Abstract P146: Serum Magnesium and Mortality in the General US Population: Results From the NHANES I Epidemiologic Follow-up Study
Introduction: Low magnesium (Mg) intake and/or status has been associated with increased risk of chronic disease, including cardiovascular disease (CVD) and cancer. However, whether and to what extent low serum Mg levels are associated with all-cause or cause-specific mortality in the general population is uncertain.
Hypothesis: We aimed to quantify the dose-response associations between low concentrations of serum Mg and mortality from all causes, cancer, CVD, and stroke in the general US population.
Methods: We analyzed prospective data on 14,353 participants aged 25-74 years with baseline measures of serum Mg concentrations from the National Health and Nutrition Examination Survey Epidemiologic Follow-up Study 1971-2006. We estimated the mortality hazard ratios (HRs) for participants within predefined and clinically meaningful categories of serum Mg levels, including <0.7, 0.7-0.74, 0.75-0.79, 0.8-0.9 (normal reference), 0.9-0.94, 0.95-0.99, and ≥1.0 mmol/L, using Cox proportional hazards models. Restricted cubic spline models were applied to examine potentially nonlinear relationships between serum Mg and mortality.
Results: During a mean follow-up of 27.6 years, 7,072 deaths occurred, 3,310 (47%) CVD deaths, 1,533 (22%) cancer deaths, and 281 (4%) stroke deaths. Twenty-one percent of all participants had low levels of serum Mg (<0.8 mmol/L) and 1.5% had extremely low serum Mg (<0.7 mmol/L). Age-adjusted all-cause mortality rates were 3845, 3491, 3471, 3400 (normal reference), 3531, 3525, and 3836 per 100,000 person-years for increasing categories of serum Mg; the HRs and 95% confidence intervals for increasing serum Mg were 1.32 (1.02-1.72), 0.93 (0.74-1.16), and 1.06 (0.96-1.18), 1.07 (0.97-1.18), 0.94 (0.77-1.13), and 0.93 (0.72-1.21), compared to the reference group (0.8-0.9 mmol/L). An L-shaped association between serum Mg concentrations and all-cause mortality was observed after adjusting for potential confounders (Figure). No statistically significant associations were observed between serum Mg and cancer, CVD, or stroke mortality.
Conclusions: Very low serum Mg levels were significantly associated with all-cause mortality in the general US population. Our findings support the hypothesis that Mg deficiency as defined by very low serum Mg may have an important influence on mortality.
Author Disclosures: X. Zhang: None. J. Xia: None. L. Del Gobbo: None. A. Hruby: None. K. He: None. Q. Dai: None. Y. Song: None.
- © 2016 by American Heart Association, Inc.