DIET AND GALLSTONES IN ITALY - THE CROSS-SECTIONAL MICOL RESULTS

Fifteen thousand nine hundred ten men and 13,674 women (age, 30-69 yea rs) were enrolled in an epidemiological survey of the general populati on, between December 1984 and April 1987. Each participant was submitt ed to ultrasonography (US) of the gallbladder and completed a food-fre quency questionnaire, covering 38 food items. A common portion size wa s identified and subjects were asked how often each item was consumed. Nutrient intake was computed by multiplying the intake frequency and nutrient content per portion for each item, and then by summing the pr oduct over all foods. Each nutrient intake was adjusted for energy int ake. Alcohol intake was calculated by summing the consumption of wine, beer, and liquor. Having excluded subjects aware of having gallstones (GS) or previously submitted to cholecystectomy (to avoid prothopatic bias), 787 males and 1,014 females with GS and 14,272 males and 10,83 6 females without GS were available for analysis, Relative risks (RR) of GS were computed by quintiles of nutrient intake. The overnight fas ting period was calculated as the difference between the specified tim e of dinner and the time of the next meal (breakfast or lunch). A sign ificant negative association was found between RR of GS and total ener gy intake for males (chi(2) for trend = 8.37; P =.004), fiber intake f or females (chi(2) = 5.45; P =.02), and daily alcohol consumption for males (chi(2) = 10.86; P = .001). A positive association was observed between RR of GS and carbohydrate (chi(2) = 5.95; P =.01 for males; ch i(2) = 9.39; P =.002 for females) and protein intake only for males (c hi(2) = 10.92; P = .01). Prevalence of GS was higher among subjects wh o had an overnight fasting period of over 12 hours than subjects with that of less than 12 hours. (RR: 1.35; 95% CI: 1.01-1.80 for males; RR : 1.28; 95% CI: 1.03-1.60 for females). These data do not confirm that high energy intake is associated with an increased risk of GS, Factor s protecting against GS comprise: low carbohydrate (males and females) and protein (males) intakes, high fiber (females) and moderate alcoho l intake (males) consumption, and a shorter overnight fasting period f or both sexes.