Background: Chronic kidney disease (CKD) is recognized as an independent cardiovascular disease (CVD) risk state, particularly in the elderly, and has been defined by levels of estimated glomerular filtration rate (eGFR) and markers of kidney damage. The relationship between CKD and CVD in younger and middle-aged adults has not been fully explored.
Methods: Community volunteers completed surveys regarding past medical events and underwent blood pressure and laboratory testing. Chronic kidney disease was defined as an eGFR <60 mL x min(-1) x 1.73 m(-2) or urine albumin-creatinine ratio (ACR) > or =30 mg/g. Premature CVD was defined as self-reported myocardial infarction or stroke at <55 years of age in men and <65 years of age in women. Mortality was ascertained by linkage to national data systems.
Results: Of 31 417 participants, the mean age was 45.1 +/- 11.2 years, 75.5% were female, 36.8% African American, and 21.6% had diabetes. A total of 20.6% were found to have CKD, with the ACR and eGFR being the dominant positive screening tests in the younger and older age deciles, respectively. The prevalences of premature myocardial infarction (MI), stroke, or death, and the composite were 5.3%, 4.7%, 0.8%, 9.2%, and 2.5%, 2.2%, 0.2%, 4.2% for those with and without CKD, respectively (P < .0001 for composite). Multivariable analysis found CKD (OR 1.44, 95% CI 1.27-1.63), age (OR 1.05 [per year], 95% CI 1.04-1.06), hypertension (OR 1.61, 95% CI 1.40-1.84), diabetes (OR 2.03, 95% CI 1.79-2.29), smoking (OR 1.91, 95% CI 1.66-2.21), and less than high school education (OR 1.59, 95% CI 1.37-1.85) as the most significantly associated factors for premature CVD or death (all P < .0001). Survival analysis found those with premature MI or stroke and CKD had the poorest short-term survival over the next 3 years after screening.
Conclusions: Chronic kidney disease is an independent predictor of MI, stroke, and death among men and women younger than age 55 and 65 years, respectively. These data suggest the biologic changes that occur with kidney failure promote CVD at an accelerated rate that cannot be fully explained by conventional risk factors or older age. Screening for CKD by using both the ACR and eGFR can identify younger and middle-aged individuals at high risk for premature CVD and near-term death.