Modulation of Blood Pressure and Obesity With the Dopamine D2 Receptor Gene Taq I Polymorphism

Abstract

Abstract-Pharmacological data suggest that obesity and blood pressure (BP) may be modulated through the dopamine D2 receptor (DD2R), which may represent an underlying mechanism that links these conditions. A TaqI polymorphism near the DD2R gene has been associated with indices of obesity in white populations. We compared anthropometric and fasting plasma biochemical parameters between 209 nondiabetic hypertensive and 174 gender-matched normotensive Chinese subjects. The hypertensives had increased dyslipidemia, increased fasting plasma glucose concentrations, and a greater degree of obesity. The A1 and A2 alleles of the DD2R gene TaqI polymorphism were identified with a polymerase chain reaction-based restriction fragment length polymorphism protocol. The A1 allele frequency was decreased in the hypertensives (42.0%) compared with the control subjects (52.0%, Pϭ0.006), and genotype frequencies were different (Pϭ0.05) between the 2 groups. In the combined population (nϭ383), systolic, diastolic, and mean arterial BPs were 6, 5, and 6 mm Hg lower, respectively, in subjects with the A1A1 genotype relative to the A2A2 genotype (all PϽ0.05), whereas skinfold thickness was increased at the iliac (PϽ0.001) and triceps (PϽ0.03) sites but not at the biceps or subscapular sites. Furthermore, this DD2R gene polymorphism was shown to be a significant independent predictor of diastolic BP and iliac and triceps skinfold thicknesses (all PϽ0.03). These contrasting associations of the DD2R TaqI polymorphism A1 allele with lower BP but increased markers of "gynoidal" or peripheral subcutaneous obesity (iliac and triceps skinfold thicknesses) in our Chinese population may provide some insight into the underlying relationship between BP and body fat distribution, but the exact nature of this link remains to be determined. (Hypertension. 2000;36:177-182.)

An affected pedigree member analysis of linkage between the dopamine D2 receptor gene TaqI polymorphism and obesity and hypertension

“…Additionally, Hanson et al [11] found linkage between chromosome 11q and body mass index (BMI) and diabetes mellitus. In a populationbased study, we have previously reported this polymorphism to be associated with both obesity and blood pressure in normoglycaemic Chinese subjects, but in diabetics only the relationship with obesity was evident [12,13]. In this study we report additional data, in a different study group, supporting a relationship between this marker and blood pressure in an affected pedigree member (APM) analysis.…”

Genetic and environmental influences on body fat and blood pressure in African-American adult twins

“…However, these studies have shown mixed results, some have been inconclusive and some have indicated common polymorphisms. [29][30][31][32] For example, a recent study found that peroxisome proliferator-activated receptor gamma 2 polymorphism (Pro12Ala), which is associated with obesity, was also associated with hypertension. 32 Undoubtedly, there will be further studies that consider such common effects and it may be that there are common genes between these phenotypes only under certain contexts.…”

Dopamine, hypertension and obesity

“…Another study in obese patients with polymorphism for this allele (Taq1) showed a gynecoid distribution of body fat, without a considerable deviation in arterial tension values. 48 Although this is not a conclusive study, the development of obesity-coexisting AHT is not discarded, because these are relatively young patients which would not have developed AHT yet.…”