Bimodal distribution of fasting plasma glucose in the Uyghur and Han populations of Xinjiang, China

Background and Objectives: Bimodality in fasting plasma glucose (FPG) distribution has been detected in several populations. However, information regarding this phenomenon among Chinese ethnic groups is minimal. This study aimed to describe and update the distribution of FPG in the Uyghur and Han populations of Xinjiang, China, as well as to estimate the cut points of FPG on the basis of bimodal distribution. Methods and Study Design: A cross-sectional study was performed among the Uyghur and Han populations of Xinjiang, China in 2013. Questionnaire survey and FPG tests were conducted among 5923 participants aged 20-80 years. We fitted the unimodal and bimodal distributions into the FPG data by ethnicity, age, gender, and location to test whether the FPG values were consistent with a bimodal distribution. Results: The FPG distribution could be described as bimodal, except for the age group of 50 years old and below among the Uyghur and Han populations and the age group of 70-80 years old among the Uyghur population (p＜0.01). However, most of the cut points estimated using this method did not fall between the corresponding means of the first and second modes. Conclusions: Although a bimodal distribution of FPG was observed in the Uyghur and Han populations of Xinjiang, China, the cut points estimated using this method were not biologically meaningful, and thus, a bimodal distribution of FPG was not useful for defining cut points to diagnose diabetes in Xinjiang.