Chronic migraine and chronic tension-type headache are associated with concomitant low back pain: Results of the German Headache Consortium study

The objective of this study was to evaluate the association between low and frequent low back pain and chronic migraine (CM) and chronic tension-type headache (CTTH) in a large, German population-based sample. Headaches were diagnosed according to International Classification of Headache Disorders-2 criteria and categorized according to frequency (episodic 1-14 days/month or chronic ⩽15 days/month) and headache type (migraine or TTH). We defined frequent low back pain as self-reported low back pain on ⩾15 days/month. We calculated odds ratios and 95% confidence intervals (CI) using logistic regression analyses, adjusting for sociodemographic covariates. There were 5605 respondents who reported headache in the previous year, of whom 255 (4.5%) had Chronic Headache. Migraine was diagnosed in 2933 respondents, of whom 182 (6.2%) had CM. TTH was diagnosed in 1253 respondents, of whom 50 (4.0%) had CTTH. Among 9944 respondents, 6030 reported low back pain, of whom 1267 (21.0%) reported frequent low back pain. In adjusted models, the odds of having frequent low back pain were between 2.1 (95% CI 1.7-2.6) and 2.7 (95% CI 2.3-3.2) times higher in all episodic headache subtypes when compared to No Headache. The odds of having frequent low back pain were between 13.7 (95% CI 7.4-25.3) and 18.3 (95% CI 11.9-28.0) times higher in all chronic headache subtypes when compared to No Headache. Low and frequent low back pain was associated with CM and CTTH. Multiple explanations may contribute to the association of headache and back pain, including the notion that the neurobiology of chronic headache, independent of primary headache type, not only involves the trigeminal pain pathway, but is also a part of abnormal general pain processing.