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.

Changes in bone mass and body composition after bariatric surgery.

Aim: To analyze the effects of body weight loss on bone mineral density (BMD) on hip (Hip BMD) and lumbar spine (Lumbar BMD) after six months of bariatric surgery. Bariatric surgery is an effective treatment for morbid obesity. Nonetheless, there are scant data on the effect of weight bearing on bone structure.Material and methods: Seventeen obese women aged 41.2 ± 11.3 yrs. who underwent Roux-en-Y gastric bypass (RYGB) were included. Body composition assessments were performed through dual-energy X-ray absorptiometry immediately before and after 6-months RYGB. Data collected pre- and post-RYGB included total body weight, body mass index (BMI), lean body mass (LM), fat mass (FM) and bone mineral content. The pre- (PRE) and post-operative (POST) results were compared.Results: Lumbar BMD POST presented a non-significant loss of 1.8% whereas Hip BMD POST showed a significant loss of 17.8%. The analysis demonstrated that BMI and LM PRE explained 26% and 49%, respectively, of Hip BMD PRE variability. In addition, LM POST explained 30% of hip BMD POST variability and was not significant for Lumbar BMD POST.Conclusions: Obesity and rapid weight loss showed direct influence in Hip BMD after six months of bariatric surgery. However, its effect on the lumbar spine area was smaller due to the higher capacity of the spine to dissipate loads through its curvature.