Blood Pressure and Decline in Kidney Function

The association between BP and decline in kidney function in older persons and the BP component most responsible for kidney disease are unknown. This study investigated the relationship between baseline BP and an incident decline in kidney function among 2181 men and women enrolled in the placebo arm of the Systolic Hypertension in the Elderly Program (SHEP). A decline in kidney function was defined as an increase in serum creatinine equal to or greater than 0.4 mg/dl over 5 yr of follow-up. The incidence and relative risk of a decline in kidney function increased at higher levels of BP for all BP components, independent of age, gender, ethnicity, smoking, diabetes, and history of cardiovascular disease. Systolic BP imparted the highest risk of decline in kidney function. The adjusted relative risk (95% confidence interval) associated with the highest compared with the lowest quartile of BP was 2.44 (1.67 to 3.56) for systolic; 1.29 (0.87 to 1.91) for diastolic; 1.80 (1.21 to 2.66) for pulse; and 2.03 (1.39 to 2.94) for mean arterial pressure. The risk associated with systolic BP remained strong in models containing other BP components, while diastolic, pulse, and mean arterial pressure had no significant association with a decline in kidney function in models containing systolic BP. Therefore, systolic BP is a strong, independent predictor of a decline in kidney function among older persons with isolated systolic hypertension.