Lean mass and strength profile of women submitted to bariatric surgery: comparison of the EWGSOP2 and FNIH classification for sarcopenia - ASBS program phase II.

Aim: To assess the effect of bariatric surgery on the lean mass of women after one year of the procedure, comparing its outcomes upon the classification from both the Foundation of the National Institutes of Health (FNIH) and the European Working Group on Sarcopenia in the Elderly People (EWGSOP). Material and methods : Twenty-eight obese women aged 40.5 ± 9.8 yrs who underwent Roux-en-Y gastric bypass (RYGB) were included. 27 of them were reassessed after 6 months of surgery, and 16 completed the one-year follow-up. Pre-sarcopenia condition was assessed through a handgrip strength test and body composition by dual-energy X-ray absorptiometry (DXA). Total body mass, body mass index, and lean mass (LM) were collected prior to, 6 and 12 months after RYGB surgery. Results : All subjects reassessed after 12 months were diagnosed with pre-sarcopenia according to the FNIH classification criteria, while according to the EWGSOP2 Consensus they presented normal values. LM represented 14% of the influence on handgrip strength ( p  = .049) after 6 months of surgery; however, its influence on strength after 12 months increased to 30% ( p  = .028). Conclusion : The FNIH classification is the most effective criteria since it uses LM content as the first test, considering that strength capacity needs more time to be affected by the surgical procedure. On the other hand, the EWGSOP2 classification should not be applied to determine the loss of LM in younger populations regardless of what may have caused such changes.