Changes in Serum Leptin Level After Multilevel Surgery in Patients with Obstructive Sleep Apnea Tarek A. Emara, MD; Alaa O. Khazbak, MD ; Omnya Mohammed, MD; Mohamed Elgaml, MBBCh; Amal Zidan, MD; Sameh M. Hosny, MD Objective: Leptin hormone plays an important role in metabolic control and is elevated in obstructive sleep apnea (OSA). The aim of this study was to assess the hypothesis that surgical treatment will reduce leptin levels in OSA patients. Study Design: Prospective study. Subjects and Methods: Twenty-three patients with multilevel OSA underwent modified genioglossus muscle advance- ment with anterolateral advancement pharyngoplasty between April 2018 and September 2019. Serum leptin level was mea- sured preoperatively and 3 months postoperatively for all patients and 18 control subjects. All patients were evaluated before and 3 months after surgery by history taking, clinical examination, polysomnography, cephalometry, and Epworth Sleepiness Scale. Results: Preoperatively, patients with OSA had a higher Leptin level (18.46 ± 4.73 ng/mL) than did control subjects (7.07 ± 1.26 ng/mL) (P < .001). Surgery resulted in a significant reduction in the level of leptin from 18.46 ± 4.73 ng/mL to 8.03 ± 2.22 ng/mL (P < .001). Reductions in leptin level was correlated with changes in apnea hypopnea index (AHI) (r = 0.61, P = .002) and minimum oxygen saturation (SaO2) (r = -0.54, P = .008). Conclusion: Effective multilevel surgery in the form of modified genioglossus muscle advancement with anterolateral advancement pharyngoplasty could significantly reduce leptin level in OSA patients and this reduction is correlated with the degree of OSA improvement in term of AHI and SaO2. Key Words: Serum leptin, multilevel obstruction, obstructive sleep apnea, genioglossus advancement, pharyngoplasty. Level of Evidence: 4 (prospective study) Laryngoscope, 00:1–6, 2020 INTRODUCTION Obstructive sleep apnea (OSA) is characterized by recurrent episodes of complete or partial upper airway obstruction during sleep caused by loss of pharyngeal muscle tone. 1,2 Obstruction may occur at oropharynx (type I), oropharynx and hypopharynx (type II), or hypo- pharynx (type III). Most patients have type II obstruction involving both the soft palate and the tongue base (ie, multilevel obstruction). 3 OSA is a common disease consti- tuting more than 85% of sleep-disordered breathing 4 which affects 26% of persons between 30 and 70 years of age. 5 Leptin is a circulating hormone structurally similar to cytokines and produced predominantly by white adi- pose tissue. 6 It is concerned in a wide range of events, including appetite suppression, regulation of body weight and energy homeostasis by binding to specific receptors in both hypothalamus and peripheral tissues. 7–9 It was also reported that Leptin is involved in regulation of many metabolic and biological functions including fertil- ity, 10 immune function, 11 bone formation, 12 angiogene- sis, 13 and glucose homeostasis. 14 Human and experimental studies showed that leptin plays an important role in the pathogenesis of OSA. The best evidence shows that it affects ventilation, disrupts sleep architecture, and causes changes in upper air way resistance and patency. 15 Most studies that investigated serum leptin have reported elevated levels of the hor- mone in OSA patients. 15,16 Effective treatment with con- tinuous positive airway pressure (CPAP) could significantly reduce elevated leptin level in OSA patients, independent of effect of weight change. 17,18 A variety of surgical procedures have been described to treat OSA patient and offer an alternative option to CPAP because of its low long term compliance. 19 The con- cept of multilevel surgery for OSA patients is developed by Riley et al. 20 and it has become increasingly clear that multilevel surgery is indicated in OSA patients with a dif- ferent surgical success rate. 21,22 In this study, we evalu- ated the effect of multilevel surgery (concurrent modified genioglossus advancement 22 and anterolateral advance- ment pharyngoplasty 23 ) on serum leptin level in patients with OSA. We hypothesized that the multilevel surgery could decrease the high serum leptin level in such group of patients. From the Otorhinolaryngology-Head & Neck Surgery Department (T.A.E., A.O.K., O.M., S.M.H.), Faculty of Medicine, Zagazig University, Zagazig, Egypt; Otorhinolaryngology-Head & Neck Surgery Department (M.E.), Al Ahrar Teaching Hospital, Zagazig, Egypt; and theClinical Pathology Department (A.Z.), Zagazig University, Zagazig, Egypt. Editor’s Note: This Manuscript was accepted for publication on June 16, 2020. The authors have no funding or conflicts of interest to disclose. (pro- spective study) Send correspondence to Alaa O. Khazbak, MD, Otorhinolaryngology- Head & Neck surgery Department, Faculty of Medicine, Zagazig University, Zagazig, Egypt. E-mail: alaakhazbak@hotmail.com DOI: 10.1002/lary.28908 Laryngoscope 00: 2020 Emara et al.: Leptin Change in OSA 1 The Laryngoscope © 2020 The American Laryngological, Rhinological and Otological Society, Inc.