Association of Longitudinal Trajectories of Systolic BP with Risk of Incident CKD: Results from the Korean Genome and Epidemiology Study
Authors: Young Su Joo, Changhyun Lee, Hyung Woo Kim, Jonghyun Jhee, Hae-Ryong Yun, Jung Tak Park, Tae Ik Chang, Tae-Hyun Yoo, Shin-Wook Kang, Seung Hyeok Han
Journal: Journal of the American Society of Nephrology (2020)

Significance Statement Although preventing CKD is an important goal of BP control, it is unknown whether systolic BP that rises over time in persons without hypertension can impair kidney function. In a prospective community-based cohort study involving 4643 Korean participants without hypertension or CKD, the authors characterized three temporal systolic BP trends and analyzed the association of these trends with subsequent development of CKD. Individuals with systolic BP on an increasing trajectory (from 105 to 124 mm Hg) had a higher risk of incident CKD compared with those exhibiting a stable trajectory. An increasing systolic BP trajectory also associated with a higher risk of developing albuminuria. These findings highlight that systolic BP that rises over time without reaching the hypertension threshold is associated with a significantly increased risk of incident CKD. Background Although hypertension is a well known risk factor for CKD, few studies have evaluated the association between temporal trends of systolic BP and kidney function decline in persons without hypertension. Methods We studied whether changes in systolic BP over time could influence incident CKD development in 4643 individuals without CKD and hypertension participating in the Korean Genome and Epidemiology Study, a prospective community-based cohort study. Using group-based trajectory modeling, we categorized three distinct systolic BP trajectories: decreasing, stable, and increasing. The primary outcome was incident CKD development, defined as two consecutive eGFR measurements &lt;60 ml/min per 1.73 m 2 . Results Among participants with an increasing systolic BP trajectory, systolic BP increased from 105 to 124 mm Hg. During 31,936 person-years of follow-up (median 7.7 years), 339 participants developed incident CKD. CKD incidence rates were 8.9, 9.6, and 17.8 cases per 1000 person-years in participants with decreasing, stable, and increasing systolic BP trajectories, respectively. In multivariable cause-specific Cox analysis, after adjustment of baseline eGFR, systolic BP, and other confounders, increasing systolic BP trajectory associated with a 1.57-fold higher risk of incident CKD (95% confidence interval, 1.20 to 2.06) compared with a stable trajectory. There was a significant effect modification of baseline systolic BP on the association between systolic BP trajectories and CKD risk ( P value for interaction =0.02), and this association was particularly evident in participants with baseline systolic BP &lt;120 mm Hg. In addition, increasing systolic BP trajectory versus a stable trajectory was associated with higher risk of new development of albuminuria. Conclusions Increasing systolic BP over time without reaching the hypertension threshold is associated with a significantly increased risk of incident CKD in healthy adults.