Background: Severe obesity is often characterized by ectopic fat deposition, which is related to development of type 2 diabetes (T2D). Thus, resolution of T2D may not be linearly associated with weight loss. The importance of ectopic fat reduction after bariatric surgery and T2D resolution is uncertain.
Objective: The aim of this pilot study is to compare body composition and body fat distribution in severely obese patients with or without T2D after biliopancreatic diversion with duodenal switch (BPD-DS) surgery in relation to diabetes resolution.
Methods: Sixty-two severely obese patients were evaluated at baseline, 6, and 12 months. Of these, 40 patients underwent BPD-DS surgery. Anthropometric measurements and abdominal and mid-thigh computed tomography scans were performed at each visit.
Results: Before BPD-DS surgery, obese patients with T2D had higher weight as well as greater ectopic fat deposition in the abdomen and mid-thigh level than obese patients without T2D (p < 0.05). Resolution of T2D was 65 and 90 % at 6 and 12 months, respectively. No difference in body composition changes at 6 and 12 months could be found between patients without T2D, patients with T2D resolution, and patients who remained T2D. Resolution of T2D was associated with a greater absolute loss of visceral adipose tissue (VAT) in comparison to patients without T2D (-1175 ± 570 cm(3) vs. -729 ± 394 cm(3) at 6 months and -1647 ± 816 cm(3) vs. -1103 ± 422 cm(3) at 12 months; all p ≤ 0.05).
Conclusion: Ectopic fat mobilization, particularly the absolute loss of VAT, may play a major role in T2D resolution following BPD-DS surgery, regardless of the amount of weight loss.
Keywords: Biliopancreatic diversion with duodenal switch surgery; Computed tomography scan; Ectopic fat; Severe obesity; Type 2 diabetes.