[The Boario project. A study of the prevalence of lithiasis in a spa population].

In order to better evaluate some epidemiological findings observed during previous studies on large samples of free living populations we carried out a case-control study on a randomly selected group of subjects in a health spa, Boario Terme. Seven-hundred and thirty subjects, aged 40-69 years, participated in the study. The study protocol included an ultrasonographic examination of the upper abdomen, a physical examination, a questionnaire, and a blood sample. Prevalence of gallstone disease was two times higher in females (37.2%) than in males (19.7%) (RRMH = 1.88). Fifty out of the 80 gallstone subjects were not aware of the disease prior the study (62.5%), and 60 did not experience any specific biliary symptom (colic) in the 5 years prior the study. The so-called "nonspecific symptoms" were not found related to gallstone disease. Gallstone disease was positively related to number of pregnancies, obesity, and economical status. In conclusion the present study confirmed some results observed during previous epidemiological studies. In regards to symptoms present data suggest that biliary colic is the only specific symptom for gallstone disease. In addition, the high number of asymptomatic gallstones observed in this study suggests the need of more investigations on high-risk populations in order to make earlier diagnosis and eventually to prevent the disease.