Abstract 13585: The Relationship Between Dietary Magnesium Intake and Incident Heart Failure Among Older Women: The Women’s Health Initiative
Background: Heart failure (HF) causes substantial burden and cost in older women. Low intake of dietary magnesium (Mg) has been associated with cardiac arrest, sudden cardiac death, fatal coronary heart disease, and stroke, although little is known about how Mg affects risk of HF.
Methods: We included 88,752 postmenopausal women of the prospective Women’s Health Initiative-Observational Study (WHI-OS). Incident hospitalized HF was adjudicated by medical record abstraction of self-reported hospitalization. Dietary intake of Mg was measured at baseline by a 122-item validated semi-quantitative food frequency questionnaire. We adjusted dietary Mg intake with calibrated total energy using the residual method. Cox proportional hazards models were used to evaluate the association adjusting for potential confounding factors, including demographics, traditional risk factors, dietary intake, and Mg-containing medications and multivitamins. Additional analyses were conducted in the subset of all black and Hispanic participants and those in the hormone therapy trial of WHI, for whom HF cases were re-adjudicated and classified into HF with preserved ejection fraction (HFpEF) and HF with reduced ejection fraction (HFrEF). Since there are great differences in risk factors and pathology between the two subtypes of HF, we explored the potential different associations of dietary Mg with both in 40,969 participants of this subset.
Results: Among participants in the OS, women in the lowest quartile of residual Mg intake (median: 154 mg/day) had 1.44 (95% CI: 1.11-1.86) times the hazard of incident HF compared to those in the highest quartile (median: 366 mg/day). Total Mg combining unadjusted dietary and supplemental Mg intake showed a similar but non-significant result (HR = 1.22, 95% CI: 0.98-1.51 comparing lowest to highest quartile). Low dietary Mg intake was also associated, although not significantly, with increased hazards of both HFpEF (hazard ratio (HR) = 1.42 comparing lowest to highest quartile, 95% CI: 0.92-2.18) and HFrEF (HR = 1.35 comparing lowest to highest quartile, 95% CI: 0.84-2.17).
Conclusions: Low dietary Mg intake at baseline was associated with higher long-term risk of incident HF. Results were similar for incident HFpEF and HFrEF.
Author Disclosures: M. Huang: None. W.H. Wu: None. T.H. Taveira: None. S. Liu: None. M.B. Roberts: None. L.W. Martin: None. G.A. Wellenius: None. K.C. Johnson: None. J.E. Manson: None. C.B. Eaton: None.
- © 2015 by American Heart Association, Inc.