[Association between insulin, insulin resistance, and gallstone disease in Korean general population]

Diabetes is one of the risk factors of gallstone diseases. Many studies found a positive association between insulin and gallstones in individuals with diabetes. However, this association is unclear in non-diabetes. So we conducted a case-control study for the evaluation of the association between gallstone diseases and fasting serum insulin level, insulin resistance in non-diabetic Korean general population.

This study was a prospective case-control study on 118 Korean subjects which included clinical examination, abdominal ultrasound, and blood chemistries. Serum fasting insulin level were determined by radioimmunoassay and concentrations of cholesterol, glucose, and triglycerides by standard enzymatic colorimetric methods. Insulin resistance was determined by the homeostasis model assessment (HOMA-IR). Body mass index (BMI), percentage of body fat, and waist hip ratio were also measured.

We studied 118 subjects with no clinical evidence of diabetes mellitus and serum glucose <126 mg/dL. Compared with controls (n=89), cases (n=29) had higher levels of serum insulin, glucose, triglyceride levels, and BMI. In t-test and chi-square test for variables, the association between gallstone disease and serum insulin, HOMA-IR index, and BMI were statistically significant (p<0.05). In multiple logistic regression analysis, gallstone disease risk increased with the level of serum insulin (p=0.024, odds ratio=1.376) and HOMA-IR index (p=0.013, odds ratio=2.006).

We suggest that hyperinsulinemia and insulin resistance could be associated with gallstone formation in individuals without clinical diagnosis of diabetes mellitus and with normal serum glucose level.