Calcium Linked to Different Effects in Kidney Disease
Higher levels linked to long-term mortality, while lower levels associated with short-term mortality
MONDAY, Jan. 11 (HealthDay News) -- Both long-term hypercalcemia and short-term hypocalcemia are associated with higher mortality in men with non-dialysis-dependent (NDD) chronic kidney disease (CKD), according to research published online Jan. 7 in the Clinical Journal of the American Society of Nephrology.
Csaba P. Kovesdy, M.D., of the Salem Veterans Affairs Medical Center in Virginia, and colleagues analyzed data from 1,243 men (mean age, 68 years) with moderate-to-advanced NDD CKD. One-quarter of patients were African-American, and most had disease stages 3 and 4. Patients had a median of 18 calcium measurements during follow-up.
The researchers note that models assessing long-term average calcium found an association between higher calcium and increased mortality. However, in time-varying analyses, lower levels of calcium were associated with increased mortality.
"These findings underscore calcium's complex pathophysiologic role in humans, which varies from that of a rapidly fluctuating intracellular messenger to that of a stable component of skeletal structure. Calcium stabilizes the membranes of excitable cells; thus, lower serum calcium can increase neuromuscular excitability, which may explain why lower calcium levels in our time-varying models could have been associated with higher short-term death rates, possibly through a higher incidence of cardiac arrhythmias," the authors write.
Two co-authors reported financial relationships with Genzyme, Shire, and Fresenius.