Orthostatic hypotension and incident chronic kidney disease: the atherosclerosis risk in communities study

Abstract

Orthostatic hypotension is associated with cardiovascular disease and mortality, but little is known of its association with incident chronic kidney disease. We evaluated this association in the Atherosclerosis Risk in Communities study. Orthostatic hypotension was defined as a decrease in systolic blood pressure ≥ 20 mm Hg or a decrease in diastolic blood pressure ≥ 10 mm Hg within 2 minutes of standing. Incident chronic kidney disease was defined using an estimated glomerular filtration rate < 60 mL/min/1.73 m², or a coded hospitalization (discharge) or death for chronic kidney disease through 2005, after exclusion of chronic kidney disease at baseline. The associations between orthostatic hypotension and chronic kidney disease were modeled using Cox proportional hazard while adjusting for confounders including resting blood pressure and medications. Among 12 593 participants, 1326 developed chronic kidney disease (6.3 cases per 1000 person-years; median follow-up of 16 years), with higher rates in blacks than whites. An increased risk of chronic kidney disease was observed among persons with orthostatic hypotension compared with those without it (blacks hazard ratio 2.0, 95% CI, 1.5 to 2.8; whites hazard ratio 1.2, 95% CI, 1.0 to 1.6; P for race interaction = 0.02). An alternative chronic kidney disease classification, based on an increase in serum creatinine at the 3- or 9-year follow-up visits, showed significant associations with orthostatic hypotension in both whites and blacks. These findings suggest that orthostatic hypotension increases the risk of chronic kidney disease in middle-aged persons, but race effects vary by choice of chronic kidney disease definition.