Objective: Ambulatory blood pressure (BP) is reportedly associated with target organ damage. However, whether ambulatory BP carries prognostic significance for the development of chronic kidney disease (CKD) has not been confirmed.
Method: We measured ambulatory BP in 843 participants without CKD at baseline from a general Japanese population and examined the incidence of CKD defined as positive proteinuria or an estimated glomerular filtration rate (eGFR) less than 60 ml/min per 1.73 m2 at health checks. The association between baseline ambulatory BP and CKD incidence was examined using the Cox proportional hazard regression model adjusted for sex, age, BMI, habitual smoking, habitual alcohol consumption, diabetes mellitus, hypercholesterolemia, a history of cardiovascular disease, antihypertensive medication, eGFR at baseline, the number of follow-up examinations, and the year of the baseline examination.
Results: The mean age of the participants averaged 62.9 ± 8.1 years, 71.3% were women and 23.7% were under antihypertensive medication. During a median follow-up of 8.3 years, 220 participants developed CKD events. The adjusted hazard ratios for CKD in a 1-standard deviation increase in daytime and night-time SBP were 1.13 [95% confidence interval (CI) 0.97–1.30] and 1.21 (95% CI 1.04–1.39), respectively. When night-time and daytime BP was mutually adjusted into the same model, only night-time BP persisted as an independent predictor of CKD.
Conclusion: Night-time BP is a better predictor of CKD development than daytime BP in the general population. Ambulatory BP measurement is considered useful for evaluating the risk of progression to CKD.
aDepartment of Nephrology, Sendai Shakai Hoken Hospital
bPlanning for Drug Development and Clinical Evaluation, Tohoku University Graduate School of Pharmaceutical Sciences
cDepartment of Preventive Medicine and Epidemiology, Tohoku Medical Megabank Organization, Tohoku University, Sendai, Japan
dDepartment of Cardiovascular Diseases, Studies Coordinating Center, Division of Hypertension and Cardiovascular Rehabilitation, University of Leuven, Leuven, Belgium
eMedical Information Technology Center, Tohoku University Hospital, Sendai
fOhasama Hospital, Hanamaki
gDepartment of Social Welfare, Faculty of Synthetic Welfare, Tohoku Fukushi University
hDepartment of Clinical Pharmacology and Therapeutics, Tohoku University Graduate School of Pharmaceutical Sciences, Sendai
iDepartment of Hygiene and Public health, Teikyo University School of Medicine, Tokyo, Japan
Correspondence to Takayoshi Ohkubo, MD, PhD, Department of Hygiene and Public Health, Teikyo University School of Medicine 2-11-1 Kaga, Itabashi, Tokyo 173-8605, Japan. Tel: +81 3 3964 1211; fax: +81 3 3964 1058; e-mail: firstname.lastname@example.org
Abbreviations: BP, blood pressure; CKD, chronic kidney disease; CKD-EPI, Chronic Kidney Disease Epidemiology Collaboration; CVD, cardiovascular disease; eGFR, estimated glomerular filtration rate; ESRD, end-stage renal disease; GFR, glomerular filtration rate; SD, standard deviation; VIF, variance inflation factor
Received 7 February, 2013
Revised 25 May, 2013
Accepted 5 July, 2013
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