Magnesium depletion score in relation to frailty prevalence and mortality in US older adults: Evidence from 1999-2018 NHANES

OBJECTIVE: This study aimed to explore the associations between magnesium depletion score (MDS) and frailty prevalence, as well as its prognostic significance for all-cause and cardiovascular mortality among US older adults with frailty. METHODS: We analyzed data from older adults participating in the 1999-2018 National Health and Nutrition Examination Survey. The primary exposure was MDS, and the main outcomes were prevalence of frailty as defined by the 49-item accumulation-deficit model and all-cause or cardiovascular mortality in frail participants. The associations between MDS and frailty prevalence or mortality were analyzed using multivariable-adjusted logistic regression and Cox proportional hazards models, respectively. RESULTS: Overall, 13,551 participants (mean age 71.31 years, 45.46 % men, 4464 with frailty) were included. Compared with the MDS = 0 group, the multivariable-adjusted odds ratio and 95 % confidence interval (CI) for frailty were 1.144 (0.899-1.456), 1.702 (1.327-2.183), and 2.661 (2.038-3.475) for the MDS = 1, MDS = 2, and MDS ≥ 3 groups, respectively. A total of 2195 (791 cardiovascular-related) deaths occurred during a median follow-up of 70 months. Compared with the MDS = 0 group, the hazard ratios and 95 % CIs for the MDS = 1, MDS = 2, and MDS ≥ 3 groups were 1.509 (1.146-1.986), 1.988 (1.515-2.611), and 2.751 (2.125-3.562), respectively, for all-cause mortality, and 1.376 (0.843-2.246), 1.933 (1.183-3.160), and 2.872 (1.817-4.541), respectively for cardiovascular mortality. CONCLUSIONS: A higher MDS is related to a higher prevalence of frailty and increased risk of all-cause and cardiovascular mortality in US older adults.