Kidney function deterioration is dependent on blood pressure levels: 11.2 year follow-up in diabetic patients

There is little evidence of how blood pressure level over 10 years affects the decline of estimated glomerular filtration rate (eGFR) in diabetic patients. The Japanese primary prevention of atherosclerosis with aspirin for diabetes (JPAD) trial was a multicenter, randomized, clinical trial done from 2002 to 2008. After completion of the JPAD trial, we followed up the patients until 2019 as a cohort study. We defined late-stage kidney disease (LSKD) as eGFR < 30 ml/min/1.73 m² or hemodialysis. Based on the mean value of systolic blood pressure (SBP) obtained average 7 times during the follow-up, we divided the patients into three groups: a high SBP group (n = 607, SBP ≥ 140 mm Hg); a moderate SBP group (n = 989, 140 > SBP ≥ 130 mm Hg); or a low SBP group (n = 913, SBP < 130 mm Hg). There was no significant deference in the mean eGFR among the high SBP, moderate SBP and low SBP groups on registration. The incidence rate of LSKD was significantly higher in the high SBP (HR 2.02, 95% CI 1.36–3.01) and moderate SBP (HR 1.54, 95% CI 1.07–2.20) groups than in the low SBP group (Log-Rank P = 0.0018). Cox proportional hazards model analysis revealed that the high SBP (HR, 1.57, P = 0.049) and moderate SBP (HR, 1.52, P = 0.037) were independent factors after adjustment for proteinuria ≥ ± , age ≥ 65 years, men, body mass index ≥ 24 kg/m², duration of diabetes ≥ 7.0 years, statin usage, eGFR ≥ 60 ml/min/1.73 m², hemoglobin A1c ≥ 7.2%, and smoking status. Our 11.2 year follow-up study demonstrated that mean SBP was independently associated with the progression to LSKD in diabetic patients. These findings may become new evidence that SBP less than 130 mm Hg is recommended for diabetic patients to prevent progression to LSKD.