Body Mass Index and Primary Headache: A Hospital-Based Study in China.

Objective: Primary headache and obesity are highly prevalent disorders in the general population. Although many studies have reported an association between the two, there is still no overall comprehension about this relationship. To gain a more accurate understanding in this regard, we analyzed data from a 2011 cross-sectional study in Chongqing, China.
Methods: Patients with a chief complaint of headache were administered a headache questionnaire and diagnosed by neurology doctors in accordance with the International Classification of Headache Disorders 2nd Edition (ICHD-II) criteria. Patients aged < 18 years or diagnosed with secondary headache were excluded.
Results: Of 1327 patients who cited headache as the chief complaint, 16 were excluded for missing data, while 396 were diagnosed with chronic headache (177 chronic migraine [CM], 186 chronic tension-type headache [CTTH], and 33 other chronic headache) and 915 with episodic headache (369 episodic migraine [EM], 319 episodic tension-type headache [ETTH], and 227 other episodic headache). Chronic headache patients had a higher number of headache days per month, longer duration of headache history, and greater tendency to overuse analgesics than episodic headache patients. The CM and ETTH patients were more apt to be overweight and had a significantly greater body mass index (BMI; p < 0.05) than the EM and CTTH patients. Overweight (odds ratio [OR] = 3.64; 95% confidence interval (CI), 1.19-8.81) and obesity (OR = 28.63; 95% CI, 2.96-276.6) were independently associated with CM but not with other headaches, and this association was not influenced by other factors such as medication overuse.
Conclusions: The relationship between headache and overweight/obesity varies depending on the type of primary headache. CM patients are more likely to have a higher body mass index than EM patients, while ETTH patients are more likely to be overweight/obese than CTTH patients.