When Obesity Becomes a HeadacheTuesday, March 3, 2009
There is now ample evidence to suggest that headaches are more common in people with overweight and obesity than in people with normal weight.
Thus, for example in a recent paper by Winter and colleagues from the University of Münster, Germany, published in Cephalalgia, reporting on a cross-sectional study of over 63,000 women, a BMI greater than 35 was associated with a 3-fold increased risk of daily migraine as well as increased risk of phonophobia and photophobia but decreased risk of a unilateral pain and aura.
These findings on obesity and headaches were recently extended to kids, in a paper just published in Headache, Andrew Hershey and colleagues on behalf of the American Headache Society Pediatric Adolescent Section. These investigators reported data in 913 consecutive kids seen at 7 pediatric headache centers in the US. While the prevalence of overweight at initial visit did not significantly differ from the general pediatric population, the higher the BMI percentile, the greater the headache frequency and associated disability. Furthermore, any increase in BMI at 3- and 6-month follow-up was significantly correlated with a further increase in headache frequency.
While the exact reasons for the link between obesity and headaches remains unclear, Marcelo Bigal and colleagues from Albert Einstein College of Medicine, Bronx, NY, USA have previously reviewed some of the putative mechanisms in an article published in Neurology. Firstly, several of the inflammatory mediators that are increased in obese individuals are important in migraine pathophysiology, including interleukins and calcitonin gene-related peptide (CGRP). Obesity is also a state of sympathetic activation, which may contribute to increase in headache frequency. Orexins modulate both pain and metabolism and dysfunction in the orexins pathways appears to be a risk factor for both conditions. Finally, conditions that are comorbid to both states (e.g., depression, sleep apnea) may also promote headaches.
Whatever the exact mechanism, clinicians should be aware of the relationship between headaches and excess weight. Whether headaches promote obesity (i.e. treatment of headaches will prevent obesity) or whether obesity promotes headaches (i.e. treatment of obesity will reduce headaches) remains to be seen.