Modulation of blood pressure and obesity with the dopamine D2 receptor gene TaqI polymorphism

Pharmacological data suggest that obesity and blood pressure (BP) may be mo dulated through the dopamine D2 receptor (DD2R), which may represent an und erlying 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 betw een 209 nondiabetic hypertensive and 174 gender-matched normotensive Chines e subjects. The hyperintensives had increased dyslipidemia, increased fasti ng plasma glucose concentrations, and a greater degree of obesity. The A1 a nd A2 alleles of the DD2R gene TaqI polymorphism were identified with a pol ymerase chain reaction-based restriction fragment length polymorphism proto col. The Al allele frequency was decreased in the hypertensives (42.0%) com pared with the control subjects (52.0%, P=0.006), and genotype frequencies were different (P=0.05) between the 2 groups. In the combined population (n =383), systolic, diastolic, and mean arterial BPs were 6, 5, and 6 mm Hg lo wer, respectively, in subjects with the A1A1 genotype relative to the A2A2 genotype (all P<0.05), whereas skinfold thickness was increased at the ilia c (P<0.001) and triceps (P<0.03) sites but not at the biceps or subscapular sites. Furthermore, this DD2R gene polymorphism was shown to be a signific ant independent predictor of diastolic BP and iliac and triceps skinfold th icknesses (all P<0.03). These contrasting associations of the DD2R TaqI pol ymorphism A1 allele with lower BP but increased markers of "gynoidal" or pe ripheral subcutaneous obesity (iliac and triceps skinfold thicknesses) in o ur Chinese population may provide some insight into the underlying relation ship between BP and body fat distribution, but the exact nature of this lin k remains to be determined.