Subclinical muscle softening in type 2 diabetes: a shear wave elastography study linking mechanical properties to metabolic profiles.

BACKGROUND

Skeletal muscle is a critical target organ in type 2 diabetes mellitus (T2DM). While muscle atrophy is a well-recognized complication, qualitative tissue remodeling often precedes macroscopic volume loss. This study aimed to characterize the mechanical properties of the rectus femoris in patients with T2DM using shear wave elastography (SWE) and to investigate their associations with lipid and uric acid profiles.

METHODS

We conducted a cross-sectional study involving 76 patients with T2DM and 67 age- and sex-matched healthy controls. We assessed shear wave velocity (SWV), muscle thickness, and cross-sectional area of the rectus femoris bilaterally. Clinical biochemical indicators were analyzed. Physical function was evaluated using the five-repetition sit-to-stand (5STS) test and the 6-meter gait speed (6MGS) test.

RESULTS

T2DM patients exhibited significantly reduced SWV compared to controls (p < 0.001), indicating muscle softening. This mechanical alteration occurred despite preserved muscle thickness and cross-sectional area. Lower muscle stiffness was strongly correlated with elevated low-density lipoprotein cholesterol (LDL-C) and uric acid levels, but not with fasting plasma glucose. Functionally, reduced SWV was associated with prolonged 5STS duration and slower gait speed.

CONCLUSION

T2DM impairs muscle mechanical properties prior to the onset of overt atrophy. This "quality-first" deterioration is closely linked to dyslipidemia and hyperuricemia rather than acute hyperglycemia. These findings suggest that metabolic-driven soft tissue remodeling serves as an early marker of diabetic myopathy. SWE offers a sensitive tool for detecting these subclinical changes.