P308 - HOW SEX AND BODY COMPOSITION AFFECT MITOCHONDRIAL ADIPOSE TISSUE RESPIRATION IN DIGESTIVE CANCER PATIENTS

P308

HOW SEX AND BODY COMPOSITION AFFECT MITOCHONDRIAL ADIPOSE TISSUE RESPIRATION IN DIGESTIVE CANCER PATIENTS

L. Guerrier^1,2, O. Bacoeur-Ouzillou^2,3, J. Touron ^2,4, A. Pinel², S. Mezher⁵, L. Cassagnes⁵, J. Gagnière ^3,6, R. Richard^7,8, C. Malpuech-Brugère^2,*

¹CHU Gabriel Montpied, ²Human Nutrition Unit, Clermont Auvergne University, ³Department of Digestive and Hepatobiliary Surgery-Liver Transplantation, CHU Estaing, Clermont-Ferrand, ⁴Fatigue and Vigilance Unit, French Armed Forces Biomedical Research Institute, Brétigny-sur-Orge, ⁵Department of Radiology, CHU Gabriel Montpied, ⁶M2ISH, ⁷Clermont Auvergne University, ⁸Department of Sport Medicine and Functional Explorations, CHU Gabriel Montpied, Clermont-Ferrand, France

Rationale: Adipose tissue (AT), an endocrine organ, plays a key role in health and disease, yet its energy metabolism is less studied than skeletal muscle due to lower mitochondrial density. Emerging evidence suggests mitochondrial dysfunction may contribute to AT disorders, potentially influenced by adiposity and sex.

Methods: A subset of 56 participants from the OxMiTiAd study (NCT05417581) was analysed. Only patients undergoing oncological digestive surgery without chemotherapy were included. The cohort consisted of 25 females and 31 males, with BMI ranging from 15.4 to 51.9 kg·m^-2. Body composition (muscle and fat mass) was assessed via computed tomography (CT) scans at the L3 vertebra. Mitochondrial function was measured in digitonin-permeabilized adipocytes using high-resolution respirometry and a substrate/inhibitor titration method.

Results: Regarding body composition, males had significantly more muscle (161±8 cm² versus 100±5 cm²) and visceral AT (225±29 cm² versus 119±18 cm²) compared to females based on L3 CT scans. However, no significant differences were observed in subcutaneous AT between the sexes. CT scans were used to calculate the skeletal muscle index, showing that BMI alone cannot distinguish low muscle mass in either males or females. For both sexes, BMI showed a strong correlation with AT surface area on CT scans (r²=0.91). Notably, sex-based differences in body composition, mitochondrial respiration did not vary between sexes.

Conclusion: This study suggests AT mitochondrial respiration is unaffected by sex or body composition, despite their link to BMI and fat distribution. Further research is needed to clarify the role of adipose mitochondrial functions in metabolic disorders and cancer.

Disclosure of Interest: None declared