Assessment of small nerve fiber function as an early marker of peripheral neuropathy in children and adolescents with type 1 diabetes mellitus (T1DM)

Purpose: This study aimed to assess subclinical peripheral diabetic neuropathy (PDN) in adolescents with type 1 diabetes mellitus (T1DM). Methods: Subjects included 53 T1DM patients (age (mean +/- SE): 15.8 +/- 0.54 years, disease duration: 6.0 +/- 0.51 years and HbA1c: 7.9 +/- 0.19%), and 37 healthy gender matched controls (age: 15.6 +/- 0.52 years). PDN was assessed by vibration perception threshold (VPT) and by quantitative sensory testing (QST). In controls, 95% confidence intervals were calculated. Results: Among patients, VPT prevalence of abnormality ranged from 60-73.4% on different sites. Higher VPT was found in patients on all examined sites (p < 0.01). In controls, VPT correlated with height (r = 0.48, p = 0.05). Regarding QST prevalence of abnormality, cold detection threshold (CDT) ranged 7.3-39.0%, cold pain threshold (CPT) ranged 22.22-29.63%, hot detection threshold (HDT) ranged 34.14-63.41%, and hot pain threshold (HPT) ranged 15.79-36.84%. In patients, CPT correlated with BMI (r = 0.42, p = 0.05) and diabetes duration, (r = 0.40, p = 0.05), HPT correlated with age (r = 0.36, p = 0.05) and height (r = 0.35, p = 0.05), while in controls with BMI (r = 0.51, p = 0.05). No correlation of VPT or QST with HbA1c was observed. Conclusion: Adolescents with T1DM in this study, although asymptomatic, showed a high prevalence of impaired indices of PDN, highlighting potential clinical implications of early identification of PDN.