The main methods included detailed clinical and anthropometric assessments, diagnosis of peripheral neuropathy via the Neuropathy Disability Score (NDS), evaluation of cardiac autonomic neuropathy using heart rate variability analysis and Ewing cardiovascular reflex tests, comprehensive laboratory investigations with fasting blood samples, measurement of serum ANGPTL4 and ANGPTL8 levels by ELISA kits, and statistical analysis performed with IBM SPSS version 25, using parametric and non-parametric tests, correlations, logistic regression, and ROC curves. The gene discussed is ANGPTL8; the disease is peripheral neuropathy.