Serum cystatin C and increased coronary heart disease prevalence in US adults without chronic kidney disease.

Previous studies indicated that serum cystatin C, a marker of renal function, was associated with cardiovascular disease (CVD). However, few data about this association are available for persons without chronic kidney disease or albuminuria. Data from 4,991 subjects in the Third National Health and Nutrition Examination Survey with an estimated glomerular filtration rate > or =60 ml/min/1.73 m2 without micro- or macroalbuminuria were analyzed. Subjects were categorized into quartiles of serum cystatin C and compared for prevalence of CVD. CVD was defined as a history of myocardial infarction, angina, or stroke. After age standardization, prevalences of CVD from the lowest to highest quartile of serum cystatin C were 6.0%, 8.8%, 11.8%, and 16.7% (p-trend = 0.006). Also, age-standardized prevalences of myocardial infarction across quartiles of serum cystatin C were 1.9%, 4.4%, 6.6%, and 8.6%; age-standardized prevalences of angina were 2.4%, 4.4%, 4.2%, and 7.1%; and age-standardized prevalences of stroke were 2.5%, 1.6%, 3.5%, and 4.4% (each p-trend <0.05). Each 1-SD higher serum cystatin C level was associated with a multivariate prevalence ratio of CVD of 1.55 (95% confidence interval [CI] 1.13 to 2.13), and multivariate-adjusted prevalence ratios were 1.44 (95% CI 1.01 to 2.07), 1.64 (95% CI 1.02 to 2.64), and 1.65 (95% CI 1.06 to 2.56) for myocardial infarction, angina, and stroke, respectively. In conclusion, a graded association exists between higher serum cystatin C and increased CVD prevalence in patients without established chronic kidney disease.