Salivary cortisol level as a stress indicator in school-aged children and the severity of the COVID-19

BACKGROUND: COVID-19 occurred as a world outbreak. We evaluated the level of stress in school-aged children with different COVID-19 courses by detection of free salivary cortisol.METHODS: Ninety children aged 6 to 18 years were examined: 60 with laboratory-confirmed SARS-CoV-2 infection (20 with mild course, 31 with moderate and nine with severe disease course) and 30 children without signs of the disease (control group). Determination of the level of free saliva cortisol was carried out in all children by enzyme immunoassay.RESULTS: The average level of free salivary cortisol in the control group was 0.158 [0.088-0.365] micrograms per deciliter (mcg/dL), and 0.740 [0.313-1.024] mcg/dL P<0.001) in the children with manifestations of SARS-CoV-2 infection. Free salivary cortisol level was higher in the patients with moderate and severe course of SARS-CoV-2-infection compared to the mild course (H=27.30, P<0.001). A positive medium correlation was noted between indicators of free salivary cortisol and erythrocyte sedimentation rate (r=0.47, P<0.001), c-reactive protein (r=0.42, P<0.001), glucose level (r=0.49, P<0.001), procalcitonin (r=0.31, P=0.044), duration of hyperthermia (r=0.39, P=0.006) and duration of treatment (r=0.42, P=0.002).CONCLUSIONS: Children with COVID-19 have a higher level of cortisol, which is one of the stress indicators, significantly depended on the course of the disease. Free salivary cortisol level is associated with the severity of the disease and its increase was accompanied by the increase in the number of leukocytes, erythrocyte sedimentation rate, C-reactive protein, procalcitonin, glucose, duration of hyperthermia, and duration of treatment.