Table 3.

Bi-directional instrumental estimates between migraine and blood pressure using GSMR.

Exposure	Outcome	Covariates	Direction	Instrumental estimatesa	se	P-Bonferroni
DBP	Any migraine	—	Forward	0.18	0.02	5.01 × 10−24
			Reverse	−0.11	0.07	0.45
	MA	—	Forward	0.12	0.05	0.18
			Reverseb
	MO	—	Forward	0.29	0.05	1.24 × 10−09
			Reverseb
SBP	Any migraine	—	Forward	0.05	0.01	2.34 × 10−06
			Reverse	−0.97	0.15	1.01 × 10−10
	MA	—	Forward	0.04	0.03	1.00
			Reverseb
	MO	—	Forward	0.06	0.03	0.36
			Reverseb
PP	Any migraine	—	Forward	−0.09	0.02	3.29 × 10−06
			Reverse	−0.79	0.10	3.21 × 10−15
	MA	—	Forward	−0.06	0.05	1.00
			Reverseb
	MO	—	Forward	−0.15	0.05	5.80 × 10−03
			Reverseb
Conditional GSMRc
DBP	Any migraine	SBP	Forward	0.32	0.03	4.16 × 10−37
SBP	Any migraine	DBP	Forward	−0.15	0.02	2.08 × 10−22

GSMR Generalized summary-data-based Mendelian randomization, se standard error, DBP diastolic blood pressure, SBP systolic blood pressure, PP pulse pressure, MA migraine with aura, MO migraine without aura.

P-values are based on two-sided Wald test and used Bonferroni correction.

^aThe instrumental estimate is corresponding to 10 mmHg increment of blood pressure for the forward direction.

^bToo few instruments to conduct reverse GSMR for migraine with aura and without aura (number of genome-wide significant index SNPs <10).

^cConditional GSMR was performed by conditioning the exposure on the corresponding covariates (using mtCOJO, https://cnsgenomics.com/software/gcta/#mtCOJO and then using the conditioned summary statistics to infer the instrumental estimates from the exposure to the outcome.