Assessment of muscle quality and quantity in individuals with diffuse idiopathic skeletal hyperostosis.

OBJECTIVES

Diffuse idiopathic skeletal hyperostosis (DISH) may reduce spinal mobility and affect muscle quantity and quality, increasing sarcopenia risk. However, longitudinal data are limited. We investigated muscle quantity, quality, and their changes in DISH using computed tomography (CT) and bioelectrical impedance analysis (BIA).

METHODS

We analysed health screening data, including data of participants who underwent CT and BIA twice over 5 years. We identified 143 DISH patients (58.0 ± 8.4 years, 19 females) and 143 age- and sex-matched controls (58.4 ± 8.8 years, 19 females). At L3, psoas and posterior paraspinal muscle (PSM) areas were measured on CT and normalized to height squared as muscle index (MI, cm2/m2). Muscle density was assessed in Hounsfield units (HU). The skeletal muscle mass index (SMI, kg/m2) was obtained from BIA.

RESULTS

At baseline, DISH had a higher MI (psoas: 347.5 ± 86.0 vs 294.8 ± 81.7, P < .001; PSM: 809.3 ± 146.2 vs 758.8 ± 130.7, P = .002) but lower HU (psoas: 36.0 ± 9.1 vs 40.9 ± 5.2, P < .001; PSM: 39.0 ± 8.8 vs 42.0 ± 7.4, P = .002). SMI was similar (7.9 ± 0.9 vs 7.7 ± 0.9, P = .212). Over 5 years, the DISH MI declined (psoas: 334.3 ± 94.9, P = .006; PSM: 782.6 ± 166.4, P = .007), while controls showed no change (psoas: 294.7 ± 94.1, P = .695; PSM: 757.2 ± 170.3, P = .776).

CONCLUSIONS

DISH patients have greater muscle mass but lower quality and trend towards decline, suggesting sarcopenia risk.