Serum γ-GTP Activity Is Closely Associated with Serum CRP Levels in Non-Overweight and Overweight Middle-Aged Japanese Men

The relationship between gamma-glutamyltransferase (gamma-GTP) and C-reactive protein (CRP) has not been established, particularly in the lean or non-overweight population. In the present study, we examined the associations between gamma-GTP and CRP in non-overweight and overweight middle-aged Japanese men. We conducted a cross-sectional study of 4,271 apparently healthy men aged 40 to 64 y (mean +/- SD, 50.5 +/- 6.6 y) who participated in health checkups. Associations between serum CRP levels, other clinical parameters, and lifestyle factors were analyzed using Spearman's rank correlation coefficient analysis and multiple linear regression analysis in the non-overweight (body mass index [BMI]<25 kg/ m(2)) and overweight (BMI >= 25 kg/m(2)) men. Associations between serum gamma-GTP activity and serum CRP levels were analyzed using analysis of covariance by comparisons of serum CRP levels of four subgroups according to gamma-GTP status. In non-overweight men, Bla high-density lipoprotein cholesterol, triacylglycerols, fasting blood glucose, aspartate aminotransferase, gamma-GTP, and smoking habit were positively associated with serum CRP levels. In overweight men, BMI, diastolic blood pressure, triacylglycerols, and gamma-GTP were positively associated with serum CRP levels. After adjustment for age, BMI, smoking status, and alcohol intake, dose-response relationships were observed between gamma-GTP and CRP levels in both overweight and non-overweight men. The results of this study indicate that an increase in serum gamma-GTP activity is closely associated with elevated CRP levels in both non-overweight and overweight middle-aged Japanese men.