Cardiac and Renal Disease Study (CARDS)

BACKGROUND:

Mild-to-moderate chronic renal insufficiency (CRI) has been reaching epidemic proportions in the United States. Studies relating mild-to-moderate chronic renal insufficiency and cardiovascular risk were limited and inconsistent. Although much had been learned about the natural history and adverse outcomes associated with end-stage renal disease (ESRD), there was little specific information regarding risk factors for the development or progression of renal disease.

The study was initiated in response to a Request for Applications entitled "NHLBI Innovative Research Grant Program" released in July, 2001. The purpose of the initiative was to support new approaches to heart, lung, and blood diseases and sleep disorders that used existing data sets or existing biological specimen collections whether obtained through National Heart, Lung, and Blood Institute support or not.

DESIGN NARRATIVE:

The population-based study used data on an ethnically diverse large cohort of male and female health plan enrollees with extended follow-up. The study evaluated: a) whether baseline and decline in renal function over time were independent predictors of coronary heart disease (CHD), stroke, heart failure and peripheral vascular disease; b) effect modifiers of these relationships,including baseline hypertension and diabetes status. The study determined whether baseline and increase over time in blood pressure level (as well as prevalent and incident hypertension) were predictive of the subsequent risk of ESRD after adjusting for diabetes and for baseline serum creatinine, proteinuria and hematuria. The study also examined other potential predictors of ESRD including demographic factors (race/ethnicity, level of education) total cholesterol level, family history of renal disease, body mass index, sagittal abdominal diameter, cigarette (as well as cigar and pipe) smoking, coffee intake, alcohol consumption, family history of renal disease and self-reported occupational exposures. The study used existing longitudinal data resources at the Northern California Kaiser Permanente Division of Research and available patient-level cross-linkage with the US Renal Data System end-stage renal disease registry to obtain comprehensive renal and cardiovascular outcomes.