Orthostatic Hypertension and Hypotension and Outcomes in CKD: The CRIC (Chronic Renal Insufficiency Cohort) Study

Abstract

Rationale & ObjectiveThere are limited data about the prevalence and prognostic significance of orthostatic hypo- and hypertension in patients with chronic kidney disease. The objective of this study is to determine the prevalence of orthostatic hypo- and hypertension in a cohort of patients with chronic kidney disease and examine their association with clinical outcomes.Study DesignProspective cohort study: Chronic Renal Insufficiency Cohort (CRIC) Study.Setting & Population7 clinical centers, participants with chronic kidney disease.ExposuresOrthostatic hypotension (decline in systolic blood pressure [BP] > 20 mm Hg) and orthostatic hypertension (increase in systolic BP > 20 mm Hg) from seated to standing position.OutcomesCardiovascular and kidney outcomes and mortality.Analytical ApproachLogistic regression was used to determine factors associated with orthostatic hypo- and hypertension; Cox regression was used to examine associations with clinical outcomes.ResultsMean age of study population (n = 3,873) was 58.1 ± 11.0 years. There was a wide distribution of change in systolic BP from seated to standing (from −73.3 to +60.0 mm Hg); 180 participants (4.6%) had orthostatic hypotension and 81 (2.1%) had orthostatic hypertension. Diabetes, reduced body mass index, and β-blocker use were independently associated with orthostatic hypotension. Black race and higher body mass index were independently associated with orthostatic hypertension. After a median follow-up of 7.9 years, orthostatic hypotension was independently associated with high risk for cardiovascular (HR, 1.12; 95% CI, 1.03-1.21) but not kidney outcomes or mortality. Orthostatic hypertension was independently associated with high risk for kidney (HR, 1.51; 96% CI, 1.14-1.97) but not cardiovascular outcomes or mortality.LimitationsOrthostatic change in BP was ascertained at a single visit.ConclusionsOrthostatic hypotension was independently associated with higher risk for cardiovascular outcomes, whereas orthostatic hypertension was associated with higher risk for kidney outcomes. These findings highlight the importance of orthostatic BP measurement in practice and the need for future investigation to understand the mechanisms and potential interventions to minimize the risk associated with orthostatic changes in BP.