Clinical ResearchElevated BP after AKIHsu, Chi-yuan*,†; Hsu, Raymond K.*; Yang, Jingrong†; Ordonez, Juan D.‡; Zheng, Sijie‡; Go, Alan S.†,§,‖ Author Information Departments of *Medicine and ‖Epidemiology and Biostatistics, University of California—San Francisco, San Francisco, California; †Division of Research, Kaiser Permanente Northern California, Oakland, California; ‡Division of Nephrology, Kaiser Permanente Oakland Medical Center, Oakland, California; and §Department of Health Research and Policy, Stanford University School of Medicine, Stanford, California Correspondence: Dr. Chi-yuan Hsu, Division of Nephrology, University of California, San Francisco, 521 Parnassus Avenue, C443, Box 0532, San Francisco, CA 94143-0532. Email: [email protected] Received November 20, 2014 Accepted May 19, 2015 Journal of the American Society of Nephrology 27(3):p 914-923, March 2016. | DOI: 10.1681/ASN.2014111114 Buy Metrics Abstract The connection between AKI and BP elevation is unclear. We conducted a retrospective cohort study to evaluate whether AKI in the hospital is independently associated with BP elevation during the first 2 years after discharge among previously normotensive adults. We studied adult members of Kaiser Permanente Northern California, a large integrated health care delivery system, who were hospitalized between 2008 and 2011, had available preadmission serum creatinine and BP measures, and were not known to be hypertensive or have BP>140/90 mmHg. Among 43,611 eligible patients, 2451 experienced AKI defined using observed changes in serum creatinine concentration measured during hospitalization. Survivors of AKI were more likely than those without AKI to have elevated BP—defined as documented BP>140/90 mmHg measured during an ambulatory, nonemergency department visit—during follow-up (46.1% versus 41.2% at 730 days; P<0.001). This difference was evident within the first 180 days (30.6% versus 23.1%; P<0.001). In multivariable models, AKI was independently associated with a 22% (95% confidence interval, 12% to 33%) increase in the odds of developing elevated BP during follow-up, with higher adjusted odds with more severe AKI. Results were similar in sensitivity analyses when elevated BP was defined as having at least two BP readings of >140/90 mmHg or those with evidence of CKD were excluded. We conclude that AKI is an independent risk factor for subsequent development of elevated BP. Preventing AKI during a hospitalization may have clinical and public health benefits beyond the immediate hospitalization. Copyright © 2016 The Authors. Published by Wolters Kluwer Health, Inc. All rights reserved.