Increased risk of sleep apnoea among primary headache disorders: a nationwide population-based longitudinal study.

<bold>Background: </bold>Primary headache disorders (PHDs) are associated with sleep problems. It is suggested that headache and sleep disorder share anatomical and physiological characteristics. We hypothesised that patients with PHDs were exposed to a great risk for developing sleep apnoea (SA).<bold>Methods: </bold>In this retrospective longitudinal study, the data obtained from the Longitudinal Health Insurance Database in Taiwan were analysed. The study included 1346 patients with PHDs who were initially diagnosed and 5348 patients who were randomly selected and age/sex matched with the study group as controls. PHDs, SA, comorbidities and other confounding factors were defined based on International Classification of Diseases, Ninth Revision, Clinical Modification. Cox proportional hazards regressions were employed to examine adjusted HRs after adjusting with confounding factors.<bold>Results: </bold>Our data revealed that patients with PHDs had a higher risk (HR 2.17, 95% CI 1.259 to 3.739, p<0.05) to develop SA compared with matched cohorts, whereas patients with migraine exhibited a high risk (HR 2.553, 95% CI 1.460 to 4.395, p<0.01). The results showed that patients with PHDs aged 18-44 exhibited highest risk of developing SA. In addition, males with PHDs exhibited an HR 3.159 (95% CI 1.479 to 6.749, p<0.01) for developing SA, respectively. The impact of PHDs on SA risk was progressively increased by various follow-up time intervals.<bold>Conclusion: </bold>Our results suggest that PHDs are linked to an increased risk for SA with sex-dependent and time-dependent characteristics. [ABSTRACT FROM AUTHOR]