Background: In dialysis patients, protein-energy wasting (PEW) is associated with high mortality, and some indicators of PEW, such as serum albumin value, subjective global assessment (SGA) score and handgrip strength (HGS), may predict mortality. However, whether PEW is associated with poor renal outcomes and whether the indicators of PEW can predict renal outcomes in patients with non-dialysis-dependent chronic kidney disease (CKD-ND) is still unclear.
Methods: We enrolled 128 clinically stable patients with CKD-ND and followed up for 33.8 ± 9.2 months. Baseline characteristics, echocardiographic information, laboratory data, HGS, SGA scores, anthropometric parameters, bioimpedance analyses and other indicators of PEW were examined in relation to the risk of reaching renal composite end points of pre-dialysis mortality or dialysis-dependent end-stage renal disease.
Results: Twenty-six patients reached composite renal end points. Multivariate Cox regression analyses showed that HGS was an independent predictor of renal outcome in patients with CKD-ND of Stages 1-5 [CKD(1-5), hazard ratio (HR) = 0.90, P = 0.004] or advanced CKD-ND of Stages 3b [defined as estimated glomerular filtration rate (eGFR) of 30-44 mL/min/1.73 m(2)] to 5 (CKD(3b-5), HR = 0.91, P = 0.031), but not serum albumin, SGA score or other indicators of PEW. When the cutoffs were set at 24.65 kg in men with CKD(1-5), 20.15 kg in men with CKD(3b-5) and 10.15 kg in women with CKD(1-5) or CKD(3b-5), which were deduced from receiver-operating characteristics analyses, patients with lower HGS had significantly poor renal outcomes in Kaplan-Meier survival analyses in all subgroups and higher HR for reaching renal end points in multivariate Cox regression analyses in all subgroups except for women with CKD(3b-5), whose HR had marginal significance (HR = 3.78, P = 0.068) after adjusting for age and eGFR.
Conclusions: This is the first study demonstrating that HGS is an independent predictor of composite renal outcomes in CKD-ND patients. HGS can be incorporated to clinical practice for assessing nutrition status and renal prognosis in patients with CKD-ND.