Aims: We have examined the relationship between gamma-glutamyltransferase (GGT) and major coronary heart disease (CHD) and stroke events and cardiovascular mortality in men free of cardiovascular disease (CVD).
Methods: A prospective study of 6997 men aged 40-59 with no history of CVD (CHD or stroke) or diabetes drawn from general practices in 24 British towns and followed up for 24 years.
Results: GGT was significantly and positively associated with increased risk of fatal (but not non-fatal CHD events), major stroke events and total CVD mortality after adjustment for established CVD risk factors. Risk of fatal CHD and CVD mortality was only elevated in the top quarter (22IU/L); risk of stroke tended to increase with increasing GGT. The adjusted relative risks (Q4 vs. Q1) were 1.43 (1.09,1.84) for fatal CHD events, 1.56 (1.20,2.04) for stroke incidence and 1.40 (1.16,1.70) for CVD mortality. When stratified by age groups stronger associations were seen between GGT and CVD mortality in the younger men (<55 years) (p=0.01 for interaction). GGT significantly predicted CVD outcomes especially in those at low and medium CHD risk based on Framingham risk score (FRS).
Conclusion: Elevated GGT is associated with significantly increased risk of stroke, fatal CHD events and CVD mortality independent of established CVD risk factors and may be a useful additional marker for long-term CVD risk.