Characteristics of study subjects according to the presence or absence of diabetes.

Data are expressed as means ± S.D.*Data are expressed as median (1st quartile, 3rd quartile). P values are from the t-test using logarithmic transformed values due to skewed distribution.†Regular: ≥3 times/week, ≥30 minutes per session; light: Abbreviations: HOMA-IR, homeostasis model assessment of insulin resistance; NAFLD, non-alcoholic fatty liver disease; LAI, liver attenuation index; 25(OH)D, serum 25-hydroxyvitamin D.