Gallstone disease is mainly due to liver metabolism disorder, biliary motor dysfunction, abnormal bile cholesterol output, and other effects, resulting in the dissolution of the solid components in the bile, stone formation. The causes of gallstones are complex, and more and more studies have proved that they are related to age, gender, obesity, high-fat diet, abnormal lipid metabolism, and other factors[1]. The potential risk factors for gallstones of population in Meizhou area were analyzed in this study. Major risk factors for gallstone formation are high serum levels of TG, LDL-C, TBA, and T-BIL.
Although dyslipidemia is common in the population, the relationship between dyslipidemia and gallstone disease is still unclear. Premkumar M et al. reported that obesity, dyslipidemia, high fat, and caloric intake were found to increase the risk of gallstone disease[19]. A Korean study demonstrated that low HDL-cholesterol was an independent predictor, was significantly associated with gallbladder stone formation in premenopausal women[20]. Brasca AP et al. found that lower HDL-C and higher TG were associated with a higher probability of gallstone disease[21]. Chang CM et al. reported that hypercholesterolemia may have an additive effect in increasing gallstone disease risk in women in Taiwan[22]. Several studies have reported that high serum TG level is positively correlated with the occurrence of gallstones. High TG is most often a multifactorial disorder of VLDL metabolism. In most high TG patients, they were usually observed with supersaturated bile and diminished gallbladder motility, both contributing to gallstone formation[23]. It was seen that gallstone disease prevalence was associated with high TG in women[21].
When lipid levels increase, serum lipids can be secreted into bile through liver cell serous membrane transport, make the concentration of lipids in bile increases, lipid shows the supersaturated state in bile and crystallize inside the gallbladder, and form gallstone gradually. Bile are synthesized by the liver and secreted through the liver tubules. Their components include bile acids, cholesterol, phospholipids, and other components. Dyslipidemia leads to the accumulation of excess lipids in the liver, affecting the liver cells' function, reducing the secretion of bile acids, and also easy to form gallstones[23]. In patients with gallstones, increased bile acid synthesis and triglyceride concentrations in the liver may be due to increased microsomal triglyceride protein (MTP) activity[24].
The relationship between serum total bile acid, serum total bilirubin, and gallstones is still inconsistent. A study showed that delayed orocecal transit time (OCTT) leads to small intestinal bacterial overgrowth (SIBO) and thus enhance serum bile acid (SBA) levels lead to the formation of gallstones[25], while a study has reported no correlation between serum total bile acids and gallstones[26]. Serum total bilirubin[27] or serum total bilirubin trend[28] is a risk factor and predictor for common bile duct stone. A study reported that serum total bilirubin level is a risk factor for predicting gallstone disease in male Taiwanese vegetarians[29]. Some studies have shown no relationship between serum total bilirubin and gallstones[30, 31].
Whether gender is a risk factor for gallstone disease remains controversial. The results of this study suggest that gender is not associated with gallstone disease. This is consistent with previous research[32, 33]. However, some studies based on western populations suggest that females are more likely to develop gallstone disease than males[34, 35]. It is believed that sex hormones levels are associated with cholesterol metabolism, and gender may be related to cholesterol stones[36]. The relationship between gender and gallstone disease may be different between Asian and Western populations, which requires further study.
In this study, age is not associated with gallstone disease. Diehl et al found that pigment stones patients were older than cholesterol stones patients[37]. Some studies have found that gallstone prevalence increased with age[38–40]. Old age was shown to represent a risk factor for gallstone disease[41]. Older people have underlying conditions such as hyperlipidemia, hypertension, and diabetes. Moreover, the function of a few organs, such as the gallbladder is abate, can lead to gallstone disease. In general, high serum levels of TG, LDL-C, TBA, and T-BIL are the main risk factors for gallstone formation in the Meizhou area.
Study Strengths And Limitations
This is the first study about the risk factors for gallstone disease among the population in the Meizhou area. The clinical characteristics, serum lipid, total bile acid, and total bilirubin levels indicators were included in the analysis to exclude the influence of related confounding factors on the results. There are some limitations to this study that should be noted. First, gallstone disease is a kind of multifactorial diseases caused by genetic and environmental factors. There were no assessment of potential gene-environment interactions. Second, this study's sample size is not very large, which may lead to some deviations in the results. Therefore, further study with a larger sample size is one of the next tasks.