Association of calcimimetic use with lower mortality in elderly patients with low body mass index and inflammation compared with non-users

Calcimimetics reduce mortality in older patients on dialysis. Because elderly patients are prone to low body mass index (BMI) and inflammation, we investigated whether this effect is independent of these conditions. This retrospective study used propensity score matching to compare 2-year all-cause mortality between calcimimetic users and non-users. Patients were stratified according to thresholds of BMI (22 kg/m 2 ) and high-sensitivity C-reactive protein (hs-CRP; 0.3 mg/dL) into Group 1 (high BMI and low hs-CRP, n = 240) and Group 2 (low BMI and high hs-CRP, n = 498). Survival was assessed using Kaplan–Meier survival curves, censored for calcimimetic use and other covariates. In Group 2, mortality was significantly lower in calcimimetic users than in non-users after matching ( P = 0.003, log-rank test), but not in Group 1. The significant difference in Group 2 was no longer observed after Cox proportional hazards regression adjusted for covariates that remained imbalanced following matching ( P = 0.051). In Group 2, median age (69 years)-stratified analysis showed significantly lower mortality in users among older patients (hazard ratio, 0.206, 95% confidence interval, 0.058–0.728, P = 0.014), but not younger patients. These findings suggest an association between calcimimetic use and reduced mortality in elderly patients with low BMI and/or inflammation, but not in those without these conditions or in non-users.