The Association between Serum Gamma Glutamyl transferase and Fasting Blood Glucose in Chinese People: A 6-Year Follow-up Study

Objective The aim of this study was to identify the relationships between gamma−glutamyltransferase (GGT) and fasting blood glucose (FBG) during a 6-year follow-up of subjects, and to evaluate if GGT is an independent factor affecting FBG. Methods Total of 1369 individuals from health examination survey at the urban area of Xuzhou, central China, were followed up for 6 years. The patients were divided into four groups according to their baseline GGT levels (in quartiles). The one-way ANOVA method was used to compare the differences of variables with basic line. The relationship between GGT and FBG levels was examined using repeated measurements ANOVA. Results The grouping of baseline GGT levels influenced changes in blood glucose during 6-year follow-up. In GGT quartile subgroups, the annual mean increase of FBG level shows a positive relationship with baseline GGT level. And this trend was even more pronounced in the highest baseline GGT group. Time course, baseline FBG and GGT groups at different individuals, which together affected the change of FBG level during the follow-up. Considering that baseline FBG may affect subsequent FBG levels, repeated measures ANOVA was used to exclude the effect of this factor. Results showed that different baseline GGT groups were still significantly associated with increased FBG levels during follow-up. GGT is an independent factor affecting FBG level（p<0.001）. Conclusions The annual mean increase of FBG level shows a positive relationship with baseline GGT level. Higher baseline GGT levels resulted in a faster annual mean increase in FBG. GGT could be used for early detection of impaired fasting glucose regulation (IFG) patients in clinical field.