Circulating interleukin-1β concentrations are independently-positively associated with γ-glutamyltransferase activity within the normal range in middle-aged apparently healthy Japanese women.

We previously demonstrated that the circulating concentrations of interleukin (IL)-1β, which is known to induce the development and progression of type 2 diabetes and its complications, were positively associated with γ-glutamyltransferase (γ-GTP) activity in middle-aged apparently healthy Japanese men. It was still unknown if the association between IL-1β concentrations and γ-GTP activity is within the normal range in apparently healthy Japanese women. In this study, we conducted a cross-sectional study of 824 apparently healthy women aged 40-64 y [mean±standard deviation age, 53.1±7.1 y; body mass index (BMI), 22.0±3.1 kg/m(2)] who participated in health checkups in Japan, and whose γ-GTP activity was within the normal range (<38 U/L). Associations of γ-GTP with IL-1β and other clinical or lifestyle factors were determined using analysis of variance (ANOVA) and one-way analysis of covariance (ANCOVA) followed by Tukey's multiple-range test. Multivariate logistic regression analyses (MLRA) were performed with γ-GTP activity as the dependent variable; independent variables included IL-1β plus clinical and lifestyle factors. ANOVA and ANCOVA indicated that IL-1β concentrations were positively associated with γ-GTP activity. MLRA showed that γ-GTP activity showed trends for higher IL-1β concentrations after adjusting for age, BMI, energy intake, alcohol intake, and smoking status. Together, IL-1β concentrations are positively associated with γ-GTP activity within the normal range in middle-aged apparently healthy Japanese women. Our results suggest that γ-GTP activity would be useful for assessing inflammation from the healthy state in Japanese women.