Plasma glucose levels are increased in patients with migraine with and without aura during spontaneous migraine attacks compared with the interictal state, according to study results published in Headache.
Previously, it was suggested that blood glucose fluctuations may contribute to migraine attacks. While there is evidence that during the interictal phase patients with migraine have impaired insulin sensitivity and higher fasting plasma insulin levels, limited data are available on changes in blood glucose levels during migraine attacks.
The goals of the study were to explore the changes in blood glucose levels during migraine attacks, the correlation between these changes and pain characteristics, and to assess for differences between patients with and without aura.
This sub-study included 31 of 38 patients from a larger study conducted at Rigshospitalet Glostrup, Greater Copenhagen, Denmark. The study cohort included adult patients aged 18 to 65 years with a diagnosis of episodic migraine with and without aura.
Blood samples were drawn during and outside of spontaneous migraine attacks. Plasma glucose values were corrected for diurnal variation of plasma glucose by subtracting the difference between the moving average (intervals of 2 hours) and overall mean from the plasma glucose values. Headache intensity was rated on a verbal rating scale (VRS) from 0 to 10 (0: no pain, 10: worst imaginable pain).
Of the 31 patients (24 women, mean age 39 years), 13 were diagnosed with migraine with and 18 without aura. The mean time from attack onset to blood sample drawing was 7.6±4.3 hours. The mean pain intensity during attacks was 6.0±2.2.
Average blood glucose levels were significantly higher in the ictal phase compared with the interictal phase (89.30±13.71 mg/dL vs 99.52±11.07 mg/dL, respectively; difference of 10.20 mg/dL; 95% CI, 4.50-15.94, P =.001). Following correction for diurnal variation, the average plasma glucose levels were still significantly higher in the ictal phase (88.63±11.70 mg/dL vs 98.83±13.16 mg/dL, respectively; difference of 10.20 mg/dL; 95% CI, 4.30-16.10, P =.0014).
The ictal increase was highest in patients investigated early during attacks and decreased linearly with time from onset of migraine (?1.57 mg/dL/hour from onset of attack with correction for diurnal variation).