The influence of diet upon liver function indices of healthy volunteers resident in a Phase I clinical trail.

In order to avoid the occurrence of "abnormal liver biochemical tests" caused by diet in Phase I clinical trial, the effect of a low-calorie and low-carbohydrate diet on biochemical indices of liver function of healthy volunteers in a Phase I unit was investigated. A single-centered, non-randomized and parallel-controlled study was designed with 46 healthy subjects consuming two types of diet (24 in the experimental group and 22 in the control group). The diets comprised a balanced normal calorie diet for the control group and a low-calorie and low-carbohydrate diet for the experimental group. All subjects were required to reside on site for 15 consecutive days. Liver biochemical indices such as alkaline phosphatase (ALP), alanine aminotransferase (ALT), aspartate aminotransferase (AST) were detected on Day-1 (baseline), Day 1, Day 2, Day 3, Day 5, Day 7, Day 9, Day 12, Day 15 and Day 22 (follow-up). There was no significant difference in age, ethnicity, occupation and other demographic data between two groups with balanced baseline. There was no significant difference in ALP between two groups and ALP remained unchanged as a function of time. However, ALT level of the experimental group remained constant as a function of time while ALT level of the control group increased with time and the level was significantly higher than the experimental group after Day 2. The difference between two groups increased with time but decreased on Day 22 as follow-up. After controlling the baseline of AST, AST exhibited a similar trend as ALT. After Day 9, 5%-18% of the patients in the control group showed hepatocyte injury, while no hepatic injury was found in the experimental group. In summary, a low-calorie, low-carbohydrate diet can effectively avoid the occurrence of liver biochemical abnormalities caused by diet in Phase I clinical trials.