Exploring the relationship between triglyceride–glucose index and peripheral neuropathy in Nigerian patients with type 2 diabetes: a comparison with other metabolic markers

Background Diabetic peripheral neuropathy (DPN) is a common complication of type 2 diabetes mellitus (T2DM) with significant morbidity. The triglyceride–glucose (TyG) index, a surrogate marker of insulin resistance, has been linked to various diabetes-related complications, but its role in predicting DPN remains uncertain, particularly in sub-Saharan African populations. This study assessed the relationship between the TyG index and DPN among Nigerian patients with T2DM and compared its performance with other metabolic markers. Methods This hospital-based cross-sectional study was conducted among adults with T2DM attending diabetes clinics in two tertiary hospitals in North-Central Nigeria. DPN was assessed using the Michigan Neuropathy Screening Instrument (MNSI), 10-g monofilament, and 128-Hz tuning fork tests. The TyG index, albumin-to-creatinine ratio (ACR), glycated haemoglobin (HbA1c), serum uric acid, and apolipoprotein A-I (Apo A-I) were measured. Data were analysed using Statistical Package for Social Sciences version 25 with appropriate parametric and non-parametric tests, correlation analyses, and ROC curve assessment to evaluate the diagnostic performance of TyG and other metabolic markers for DPN. Results The prevalence of DPN was 61.8% (n = 63). DPN was associated with longer diabetes duration, higher hypertension prevalence, lower physical activity, and worse renal indices. Participants with DPN had lower Apo A-I (p = 0.013), higher urine albumin (p < 0.001), and higher ACR (p < 0.001). The TyG index did not differ significantly between groups (p = 0.218) and showed poor diagnostic performance (AUC 0.427, p = 0.218). By contrast, ACR (AUC 0.757, p < 0.001) and Apo A-I (AUC 0.647, p = 0.013) demonstrated better discriminatory ability. Conclusion TyG index had poor diagnostic utility for DPN, whereas ACR and Apo A-I were significantly associated with neuropathy and provided superior discrimination in the studied population. These findings support the use of renal and lipid-related markers alongside systematic neuropathy screening to identify high-risk patients. Larger longitudinal studies are needed to validate potential predictive markers for early detection and prevention.