Associations Between Morning Salivary and Blood Cortisol Concentrations in Individuals With Obstructive Sleep Apnea Syndrome: A Meta-Analysis

Abstract

BackgroundObstructive sleep apnea syndrome (OSAS) may be associated with an increase in hypothalamic-pituitary-adrenocortical axis activity (HPA AA). We reviewed research comparing morning salivary and blood (serum and plasma) cortisol concentrations of individuals with OSAS to those of healthy controls.MethodsWe made a systematic search without any restrictions of the PubMed/Medline, Scopus, Cochrane Library, and Web of Science databases for relevant articles published up to August 25, 2019.ResultsSixteen studies were analyzed in this meta-analysis; five studies compared morning salivary concentrations, five compared serum concentrations, four compared plasma cortisol concentrations, and two compared both salivary and plasma concentrations. In pediatric samples, compared to healthy controls, those with OSAS had significantly lower saliva morning cortisol concentrations (MD = -0.13 µg/dl; 95% CI: 0.21, -0.04; P = 0.003). In contrast, no significant differences were observed for serum cortisol concentrations, plasma cortisol concentrations, or salivary morning cortisol concentrations between adults with and without OSAS (p = 0.61, p = 0.17, p = 0.17).ConclusionCortisol concentrations did not differ between adults with OSAS and healthy controls. In contrast, morning salivary cortisol concentrations were lower in children with OSAS, compared to healthy controls. Given that a reduced HPA AA is observed among individuals with chronic stress, it is conceivable that children with OSAS are experiencing chronic psychophysiological stress.

Compared to Individuals with Mild to Moderate Obstructive Sleep Apnea (OSA), Individuals with Severe OSA Had Higher BMI and Respiratory-Disturbance Scores

“…For morning saliva and blood cortisol levels, compared to adult healthy controls, adults with OSAS had no difference in cortisol levels [21]. In contrast, compared to healthy controls, children with OSAS had statistically significant lower cortisol levels [21]. Although salivary morning cortisol levels in adults with OSAS did not differ significantly from those of healthy controls, children with OSAS had significantly lower cortisol concentrations than control subjects.…”

“…First, a systematic sample bias cannot be ruled out; second, it is conceivable that data from individuals with undiagnosed OSA living in the general population might have yielded another pattern of results. Third, exclusively data of adults were analyzed, while children with OSA were at increased risk of a chronically stressed psychophysiological mechanism, as reflected in a continuously decreased cortisol secretion [21]. Next, a more multifaceted analysis, such as phenotyping individuals with OSA, might have yielded further results [102].…”

“…Next, OSA appeared to be an independent factor for cardiovascular diseases [11][12][13][14] and all-cause mortality [14], while further associations were observed among the occurrence of OSA and diabetes mellitus [15][16][17][18][19] and hormonal disorders [20]. For morning saliva and blood cortisol levels, compared to adult healthy controls, adults with OSAS had no difference in cortisol levels [21]. In contrast, compared to healthy controls, children with OSAS had statistically significant lower cortisol levels [21].…”

The Effect of Adenotonsillectomy on Children’s Behavior and Cognitive Performance with Obstructive Sleep Apnea Syndrome: State of the Art

“…In confirmation of possible chronic psychophysiological stress, in their meta-analyses and meta-regressions about the comparison between children with OSAS and healthy controls, Imani and colleagues demonstrated that plasma levels of IL-6 ((95% CI: 0.27, 1.41; p = 0.004; I 2 = 72% (P h = 0.03))) [52] and serum levels of TNF-α (0.21 pg/mL (95% CI = 0.05, 0.37; p = 0.01), I 2 = 77% (P h = 0.005)) [53] were significantly higher in children with OSAS, while the morning saliva cortisol concentrations were significantly lower (MD = −0.13 µg/dL; 95% CI: 0.21, −0.04; p = 0.003 I 2 = 0% (P h = 0.34)) in children with OSAS [54].…”

Pediatric Obstructive Sleep Apnea: Knowledge and Attitudes of Medical and Dental Students and Fresh Graduates from Saudi Arabia

“…Other than respiratory disease, OSA has been associated with metabolic, cardiovascular, dental, and other diseases. In children, undiagnosed and/or untreated OSA can also be associated with impaired growth and learning and behavioral problems, with consequent poor school performance [ 4 , 5 ].…”