For neurologist Lee Peterlin, migraines run in the family. She and her sister, Jackie, both suffer from migraine headaches that have been, at times, completely debilitating. That’s one reason why, several years ago, she started looking into why they and 30 million other Americans suffer from a neurological disorder whose cause, at least in part, remains a mystery despite the wealth of potential research subjects.
One thing researchers have long known, however, is that migraine sufferers—or migraineurs—are significantly more likely to be women of reproductive age. After puberty, body fat makes a significant jump in this population. Could body composition play a role in whether patients develop migraines?
Inspired by this kernel of knowledge, Peterlin searched the literature for previous research linking migraine with obesity. She turned up several promising studies, including research connecting obesity to a five times greater chance of developing chronic migraines and an increase in headaches in migraineurs who were sedentary, a potent risk factor for weight gain.
Both obesity and being underweight are associated with an increased risk for migraine, according to a meta-analysis published in the April 12, 2017, online issue of Neurology®, the medical journal of the American Academy of Neurology. The researchers looked at all available studies on body mass index (BMI) and migraine.
“As obesity and being underweight are potentially modifiable risk factors for migraine, awareness of these risk factors is vital for both people with migraine and doctors,” said study author B. Lee Peterlin, DO, of Johns Hopkins University School of Medicine and a member of the American Academy of Neurology. “More research is needed to determine whether efforts to help people lose or gain weight could lower their risk for migraine.”
A total of 12 studies with 288,981 participants were included in the meta-analysis. When the researchers compiled all of the results and adjusted for age and sex, they found that obese people were 27 percent more likely to have migraine than people of normal weight. People who were underweight were 13 percent more likely to have migraine than people of normal weight.
Besides seeing headache patients in the clinic, Peterlin says, she decided to focus her research on proteins that provide a link between obesity and migraine. Those include adiponectin and leptin, proteins secreted by adipose tissue that modulate immune and inflammatory components such as interleukin-6, tumor necrosis factor-alpha and nuclear factor kappa beta. Previous studies have shown that each of these compounds changes in concentration in those with either migraine or obesity.
“With several adipokines, and in particular with leptin and adiponectin,” Peterlin explains, “you have proteins that change several factors that we know are abnormal with both conditions. It’s a natural starting point in trying to understand what connects migraines and obesity.”
In another small pilot study earlier that was published in 2008, Peterlin and her colleagues evaluated adiponectin blood concentrations among episodic and chronic migraineurs and controls. They found significantly elevated levels in chronic migraineurs and a trend toward elevation in those with episodic migraine, suggesting that this fat tissue-associated protein may indeed play a role in migraines.
Peterlin has since focused her work on further examining the link between migraine and adipokines, as well as other pro-inflammatory compounds also linked with obesity. Knowing that these proteins are all associated with adipose tissue, she and her colleagues are also exploring whether the placement of fat—superficial or deep—might also play a role in migraines.
These investigations aren’t simply a matter of curiosity, Peterlin says. Understanding how obesity and migraine are linked could give physicians new tools to treat migraines, a problem that remains frustratingly intractable for some patients despite many different treatment options. Unlike some other conditions associated with migraine, such as stroke, she explains that obese patients can play an important role in their own treatment.
“Through diet, exercise and possibly even other interventions, such as bariatric surgery if indicated,” Peterlin says, “patients can actively participate in their own care to address obesity. Weight loss is a non-pharmacogenic ‘pill’ that’s been found to be medically sound and cost-effective for numerous other disorders. The headache community is showing that weight loss might play a helping role in migraines as well.”
Finding the connections between obesity and migraines may also help doctors better treat migraines using more traditional methods, like tricyclic antidepressants. Although they are a treatment of choice for many migraine sufferers, says Peterlin, some drugs in this class, such as nortriptyline and amitriptyline, can lead to weight gain—a problem for patients who are already overweight or obese. Another tricyclic antidepressant, protriptyline, has the opposite effect.
“If a patient is already in the weight danger zone,” Peterlin says, “that drug might be the better choice. Based on our research, taking body status into consideration should be an important factor in which drugs a physician prescribes.”
Peterlin points out that she and her colleagues have already made many important discoveries, but developing the full picture connecting obesity and migraine will take time.
“We know now that fat is more than just a storage depot,” she says. “Eventually, we’ll know just what part it plays in causing migraines.”
Obesity was defined as a BMI of 30 or higher. Underweight was defined as a BMI of less than 18.5.
The body mass index (BMI) or Quetelet index is a value derived from the mass (weight) and height of an individual. The BMI is defined as the body mass divided by the square of the body height, and is universally expressed in units of kg/m2, resulting from mass in kilograms and height in metres.
The BMI may also be determined using a table or chart which displays BMI as a function of mass and height using contour lines or colours for different BMI categories, and which may use other units of measurement (converted to metric units for the calculation).
Peterlin said the risk between obesity and migraine was moderate and similar in size to the link between migraine and bipolar disorders and ischemic heart disease, a condition of recurring chest pain or discomfort when part of the heart does not receive enough blood.
Credit : Johns Hopkins University School of Medicine and a member of the American Academy of Neurology