Research Article The Rise of IGFBP4 in People with Obstructive Sleep Apnea and Multilevel Sleep Surgery Recovers Its Basal Levels Abdulmohsen Alterki, 1 Eman Al Shawaf , 2 Irina Al-Khairi, 2 Preethi Cherian , 2 Devarajan Sriraman , 3 Maha Hammad , 2 Thangavel A. Thanaraj, 4 Mahmoud A. K. Ebrahim, 1 Fahd Al-Mulla , 4 Mohamed Abu-Farha , 2 and Jehad Abubaker 2 1 Department of Otolaryngology Head & Neck Surgery, Zain and Al Sabah Hospitals and Dasman Diabetes Institute, 15462, Kuwait 2 Department of Biochemistry and Molecular Biology, Dasman Diabetes Institute, 15462, Kuwait 3 Special Service Facility Department, Dasman Diabetes Institute, 15462, Kuwait 4 Department of Genetics and Bioinformatic, Dasman Diabetes Institute, 15462, Kuwait Correspondence should be addressed to Mohamed Abu-Farha; mohamed.abufarha@dasmaninstitute.org and Jehad Abubaker; jehad.abubakr@dasmaninstitute.org Received 24 May 2021; Revised 17 September 2021; Accepted 25 September 2021; Published 4 October 2021 Academic Editor: Jie Mei Copyright © 2021 Abdulmohsen Alterki et al. This is an open access article distributed under the Creative Commons Attribution License, which permits unrestricted use, distribution, and reproduction in any medium, provided the original work is properly cited. IGFBP4 is the smallest member of the insulin-like growth factor binding protein family (IGFBP). It is a hepatic protein that plays a role in modulating the activity and bioavailability of IGF-I. The expression of IGFBP4 was found to increase under conditions of hypoxia. Obstructive sleep apnea (OSA) is a common disorder, characterized by cyclic episodes of intermittent hypoxia and fragmented sleep. Our aim was to quantify levels of circulating IGFBP1, IGFBP2, IGFBP3, IGFBP4, and IGFBP7 in fasting plasma samples of 69 Kuwaiti participants and explore its correlation with indices of OSA. The quantification was performed using multiplexing assay. The study involved 28 controls and 41 patients with OSA. Levels of circulating IGFBP4 were significantly higher in people with OSA (289:74 ± 23:30 ng/ml) compared to the control group (217:60 ± 21:74 ng/ml, p =0:028 ). The increase in IGFBP4 correlated significantly and positively with AHI (r = :574, p = :01) and AI (r = :794, p = :001) in people with moderate and severe OSA. There was a significant decline in circulating IGFBP4 after 3 months of surgery (225:89 ± 18:16 ng/ml, p =0:012). This was accompanied by a prominent improvement in OSA (AHI 8:97 ± 2:37 events/h, p = 0:001). In this study, our data showed a significant increase in circulating IGFBP4 in people with OSA. We also report a significant positive correlation between IGFBP4 and indices of OSA at baseline, which suggests IGFBP4 as a potential diagnostic biomarker for OSA. There was a significant improvement in OSA after 3 months of surgical intervention, which concurred with a significant decline in IGFBP4 levels. Altogether, the detected change suggests a potential link between IGFBP4 and OSA or an OSA-related factor, whereby OSA might play a role in triggering the induction of IGFBP4 expression. 1. Introduction Obstructive sleep apnea (OSA) is a chronic sleep disorder that features fragmented sleep. It is characterized by having repeated episodes of airflow cessation (apnea) or airflow reduction (hypopnea), which leads to intermittent hypoxia (i.e., a decline in oxyhemoglobin saturation), interrupted sleep, and augmented heart rate oscillations, intrathoracic pressure, and hypertension [1, 2]. The chronic presence of these disruptions activates various pathological mechanisms that would elicit vascular damage and might play a role in the development of cardiovascular morbidities [1, 3]. OSA is a common disorder that is mostly prevalent among people with obesity [1] and has been associated with diabetes and cardiovascular disease (CVD) [4]. OSA treatment options involve lifestyle modifications, weight reduction, and the use of surgical procedures or external therapies that help keeping an open airway during Hindawi Disease Markers Volume 2021, Article ID 1219593, 9 pages https://doi.org/10.1155/2021/1219593