Sydney, Feb 24 (IANS): Australian researchers have identified a concrete genetic link between migraine and blood sugar levels.

According to Queensland University of Technology (QUT) researchers, the co-occurrence of migraine and glycemic (blood sugar levels) traits had been reported in observational epidemiological studies but it was unknown how they were genetically linked.

"About 15 per cent of the global population is affected by migraine, and as far back as 1935, migraine was described as a 'glycemic headache'," said Professor Dale Nyholt, from the QUT Center for Genomics and Personalized Health.

"Glycemic traits such as insulin resistance, hyperinsulinemia (too much insulin), hypoglycemia (low blood sugar level) and Type 2 diabetes are associated with migraine and headache.

"By identifying genetic correlations and shared loci and genes in our analyses we have inferred causal association and thus confirmed and improved understanding of the relationship between migraine, headache and glycemic traits."

In the paper, published in the journal Human Genetics, the researchers analysed the genomes of thousands of migraine patients to determine genetic links. They performed cross-trait analyses to identify shared genomic regions, loci, genes and pathways, then tested for casual relationships.

"Out of the nine glycemic traits we looked at, we found a significant genetic correlation for fasting insulin (blood insulin level) and glycated haemoglobin with both migraine and headache, while two-hour glucose was genetically correlated only with migraine," said QUT researcher Rafiqul Islam.

"We also found regions harbouring genetic risk factors shared between migraine and fasting insulin, fasting glucose, and glycated haemoglobin, and for headache, shared regions with glucose, fasting insulin, glycated haemoglobin, and fasting proinsulin.

"Further analyses produced evidence for a causal relationship between migraine and headache with multiple glycemic traits."

The researchers stated that the findings provide avenues to develop novel treatment strategies for managing glycemic traits in migraine and headache patients, particularly increasing fasting proinsulin level to protect against headache.