Plasma calcitonin gene-related peptide concentration is comparable to control group among migraineurs and tension type headache subjects during inter-ictal period

Calcitonin gene-related peptide (CGRP) is known to increase during acute attack of migraine and tension type headache (TTH). However, its concentration during inter-ictal period is not known. This may help us to understand the pathophysiology of these headaches. The objectives of this study are to find out the concentration of CGRP in plasma during inter-ictal period among migraineurs and TTH and to compare it with control group through cross-sectional study from headache clinic of a tertiary centre. Study sample comprised of three groups: migraineurs, TTH subjects as well as a healthy control group. Fifty subjects in each group were included after screening for the respective inclusion criteria and exclusion criteria. None of the subjects was blood relatives of other subject. Their venous blood was drawn and plasma was separated to be kept at -70A degrees C. CGRP was analysed with commercially available ELISA kit. Data were analysed with the help of SPSS V 11.0 for Windows. Chi-square, independent sample t test and one-way ANOVA with post hoc Tukey and univariate regression were performed. Plasma CGRP concentration was not different among three diagnostic groups (F = 0.78; P = 0.49). Similarly, plasma CGRP concentration was not different among episodic TTH and chronic TTH groups (t = 0.32; P = 0.97) and comparison of episodic and chronic migraine groups also revealed similar results in this study (1.14 vs. 0.94 ng/ml; P = 0.23). The presence of aura did not affect the inter-ictal CGRP levels among migraineurs (F = 0.16; P = 0.85). In conclusion, this study suggests that migraine and TTH could be episodic disorders and subjects have comparable CGRP levels during inter-ictal period.