Appropriate body mass index cutoffs for type 2 diabetes in Xinjiang population: defining the influence of liver aminotransferase

Background/Purpose: Recent study suggested that type 2 diabetes (T2DM) attributed to body mass index (BMI) could be influenced by liver aminotransferase. We aim to ascertain the cut-off point of BMI associated with T2DM and the influence of both elevated aminotransferase (AST) and alanine aminotransferase (ALT). Materials and Methods: In our retrospective cohort study, T2DM was diagnosed when FBS ≥ 7.0 mmol/L, BMI of participants with baseline fasting (FBS) < 7.0 mmol/L was divided by percentiles and by aminotransferanse (ALT and AST ≥ 20 U/L, ALT or AST < 20 U/L). Hazard ratios and the turning point of BMI of high T2DM risk was estimated in totality and different aminotransferanse groups. Results: During an average follow-up time of 3.71 years of 33346 participants, 1486 developed T2DM, and the average baseline BMI of participants who developed T2DM was 26.22 kg/m(2). Cumulative incidence of T2DM was more than 5% when ALT and AST ≥ 20U/L, age over 44, male sex or BMI over 25.39 kg/m(2); The risk of T2DM incidence increased as the BMI grow. The turning point of BMI at high risk of T2DM was 25.0 kg/m(2) in totality, 25.1 kg/m(2) when ALT or AST < 20 U/L and 26.1 kg/m(2) when ALT and AST ≥ 20U/L. Conclusions: BMI of 25.0 kg/m(2) was the cutoff point for T2DM development, and there is greater association between BMI and T2DM when ALT or AST < 20 U/L.