Serum creatinine is associated with coronary disease risk even in the absence of metabolic disorders.

Background: In view of recent evidence that serum creatinine and dysfunctional apolipoprotein (apo)A-I may serve as inflammation mediators in people with enhanced inflammation, we studied whether or not these molecules were interrelated and associated with coronary heart disease (CHD) likelihood even in subjects without metabolic syndrome (MetS) or type-2 diabetes.

Methods: Among unselected middle-aged Turkish adults with available serum apo A-I, lipoprotein(a) and creatinine measurements, 697 participants (designated as 'healthy') were enrolled, after exclusion of the stated metabolic disorders. CHD was identified in 87 subjects, roughly half during 3.1 years' follow-up.

Results: 'Healthy' individuals were overweight and had partly impaired fasting glucose but otherwise normal serum creatinine and other biochemical measurements. Being consistent with lacking anti-inflammatory activity, apoA-I was linearly and positively associated with apoB, in women further with creatinine. Logistic regression analyses showed that, beyond age, not non-HDL-cholesterol, systolic blood pressure and smoking status, but serum creatinine in each sex (OR in men 1.63 [95% CI 1.14; 2.31]) and CRP in women were significantly associated with CHD likelihood. The combined highest and lowest creatinine quartiles in women displayed an OR 2.14 (1.02; 4.51) compared with the intermediate quartiles, after similar adjustments.

Conclusion: Elevated creatinine levels within normal range, linked to apoA-I dysfunctionality, are independently associated with CHD likelihood even in non-diabetic subjects without MetS. In such women the lowest creatinine quartile is also linked to CHD risk.