Abstract
BACKGROUND: Monoamine oxidase (MAO) activity has been traditionally implicated in blood pressure through its effects on biogenic amine levels such as catecholamines, serotonin, and dopamine. Nowadays, this role is considered relegated to side-effects such as orthostatic hypotension and/or hypertensive crisis derived from MAO-inhibitory treatments in patients with psychiatric disease. METHODS: In the present work we have found an association between a polymorphic variant of MAOB gene and arterial hypertension in obese hypogonadic patients. The study cases comprised a series of 219 nondiabetic males with a body mass index ≥30 kg/m(2) and aged <45 years. Hypogonadism was defined as subnormal testosterone concentrations, when free testosterone values ranged <65 pg/ml. RESULTS: MAOB rs3027452-A allele carriers were significantly over-represented among hypertensive (HT) patients (25.49%) in comparison to either the non-HT patients (10%, OR = 3.079 CI(95) [1.364-6.952], p = .005, Chi-square test) and the control population series of nonobese nor hypogonadic males (also 10%, p = .003 Chi-square test). Upon adjusted, an independent association was shown with the hypogonadic group with hypertension when compared with nonhypertensive hypogonadics (Beta = 3.653, p = .005). When quantitative analysis was performed, hypertensive patients harboring rs3027452-A allele showed higher systolic blood pressure values (p = .038, Mann-Whitney U-test) as well as an increased Systolic-Diastolic range despite following HT treatment (∆mmHg 54 vs. 48 for rs3027452-A and rs3027452-G respectively, p-value .019, Mann-Whitney U-test). Previous studies on MAOB revealed that rs3027452-A allele has been correlated to a lower activity of the enzyme, what gives a functional evidence over our observation. CONCLUSION: If this result could be extrapolated to other hypertensive patient groups, it would implicate a review of the markers and therapeutic targets on human hypertension.