Magnetic Resonance Imaging to Assess Body Composition Change in Adolescents With Obesity After Sleeve Gastrectomy

Abstract

Objectives: Metabolic and bariatric surgery is the most effective weight loss treatment for severe obesity. The number of adolescents undergoing sleeve gastrectomy is increasing. We investigated changes in body composition in adolescents undergoing sleeve gastrectomy 12-26 weeks post-operatively using whole-body magnetic resonance imaging (WB-MRI).

Methods: This prospective cohort study assessed changes in adipose tissue compartments (ie, visceral, subcutaneous, and intermuscular) and muscle in 18 obese adolescents, ages 14-19, 89% female, with body mass index z -score of 2.6 ± 0.25 (range 2.16-3.2). All underwent WB-MRI 1.5-17 weeks pre-operatively and 12-26 weeks post-operatively.

Results: Pre- and post-operative WB-MRI showed decreases in all adipose tissue compartments, as well as decreased skeletal muscle and liver fat fraction ( P < 0.0001). The post-operative percentage loss of adipose tissue in subcutaneous, visceral, and intermuscular compartments (89.0%, 5.8%, 5.2%, respectively) was similar to the pre-operative percentages of corresponding adipose tissue compartments (90.5%, 5.0%, 4.5%, respectively). Of note, participants with obstructive sleep apnea had significantly higher pre-operative volume of subcutaneous and intermuscular adipose tissue than participants without obstructive sleep apnea ( P = 0.003).

Conclusions: We found, contrary to what is reported to occur in adults, that pre-operative percentage loss of adipose tissue in subcutaneous, visceral, and intermuscular compartments was similar to the post-operative percentage loss of corresponding adipose tissue compartments in adolescents 12-26 weeks after sleeve gastrectomy.

Figure 1.

Composition of pre-operative whole-body tissue volume and post-operative change after 12–26 weeks; (1A) Subcutaneous, visceral, intermuscular adipose tissue compartments (SAT, VAT, IMAT respectively), skeletal muscle and residual tissue as percentages of total pre-operative tissue volume and post-operative change as percentage of total tissue; (1B) SAT, VAT and IMAT as percentage of total pre-operative adipose tissue volume and percentage of post-operative change of total adipose tissue volume; (1C) Comparison of lean tissue components (skeletal muscle, residual tissue) as percentage of pre-operative total lean tissue volume and post-operative change of lean tissue components as percentage of change of total lean tissue volume