Continued loss in visceral and intermuscular adipose tissue in weight-stable women following bariatric surgery.

Objective To assess changes in total (TAT), subcutaneous (SAT), visceral (VAT), and intermuscular (IMAT) adipose tissue by whole-body MRI before surgery and at 12 months and 24 months post-surgery in a subset of participants of the Longitudinal Assessment of Bariatric Surgery-2. Methods From 0 to 12 months, n = 20 females and 3 males; from 12 to 24 months, n = 42 females and 7 males. Paired t-tests and GLM repeated measures examined changes in TAT, SAT, VAT, and IMAT at 12 and 24 months, with sex and age as covariates. Results Changes from 0 to 12 months included weight (−41.9 ± 12.1 kg; −36%), TAT (−33.5 ± 9.6 kg; −56%), SAT (−29.2 ± 8.2 kg; −55%), VAT (−3.3 ± 1.6 kg; −73%), and IMAT (−0.99 ± 0.68 kg; −50%), all P < 0.001. In females, from 12 to 24 months, despite relative weight stability (−1.8 ± 6.5 kg, −2%; P = 0.085), VAT (−0.5 ± 0.7 kg; −30%; P < 0.001) and IMAT (−0.2 ± 0.4 kg; −14%; P = 0.012) decreased further. In males, from 12 to 24 months, weight increased (5.1 ± 5.2 kg; 6%; P = 0.04) with no significant changes in TAT or sub-depots. Conclusions Bariatric surgery continues to induce favorable changes in body composition, i.e., persistent adipose tissue loss at 24 months in the absence of further significant weight loss.