0.98 to 1.58). Categorization based on chemical groups showed that acetic acid and propionic acid derivatives were associated with a higher risk of nephrotic syndrome. CONCLUSIONS:The use of conventional NSAIDs was associated with a higher risk of nephrotic syndrome starting from at least 2 weeks of exposure, as well as for recent and past exposure up to 2 years before the diagnosis of nephrotic syndrome. This higher risk appeared mainly attributable to acetic acid and propionic acid derivatives.
