Migraine and obesity.

Obesity is an epidemic problem seen in many people with and without migraine. How are obesity and migraine linked, and what are the risk factors for migraineurs battling the bulge? First, a definition of obesity is needed. Typically, obesity is defined as a body mass index (BMI) of 30 or more. BMI calculators are available online or as apps on smart phones, but if calculation is desired, this is the formula: Weight in pounds/(inches height)(inches height) ¥ 703. There is more cardiovascular risk and diabetes risk associated with abdominal obesity, that is, fat around the belly. Because of this fact, it may be useful to define obesity in terms of abdominal obesity as well as total body obesity. Abdominal obesity is defined by waist circumference greater than 40 inches in men or greater than 35 inches in women or waist to hip ratio greater than 0.9 for men and greater than 0.85 for women. Migraine that occurs more than 15 days per month at least 4 hours per day is considered chronic migraine. Why is it that those who have migraines just a few days per month often slowly progress to a chronic pattern? There are a number of possible reasons for this increase, some that can be changed, and others that cannot. Using acute pain medicines too frequently is a common reason for transformation to daily headache, but others include too much caffeine, snoring, and sleep apnea, thyroid disorders, head trauma, stress, depression, and anxiety, but for the purposes of this toolbox, we will be looking at obesity as a risk for chronic migraine. Normal weight people with migraine have about a 3% chance of developing chronic headaches in a year. If they are overweight, they have 3 times that chance. With obesity, the chance of chronic migraine is 5 times that of a normal weight individual with migraine. Obesity is an inflammatory state in which multiple pain-generating hormones are produced and released from fat cells, including calcitonin gene-related peptide, substance P, tumor necrosis factor-a, and interleukin-6. During a migraine, there is a similar release of these same pain-promoting hormones and neurochemicals. It may be that there is an additive effect coming from the 2 sources of these chemicals, obesity and migraine, that predisposes obese individuals with migraine to have more headaches. Levels of insulin, glucose, and plaque promoting LDL cholesterol are higher in migraine patients than the general population. This is also true of obese individuals, which may in part contribute to the higher risk of heart and stroke in migraineurs. Coupled with the elevated glucose and insulin in obese and prediabetic individuals, there is again an additive effect. Obesity has not been found to cause migraines, only to promote their frequency. But with high-frequency migraine, an individual begins to have problems keeping up with work, social and family activities, as well as feeling awful. Clearly, no one wants to be obese, and no one wants to have a lot of migraines, so how can one turn this around? Headache: The Journal of Head and Face Pain © 2013 American Headache Society Published by John Wiley & Sons, Inc. doi: 10.1111/head.12080