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

Toro-Ramos, Tatiana; Goodpaster, Bret H; Janumala, Isaiah; Lin, Susan; Strain, Gladys W; Thornton, John C; Kang, Patrick; Courcoulas, Anita P; Pomp, Alfons; Gallagher, Dympna

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.