Objective: The study was designed to investigate the differences in salivary cortisol (hypothalamic-pituitary-adrenocortical [HPA] axis), immunoglobulin A (IgA) (immune system) concentrations and α-amylase (sympathetic nervous system [SNS]) activity between children with chronic tension-type headache (CTTH) and healthy children.
Methods: Thirty-six children, 10 boys and 26 girls (age: 9 ± 2 years) with CTTH and 36 age- and sex-matched healthy children were recruited. Salivary cortisol, α-amylase activity, salivary flow rate, IgA concentration and IgA rate were collected from non-stimulated saliva. A headache diary was used for collecting data on intensity, frequency and duration of headache for four weeks.
Results: Children with CTTH showed lower IgA concentration (p = .008) and IgA rate (p = .039), but not lower cortisol concentration (p = .447), salivary flow rate (p = .289) or α-amylase activity (p = .559), as compared to healthy children. Neither age (p > .582) nor gender (p > .227) influenced salivary markers. A significant association between the number of years with headache and IgA concentration (r(s) = - 0.385; p = .023) was found: the greater the number of years with headache, the lower the IgA concentration.
Conclusions: These results suggest that children with CTTH present with deficits in the immune system, but not dysfunction in the HPA axis or SNS. Future studies are needed to elucidate the direction of these relationships.