Genetic variation in CYP11B2 and AT1R influences heart rate variability conditional on sodium excretion.

Sympathetic tone increases with stimulation of the renin-angiotensin system and is under the influence of salt intake. In the European Project On Genes in Hypertension (EPOGH), we investigated whether polymorphisms in the genes encoding aldosterone synthase (CYP11B2 C-344T) and the type-1 angiotensin II receptor (AT1R A1166C) affect the autonomic modulation of heart rate at varying levels of salt intake. We measured the low frequency (LF) and high frequency (HF) components of heart rate variability and their ratio (LF:HF) in the supine and standing positions in 1797 participants (401 families and 320 unrelated subjects) randomly selected from 6 European populations, whose average urinary sodium excretion ranged from 163 to 245 mmol/d.

Angiotensinogen promoter haplotypes are associated with blood pressure in untreated hypertensives.

Background: The polymorphic angiotensinogen (AGT) gene is one of the most promising candidates for blood pressure (BP) regulation and essential hypertension.

Objectives: To investigate whether AGT haplotype analysis adds significant information compared to single polymorphism analysis with respect to different BP phenotypes in an untreated hypertensive sample.

Methods: Two hundred and twelve untreated hypertensive subjects of Caucasian origin were genotyped for the AGT polymorphisms C-532T, A-20C, C-18T, and G-6A.