Association between Blood Pressure and Renal Progression in Korean Adults with Normal Renal Function

Background Although hypertension (HTN) is a well-established major risk factor for renal progression in patients with chronic kidney disease (CKD), few studies investigating its role in renal deterioration in the general population with normal renal function (NRF) have been published. Here, we analyzed the correlation between blood pressure (BP) and impaired renal function (IRF) in Korean adults with NRF. Methods Data for the study were collected from the national health screening database of the Korean National Health Insurance Service. Patients whose baseline estimated glomerular filtration rate (eGFR) was less than 60 mL/min/1.73 m² or whose baseline urinalysis showed evidence of proteinuria were excluded. IRF was defined as an eGFR below 60 mL/min/1.73 m². We performed follow up for eGFR for 6 years from 2009 to 2015 and investigated IRF incidence according to baseline BP status. We categorized our study population into two groups of IRF and NRF according to eGFR level in 2015. Results During 6 years of follow-up examinations, IRF developed in 161,044 (2.86%) of 5,638,320 subjects. The IRF group was largely older, and the incidence was higher in females and patients with low income, HTN, diabetes mellitus, dyslipidemia, and obesity compared with the NRF group. Subjects whose systolic BP was more than 120 mmHg or whose diastolic BP was more than 70 mmHg had an increased risk of developing IRF compared with subjects with lower BP (odds ratio [OR], 1.037; 95% confidence interval [CI], 1.014-1.061 vs. OR, 1.021; 95% CI, 1.004-1.038). Conclusion BP played a major role in renal progression in the general population with NRF. Strict BP control may help prevent CKD in the general population.