Genetics and epidemiology of gallbladder disease in New World native peoples.

Native peoples of the New World, including Amerindians and admixed Latin Americans such as Mexican-Americans, are highly susceptible to diseases of the gallbladder. These include cholesterol cholelithiasis (gallstones) and its complications, as well as cancer of the gallbladder. Although there is clearly some necessary dietary or other environmental risk factor involved, the pattern of disease prevalence is geographically associated with the distribution of genes of aboriginal Amerindian origin, and levels of risk generally correspond to the degree of Amerindian admixture. This pattern differs from that generally associated with Westernization, which suggests a gene-environment interaction, and that within an admixed population there is a subset whose risk is underestimated when admixture is ignored. The risk that an individual of a susceptible New World genotype will undergo a cholecystectomy by age 85 can approach 40% in Mexican-American females, and their risk of gallbladder cancer can reach several percent. These are heretofore unrecognized levels of risk, especially of the latter, because previous studies have not accounted for admixture or for the loss of at-risk individuals due to cholecystectomy. A genetic susceptibility may, thus, be as "carcinogenic" in New World peoples as any known major environmental exposure; yet, while the risk has a genetic basis, its expression as gallbladder cancer is so delayed as to lead only very rarely to multiply-affected families. Estimates in this paper are derived in part from two studies of Mexican-Americans in Starr County and Laredo, Texas.

Risk factors for developing complications while awaiting a cholecystectomy

Background. Laparoscopic Cholecystectomy is the gold standard for patients who are diagnosed with biliary colic (NIH, 1993). It has been demonstrated that individuals who wait a longer time between diagnosis and treatment are at increased risk of having complications (Rutledge et al., 2000; Contini et al., 2004; Eldar et al., 1999). County hospitals, such as Ben Taub General Hospital (BTGH), have a particularly high population of uninsured patients and consequently long surgical wait periods due to limited resources. This study evaluates patients the risk factors involved in their progression to complications from gallstones in a county hospital environment. ^ Methods. A case-control study using medical records was performed on all patients who underwent a cholecystectomy for gallstone disease at BTGH during the year of 2005 (n=414). The risk factors included in the study are obesity, gender, age, race, diabetes, and amount of time from diagnosis to surgery. Multivariate analysis and logistical regression were used to assess factors that potentially lead to the development of complications. ^ Results. There were a total of 414 patients at BTGH who underwent a cholecystectomy for gallstone disease during 2005. The majority of patients were female, 84.3% (n=349) and Hispanic, 79.7% (n=330). The median wait time from diagnosis to surgery was 1.43 weeks (range: 0-184.71). The majority of patients presented with complications 72.5% (n=112). The two factors that impacted development of complications in our study population were Hispanic race (OR=1.81; CI 1.02, 3.23; p=0.04) and time from diagnosis to surgery (OR=0.98; CI 0.97, 0.99; p<0.01). Obesity, gender, age, and diabetes were not predictive of development of complications. ^ Conclusions. An individual's socioeconomic status potentially influences all aspects of their health and subsequent health care. The patient population of BTGH is largely uninsured and therefore less likely to seek care at an early stage in their disease process. In order to decrease the rate of complications, there needs to be a system that increases patient access to primary care clinics. Until the problem of access to care is solved, those who are uninsured will likely suffer more severe complications and society will bear the cost. ^