METHODS: Patients (n=605, mean age 56.2±9.4years, 82.3% male) with arterial hypertension and cardiac ejection fraction (EF) ≥40% were studied. Cardiac parameters were assessed by echocardiography.
RESULTS: The cohort comprised subjects with coronary heart disease (73.1%) and myocardial infarction (48.1%) with a mean EF of 63.7±8.9%. Analysis of SNPs rs10830962, rs4753426, rs12804291, rs10830963, and rs3781638 revealed two haplotypes 1 and 2 with frequencies of 0.402 and 0.277, respectively. Carriers with haplotype 1 (CTCCC) showed compared to non-carriers a higher mean 24-hour systolic BP (difference BP: 2.4mmHg, 95% confidence interval (CI): 0.3 to 4.5mmHg, p=0.023). Haplotype 2 (GCCGA) was significantly related to EF with an absolute increase of 1.8% (CI: 0.45 to 3.14%) in carriers versus non-carriers (p=0.009).
CONCLUSIONS: Genetics of MTNR1B point to impact of the melatonin signalling pathway for BP and left ventricular function. This may support the importance of the melatonin system as a potential therapeutic target.