New research due to be presented at the American Academy of Neurology's 68th Annual Meeting in Vancouver, Canada, has found that there may be a genetic association between migraines, tension-type headaches and irritable bowel syndrome.
Irritable bowel syndrome (IBS) is a disorder of the digestive system, characterized by abdominal pain and discomfort and changes in bowel movement patterns.
It is estimated that around 25-45 million people in the US have IBS, with the condition being more common among men than women.
The exact cause of IBS is unclear, though researchers have suggested the condition may arise as a result of changes to the way the gut, brain and nervous system communicate.
Additionally, previous research has shown that people with IBS and other gastrointestinal disorders often have more headaches or migraines than those without such disorders. Could the conditions be linked?
This is what study coauthor Dr. Derya Uluduz, of Istanbul University in Turkey, and colleagues set out to establish with their latest study.
Genes in IBS, headache groups differed to those of healthy controls
To reach their findings, the researchers enrolled 107 patients with episodic migraine, 53 patients with episodic tension-type headache (ETTH), 107 patients with IBS and 53 healthy controls.
- Worldwide, between 9-23% of people have IBS
- The majority of people who have IBS are under the age of 50, though the condition can also affect older adults
- Around 2 in 3 people with IBS are female.
The team assessed the patients with IBS for any incidence of migraine and ETTH, while incidence of IBS was assessed among patients with migraine or ETTH.
Compared with patients who had ETTH, those with migraine were almost twice as likely to have IBS; 54.2% of patients with migraine also had IBS, compared with 28.3% of those with ETTH.
Among the patients with IBS, 35.5% also had migraine and 22.4% also had ETTH.
Next, the researchers analyzed presence of the serotonin transporter gene and the serotonin receptor 2A gene among all patient groups and healthy controls.
"In IBS patients with constipation, serotonin secretion in plasma is being decreased," the authors explain. "There is defect in serotonin signaling in IBS and decrease in mucosal serotonin and immune-reactivity of serotonin transporter."
The team found that patients with IBS, migraine or ETTH all had at least one gene that was different to those of the healthy controls, suggesting that the three conditions may share a genetic link.
Commenting on their findings, Dr. Uluduz says:
"Since headache and irritable bowel syndrome are such common conditions, and causes for both are unknown, discovering a possible link that could shed light on shared genetics of the conditions is encouraging.
Further studies are needed to explore this possible link. Discovering shared genes may lead to more future treatment strategies for these chronic conditions."
Last December, Medical News Today reported on a study that suggested low vitamin D levels may be linked to IBS.