Early improvement in obstructive sleep apnea and increase in orexin levels after bariatric surgery in adolescents and young adults

Abstract

Background Obstructive sleep apnea (OSA) associated with obesity is known to improve after bariatric surgery, but little is known about early changes in this condition following surgery. Objectives To study the clinical course of OSA after bariatric surgery. Setting Children's hospital in the United States. Methods Adolescents and young adults with obstructive sleep apnea undergoing vertical sleeve gastrectomy (n=6) or gastric bypass (n=1) were enrolled in this prospective study. Participants underwent formal polysomnography before and at 3 and 5 weeks following bariatric surgery. Anthropometric measurements and assay for orexin and leptin were also performed at study visits. Thirty-one adolescents who underwent 2 polysomnography studies that were 4 weeks apart served as control subjects. Results Baseline mean (range) age of participants was 17.8 (15.4-20.7) years, 71% were male, with body mass index of 55.2 (41.3-61.6) kg/m2 and had a median apnea hypopnea index (AHI) of 15.8 (7.1-23.8) events/hour. Differences in least-square means from longitudinal analysis did not show significant differences in AHI in the control group but showed significant post-operative decline in AHI relative to baseline. AHI declined post-operatively from baseline by 9.2 events/hour (95% CI: 3.8 to 14.5) at 3 weeks (p=0.002) and 9.1 events/hour (95% CI: 3.8 to 14.5) at 5 weeks (p=0.002); there was no significant change from 3 to 5 weeks in AHI. Leptin decreased and orexin levels increased significantly by 3 weeks postoperatively. Conclusions These observations suggest that OSA responds early and out of proportion to weight loss following metabolic/bariatric surgery, thus weight independent factors may at least in part be responsible for early improvement in OSA postoperatively.

The Metabolic Rearrangements of Bariatric Surgery: Focus on Orexin-A and the Adiponectin System

“…Moreover, Cigdem et al showed that laparoscopic gastric band application resulted not only in significant weight loss but also in decreased Orexin-A serum levels [ 51 ]. Amin et al demonstrated a rise in Orexin and a decrease in leptin in a cohort of obese subjects affected by obstructive sleep apnea, after bariatric surgery, showing that metabolic changes were also occurring in the same time span and thus it was plausible that physiologic rather than anatomic changes may underlie the clinically significant improvement in obstructive sleep apnea as early as 11 days following bariatric surgery [ 52 ]. The regulation of Orexin and the involvement of the nervous system both depend on mechanical factors but also on chemical mediators and hormones that are in circulation after the intervention.…”

Cardiometabolic risk in obese children

“…Youth should be Tanner 4–5 in pubertal development and have achieved at least near final height 17 . The most common procedures used in children and associated with significant weight loss and improvement in metabolic control are: Roux-en-Y gastric bypass, sleeve gastrectomy, or laparoscopic adjustable gastric banding 188,193–195 . Post-surgical weight loss is often variable but usually ranges between 20–50% of initial body weight.…”

Potential mechanisms of sleeve gastrectomy for reducing weight and improving metabolism in patients with obesity

“…The arcuate nucleus of the hypothalamus is one of the main regulating organs for appetite. Studies have shown that many brain neurotransmitters, including dopamine and serotonin, and various neuropeptides, including neuropeptide Y (NPY), leptin, orexin A, ghrelin, growth hormone releasing factor, leptin, and glucagon-like peptide-1 (GLP-1), can affect the appetite [18][19][20][21][22]. Neurotransmitters and neuropeptides undergo changes during and after the process of SG, which in turn affect the appetite and food intake.…”