A CASE-CONTROL STUDY OF ULCERATIVE-COLITIS WITH RELATION TO SMOKING-HABITS AND ALCOHOL-CONSUMPTION IN JAPAN

Epidemiologic studies of ulcerative colitis in western countries have shown that former smokers are at greater risk than those who never smo ked, but current smoking and alcohol drinking habits appear to be inve rsely associated with the development of this disease. The present cas e-control study examines whether these relations are found among Japan ese people, after adjustment for the separate effects of smoking and a lcohol consumption. The subjects were 384 patients with ulcerative col itis who first received financial aid for treatment of this disease wi thin the 2-year period from April 1988 to March 1990. From the same pu blic health centers, age- and sex-matched paired controls were selecte d randomly from rosters of persons attending health checkup programs. Information on smoking behavior and alcohol use was obtained by self-a dministered questionnaires. Compared with nonsmokers, former smokers w ere at increased risk of suffering from this disease (odds ratio (OR) = 1.67, 95% confidence interval (CI) 0.97-2.88); current smokers were at decreased risk (OR = 0.30, 95% Cl 0.18-0.50); and usual consumption of alcohol reduced the risk compared with less frequent use (OR = 0.5 7, 95% CI 0.37-0.86). Significant dose-response relations were observe d between these two factors and the disease. in conclusion, the relati ons between both smoking and alcohol consumption and ulcerative coliti s among Japanese people exist independently and are consistent with th ose reported in several previous studies outside Japan.