Association of Peripheral Neuropathy with Regional Plantar-Pressure Patterns in Patients With Type 2 Diabetes Mellitus

Abstract

Introduction: Diabetic peripheral neuropathy and altered plantar loading are important contributors to diabetic-foot complications in patients with Type 2 Diabetes Mellitus (T2DM). Vibration perception threshold (VPT) provides a quantitative assessment of sensory dysfunction, while plantar-pressure mapping identifies regional loading abnormalities. Aim of the study was to assess peripheral neuropathy using VPT, describe regional plantar-pressure patterns, and evaluate their association with glycaemic parameters and high/very-high plantar loading in patients with T2DM. Material and Methods: A retrospective cross-sectional study was conducted using records of 71 patients with T2DM. Right and left VPT values, VPT severity, regional plantar-pressure categories, fasting blood sugar (FBS), post-prandial blood sugar (PPBS), HbA1c, age, and gender were analyzed. Appropriate available-case analyses, group comparisons, and Spearman correlation tests were performed. Results: Among 65 patients with evaluable VPT data, 55.4% had severe neuropathy based on maximum VPT severity. Mean right and left VPT values were 25.1±13.6 V and 24.4±13.6 V, respectively, with strong bilateral correlation (ρ=0.890, p<0.001). Very-high plantar loading was most frequent in the forefoot. Age showed a significant positive correlation with mean VPT (ρ=0.303, p=0.017). FBS, PPBS, HbA1c, and regional plantar-pressure severity showed no significant correlations with VPT. Conclusion: Peripheral neuropathy and elevated plantar loading were common, but their severity did not significantly correlate, suggesting that neurological and biomechanical assessments provide complementary information in diabetic-foot risk evaluation.

Keywords: Type 2 Diabetes Mellitus; diabetic peripheral neuropathy; vibration perception threshold; biothesiometry; plantar pressure; HbA1c.