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.

[Glucose effectiveness and components of the metabolic syndrome in recently diagnosed hypertensive patients]. / Efectividad de la glucosa y componentes del síndrome metabólico en pacientes con hipertensión arterial esencial de diagnóstico reciente.

BACKGROUND: Glucose effectiveness (SG) is a parameter that indicates the glucose ability to clearing itself from the plasma independently of insulin's action. Our purpose was to analyze the cluster characteristics associated with the metabolic syndrome in a group of non-obese, recent-onset hypertensives and to test if there was a correlation with SG and the effectiveness of glucose at basal insulin point (GEZI). PATIENTS AND METHOD: We studied 36 patients with mild hypertension with normal basal glucose levels. We determined plasma lipid subfractions, apolipoproteins and urate levels. An intravenous glucose tolerance test (TTGI) and minimal model analysis according to Bergman was performed and SG, GEZI and insulin sensitivity (SI) were calculated. RESULTS: Patients with lower SG and GEZI had higher levels of total triglycerides (Tg) (r = 0.42; p = 0.01 and r = 0.48; p = 0.002, respectively) and triglycerides bind to VLDL (Tg-VLDL) (r = 0.40; p < 0.01 and r = 0.49; p = 0.002, respectively). When the cluster of metabolic syndrome was analyzed, SG was inversely related to uric acid levels and to the waist-hip index. However, SI was only related to the uric acid levels (r = 0.38; p = 0.01). CONCLUSIONS: In non-obese, recently diagnosed hypertensive patients, the SG parameter seems to be an early marker for the development of metabolic syndrome.

[Clinical and biological characteristics of a group of 54 pregnant women with HELLP syndrome]. / Características clinicobiológicas de un grupo de 54 gestantes con síndrome HELLP.

BACKGROUND AND OBJECTIVE: The HELLP syndrome is a rare form of preeclampsia with a variable presentation with substantial maternal and perinatal morbidity and mortality. The aim of this study was to determine its clinical and biological characteristics in our hospital. PATIENTS AND METHOD: An observational study of all cases of confirmed HELLP syndrome from 1999 to 2002 was carried out. RESULTS: There were 54 cases of HELLP syndrome. Mean maternal age was 30.06 (16-41) years. 57.4% were primiparous. Mean gestational age at diagnosis of HELLP syndrome was 31.75 (20-41) weeks. Symptoms and signs were dominated by the digestive ones. Hypertension was observed in all cases. 77.8% pregnancies were delivered by caesarean section. Mean birth weight was 1674.52 g (150-3800 g). There were 12 perinatal deaths and one maternal death. CONCLUSIONS: HELLP syndrome is an uncommon but potentially serious complication of pregnancy which is associated with an increased risk of adverse maternal and fetal outcomes. Management should be multidisciplinary and based on strict control by maternal and fetal symptoms.

Abnormal levels of antioxidant defenses in a large sample of patients with hypertensive disorders of pregnancy.

Increased levels of oxidative stress have been demonstrated in Preeclampsia in previous studies, but this finding has not been established in other hypertensive disorders in pregnancy (HDP). We measured different markers of lipid peroxidation and antioxidant defenses by spectrophotometry or enzymoimmunoanalysis in 339 pregnant women: 85 with gestational hypertension (GH), 88 chronic hypertension (CH), 104 Preeclampsia and 62 healthy pregnant control women (PCW). Lower activity of superoxide dismutase and higher levels of catalase were found in GH, CH and preeclampsia compared with PCW (964.4±116.5, 970.0±120.4, 971.2±137.5 and 1063.4±133.7 U g(-1) Hb, P<0.001; and 313.0±71.7, 292.2±45.3, 297.1±47.2, 215.5±26.2 U mg(-1) Hb, P<0.0001; respectively). Regarding the glutathione REDOX cycle, we found the following in GH, CH and preeclampsia compared with PCW: a decrease in its reduced form (2.6±0.6, 2.7±0.8, 2.7±0.9, 3.3±1.3 µmol l(-1), P<0.003), a parallel increase in the oxidized form (185.6±68.9, 194.7±75.0, 184.3±78.3, 85.1±27.5 µmol l(-1), P<0.0001) and an increment in glutathione peroxidase (85.9±22.0, 86.4±20.9, 82.1±23.5 and 77.2±19.7 U g(-1) Hb, P<0.04) and glutathione reductase (6384.3±1261.9, 6724.6±1154.1, 6287.9±1399.9 and 6044.4±1208.4 mU g(-1) Hb, P<0.01, respectively). Nitrites/nitrates were higher in patients with preeclampsia than in PCW (31.50±15.08, 26.80±8.39 µmol l(-1), P<0.002). Although malondialdehyde and oxidized-LDL levels were similar among groups, free fatty acids were increased in every HDP (GH 514.6±194.6, CH 501.3±197.4, preeclampsia 555.2±230.1 µmol l(-1)) compared with PCW (351.4±146.1 µmol l(-1)), P<0.0001. Our results show an oxidation/reduction imbalance with an increase in oxidative stress coupled with a decreased capacity of antioxidant systems, not only in preeclampsia but also in every HDP.