Evaluation of the Predictive Value of the Serum Calcium-Magnesium Ratio for All-Cause and Cardiovascular Mortality in Incident Dialysis Patients

Abstract

Background/Aim: Cardiovascular disease is the most serious cause of death in patients on hemodialysis. Low serum magnesium (Mg) and high serum calcium (Ca) levels have been associated with poor outcome and cardiovascular mortality in patients on maintenance and initiation dialysis. As a more accurate marker is warranted, we evaluated the efficacy of a novel serum Ca-Mg marker of all-cause and cardiovascular mortality that indicates vessel calcification. Methods: We recruited 378 consecutive patients with end-stage renal disease who started dialysis between January 2009 and December 2015 at the Japanese Red Cross Ishinomaki Hospital. We collected data of patients' demographic characteristics and comorbidities from their electronic medical records. We retrospectively examined the association of the serum Ca-Mg ratio with all-cause and cardiovascular mortality using the Cox proportional hazard model, and determined the value that predicted cardiovascular death using the receiver operating characteristic (ROC) curve. Results: Overall, 253 patients with serum Mg and Ca data were analyzed. The 3-year survival rate of this group was 0.70 (95% confidence interval [CI] 0.55-0.80), and the hazard ratio for the risk of death was 3.94 (95% CI 1.37-11.31). The 3-year cardiovascular mortality rate was 0.12 (95% CI 0.05-0.23), which was significantly higher than that of the other groups. The ROC curve of cardiovascular mortality with the Ca-Mg ratio was greater than that of Mg (area under the curve 0.75 vs. 0.69, p = 0.037). Conclusion: A high Ca-Mg ratio was significantly associated with all-cause and cardiovascular mortality, and it was more accurate than serum Mg.

Magnesium Status and Calcium/Magnesium Ratios in a Series of Cystic Fibrosis Patients

“…Alternatively, a moderate Ca/Mg ratio (3.91-4.70) had the lowest mortality risk [26]. In addition, a high Ca/Mg ratio of 4.37 was significantly associated with all-cause and CVD mortality in incident dialysis patients [25]. In our study, the mean serum Ca/Mg ratio was 4.89 ± 0.54 (4.26 to 6.20).…”

Magnesium Status and Ca/Mg Ratios in a Series of Children and Adolescents with Chronic Diseases

“…Serum Mg level is to a lesser extent likely related to body Mg content because it represents only 0.3% [ 11 ]. Since there is no functional biomarker for Mg status, serum Ca/Mg ratios can assess its homeostasis and measurement [ 30 ]. Ca and Mg physiology helps to comprehend the potential impact of the Ca/Mg ratio, since one is physiologically antagonistic to the other [ 13 ].…”

“…The Ca/Mg intake ratio is a significant accurate marker of CVD and all-cause mortality in patients starting dialysis. It is clinically uncertain whether an increased Mg and/or reduced Ca level improves CVD mortality risk [ 30 ]. Therefore, based on the Ca/Mg intake ratio, our series had a high risk of developing NCDs.…”

“…Low serum Mg levels or high serum Ca levels can pathologically contribute to CVD risk. In addition, serum Ca/Mg ratios may be more characteristic of homeostasis than measurements of serum Mg [ 30 ]. An adequate diet balances between Ca (milk products, eggs, fish, leafy vegetables, seeds, and nuts) [ 31 ] and Mg (cereals, nuts, seeds cocoa, soybeans, spinach, marine vegetables, and tomatoes) [ 32 ] are needed to reduce the risk of these non-communicable diseases (NCDs) [ 33 , 34 ].…”

Dietary Magnesium Supplements – Is there any Problem?

“…Worthy of note that in order to keep the homeostasis presumably there is an optimal intake of Ca++ and Mg++. Sato and coworkers demonstrated a significant correlation between high Ca:Mg ratio and all-cause and cardiovascular mortality among dialysis patients [11]. Durlach recommended that in order to maintain healthy relations total dietary Ca:Mg ratio should remain close to 2.0 [12].…”