MO538: Lower Serum Levels of Magnesium are Associated With Higher Risk of Fractures in Haemodialysis Patients

Abstract BACKGROUND AND AIMS Magnesium (Mg) deficiency is associated with altered bone metabolism, However, the relationship between Mg and the risk of fragility fractures haemodialysis (HD) patients is still unclear. The aim of this study was to evaluate the association between pre-dialysis Mg serum levels and the risk of incident bone fractures in a cohort of prevalent HD patients. METHOD We performed a prospective study of 206 prevalent HD patients followed from 2009 until 2021. Demographic, clinical and biochemical parameters were evaluated. RESULTS A total of 37 episodes of fragility fractures were identified with a median HD vintage of 42 months, which corresponds to an incidence rate of 29/1000 person-years. The mean age of the studied population was 68.3 ± 13.1 years, 121 (59%) were male and the median follow-up time on HD was 58 months. Patients with incident fractures showed significantly lower Mg levels compared with those without fractures (2.3 ± 0.3 versus 2.8 ± 0.4 mg/dL, P < 0.001). In a multivariable analysis, lower Mg levels (P = 0.02) were independently associated with increased risk of fracture, in a model adjusted to age, female gender, albumin and dialysis vintage. Patients with a Mg serum level < 2.2 mg/dL (lowest quartile) had a 1.32-fold higher risk for fragility fractures than those in the highest quartile [95% confidence interval (95% CI), 1.15–1.48; P < 0.001]. CONCLUSION This study shows that the incidence of bone fragility fractures in HD patients is high and significantly associated with lower pre-dialysis Mg levels. Management of fracture risk in HD patients and assessment of its risk factors requires further study.