Impact of the metabolic disease status in obesity and surgical weight loss on human adipose tissue bioenergetics

• Published in: The Journal of physiology Vol. 603; no. 9; pp. 2583 - 2617
• Main Authors: Pinho, Aryane Cruz Oliveira, Lazaro, André, Barbosa, Pedro, Porter, Craig, Tralhão, José G., Carvalho, Eugenia
• Format: Journal Article
• Language: English
• Published: England Wiley Subscription Services, Inc 01.05.2025
• Subjects: Adipose tissue; Adipose Tissue - metabolism; Adult; Bariatric Surgery; Bioenergetics; Body fat; Body weight loss; Diabetes; Diabetes mellitus (non-insulin dependent); Diabetes Mellitus, Type 2 - metabolism; Efficiency; Electron transport chain; Energy Metabolism; Energy resources; Explants; Female; Gastrointestinal surgery; Humans; Insulin Resistance; Male; Metabolic Diseases - metabolism; Metabolic disorders; Middle Aged; Mitochondria; Mitochondria - metabolism; Obesity; Obesity - metabolism; Obesity - surgery; Oxidation; Oxidative Phosphorylation; OXPHOS capacity; Phosphorylation; Pyruvic acid; Respiration; Risk factors; Substrate preferences; Surgery; Titration; type 2 diabetes; Weight control; Weight Loss; bariatric surgery; type 2 diabetes; OXPHOS capacity; mitochondria; adipose tissue; insulin resistance; obesity
• ISSN: 0022-3751; 1469-7793; 1469-7793
• DOI: 10.1113/JP286103

Obesity is associated with insulin resistance (IR) development, a risk factor for type 2 diabetes (T2D). How mitochondrial bioenergetics, in adipose tissue (AT), differs according to distinct metabolic profiles (i.e. insulin sensitive (IS), IR normoglycaemic (IR‐NG), pre‐diabetes (PD) and T2D) is still poorly understood. The purpose of this study was to evaluate and compare bioenergetics and energy substrate preference by omental AT (OAT) and subcutaneous AT (SAT) from subjects with obesity (OB, n = 40) at distinct metabolic stages. Furthermore, AT bioenergetics was also evaluated pre‐ and post‐bariatric/metabolic surgery (BMS). High‐resolution respirometry (HRR) was used to measure the real‐time oxidative phosphorylation (OXPHOS) capacity and mitochondrial substrate preferences in both tissues. Substrate‐uncoupler‐inhibitor titration protocols were used: SUIT‐P1 (complex I and II‐linked mitochondrial respiration) and SUIT‐P2 (fatty acid oxidation (FAO)‐linked mitochondrial respiration). Flux control ratios (FCRs) were calculated. In SUIT‐P1, lower OXPHOS capacity was observed in AT, particularly in SAT, during the establishment of IR (OB‐IR‐NG) and in the T2D group, due to alterations of mitochondrial coupling, evaluated by FCRs. In SUIT‐P2, the OXPHOS coupling efficiency was highest in the OB‐IR‐NG group. AT from OB‐IS, OB‐IR‐NG and OB‐IR‐PD preferred pyruvate, malate and glutamate oxidation and/or FAO during OXPHOS, whereas AT from T2D preferred succinate oxidation. BMS enhanced mitochondrial respiration in OAT, even under poor OXPHOS coupling efficiency. In conclusion, real‐time OXPHOS analysis by HRR may be a sensitive biomarker of mitochondrial fitness, particularly in AT. Interventions based on modulating energetic substrate availability may become a good tool for obesity treatment stratification. Key points Omental adipose tissue shows higher oxidative phosphorylation (OXPHOS) capacity compared to subcutaneous adipose tissue in paired explants from subjects with obesity. The OXPHOS capacity of adipose tissue differs through the progression of metabolic disease. Subjects with obesity and diabetes have the lowest OXPHOS capacity in paired explants of subcutaneous and omental adipose tissues. Bariatric surgery enhanced the OXPHOS capacity in omental adipose tissue, even under poor OXPHOS coupling efficiency. Assessment of the oxidative capacity in fresh adipose tissue explants could be a sensitive tool for early diagnosis of metabolic disease. figure legend Changes in the mitochondrial respiratory capacity in adipose tissue during obesity‐related metabolic disease progression and after bariatric/metabolic surgery. AT, adipose tissue; OAT, omental adipose tissue; OB‐IS, insulin sensitive; OB‐IR‐NG, insulin resistance normoglycaemic; OB‐IR‐PD, insulin resistance prediabetic; OB‐IR‐T2D, type 2 diabetic; OB‐II, obesity grade II; OB‐III, obesity grade III; OB‐IV, obesity grade IV; OXPHOS, oxidative phosphorylation; SAT, subcutaneous adipose tissue. Created with BioRender.com.