γ-Glutamyltransferase and mortality risk from heart disease and stroke in Japanese men and women: NIPPON DATA90

Background: Studies have shown that baseline serum γ- glutamyltransferase (GGT) is independently associated with cardiovascular disease (CVD) risk in men and women. However, less is known whether GGT is similarly associated with both stroke and heart disease (HD) risk in Asia. We examined an association between serum GGT and deaths from stroke and HD in Japanese men and women. Methods: From 1990 to 2005, we followed 7488 adults (3089 men) randomly selected from 300 districts throughout Japan, aged 30-95 with no history of coronary disease nor stroke at baseline. Cox proportional hazards models were used to estimate adjusted hazard ratios (HRs) according to sex-specific GGT strata. Results: During the study period, observed deaths from HD and stroke were 165 (83 men), and 135 (66 men), respectively. After adjustment for confounding factors, HRs of HD death for 25th, 50th, 75th, and 90th GGT percentiles in reference to the lowest GGT stratum were 1.61, 2.28, 2.48, and 4.59 in women (P for trend = 0.001), and 0.90, 0.74, 1.42, and 1.56 in men (P for trend = 0.250). The corresponding HRs of total stroke death were 1.52, 0.95, 1.22, and 1.34 in women (P for trend = 0.785), and 0.75, 0.91, 1.26, and 1.02 in men (P for trend = 0.642). Results were similar when analysis was limited to never-drinkers. Conclusion: This cohort study of representative Japanese men and women suggested that baseline GGT independently predicts future HD mortality risk, especially in women, but not stroke mortality risk in Asian.