Combination of clinical frailty score and myostatin concentrations as mortality predictor in hemodialysis patients.

[en] BACKGROUND AND AIMS: Frailty is common among hemodialysis (HD) patients. Its assessment is usually based on clinical criteria. In the present work, we evaluated the interest of combining clinical frailty score and biomarkers to predict mortality of chronic HD patients. Four biomarkers were assessed: myostatin, insulin-like growth factor-1 (IGF-1), dehydroepiandrosterone sulfate (DHEA-S) and serum creatinine-to-cystastin C ratio (SCr/SCys).
METHODS: Prevalent HD patients were enrolled from September 2016 to October 2017 in two centers in this observational prospective study and followed up for 5 years. Serum levels of myostatin, IGF-1, DHEA-S and SCr/SCys were measured at baseline. Frailty was assessed using Fried frailty score (≥3 indicates frailty). The ability to predict 5-year mortality was assessed by calculating Cox regression analyses and areas under the curve (AUC).
RESULTS: We included 125 HD patients with the following characteristics: median age of 67 [53;78] years; 40 % of women; 41% of diabetics and median dialysis vintage of 30 [16;54] months. Among them, 46% were classified as "Frail" according to Fried score. Mortality rate at 5 years was 56%. The median follow up was 49 [19;60] months. Cox univariate analysis showed that higher age, frailty phenotype and decreased concentrations of myostatin, IGF-1, DHEA-S and SCr/SCys were associated with higher mortality. In multivariate analysis, only myostatin remained significant among the biomarkers. The AUC of Fried score and myostatin to predict mortality was significant and comparable: 0.72 (95% CI: 0.63 to 0.80) and 0.72 (95% CI: 0.64 to 0.80), respectively. Combining myostatin with Fried score improved significantly the AUC (AUC = 0.79, 95% CI: 0.71 to 0.86) compared to Fried score alone or myostatin alone (p=0.0049 and p=0.0035 respectively).
CONCLUSION: Decreased concentrations of myostatin seem to be independently associated with higher risk of mortality. Combining Fried frailty score with myostatin concentration could improve the prediction of five-year mortality in chronic HD patients.