New-onset hypertension and risk for chronic kidney disease in the Japanese general population

Objectives: Our aims were to assess the progression rate of normotension and prehypertension to hypertension in Japan, and the effect of the new-onset hypertension on chronic kidney disease (CKD). Methods: This was a nationwide study of 45 378 Japanese aged 40-74 years (mean age 60 years, 37% men) without hypertension or cardiovascular disease at baseline. At baseline and 3-year follow-up, blood pressure (BP) and kidney function were assessed. CKD was defined as an estimated glomerular filtration rate (eGFR) below 60 ml/min per 1.73m² or the presence of proteinuria (≥1 + by a dipstick). Results: At 3-year follow-up, the incidence rates of hypertension among participants with optimal BP (<120/ 80 mmHg, n = 18 724), normal BP (120-129/80-84 mmHg, n = 15 017) and high-normal BP (130-139/85- 89 mmHg, n = 11 637) were 8, 23, and 39% in men, and 6, 20, and 37% in women, respectively. Among those without CKD at baseline (n = 42 625), 2142 participants (5%) had developed CKD during follow-up. Irrespective of the baseline BP classifications, participants with new-onset hypertension had a higher risk for proteinuria [odds ratio (95% confidence interval) 1.7 (1.3-2.3) in men and 1.6 (1.2-2.2) in women], but not for eGFR below 60 ml/min per 1.73m², compared with those who maintained optimal BP during follow-up. Men who remained in the high-normal BP range during follow-up showed higher risk for proteinuria [odds ratio (95% confidence interval) 1.6 (1.1-2.3)], but not for eGFR below 60 ml/min per 1.73m². Conclusions: This nationwide longitudinal study suggests that, over 3 years of follow-up, women and men with new-onset hypertension and men with high-normal BP were at higher risk of newly developing proteinuria.