Serum phosphorus concentration and coronary artery calcification in subjects without renal dysfunction

Abstract

Serum phosphorus (P) concentration is associated with coronary artery calcification (CAC) as well as cardiovascular events in patients with chronic kidney disease. It has been suggested that this relationship is extended to subjects without renal dysfunction, but further explorations in diverse races and regions are still needed. We performed a cross-sectional study of 2,509 Korean subjects (Far Eastern Asian) with an estimated glomerular filtration rate of > 60 ml/min/1.73m2 and who underwent coronary computerized tomography. Serum P concentration was divided into pre-determined 4 categories: < 3.2, 3.2< to <3.6, 3.6< to 4.0 and >4.0 mg/dL. Agatston score (AS), an index of CAC, was divided into 3 categories: 0, 0< to < 100, and >100. A multinomial logit model (baseline outcome: AS = 0) was applied to estimate the odds ratio (OR) for each serum P category (reference: < 3.2mg/dL). Mean age of subjects was 53.5±9.1 years and 36.9%were female. In the adjusted model, serum P concentration of 3.6< to <4.0 mg/dL and >4.0 mg/dL showed high ORs for AS of >100 [OR: 1.58, 95% confidence interval (CI): 1.04-2.40 and OR: 2.11, 95% CI: 1.34-3.32, respectively]. A unit (mg/dL) increase in serum P concentration was associated with 50% increase in risk of AS >100 (OR: 1.50, 95% CI: 1.16-1.94). A higher serum P concentration, even within a normal range, may be associated with a higher CAC in subjects with normal renal function.