Multiple Factors Predict Physical Performance in People with Chronic Liver Disease

Objective The aim of this study was to assess whether physical performance correlates with metabolic and inflammatory measures in research subjects with chronic liver disease. Design This is a prospective, descriptive cohort study correlating performance on a 6-min walk test with cardiorespiratory variables, metabolic measures (glucose [GLU], C-peptide insulin, and lipids), liver enzymes (aspartate aminotransferase and alanine aminotransferase), and the proinflammatory cytokine interleukin-8 (IL-8). Results This study enrolled 51 subjects (18 women) with chronic liver disease: 41% (n = 21) with nonalcoholic fatty liver disease and 59% (n = 30) with hepatitis C virus. Age, resting heart rate, and fasting GLU correlated significantly with distance walked (P's < 0.05). First quartile poor performers (n = 14) and fourth quartile high performers (n = 14) showed differences in age, sex, fasting GLU, and IL-8 level (P's < 0.05). Combining the number of abnormal serum values (IL-8, C-peptide insulin, GLU, aspartate aminotransferase, alanine aminotransferase, high-density lipoprotein, triglyceride, and total cholesterol) did not correlate with distance walked (P > 0.90). However, in multiple regression analysis, a model that included sex, age, resting heart rate, IL-8 level, and fasting GLU level explained approximately 39% of the variance in the distance walked during the test. Conclusions Older age, female sex, abnormal levels of the proinflammatory cytokine IL-8, abnormalities of GLU metabolism, and high resting heart rate are associated with poor physical performance in subjects with chronic liver disease. Poor physical performance is associated with physiologic, metabolic, and inflammatory abnormalities in subjects with nonalcoholic fatty liver disease and hepatitis C virus.