Handgrip strength and mortality in a cohort of kidney failure patients: Comparative analysis of different normalization methods

Objectives

Reduced handgrip strength (HGS) is associated with adverse clinical outcomes. We analyzed and compared associations of HGS with mortality risk in dialysis patients, using different normalization methods of HGS.

Methods

HGS and clinical and laboratory parameters were measured in a cohort of 446 incident dialysis patients (median age 56 y, 62% men). The area under the receiver operating characteristic curve (AUROC) was used to compare different normalization methods of HGS as predictors of mortality: absolute HGS in kilograms; HGS normalized to height, weight, or body mass index; and HGS of a reference population of sex-matched controls (percentage of the mean HGS value [HGS%]). Multivariate linear regression analysis was used to assess HGS predictors. Competing risk regression analysis was used to evaluate 5-year all-cause mortality risk. Differences in survival time between HGS% tertiles were quantitated by analyzing the restricted mean survival time.

Results

The AUROC for HGS% was higher than the AUROCs for absolute or normalized HGS values. Compared with the high HGS% tertile, low HGS% (subdistribution hazard ratio [sHR] = 2.36; 95% CI, 1.19–3.70) and middle HGS% (sHR = 1.79; 95% CI, 1.12–2.74) tertiles were independently associated with higher all-cause mortality and those with high HGS% tertile survived on average 7.95 mo (95% CI, 3.61–12.28) and 18.99 mo (95% CI, 14.42–23.57) longer compared with middle and low HGS% tertile, respectively.

Conclusions

HGS% was a strong predictor of all-cause mortality risk in incident dialysis patients and a better discriminator of survival than absolute HGS or HGS normalized to body size dimensions.