A comprehensive investigation of nutritional status and psoas muscle mass in predicting five-year survival in patients with liver transplant.

BACKGROUND/PURPOSE: Although nutrition and sarcopenia have impacts on the surgery outcome of patients who have received living donor liver transplant (LDLT), the use of the prognostic nutritional index (PNI) or psoas muscle mass index (PMI) as an indicator for five-year survival in those patients is still unclear. METHODS: A total of 138 patients receiving LDLT were followed at a medical center in Taiwan. As well as analysis of clinical factors using Cox regression, time-varying PNI and PMI values as before surgery (0) and at 3-, 6-, and 12- months after LDLT were analyzed by time-dependent Cox analysis. For those 124 patients who survived after 3 months of LDLT, the values of PNI-3m, PMI-3m and their combination were further analyzed. RESULTS: PNI and PMI were noted to be highly associated with mortality at three months post-LDLT (PNI-3m hazard ratio [HR] = 0.89, 95% confidence interval [CI]: 0.85-0.94, p < 0.001; PMI-3m HR = 0.58, 95% CI: 0.41-0.82, p = 0.002). Per the Youden index, the cut-off point of PNI-3m was 42.35, and that of PMI-3m was 1.94. Compared to the subjects with higher levels of PNI-3m and PMI-3m (N-high/M-high), the HRs for subjects with N-high/M-low, N-low/M-high, and N-low/M-low were 5.27 (p = 0.004), 4.46 (p = 0.010) and 12.97 (p < 0.001) respectively. CONCLUSION: PNI and PMI at the third month post-LDLT serve as excellent predictors for 5-year survival. For patients with lower levels of PNI-3m or PMI-3m, combination use of these indexes is suggested to provide better prognostic information.

High Protein Diet and Huntington's Disease.

Huntington's disease (HD) is a neurodegenerative disorder caused by the huntingtin (HTT) gene with expanded CAG repeats. In addition to the apparent brain abnormalities, impairments also occur in peripheral tissues. We previously reported that mutant Huntingtin (mHTT) exists in the liver and causes urea cycle deficiency. A low protein diet (17%) restores urea cycle activity and ameliorates symptoms in HD model mice. It remains unknown whether the dietary protein content should be monitored closely in HD patients because the normal protein consumption is lower in humans (~15% of total calories) than in mice (~22%). We assessed whether dietary protein content affects the urea cycle in HD patients. Thirty HD patients were hospitalized and received a standard protein diet (13.7% protein) for 5 days, followed by a high protein diet (HPD, 26.3% protein) for another 5 days. Urea cycle deficiency was monitored by the blood levels of citrulline and ammonia. HD progression was determined by the Unified Huntington's Disease Rating Scale (UHDRS). The HPD increased blood citrulline concentration from 15.19 µmol/l to 16.30 µmol/l (p = 0.0378) in HD patients but did not change blood ammonia concentration. A 2-year pilot study of 14 HD patients found no significant correlation between blood citrulline concentration and HD progression. Our results indicated a short period of the HPD did not markedly compromise urea cycle function. Blood citrulline concentration is not a reliable biomarker of HD progression.