1. Coffee drinking and serum gamma-glutamyltransferase: an extended study of Self-Defense Officials of Japan
- Author
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S, Honjo, S, Kono, M P, Coleman, K, Shinchi, Y, Sakurai, I, Todoroki, T, Umeda, K, Wakabayashi, K, Imanishi, H, Nishikawa, S, Ogawa, M, Katsurada, K, Nakagawa, and N, Yoshizawa
- Subjects
Male ,Alcohol Drinking ,Japan ,Surveys and Questionnaires ,Smoking ,Linear Models ,Humans ,gamma-Glutamyltransferase ,Middle Aged ,Coffee ,Body Mass Index - Abstract
To examine the effect of coffee drinking on serum gamma-glutamyltransferase (GGT) level in relation to alcohol drinking, smoking, and degree of obesity in middle-aged Japanese men.From 1986 to 1994, a total of 7,637 male officials of the Self-Defense Forces of Japan aged 48-59 years received a preretirement health examination. Coffee drinking was ascertained by a self-administered questionnaire, and serum GGT level was measured. After excluding 1,360 men with a possible pathologic condition influencing liver enzyme levels and 182 former alcohol drinkers, effect of coffee drinking on serum GGT was examined by a multiple linear regression model and analysis of variance adjusting for alcohol drinking, smoking, and body mass index (BMI).The adjusted percentage of difference in serum GGT was -4.3 (95% CI = -5.0; -3.5) per cup of coffee. The inverse coffee-GGT relation was most prominent among men drinkingor = 30 ml of ethanol and smokingor = 15 cigarettes daily; and positive associations of alcohol and smoking with GGT were attenuated by coffee drinking, more clearly among men with BMIor = 25.00 kg/m2. Adjusted percentages of difference in serum GGT were -2.6% (p = 0.0003) per cup of brewed coffee, and -5.1% (p = 0.0001) per cup of instant coffee, independently of each other.The present study suggests that coffee consumption may weaken GGT-induction by alcohol, and possibly by smoking. These effect modifications by coffee may differ according to the degree of obesity.
- Published
- 2000