Impact of serum calcium and phosphate on coronary atherosclerosis detected by cardiac computed tomography.

AIMS High calcium (Ca), phosphate (P), and Ca-P product (CPP) are associated with cardiovascular disease in patients with chronic kidney disease. Whether this relationship persists in individuals with normal kidney function is not yet elucidated. We explored the relationship of serum Ca, P, and CPP to coronary atherosclerosis assessed by cardiac computed tomography angiography (cCTA) in participants with normal kidney function. METHODS AND RESULTS This study included 7553 participants (52 ± 10 years, male 57%) with near-normal kidney function (estimated glomerular filtration rate > 60 mL/min/1.73 m2) who underwent cCTA. The relationship of Ca, P, and CPP to coronary atherosclerosis [coronary artery Ca score (CACS) >100 and the presence of coronary artery disease (CAD)] was evaluated. Higher Ca, P, and CPP were significantly associated with CACS > 100 continuously [adjusted odds ratio (OR) per mg/dL: Ca 1.21, P = 0.026; P 1.29, P < 0.001; CPP 1.03, P < 0.001]. However, they correlate only weakly with the presence of CAD (OR: Ca 1.17, P = 0.001; P 1.05, P = 0.173; CPP 1.01, P = 0.034). This discrepancy was because calcified or mixed plaque and non-calcified plaque (NCP) were included in CAD. A significant relationship was demonstrated between calcified or mixed plaque and Ca, P, and CPP (OR: Ca 1.20, P = 0.001; P 1.13, P = 0.003; CPP 1.02, P = 0.001), but not NCP. CONCLUSION Elevated serum levels of Ca, P, and CPP are significantly associated with the presence of calcified coronary atherosclerotic plaque. It is unclear if there is a causal relationship. This relationship is thought to contribute to vascular calcification, but is less closely associated with NCP.