Gallstone disease in a Swedish population : An epidemiological investigation

Sammanfattning: Gallstones in a Swedish population. Olle MuhrbeckKarolinska Institutet, Division of Surgery, Danderyd Hospital, Stockholm, SwedenThe main objective of the present thesis was to study the prevalence ofgallstone disease in a community survey in Danderyd. Symptoms and riskfactors for gallstone disease and the changing incidence of cholecystectomyin Stockholm County was also studied. In a further study plasma levels oflathosterol and 7-a-hydroxy-4-cholestene-3-one was also investigated ascirculating markers for the biosynthesis of cholesterol and bile acids.Incidence of cholecystectomy per 100 000 inhabitants 1932-1957 showed anincrease from less than 100 to 315 and from 1958-1990 a decrease to 67. Afterthe introduction of the laparoscopic technique an increase was again notedto a present incidence of 110. Changing indications are believed to be thecause. Acute cholecystectomy had an increasing part of all cholecystectomiesand in relation to elective operations increased from 0.15 to 0.40.The prevalence of gallstone disease in 556 randomly selected men and wo-men aged 40 and 60 years was in men 4% and 15%. In women the pre-valence was 11% and 25%, in overall 15%. Fifty per cent of subjects withgallstone disease were cholecystectomised.Several symptoms were investigated but there was no single symptom thatcould predict gallstones in men or women. Subjects already cholecyst-ectomised and patients waiting for elective cholecystectomy hadsignificantly more symptoms than subjects with incidental gallstones.Common risk factors for gallstone disease were investigated. Heredity was asignificant risk factor as relatives to subjects with gallstone disease hadknown gallstones in 39% compared with 18% in relatives to gallstone freesubjects. Obesity was a risk factor for gallstone formation in women but notmen. Weight increase since age 20 was a significant risk factor in women butnot in men. Parity was a risk factor in women with five or more children(RR 4.05). Duration of fertility period or breast feeding was not a risk factoralthough increased age of menopause was correlated positively togallstones.Plasma levels of 7-a-hydroxy-4-cholestene-3-one were not depressed ingallstone subjects but 40% higher. There was no difference in the plasmalevels of lathosterol. Hypersecretion of cholesterol in gallstone subjects isnot due to a single metabolic defect but rather of multifactorial aetiology.Key words: Cholelithiasis, cholecystectomy, cholesterol, epidemiology/Sweden, incidence, lathosterol, mass screening, prevalence, risk factors,symptoms, ultrasonography, 7-a-hydroxy-4-cholesten-3-oneISBN 91-628-1692-6