Foot dorsum thermal quantitative sensory testing thresholds in healthy Vietnamese adults: Reference data

Objective: To provide preliminary reference data for thermal quantitative sensory testing (QST) at the foot dorsum in healthy Vietnamese adults and to examine associations with demographic and metabolic variables. Methods: This cross-sectional study included 68 healthy Vietnamese adults (23-80 years). Participants were screened to exclude diabetes and prediabetes according to ADA 2024 criteria. Cold Detection Threshold (CDT), Warm Detection Threshold (WDT), and Heat Pain Threshold (HPT) were assessed bilaterally at the foot dorsum using the Q-Sense device and the Method of Limits protocol. Reference intervals (2.5th-97.5th percentiles) were estimated using non-parametric methods. Multivariable linear regression was used to evaluate associations with age, sex, BMI, LDL-C, triglycerides, and HbA1c. Results: Bilateral symmetry supported the use of averaged bilateral values. Age was independently associated with all QST parameters (CDT β = -0.0299; WDT β = 0.0801; HPT β = 0.0739; all p < 0.001). In the reduced model, BMI was associated with CDT (β = 0.0929, p = 0.030), but this was not observed in the full model. LDL-C was associated with WDT in both models (β = 0.0122, p = 0.007; β = 0.0121, p = 0.011). Sex was not consistently associated with any parameter. Conclusions: This study provides preliminary reference data for thermal QST in a Vietnamese population. Age was the most determinant of thermal thresholds. LDL-C was associated with warm detection thresholds, while BMI was not significant in the full model. Significance: These data may support interpretation of thermal QST in clinical practice.