G-protein beta-3 subunit gene C825 T polymorphism: influence on plasma sodium and potassium concentrations in essential hypertensive patients.

The C825T polymorphism of the beta-3 subunit of the protein G (GNB3) has been related to an increased activity of the Na+/H+ exchanger (NHE-1) through the synthesis of an anomalous hyperactive protein. Because of the important role of this system in essential hypertension (EH), we analysed the distribution of the different genotypes of this polymorphism in normotensive subjects (NS) and essential hypertensive patients (EHP), their relationship with the condition of salt sensitivity, plasma sodium and potassium concentrations and plasma renin activity (PRA) in EHP. 144 subjects (78 EHP and 76 NS) were studied. Salt sensitivity was assessed by the rapid protocol of Weinberger and genotype determination for GNB3 C825T polymorphism was performed by PCR. The distribution of the different genotypes was similar among EHP (CC 37.2%; CT 41.1%; TT 16.7%) and NS (CC 32.9%; CT 55.3%; TT 11.8%). In regard to general characteristics of EHP (including blood pressure levels) and the condition of salt sensitivity, there were no differences among the different genotypes. Plasma sodium concentration was higher and plasma potassium was lower in TT patients (141.0+/-1.7 and 3.7+/-0.1) than in CC patients (139.1+/-1.9 and 4.0+/-0.3) p<0.05. CT patients had intermediate values (139.9+/-1.9 and 3.9+/-0.2). PRA values were similar in the three genotypes as were the rest of analytical parameters studied. Our data demonstrate an association between the C825T polymorphism of the GNB3 and plasma sodium and potassium concentrations in EHP, as expression of an increase in NHE-1 activity, without modifications in PRA nor relationship with salt sensitivity.

Differences in the prevalence of metabolic syndrome and levels of C-reactive protein after puerperium in women with hypertensive disorders during pregnancy.

To measure high-sensitivity C-reactive protein (hsCRP) levels and to assess the presence of metabolic syndrome (MS) after puerperium in women diagnosed with various hypertensive disorders during pregnancy (HDP), a consecutive, cross-sectional case study at the 15th week after gestation. The sample consisted of 264 women who were admitted to a women's hospital. The diagnoses consisted of transient gestational hypertension (TGH=43.2%), preeclampsia (PC=29.5%), chronic hypertension (CH=20.1%) and PC superimposed on CH (7.2%). A diagnosis of previous hypertension was present in 45.8% of the CH group. The prevalence of MS was 16.7% (CH=42.1%, TGH=13.9%, PC=4.1%, P<0.001). The average hsCRP levels for the CH, TGH and PC groups were 3.79 ± 2.76, 3.55 ± 3.15 and 2.89 ± 3.02, respectively (P=0.040). The levels of hsCRP were higher in women with MS (4.71 ± 3.15 vs. 3.01 ± 2.88 mg l(-1) in those without MS, P<0.001), and they increased when a higher number of MS criteria was fulfilled (P<0.001). The results demonstrated a positive correlation between hsCRP levels and body mass index (BMI) (r=0.46), waist circumference (r=0.50) or the number of fulfilled MS criteria (r=0.56). The results suggest differences in vascular risk that depend on the type of HDP and on the prevalence of MS. The prevalence of MS was notably higher in the CH group, intermediate among the TGH group and much lower in the PC group. Differences in hsCRP levels also depended on the type of HDP (higher levels in CH and TGH patients in comparison with PC patients). Women with MS had higher hsCRP levels compared with women without MS, and the levels correlated with the number of MS criteria fulfilled. This result suggests that subclinical inflammatory status is correlated with the number of MS components present. Furthermore, hsCRP levels increased with increasing BMIs and waist circumferences.