Objective: Cytokines are pain mediators in neurovascular inflammation. This study examined interleukin 6 (IL-6) levels in the serum of tension-type headache (TTH) patients, to determine if inflammation plays a role in the pathogenesis of this condition.
Methods: Serum IL-6 levels were studied in 42 patients and 37 healthy controls from the same region. Of the patients, 20 (47.6%) experiencing TTH less than 15 days per month were placed in episodic tension-type headache (ETTH) group, and 22 (52.3%) with TTH more than 15 days per month were placed in chronic tension-type headache (CTTH) group.
Results: The IL-6 level was significantly higher in the patients than in the controls. The IL-6 level of CTTH patients was higher than the controls (P<0.01). The IL-6 level was similar between ETTH and CTTH patients. Correlation analysis revealed a positive relationship only between age and IL-6 level in the patients.
Conclusions: CTTH and ETTH patients had an elevated serum IL-6 level compared with controls. Therefore, we believe that IL-6 may be involved in pain induction or inflammatory mechanisms in TTH. Furthermore studies of the possible connection between chronicity of headaches and cytokine levels are needed.