LAUSR

AIMS/INTRODUCTION Fat mass and fat-free mass affect glycated hemoglobin A1c (HbA1c) levels and blood glucose levels, respectively. The aim of the present study was to examine the association between fat mass index and fat-free mass index with HbA1c. MATERIALS AND METHODS We conducted a cross-sectional study that included 3,731 men and 9,191 women aged 20 years or older, living in Miyagi Prefecture, Japan, who were not treated for diabetes. The fat mass index and fat-free mass index were calculated as fat mass and fat-free mass divided by the height squared, respectively. The indices were classified into sex-specific quartiles and combined into 16 groups. An ANCOVA was used to assess associations between the combined fat mass index and fat-free mass index with HbA1c adjusted for potential confounder. The linear trend test was conducted by stratifying the fat mass index and fat free mass index, entering the number as a continuous term in the regression model. RESULTS In multivariable models, a higher fat mass index was related to higher HbA1c levels in men and women in all fat-free mass index subgroups (P<0.001 for linear trend). When we excluded the participants who had been pointed out to have diabetes, fat-free mass index was also related to higher HbA1c levels in most fat mass index subgroups (P<0.05 for linear trend). CONCLUSIONS Fat mass index was positively related to HbA1c levels. Fat free mass index was also related to HbA1c levels when we excluded participants who had been pointed out to have diabetes.