Chen Q, et al. – In a study population of Chinese patients with coronary heart disease (CHD), researchers explored the associations of baseline serum calcium and phosphorus levels with long–term mortality risk. This study offers the first evidence that there exists a link between lower serum calcium at baseline and an increased risk of all–cause and cardiovascular mortality.

Methods

• Researchers performed a prospective cohort study among 3187 patients with CHD from October 2008 and December 2011 in China.
• They used Cox proportional hazards model to assess the associations of serum calcium and phosphorus at baseline with the risk of death.

Results

• Findings demonstrated that during follow-up (mean, 4.9 years), 295 patients died, 193 of which resulted from cardiovascular causes.
• Researchers observed that multivariable-adjusted hazard ratios (HR) for each 1 mmol/L increase in serum calcium at baseline were 0.27 (95% confidence interval (CI) 0.14–0.51) for all-cause mortality and 0.26 (95% CI 0.12–0.54) for cardiovascular mortality.
• They also noted that patients in the highest compared to the lowest quartile of serum calcium were at lower risk of all-cause mortality (HR, 95% CI 0.57, 0.40–0.82) and cardiovascular mortality (0.50, 0.32–0.79) (both Ptrend < 0.001).
• Data highlighted that this inverse association between serum calcium and the risk of mortality did not change when participants were stratified by sex, age groups, level of overweight, types of CHD, and history of diabetes.
• Researchers also observed a graded positive association between baseline serum phosphorus and the risks of mortality.