Abstract
BACKGROUND: Chronotype refers to an individual's preferred timing of activity and rest within a 24-h period, reflecting behavioral manifestations of the endogenous circadian rhythm. Variations in circadian timing may contribute to the temporal characteristics and pathophysiology of tension-type headache (TTH). TTH is the most common primary headache disorder and can have a significant impact on quality of life. While chronotype has been shown to influence pain perception, mood, and sleep quality in various chronic pain conditions, its relationship to TTH remains insufficiently explored. AIM: We aimed to determine the distribution of chronotypes among patients with TTH and to assess their associations with pain characteristics, depression, sleep quality, and quality of life. METHODS: This cross-sectional study involved 77 adult patients diagnosed with TTH according to the International Classification of Headache Disorders (ICHD)-III criteria. Patients were recruited from the neurology outpatient clinic at SANKO University Hospital between June 2021 and June 2022. Data were collected using the Morningness-Eveningness Questionnaire (MEQ), the Visual Analogue Scale (VAS), the Hospital Anxiety and Depression Scale (HADS), the Pittsburgh Sleep Quality Index (PSQI), and the Short Form-36 (SF-36). Chronotypes were categorized as morning, intermediate, or evening. Group differences were analyzed using ANOVA, Kruskal-Wallis and linear regression models. RESULTS: The mean age of the study sample was 29.0 [24.0-35.0] years. Fifty-five participants (71.4%) had an intermediate chronotype, 14 (18.2%) had a morning chronotype, and 8 (10.4%) had an evening chronotype. Those with an evening chronotype had a significantly lower BMI than those with an intermediate chronotype (p = 0.035) and lower scores on the SF-36 Role Limitations due to Physical Problems domain than those with a morning chronotype (p = 0.039). Chronotype (as assessed by the MEQ) was negatively correlated with sleep quality, with evening chronotypes showing poorer PSQI scores. No significant differences were found in VAS (pain intensity) and HADS (depression) scores among chronotypes. Linear regression analyses indicated that chronotype significantly predicted SF-36 Bodily Pain scores, whereas sex significantly predicted VAS pain intensity (p = 0.001). CONCLUSIONS: Evening chronotype is associated with poorer sleep quality and greater role limitations due to physical problemsin patients with TTH, which can potentially exacerbate the disabilities associated with headaches. Tailored interventions targeting chronotype and sleep may improve quality of life in this population.