Early Sensory Dysfunction in Type 2 Diabetes: Vibration Perception Abnormalities in Patients Without Neuropathic Symptoms

Background/Objectives: Type 2 diabetes mellitus (T2DM) is associated with peripheral sensory dysfunction, and sensory abnormalities may develop before the onset of clinically apparent neuropathic symptoms. This study aimed to compare vibration perception thresholds (VPTs) between patients with T2DM without self-reported symptoms of peripheral neuropathy and individuals without disorders of glucose metabolism and to determine whether T2DM is independently associated with higher VPT. Methods: This cross-sectional study included 160 participants: 98 patients with T2DM and 62 controls. VPT was assessed using the Biothesi-VPT device at eight standardized anatomical sites on each foot. Group comparisons were performed using the Mann–Whitney U, Kruskal–Wallis, and Pearson’s chi-square tests. Multivariable linear regression was used to assess the association between T2DM and overall VPT after adjustment for age, sex, and body mass index (BMI). Results: Patients with T2DM had significantly higher VPTs at all anatomical sites on both feet (all p < 0.001). Median integrated VPT was 16.5 V (IQR, 10.2–25.2) versus 5.6 V (IQR, 2.8–11.1) for the right foot and 16.2 V (IQR, 9.7–25.6) versus 6.6 V (IQR, 2.6–10.5) for the left foot in patients with T2DM and controls, respectively (both p = 0.001). After adjustment for age, sex, and BMI, T2DM remained independently associated with higher overall VPT (B = 6.482; 95% CI, 3.495–9.477; p < 0.001). Age was also independently associated with higher VPT, whereas sex and BMI were not. ABI did not differ significantly between groups. Conclusions: Patients with T2DM without self-reported neuropathic symptoms had impaired vibration perception compared with controls, and T2DM remained associated with higher VPT after adjustment for age, sex, and BMI. Quantitative VPT assessment may help identify early peripheral sensory dysfunction in T2DM, although its diagnostic and prognostic value requires prospective evaluation.