PREVALENCE RATES OF GALLSTONE DISEASE IN ITALY - THE CHIANCIANO POPULATION STUDY

The prevalence of gallstone disease and associated factors in the enti re population of subjects aged 15-65 years born and resident in Chianc iano Terme (Siena - Tuscany) was examined in the years 1985 and 1986. The investigation included gallbladder ultrasonography, administration of a questionnaire on personal and family history, physical examinati on and blood chemistry. A total of 1809 subjects (attendance rate 87.7 %) participated in the study. Personal history and physical examinatio n showed that Chianciano inhabitants have a low prevalence of obesity (4.3%) and only 4.4% of the female population had more than two pregna ncies. Overall prevalence of gallstone disease (cholecystectomy + chol elithiasis) was 5.9% (3.7% for males and 8.4% for females). Age standa rdized relative risk of gallstone disease for females was 2.25 (95% co nfidence limits = 1.68-2.68). Prevalence of cholelithiasis was 3.5% (2 .7% for males and 4.2% for females). Prevalence of gallstone disease i ncreased with increasing age in both sexes, being extremely low in the age interval of 15-29 years (0.25%). The overall gallstones/cholecyst ectomy ratio was found to be lower(l:l) in females than in males (2.7: 1). Although subjects with gallstones reported more frequently biliary colics and nonspecific dyspeptic symptoms, the diagnostic power of al l symptoms in identifying cholelithiasis was very poor due to low sens itivity. Only one third of subjects with gallstones was aware of havin g the disease. Age, obesity and number of pregnancies were positively associated with gallstone disease in univariate analyses. The associat ion with obesity and parity disappeared in multivariate analysis. Bloo d lipids and glucose were not associated with the disease both in univ ariate and multivariate analyses. Our data show that the prevalence of gallbladder disease in Chianciano is lower than that previously repor ted in italy. This difference could be related to a lower prevalence o f obesity and to a smaller number of pregnancies or to the effect of e nvironmental and genetic factors.