Background
. Chronic kidney disease is recognized as an independent cardiovascular disease 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 the presence of chronic kidney disease (CKD) and premature cardiovascular disease (CVD) has not been previously described.
Methods.
Volunteers at risk for chronic kidney disease completed surveys regarding past medical events and underwent blood pressure, and laboratory testing. Estimated GFR was computed using a 4-variable equation and the urine albumin:creatinine ratio (ACR) was measured. Data were stratified by decile of age. Premature CVD was defined as a myocardial infarction (MI) or stroke < age 55 years in men and <65 years in women. Mortality was ascertained by linkage to national data systems.
Results.
Of 34,614 the mean age was 46.5 γ 11.5 years, 68.5% were female, 36.2% African American, and 23.0% had diabetes. A total of 21.5% were found to have CKD (defined as eGFR < 60 ml/min/1.73 m2 and or ACR >= 30 mg/g), with the ACR and eGFR being the dominant positive screening tests for CKD in the younger and older age deciles, respectively, p<0.0001 for both trends. The composite rates of premature MI, stroke, or death for those with and without CKD were 8.0 and 3.9%, p < 0.0001. Multivariate analysis found CKD, OR = 1.43, 95% CI 1.26 –1.61; hypertension OR = 1.65, 95% CI 1.43–1.89; diabetes, OR = 1.94, 95% CI 1.72–2.19; smoking, OR 1.87, 95% CI 1.62 – 2.15; female gender, OR=1.64, 95% CI 1.45–1.87; and less than high school education, OR=1.56, 95% CI 1.35–1.82, as the most significant predictors of premature CVD or death (all p <0.0001). Survival analysis found those with premature MI or stroke and CKD had the poorest short term survival over the next three years after screening, p<0.0001.
Conclusions:
Chronic kidney disease is an independent predictor of premature MI, stroke, and death. These data suggest the biologic changes that occur with CKD promote CVD at an accelerated rate that cannot be fully explained by conventional risk factors. Screening for CKD by using both the ACR and eGFR can identify individuals at high risk for premature CVD and near term death.
Chronic kidney disease in sub-Saharan Africa: a public health priority