Lack of association between serum gamma-glutamyltransferase and carotid atherosclerosis: the Namwon Study.

OBJECTIVES: There is little evidence for an association between gamma-glutamyltransferase (GGT) and carotid atherosclerosis, an independent predictor of cardiovascular disease. We examined the association between serum GGT and carotid atherosclerotic parameters, including carotid intima-media thickness (IMT) and plaques, in a large general population. METHODS: The study population consisted of community-dwelling adults who participated in the baseline survey of the Namwon Study. A total of 9120 subjects aged 45-74 years were included in the analyses. High-resolution B-mode ultrasound was used to measure carotid IMT and to evaluate the presence of carotid plaques. A mean carotid IMT of ≥1.0 mm was classified as 'high carotid IMT'. RESULTS: Serum GGT levels were classified into quartiles. In a fully adjusted model, we found no linear trend between GGT quartile and mean carotid IMT (P for trend = 0.167). Compared with the first quartile (the reference category), the odds ratios (ORs) and 95% confidence intervals (CIs) for high carotid IMT were 0.89 (0.68-1.16), 1.10 (0.84-1.43), and 0.97 (0.71-1.33) for the second, third, and fourth quartiles (P for trend = 0.754), respectively. The ORs (95% CIs) for carotid plaques were 0.89 (0.77-1.02), 0.95 (0.82-1.10), and 0.94 (0.79-1.11) for the second, third, and fourth quartiles, respectively, in the fully adjusted model (P for trend = 0.644). CONCLUSIONS: No significant association of GGT concentration with carotid IMT or plaques was found in this large cross-sectional study. Further longitudinal studies are needed to confirm our findings.