LIFE-STYLE AND ANTI-HELICOBACTER PYLORI IMMUNOGLOBULIN-G ANTIBODY AMONG OUTPATIENTS

Since eradication of Helicobacter pylori (H. pylori) is thought to be a preventive measure against stomach cancer, several studies have exam ined factors associated with the infection. This paper reports the ass ociation of the infection with lifestyle factors observed in a hospita l-based case-control study. Cases were 140 anti-H. pylori IgG antibody -positive outpatients (75 males and 65 females). Controls were 52 anti body-negative outpatients (22 males and 30 females). Both groups had u ndergone gastroscopy at Aichi Cancer Center Hospital between February 1995 and February 1997, and lifestyle data collected on the first visi t were linked to calculate odds ratios. A strong association was obser ved with smoking among males; age-adjusted odds ratio (OR) = 7.85, 95% confidence interval (CI), 2.03-30.4. Rice breakfast (OR = 3.74; 95%CI , 1.30-10.8) and soybean paste soup (every day vs. occasionally, OR = 5.24; 95%CI, 1.80-15.2) were also associated with antibody positivity in males, but not in females. In females, pickled Chinese cabbage (gre ater than or equal to 1/week vs. less than or equal to 3/month, OR = 2 .82; 95%CI, 1.06-7.48) and lettuce (greater than or equal to 1/week vs . less than or equal to 3/month, OR = 2.90; 95%CI, 1.09-7.76) were sig nificantly associated with positivity. Multivariate analysis gave simi lar estimates for the above factors. Although the association between smoking and H. pylori infection has not been detected in past studies of a general population, except one recent one, this study on outpatie nts suggested a possible association. Smoking may work as a cofactor d isturbing incidental eradication of H. pylori by antibacterial agents administered for other reasons.