Chronic headache and body mass index: a case-control study.

In recent years clinical research has focused on the possible role played by obesity as a risk factor for headache chronification.The aim of this case-control, hospital-based study was to evaluate: the prevalence of overweight and obesity in subjects with chronic migraine (CM) and chronic tension-type headache (CTTH); and the possible correlations between body mass index (BMI) and both headache types. Materials and methods: We studied 79 patients, 46 with CM and 33 with CTTH, consecutively referred to the Adult Headache Centre of the University of Palermo (A.H. Study) between 2007 and 2009, and 316 controls without headache (each patient was matched by sex and age to four controls).The headache diagnosis was established according to the ICHD-II criteria. BMI classes were defined according to WHO guidelines. Results:Mean age was 47.6 years (±17.8 yrs) for the 79 patients with chronic headache (66 F, 13 M) and 47.6 years (±17.8 yrs) for the 316 controls (264 F, 52 M). The BMI status did not differ between groups (mean BMI was 27.7±4.8 in chronic headache patients and 27.3±5.1 in controls). In the chronic headache group, 32.9% were obese, 40.5% pre-obese and 26.6% overweight. In the control group, 26.0 % were obese, 40.3% pre-obese and 33.7% overweight. Following multiple logistic regression analysis, the presence of obesity and pre-obesity was not associated with chronic headache (obesity: OR=1.4, 95% CI 0.7-2.9; pre-obesity: OR=1.6, 95% CI 0.5-2.2). Conclusion: Our data suggest that BMI abnormalities are not associated with CDH. However, considering previous reports of an association of obesity and migraine in population-based studies, we cannot exclude a selection bias