Nonprotein calorie supplement improves adherence to low-protein diet and exerts beneficial responses on renal function in chronic kidney disease.

OBJECTIVE: Malnutrition is common in patients with chronic kidney disease (CKD) who are on low-protein diets and is a powerful predictor of morbidity and mortality in CKD. Studies have shown that patients on low-protein diets often have difficulty meeting nutritional energy requirements. Our study evaluated the effects of a nonprotein calorie (NPC) supplement on renal function and nutritional status in patients on a low-protein diet. DESIGN: This was a prospective, randomized, open-label, controlled clinical trial. SUBJECTS: A total of 109 patients with CKD (men, 67%; mean age, 54.5 ± 13 years) with stage 3 to 4 disease were randomly assigned to the intervention group (n = 55) or the control group (n = 54). INTERVENTION: All participants received individualized dietary counseling aimed at achieving a daily protein intake of 0.6 to 0.8 g and a daily energy intake of 30 to 35 kcal/kg. The intervention group consumed a 200-kcal NPC supplement daily. The control group received dietary counseling only. MAIN OUTCOME MEASURE: The estimated glomerular filtration rate (eGFR) was calculated using the 4-variable Modification of Diet in Renal Disease (MDRD) Study equation. Urine protein excretion, dietary protein and energy intake, and serum levels of creatinine, urea nitrogen, cholesterol, triglycerides, and albumin were assessed at baseline, at 12 weeks, and at 24 weeks. RESULTS: Dietary protein intake and urine protein excretion levels decreased significantly in the intervention group and were significantly lower than those of the control group. In addition, serum levels of creatinine and urea nitrogen decreased significantly, and eGFR increased significantly in the intervention group compared with baseline assessments. No significant differences were observed in the control group. CONCLUSIONS: The NPC supplement improved patient adherence to the low-protein diet and reduced urine protein excretion in patients with CKD.

Handgrip strength is an independent predictor of renal outcomes in patients with chronic kidney diseases.

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.