VARIATIONS IN THE PERCEPTION OF BITTER TASTE MAY MODULATE THE RISK OF HYPERTENSION

Abstract

Objective: The perception of bitter taste conditioned by the TAS2R38 gene (combined Proline/Alanine/Valine and Isoleucine phenotypes) may be associated with food consumption. Individuals with one copy of PAV are bitter tasters, with two copies of AVI are non-bitter tasters, and with AAV < AAI < PAI are intermediate bitter tasters. Consumption salt balance is determined by the function of the epithelial sodium channels that lead to its preference and the bitter taste receptors associated with its aversion. In turn, a chronic high salt intake was associated with the inhibition of bitter receptors with less salty taste aversion leading to potential higher consumption and risk of hypertension. The objective was to evaluate the influence of bitter taste perception on the risk of arterial hypertension. Design and method: DNA from 339 individuals was quantified and genotyped by reverse transcription followed by polymerase chain reaction (RT-PCR). Blood pressure was determined by standard methods. Arterial hypertension was diagnosed in 141 individuals who were compared with 198 normotensive individuals. Thyroid functional status is determined by clinical history, physical examination, FT4, FT3, TSH, antiperoxidase, antithyroglobulin, and TRAB antibodies. Hypothyroidism at 33.3%, hyperthyroidism 14.3% and euthyroidism 52.35%. Statistics: chi2 and t-Student, considering significance <0.05. Results: The frequencies of the TAS2R38 diplotypes were: PVI/PVI (26%); PVV/PVI (0.9%); PVV/AVI(10.6%); PVV/AVV(0.9%); AVV/AVV(2.4%); PAI/PVI(0.3%); PAV/PVI(5.95%); PAV/AVI(37.5%); AAV/AAV(12.7%); PAV/AAV(2.75%) and PAV/AAI(0.3%). The TAS2R38 AAV/AAV and PAV/AAV diplotypes showed a lower risk of hypertension adjusted for thyroid dysfunction, compared to the remaining diplotypes of this gene, with OR = 0.458[0.236-0.887], p = 0.021. Other diplotypes showed no significant association. Conclusions: Individuals with bitter tasting associated with AAV genotypes may be less likely to develop hypertension compared to other bitter tasters. The lower risk of hypertension in these genotypes may be associated with greater functionality of bitter taste receptors associated with aversion to salt intake. In conclusion, the genetic polymorphisms of the bitter taste gene may influence the risk for arterial hypertension and may therefore be considered potential future therapeutic targets. The absence of bitter-insensitive individuals (AVI/AVI) in this sample limits the understanding of the influence of these genotypes on the risk of hypertension.