Lower Diastolic Blood Pressure was Associated with Higher Incidence of Chronic Kidney Disease in the General Population Only in those Using Antihypertensive Medications

BACKGROUND/AIMS: The association of diastolic blood pressure (DBP) with incidence of chronic kidney disease (CKD) in the general population is not well examined. METHODS: Using national health check-up database from 2008 to 2011 in the general Japanese population aged 39-74 years, we evaluated the association between DBP and incidence of CKD 2 years later in 127,954 participants without CKD. DBP was categorized by every 5 mm Hg from the lowest (<60 mm Hg) to the highest category (>100 mm Hg) and was further stratified into those with and without antihypertensive medications (BP meds). We calculated the OR for estimating adjusted risk of incident CKD using logistic regression model. RESULTS: Participants were 62% female and 25.9% with BP meds, mean age of 76 years with estimated glomerular filtration rate of 78.2 ± 13.4 and DBP of 76 ± 11 mm Hg. Two years later, 12,379 (9.7%) developed CKD. Compared to DBP 60-64 mm Hg without BP meds as reference, multivariate analysis showed no difference in CKD risk at any DBP category among those without BP meds. However, in those with BP meds, risk increased according to lower DBP from 95 to 60 mm Hg (p for trend 0.05) with OR 1.51 (95% CI 1.14-1.99) in DBP <60 mm Hg. In subgroup analysis within those with or without BP meds, CKD risk was lower at higher DBP (p for trend 0.02) only in those without BP meds. CONCLUSION: Lower DBP was associated with higher risk of incident CKD only in the general population taking antihypertensive medication.