Insomnia in tension-type headache: a population-based study

BACKGROUND: Tension-type headache (TTH) represents the most common type of headache among the general population. Although such headaches are usually mild in severity, some individuals with TTH experience severe symptoms and psychiatric comorbidities. Such patients may also experience sleep disturbances, which have been associated with headache exacerbation. Nevertheless, information regarding the prevalence and impact of insomnia among individuals with TTH in a population-based setting is limited. Therefore, the aim of the present study was to evaluate the prevalence and impact of insomnia among individuals with TTH using data from the Korean Headache-Sleep Study (KHSS). METHODS: We analysed data from the KHSS—a nation-wide, cross-sectional, population-based survey on headache and sleep involving Korean adults aged 19 to 69 years. Insomnia was defined as an Insomnia Severity Index score ≥ 10. RESULTS: Among 2695 participants, 570 (21.2%) and 290 (10.8%) were classified as having TTH and insomnia, respectively. Among individuals with TTH, 113 (19.8%) met the criteria for probable migraine (PM). The prevalence of insomnia among individuals with TTH was significantly higher than that among individuals without headache (13.2% vs. 5.8%, p < 0.001). However, among the TTH group, the prevalence of insomnia did not significantly differ between participants fulfilling PM criteria and those not fulfilling PM criteria (14.2% vs. 12.9%, p = 0.725). Among individuals with TTH, headache frequency [median and interquartile range (IQR): 1.0 (0.3–3.0) vs. 0.4 (0.2–1.0), p = 0.002], visual analogue scale scores for headache intensity [median and IQR: 5.0 (4.0–7.0) vs. 4.0 (3.0–6.0), p < 0.001], Headache Impact Test-6 scores [median and IQR: 46.0 (40.0–52.0) vs. 42.0 (38.0–46.0), p < 0.001], anxiety prevalence (28.0% vs. 6.7%, p < 0.001), and depression prevalence (21.3% vs. 1.6%, p < 0.001) were significantly higher in those with insomnia than in those without insomnia. CONCLUSIONS: Our findings indicate that insomnia is prevalent among individuals with TTH. Moreover, insomnia was associated with exacerbation of headache symptoms and psychiatric comorbidities. Therefore, identification of insomnia among individuals with TTH is required to improve the management of headache symptoms in such patients. ELECTRONIC SUPPLEMENTARY MATERIAL: The online version of this article (10.1186/s10194-017-0805-3) contains supplementary material, which is available to authorized users.