Energy balance in hypothalamic obesity in response to treatment with a once-weekly GLP-1 receptor agonist

Background/Objectives Hypothalamic obesity (HO) frequently occurs following suprasellar tumors from a combination of decreased energy expenditure and increased energy intake. Glucagon-like peptide-1 receptor agonist (GLP1RA) therapy is associated with increased satiety and energy expenditure. We hypothesized GLP1RA therapy in patients with HO would cause both lower energy intake and increased energy expenditure. Subjects/Methods Forty-two patients aged 10-26 years (median 16 years) with HO with suprasellar tumors were randomized to GLP1RA (exenatide extended release once-weekly, ExQW, n = 23) or placebo (n = 19). Thirty seven (81%) patients completed the 36-week double-blind placebo-controlled trial. Total energy expenditure (TEE) was measured with doubly labeled water, physical activity was assessed with actigraphy, and intake was estimated with ad libitum buffet meal. Results are presented as adjusted mean between-group difference. Results As compared with treatment with placebo, treatment with ExQW was associated with decreased energy intake during a buffet meal (-1800 kJ (-430 kcal), 95% CI -3 184 to -418 kJ, p = 0.02). There were no significant differences in physical activity between groups. ExQW (vs. placebo) treatment was associated with a decrease in TEE (-695 kJ/day (-166 kcal/day), 95% CI -1 130 to -264 kJ/day, p < 0.01, adjusted for baseline TEE). The treatment effect was still significant after further adjustment for change in body composition (-372 kJ/day (-89 kcal/day), 95% CI -699 to -42 kJ/day, p = 0.04) or change in leptin (-695 kJ/day (-166 kcal/day), 95% CI -1 130 to -264 kJ/day, p < 0.01). This decrease in TEE occurred despite an increase in lean mass and fat mass (1.7 vs. 1.3 kg lean mass, p = 0.88 and 1.5 vs. 4.6 kg fat mass, p = 0.04, ExQW vs. placebo). Conclusions Treatment with a GLP1RA was associated with a decrease in food intake but also a decrease in TEE that was disproportionate to change in body composition.