alcohol consumption, increase in serum GGT and development of the metabolic syndrome. Prevention of the metabolic syndrome [1][2][3] , a complex of multiple coronary risk factors, such as hypertension (HYT), impaired glucose tolerance (IGT) and dyslipidemia, should be targeted by health promotion activities for people living in modern society including occupational fields, where coronary heart disease is a leading cause of death and obesity, the most powerful promoter of the metabolic syndrome, is epidemic 4) . Meanwhile, moderate alcohol consumption has been shown to protect against the development of coronary heart disease and death [5][6][7] , and it may even protect against the development of non-insulin dependent diabetes mellitus (NIDDM) 8,9) although this is still disputed 10) . The protective effects of moderate alcohol consumption on coronary heart disease have been attributed to high serum HDL-cholesterol levels, suppressed coagulation capacity of platelets, or the suspected role of anti-oxidant substances contained in alcoholic beverages 11,12) . More recently, beneficial effects on insulin resistance, the core pathology of the metabolic syndrome, have been proposed as another possible mechanism 13) , implying that improved insulin resistance in moderate alcohol consumers may suppress the development of the metabolic syndrome, and thus coronary heart disease, but there have also been contradictory studies suggesting increases in insulin resistance after alcohol consumption [14][15][16][17] . In addition, high serum gamma-glutamyltransferase (GGT), a wellknown biological indicator of alcohol consumption 18,19) , has been shown to be associated with the metabolic syndrome [20][21][22] . The aim of the present study is to clarify The relationships between alcohol consumption, serum gammaglutamyltransferase (GGT) levels, and the prevalence of major coronary risk factors were analyzed crosssectionally in 2,399 male and 1,402 female middle-aged workers, to clarify the effects of moderate alcohol consumption on the development of the metabolic syndrome. Male moderate drinkers, consuming less than 60 ml of alcohol per day, had a lower prevalence of upper body obesity and low serum HDL-cholesterolemia (LHDLC) in comparison with nondrinkers, but not of hypertension, impaired glucose tolerance or hypertriglyceridemia (HTG). In women, alcohol consumption did not show any significant associations with the coronary risk factors. Men with an elevated serum GGT (EGGT) of 40 U/l or above had a significantly higher odds ratio for all the coronary risk factors as compared with those with normal GGT, even after adjusting for alcohol consumption, together with age, body mass index, cigarette consumption and physical activity. Women with an EGGT of 25 U/l or above had similar findings, although significance was found only in HTG. Nearly 80% and 55% of the appearance of EGGT in men and women were attributable to alcohol consumption, and 20% and 10% of the male and female moderate drinkers had EGGT. These results suggest tha...