Obesity is not associated with contrast nephropathy

BACKGROUND: Exposure to radiocontrast media may result in acute kidney injury (AKI) or traditionally defined contrast nephropathy (CN), both of which may lead to increased morbidity and mortality. The pathogenesis of both these variants of contrast-induced nephropathy (CIN) may involve inflammatory mediators that lead to renal impairment. A link between obesity and inflammation has been clearly established, but whether obesity is independently associated with CIN is unknown. OBJECTIVE: To determine whether obesity, when stratified by body mass index (BMI), is a risk factor for CIN in a large and hemodynamically stable population of hospitalized United States veterans. DESIGN: Retrospective chart review. MEASUREMENTS: Presence or absence of AKI or CN after intravenous radiocontrast administration and comparison of patient characteristics between those with versus without AKI or CN. RESULTS: The overall prevalence of AKI and CN was 16.1% and 12.6%, respectively. Patients with AKI or CN were comparable to those without radiocontrast injury, except that affected patients tended to be older and diabetic. When stratified by BMI, obesity was not found to be associated with the development of AKI or CN after exposure to radiocontrast. CONCLUSION: Obesity does not appear to be an independent risk factor for AKI or CN after exposure to radiocontrast.