Blood pressure control in chronic kidney disease according to underlying renal disease: the Fukushima CKD cohort.

Background: Inadequate blood pressure control is one of the important causes of chronic kidney disease (CKD), but only a limited number of reports have examined blood pressure control in Japanese patients with pre-dialysis CKD. Differences in blood pressure control due to underlying renal disease in pre-dialysis patients with CKD were investigated in the present study using the baseline data of the Fukushima CKD cohort study.

Methods: The study involved 1351 CKD patients, classified by underlying disease of primary renal disease, hypertensive nephropathy, diabetic nephropathy, other nephropathies, or unknown. Target blood pressure of CKD patients was defined as < 130/80 mmHg in patients under 75 years old with diabetes and/or proteinuria, and < 140/90 mmHg in other patients.

Results: The achievement rate of target systolic blood pressure was lower in the diabetic and hypertensive nephropathy groups than in the primary renal disease group (33.3%, 46.0% vs. 68.1%, p < 0.001). However, the number of antihypertensive medications increased in the diabetic and hypertensive nephropathy groups compared to the primary renal disease group (2.16, 2.04 vs. 1.55, p < 0.001). Inadequate blood pressure control was independently related to the underlying renal disease, with a significant difference between diabetic nephropathy and primary renal disease (odds ratio 3.19; 95% confidence interval, 2.16-4.69; p < 0.001).

Conclusion: This study showed that blood pressure control differs by the underlying renal disease. Blood pressure control was poor especially in diabetic nephropathy despite multidrug combination antihypertensive treatment. It is necessary to verify whether strict blood pressure control improves patients' prognosis in diabetic nephropathy.