Supplementary Materials for Association between Free Triiodothyronine and Diabetic Peripheral Neuropathy in Euthyroid Patients with Type 2 Diabetes

A total of 1,422 eligible euthyroid patients with T2DM who underwent electromyography during hospitalization at Zhongshan Hospital, Fudan University, were enrolled from January 2016 to December 2020.These patients were divided into DPN group and non DPN group, and underwent electromyographic examinations, including nerve conduction velocity (NCV), terminal motor and sensor latency (DML and DSL), sensory nerve action potential (SNAP) amplitude, and compound muscle action potential (CMAP) amplitude(Table S2-4).

In DPN group and non DPN group, the nerve conduction parameters were regressed with FT3, and age, sex, smoking, drinking, glycosylated hemoglobin, duration of type 2 diabetes, body mass index, systolic blood pressure, serum sodium, potassium, calcium, cholesterol, triglycerides, low-density lipoprotein, high-density lipoprotein, insulin resistance index were gradually corrected (Table S5). The double sample Mendelian randomized analysis method was used to provide evidence for the causal relationship between serum free triiodothyronine level and diabetes peripheral neuropathy through genome-wide association research and the public data of the Thyroidomics Consortium (FT3) and the UK Biobank (ICD10: G63.2) (TableS1, TableS6, Figure S1).