Lifestyle and the development of increased serum gamma-glutamyltransferasein middle-aged Japanese men

To identify the lifestyle factors responsible for increases in serum gamma- glutamyltransferase (GGT), 1014 hepatobiliary dysfunction-free (no medicati on for and no past history of liver disease, less than or equal to 39 U/L o f serum aspartate and/or alanine aminotransferase, and less than or equal t o 59 U/L of serum GGT) Japanese male office workers aged 35-55 years were e xamined annually over five successive years (average period 4.5 years, SD 1 .11 years). From the Cox proportional hazards model without serum GGT at en try, significant correlates with the incidence of increased (greater than o r equal to 60 U/L) serum GGT levels were the slope of body mass index (BMI) , alcohol intake, cigarette smoking and coffee drinking (negative). In the model including serum GGT at entry, the slope of BMI and coffee drinking (n egative) remained as significant factors for the incidence of increased ser um GGT levels. From stepwise regression analyses for the slope of log serum GGT at entry, not including serum GGT in the model, significant correlates with the slope of serum GGT were, in order of relative importance, the slo pe of BMI, alcohol intake and coffee drinking (negative). In the model with serum GGT at entry, the slope of BMI and coffee drinking (negative) remain ed as statistically significant. Our results indicate that an increase in b ody weight is the strongest determinant for increases in serum GGT and that coffee drinking may be associated with a reduced risk of the development o f increased serum GGT levels.