Hypothetical intervention of targeted systolic blood pressure control of < 120 mmHg on renal prognosis for persons with stage 3–4 chronic kidney disease: an application of parametric g-formula using health checkup data in Japan

Abstract

The revised KDIGO guidelines recommend maintaining systolic blood pressure (sBP) < 120mmHg in patients with chronic kidney disease (CKD), based on cardiovascular and survival benefits. However, the renal benefit of this strategy remains less clear. We used data of routine health checkups in Japan. Persons whose estimated glomerular filtration rate (eGFR) was < 60mL/min/1.73 m2 in 2015 without end-stage disease were followed until 2020. We estimated the 5-year benefit of hypothetical targeted sBP control using parametric g-formula modeling, accounting for both time-fixed and time-varying confounding variables. Four sensitivity analyses, including analysis using a marginal structural model (MSM) and positive control outcome analysis, were also done. We enrolled 28,972 persons with CKD (median age: 54years, male: 69%, baseline eGFR [median]: 56mL/min/1.73m2). As compared with the natural course without a targeted intervention, there was no renoprotective effect of targeted sBP control, with a 5-year difference in eGFR of 0.65mL/min/1.73 m2 (95% confidence interval - 0.42 to 1.65mL/min/1.73 m2). MSM analysis found a similar result. In contrast, the positive control analysis using the cardiovascular outcome showed that targeted sBP control would reduce the cardiovascular disease incidence by 6.0% over 5years. A targeted sBP control strategy maintaining < 120mmHg may not yield a renoprotective effect for patients with stage 3-4 CKD, although it was expected to offer a cardiovascular benefit. Future research may be warranted in higher-risk populations, such as elderly people or those with more advanced kidney disease.