Quantitative ultrasound assessment of lower limb muscle morphology in type 2 diabetes with and without peripheral neuropathy.

BACKGROUND

Diabetic peripheral neuropathy (DPN) is associated with progressive skeletal muscle degeneration, particularly in distal lower limb muscles. Advanced imaging modalities such as CT and MRI can detect these changes; however, their routine clinical use is limited. This study aimed to evaluate the utility of quantitative musculoskeletal ultrasound for assessing lower limb muscle morphology in individuals with type 2 diabetes with and without DPN.

METHODS

In this cross-sectional study, 215 participants were included and categorized into three groups: T2DM with DPN (n = 129), T2DM without DPN (n = 43), and healthy controls (n = 43). DPN was assessed using the 10-g monofilament test and vibration perception threshold (VPT). Ultrasound measurements of the muscle thickness and cross-sectional area (CSA) were obtained for proximal and distal lower limb muscles using a standardized protocol. Group comparisons were performed using the Kruskal-Wallis test with DSCF post-hoc analysis. Associations were assessed using Spearman's correlation.

RESULTS

Quantitative ultrasound revealed that participants with DPN demonstrated significantly reduced muscle thickness and CSA across most lower limb muscles compared with both T2DM without DPN and controls (p < 0.001), with the largest effect sizes observed in distal muscles, including tibialis anterior, extensor hallucis longus, extensor digitorum brevis, and abductor hallucis brevis. Ultrasound-derived muscle measurements showed significant correlations with neuropathy severity score and age.

CONCLUSIONS

Quantitative musculoskeletal ultrasound can be used as a feasible and sensitive imaging modality for detecting diabetes-related muscle changes in the lower limb muscles enabling early detection and monitoring of neuromuscular involvement in type 2 diabetes.