Is daily headache related to asthma? Results from a population-based survey

Objective: Despite the high worldwide prevalence of asthma and headache, little is known about the association between these conditions. The objective of our study was to evaluate the association between asthma and daily headache in a representative sample of the general population of South Korea. Methods: We retrospectively analyzed 7984 individuals included in the Second Korean National Health and Nutrition Examination Survey (KNHANES II), a prospectively administered survey performed in 2001 by a government organization within the Ministry of Health and Welfare. After adjustment of risk factors for daily headache, multivariate logistic regression analysis was performed to evaluate the association between asthma and daily headache. Results: Of 7984 individuals, 69 (0.9%) had daily headache and 429 (5.4%) had asthma symptoms. Daily headache was significantly more prevalent in subjects with asthma symptoms (14/429, 3.3%) than in those without (55/7555, 0.7%; p<0.001). Of the 4833 nonsmokers, 46 (1.0%) had daily headache and 287 (5.9%) had asthma symptoms, with daily headache being significantly more prevalent in subjects with asthma symptoms (11/231, 4.8%) than in those without (35/4602, 0.8%; p<0.001). Multivariate logistic regression showed that the odds ratios for daily headache were 2.3 (95% CI: 1.21-4.33, p=0.01) in all individuals with asthma symptoms and 3.4 (95% CI: 1.65-7.12, p=0.001) in nonsmokers with asthma symptoms. Conclusion: Individuals with asthma symptoms are at higher risk of daily headache than those without the symptoms, suggesting a link between these conditions.