Primary headache disorders susceptibility is associated with fasting-related headache: evidence from a multinational study across 14 countries

Abstract

Background Fasting-related headache has traditionally been attributed to dehydration, caffeine withdrawal, and sleep disruption, but pre-existing primary headache disorders may also play an important role in determining susceptibility.Objectives To determine the prevalence, clinical characteristics, and predictors of headache during Ramadan fasting and to explore the relative contribution of pre-existing primary headache disorders and the lifestyle-related factors assessed in this study to headache occurrence during fasting.Methods In this multinational cross-sectional survey across 14 countries, adults (18-65 years) observing Ramadan fasting completed a 17-item questionnaire. Headache during Ramadan was the primary outcome. Classification and regression tree (CRT) modelling were used to identify predictors and characterize fasting related headache.Results Headache attacks occurred mainly in the afternoon/pre-iftar period and improved after iftar in 54.6% of cases. Pre-existing primary headache disorders, particularly migraine, were more strongly associated with headache occurrence within the exploratory CRT model than the lifestyle variables assessed in this study.Conclusion Fasting-related headache is highly prevalent and is influenced by both lifestyle-related factors and underlying headache susceptibility. A history of primary headache disorders was strongly associated with headache occurrence during Ramadan fasting, highlighting the importance of considering individual headache history alongside fasting- related exposures when assessing vulnerability.