Coen, Paul M., Menshikova, Elizabeth V., Distefano, Giovanna, Zheng, Donghai, Tanner, Charles J., Standley, Robert A., Helbling, Nicole L., Dubis, Gabriel S., Ritov, Vladimir B., Xie, Hui, Desimone, Marisa E., Smith, Steven R., Stefanovic-Racic, Maja, Toledo, Frederico G. S., Houmard, Joseph A., Goodpaster, Bret H.
funding text
This study was supported by the National Institute of Diabetes and Digestive and Kidney Diseases (R01-DK-078192 and R01-DK-078192-02S1 to B.H.G.), the University of Pittsburgh Clinical Translational Research Center (M01-RR-00056), and the Obesity and Nutrition Research Center (P30-DK-46204).
abstract
Both Roux-en-Y gastric bypass (RYGB) surgery and exercise can improve insulin sensitivity in individuals with severe obesity. However, the impact of RYGB with or without exercise on skeletal muscle mitochondria, intramyocellular lipids, and insulin sensitivity index (SI) is unknown. We conducted a randomized exercise trial in patients (n = 101) who underwent RYGB surgery and completed either a 6-month moderate exercise (EX) or a health education control (CON) intervention. SI was determined by intravenous glucose tolerance test. Mitochondrial respiration and intramyocellular triglyceride, sphingolipid, and diacylglycerol content were measured in vastus lateralis biopsy specimens. We found that EX provided additional improvements in S-1 and that only EX improved cardiorespiratory fitness, mitochondrial respiration and enzyme activities, and cardiolipin profile with no change in mitochondrial content. Muscle triglycerides were reduced in type I fibers in CON, and sphingolipids decreased in both groups, with EX showing a further reduction in a number of ceramide species. In conclusion, exercise superimposed on bariatric surgery-induced weight loss enhances mitochondrial respiration, induces cardiolipin remodeling, reduces specific sphingolipids, and provides additional improvements in insulin sensitivity.