INS and Insulin resistance: Therefore, in this community-based prospective cohort study with a median follow-up of 8.9 years, we aimed to examine the temporal relationship and the magnitude of association between serum TMAO and (1) the incidence of type 2 diabetes; (2) the yearly changes in glycemic traits, including fasting glucose, glycated hemoglobin (HbA1c), insulin, and homeostasis model assessment of insulin resistance (HOMA-IR) in southern China.