Migraine and restless legs syndrome are associated in adults under age fifty but not in adults over fifty: a population-based study

BACKGROUND: Recent studies have shown an association between migraine and restless legs syndrome (RLS). However, migraine prevalence peaks from the 20s to 40s whereas RLS prevalence peaks after the 50s. Despite this, reports on how migraine and RLS may be associated by age is limited. Therefore, the purpose of this study is to investigate the comorbidity between migraine and RLS according to age. METHODS: We selected a stratified random population sample of Koreans aged 19 to 69 years and evaluated them with a 60-item semi-structured interview designed to identify RLS, headache type, and clinical characteristics of migraine. To assess the association between migraine and RLS according to age, we divided participants into 5 age groups (19–29, 30–39, 40–49, 50–59, and 60–69 years) and analysed each group. RESULTS: Subjects with migraine showed an increased RLS prevalence in the 19–29 (Odds ratio [OR] = 6.6, 95 % confidence interval [CI] = 1.2–36.8) and 40–49 (OR = 6.7, 95 % CI = 1.5–33.5) age groups compared to non-headache controls but failed to showed a significant association in the 50–59 (OR = 1.1, 95 % CI = 0.2–5.6) and 60–69 (OR = 0.4, 95 % CI = 0.1–4.0) age groups. Migraineurs with 1–10 (12.5 %, OR = 2.0, 95 % CI = 1.3–3.2, p = 0.003) and >10 (12.5 %, OR = 2.5, 95 % CI = 1.0–5.6, p = 0.038) attacks per month showed an increased RLS prevalence compared to migraineurs with <1 attack per month (2.1 %). Subjects with non-migraine headaches showed an increased odds for RLS (OR = 1.8, 95 % CI = 1.3–2.7) compared to non-headache controls. There was no significant difference (9.1 % vs. 6.9 %, p = 0.339) in the RLS prevalence between migraineurs and non-migraine headache subjects. CONCLUSIONS: Our results suggest that migraine and RLS are differently associated according to age. ELECTRONIC SUPPLEMENTARY MATERIAL: The online version of this article (doi:10.1186/s10194-015-0554-0) contains supplementary material, which is available to authorized users.