Magnesium oxide and hip fracture in the elderly: a population-based retrospective cohort analysis.

ABSTRACT

Using national insurance claims of Taiwan, we found that magnesium oxide (MgO) use is associated with an increased risk of hip fracture in the elderly. Further studies are warranted to explore the mechanisms associated with MgO use that lead to hip fracture. PURPOSE: The purpose of this study was to investigate the association between MgO use and hip fracture risk in the elderly (age > 65 years). METHODS: This nationwide population-based retrospective study was conducted from 1996 to 2013. Individuals with (n = 26,069) and without (n = 26,069) MgO use were enrolled after propensity score matching. Primary outcome was a hip fracture. After adjusting for age, sex, comorbidities, and medications, multivariate Cox proportional hazards regression models were used to calculate incidences and risk of hip fracture [hazard ratio (HR)]. RESULTS: During the mean follow-up duration of 4.8 years in the MgO cohort and 5.7 years in the non-MgO cohort, respectively 1547 and 1107 cases developed a hip fracture. MgO use was identified as a risk factor for hip fracture in both univariate [crude HR, 1.68; 95% confidence interval (CI), 1.55-1.81; p < 0.001] and multivariate [adjusted HR (aHR), 1.66; 95% CI, 1.54-1.80; p < 0.001] Cox proportional hazards regression models. The cumulative incidence of hip fracture was significantly higher in the MgO cohort than in the non-MgO cohort (1.23 per 100 person-years vs. 0.74 per 100 person-years, logrank test, p < 0.001). CONCLUSION: MgO use is an independent risk factor for hip fracture in the elderly.