A case-control study of spermidine in obstructive sleep apnea.

Background and purpose: Obstructive sleep apnea (OSA) is a common sleep dis-order. Despite many studies, its etiology is not clearly known. Polyamines are ubiquitous positively charged amines found in all or-ga-nisms and one of the polyamines types is spermidine. In the literature, some articles demonstrate relationship between sleep dis-orders and polyamines. The common point of OSA and polyamines is oxidative stress. This study aimed to determine the serum levels of spermidine in patients with OSA and compare the results with healthy subjects.

Methods: This cross-sectional case-cont-rol study was designed with 69 subjects. Sub-jects were selected from people who were referred to polysomnography due to complaints of sleep disturbance and snoring. They were divided into two groups according to their Apnea Hypopnea Index (AHI) scores: control (n=29; AHI<5), and OSA (n=40; AHI≥5). Spermidine levels were determined in serum samples by using an enzyme-linked immunosorbent assay (ELISA) kit.

Results: After adjusting for age, body mass index (BMI), and gender, there was no significant difference in spermidine levels between OSA and controls (p=0.063, p=0.063, and p=0.818, respectively). There was no correlation between AHI and spermidine levels (rho=-0.063; p=0.698). The area under the Receiver Operating Characteristic (ROC) curve (AUC) was found to be 0.635 for spermidine.

Conclusion: These results demonstrated that decreased levels of spermidine in OSA patients was related to age, BMI, and gender. The relationship between OSA and the polyamines pathway should be the subject of future studies with more homogenous groups to understand the roles of polyamines in OSA pathogenesis.