[Optimal measurement time for evaluating gallbladder contraction function by oral protein bar combined with olive...

Objective: To explore the optimal time window for evaluating gallbladder contraction function by oral standardized protein bar combined with olive oil, and verify the measurement stability of this novel method compared with the traditional fried egg test. Methods: This is a prospective, multicenter, single-blind, randomized crossover controlled trial. A total of 112 healthy volunteers from 4 centers (the First Hospital of Lanzhou University, First Hospital of Qinhuangdao, the Liaoning Jinqiu Hospital, and the Honghui Hospital Affiliated to Xi'an Jiaotong University) were enrolled and randomly assigned to two groups using a random number table, with a 1-week washout period between two intervention cycles. Group A received oral fried egg intervention in the first cycle and oral standardized protein bar plus 50 ml extra virgin olive oil in the second cycle; while group B received the interventions in reverse order. Gallbladder ultrasound was performed at fasting state and 30, 50, 70, 90 and 110 min after intervention to measure the long diameter, wide diameter and anteroposterior diameter of the gallbladder, and calculate the gallbladder volume and gallbladder contraction rate. The changing trends of gallbladder contraction rate at each time point were compared between the two interventions, the coefficient of variation (CV) was used to evaluate the measurement stability of the two methods, and paired t-test, repeated measures analysis of variance, and Feltz-Miller asymptotic test were used for statistical analysis. Results: Among the 112 subjects, 47 were male and 65 were female, with an age of (30.6±7.1) years(range:19 to 62 years) and a fasting gallbladder volume of (20.0±7.1) ml. Under both interventions, the gallbladder contraction rate of the subjects began to increase at 30 min after intervention, reached the peak at 50 to 70 min, and then gradually decreased. There was no significant difference in the level of gallbladder contraction rate between the two groups at the peak time point (t=0.421,P=0.674). The intragroup CV of gallbladder contraction rate at each time point in the oral protein bar plus olive oil group was significantly lower than that in the fried egg group (all P<0.05), indicating better measurement stability. No serious adverse events such as acute pancreatitis and gastrointestinal bleeding occurred in either group, and the incidence of mild gastrointestinal adverse events showed no significant difference between the two groups (χ²=0.269, P=0.604). Conclusions: The optimal measurement time window for evaluating gallbladder contraction function with oral protein bar combined with olive oil is 50-70 min after intervention. This method is easy to operate with favorable safety, and its measurement stability is significantly better than the traditional fried egg test, providing a new method option for standardized clinical evaluation of gallbladder contraction function.