Abstract
The relationship between blood pressure (BP) and kidney function among individuals with chronic kidney disease (CKD) remains controversial. This study evaluated the association between BP and estimated glomerular filtration rate (eGFR) decline among adults with nondiabetic stage 3 CKD. The Multi-Ethnic Study of Atherosclerosis participants with an eGFR 30-59 ml min(-1) per 1.73 m2 at baseline without diabetes were included. Participants were followed over a 5-year period. Kidney function change was determined by annualizing the change in eGFR using cystatin C, creatinine and a combined equation. Risk factors for progression of CKD (defined as a decrease in annualized eGFR>2.5 ml min(-1) per 1.73 m2) were identified using univariate analyses and sequential logistic regression models. There were 220 participants with stage 3 CKD at baseline using cystatin C, 483 participants using creatinine and 381 participants using the combined equation. The median (interquartile range) age of the sample was 74 (68-79) years. The incidence of progression of CKD was 16.8% using cystatin C and 8.9% using creatinine (P=0.002). Systolic BP>140 mm Hg or diastolic BP>90 mm Hg was significantly associated with progression using a cystatin C-based (odds ratio (OR), 2.49; 95% confidence interval (CI), 1.12-5.52) or the combined equation (OR, 2.07; 95% CI, 1.16-3.69), but not when using creatinine after adjustment for covariates. In conclusion, with the inclusion of cystatin C in the eGFR assessment hypertension was an important predictor of CKD progression in a multi-ethnic cohort with stage 3 CKD.