Myosteatosis as a metabolic risk in hidradenitis suppurativa: a CT-based study

Background Hidradenitis suppurativa (HS) is a chronic inflammatory skin disorder linked to obesity, metabolic syndrome, and systemic inflammation. Myosteatosis is associated with adverse metabolic outcomes, but its relationship with HS has not been explored. The present study aimed to compare muscle and fat composition, focusing on myosteatosis and sarcopenia, between HS patients and controls, and to assess associations with clinical and metabolic parameters. Methods This retrospective study included 61 HS patients and 59 age- and sex-matched controls with non-contrast thoracoabdominal computed tomography (CT) scans. Muscle and fat compartments at the 12th thoracic vertebra were quantified. Sarcopenia and myosteatosis were defined using established CT-based criteria. Clinical and laboratory data, including fasting glucose, lipid profile, and comorbidities, were collected. Results According to logistic regression analyses, myosteatosis showed significant independent associations with HS and with a history of biologic therapy (HS: OR = 3.88, p = 0.004; biologic therapy: OR = 0.085, p = 0.014). HS patients exhibited significantly higher intermuscular adipose tissue (IMAT) (1574.8 ± 1243.8 cm 2 vs. 1112.7 ± 822.5 cm 2 , p = 0.029), low attenuation muscle area (LAMA) (5013.1 ± 1999.8 cm 2 vs. 2996.4 ± 1220.7 cm 2 , p < 0.001), and LAMA/BMI indices (low attenuation muscle area normalized to BMI), alongside lower normal attenuation muscle area (NAMA)/BMI indices ( p < 0.001), indicating increased myosteatosis and reduced muscle quality. Sarcopenia prevalence was similar. Hypertensive patients had lower NAMA/TAMA (total abdominal muscle area) and higher LAMA/BMI indices. Disease severity negatively correlated with HDL cholesterol ( p < 0.001). BMI, TAMA, subcutaneous, and visceral adipose tissue were similar between groups. Conclusion This study demonstrates that HS is independently associated with myosteatosis, but not with sarcopenia. A history of long-term biologic therapy was also strongly and independently linked to myosteatosis, suggesting a previously underrecognized interaction between systemic inflammation, treatment exposure, and muscle quality. Muscle fat infiltration may represent an underrecognized metabolic risk factor in HS, highlighting the need for further prospective studies.