Systolic blood pressure, low-density lipoprotein cholesterol levels, and adverse kidney outcome: results from KNOW-CKD.

It is unknown whether intensive control of blood pressure (BP) and lipids can delay the progression of chronic kidney disease (CKD). This study examined the combined association of strict targets of systolic BP (SBP) and low-density lipoprotein cholesterol (LDL-C) levels with adverse kidney outcomes. In total, 2012 patients from the KoreaN Cohort Study for Outcomes in Patients With CKD (KNOW-CKD) were classified into four groups according to SBP of 120 mmHg and LDL-C of 70 mg/dl: group 1, <120 and <70; group 2, <120 and ≥70; group 3, ≥120 and <70; group 4, ≥120 and ≥70. We constructed time-varying models treating two variables as time-varying exposures. The primary outcome was the progression of CKD, defined as a ≥50% decrease in estimated glomerular filtration rate from the baseline or the onset of kidney failure requiring replacement therapy. The primary outcome events occurred in 27.9%, 26.7%, 40.3%, and 39.1% from groups 1 to 4. In the time-varying model, the hazard ratios (95% confidence intervals) for the primary outcome were 0.48 (0.33-0.69), 0.78 (0.63-0.96), and 0.96 (0.74-1.23) for groups 1 to 3, respectively, compared with group 4. When less stringent cut-offs of SBP of 130 mmHg and LDL-C of 100 mg/dl were used, this graded association was lost, while only SBP was associated with adverse kidney outcomes. In this study, the lower targets of SBP of <120 mmHg and LDL-C < 70 mg/dl were synergistically associated with a lower risk of adverse kidney outcomes.