Summary
This cross-sectional study aims to investigate awakening cortisol indicators and to explore their association with stress perception, advanced glycation end products (AGEs), depression and anxiety in parents of children with chronic conditions. We included five parental groups according to children’s diagnoses: Down syndrome (DS; N= 31), autistic spectrum disorder (ASD; N = 29), cerebral palsy (CP; N = 15), diabetes mellitus type 1 (DMT1; N = 38), and a control group of heathy children (CG; N = 33). Salivary cortisol and AGEs were measured, alongside with psychological indices. Partial correlation and multiple linear regression were used in the analysis to identify parental characteristics associated with total awakening cortisol output (area under the curve with respect to the ground, AUCG), cortisol awakening response (area under the curve with respect to the increase, AUCI), perceived stress, and health outcomes (AGEs, depression and anxiety). There was no difference between groups for AUCG, while DS and DMT1 groups showed reduced AUCI (β = –0.241, p = 0.040; β = −0.249, p = 0.028, respectively), and ASD parents had a borderline insignificant result (β = −0.205, p = 0.081). Nonsmokers had higher AUCG, and parental sedentary activity and sleep duration were associated with AUCI. AUCG was positively associated with AGEs (β = 0.218, p = 0.013), anxiety (β = 0.207, p = 0.004), and with depression (β = 0.156, p = 0.034), unlike the AUCI. DS parental group showed lower general stress perception (β = −0.260, p = 0.005). Parents of children with DMT1 had more pronounced depressive symptoms (β = 0.183, p = 0.039), while CP parents had a borderline insignificant result for depression (β = 0.143, p = 0.058). Based on these results, parents of children with chronic conditions have altered awaking cortisol response and are under increased risk of adverse health consequences.

Relevance
This study, along with stress analysis, confirms the connection between physical activity and the cortisol response, which can have different health consequences. This is a very important segment in the prevention and treatment of patients with chronic lung diseases because cortisol is a very important hormone that has a strong connection with numerous chronic diseases and oxidative stress. In this study, the connection between the cortisol response and oxidative stress was found, which also has important implications for the development of chronic pulmonary diseases. Although this study did not include patients with respiratory diseases, it shows that stress factors can be important triggers for the development of pathophysiological mechanisms that lead to the development of chronic diseases.