Fan J, Shi X, Jia X, et al. - Birth weight is not associated with essential hypertension, but a causal link of childhood obesity with the risk of essential hypertension was found.

• From the meta-analysis of a genome-wide association study, instrumental variables based on single nucleotide polymorphisms (SNPs) linked with birth weight (n = 160,295) and childhood obesity (n = 6,889, 1509 cases and 5380 controls) were found.

• From the UK Biobank essential hypertension consortium, summary level data were extracted (n = 463,010, 54,358 cases and 408,652 controls).

• Two Mendelian randomization analysis methods were employed.

• No increased risk of essential hypertension was observed in relation to genetic predisposition to higher birth weight.

• When using seven SNPs that achieved genome-wide significance, per one standard deviation rise in childhood BMI was significantly related to an elevated risk of essential hypertension (odds ratio = 1.0075).