Abstract: Objective The aim of this study was to investigate the prevalence and risk factors of gallstones in non-obese individuals at physical examination. Methods Obese and non-obese persons [body mass index (BMI)≤24 kg/m²] attended physical examinations at Health Management Center, Second Affiliated Hospital, Xi'an Jiaotong University between January 2021 and December 2021, and all underwent abdominal ultrasonography and blood biochemical parameter tests. The univariate and multivariate Logistic regression analysis was applied to reveal the risk factors for gallstone formation. Results There were 66221 persons participating the physical examination in 2021 in our hospital, and 31427 of them were overweight or obese, finding 1591 cases (5.1%) with gallstones and 862 cases (2.7%) having cholecystectomy history, while out 34794 non-obese persons found 1309 cases (3.8%) of gallstones and 657 cases (1.9%) having cholecystectomy, significantly different between the two groups (P< 0.001); the gallstones in the non-obese population were more common in females, relatively elderly and those with relative high BMI, systolic blood pressure (SBP), diastolic blood pressure (DBP), fasting blood glucose (FBG), triglycerides (TG), total cholesterol (TC), high density cholesterol (HDL-C), low density lipoprotein cholesterol (LDL-C), uric acid (UA),alanine aminotransferase(ALT), aspartate transaminase(AST),alkaline phosphatase(ALP),glutamyl transpeptidase(GGT)and total bilirubin(TBIL)levels; the multivariate Logistic regression analyses showed that the age, female, BMI, FBG, fatty liver diseases and GGT levels were all the independent risk factors for gallstone occurrence in the non-obese population, while blood HDL-C level was the protective factors; out the non-obese population, the gallstones were found in 65.0% of women, 62.4% of those older than 45 years, 32.7% of those with high SBP, 29.4% with low serum HDL-C level, 27.3% with high serum LDL-C level, 24.6% with high serum TG level, 21.3% with high DBP, 21.3% with high TC level, 19.6% with high FBG, 16.8% with fatty liver diseases and 16.0% with high UA level. Conclusion The prevalence of gallstones in non-obese population is relatively lower than that in the overweight and obese population, while the entity is not uncommon in the population, especially in female, in those with a variety of relatively metabolic disorders, such as increased blood glucose level, lipid metabolism disorders and fatty liver.

Key words: Gallstones, Non-obese population, Prevalence, Physical examination, Risk factors