Clonidine reduces elevated cerebrospinal fluid catecholamine levels in patients with essential hypertension

Cerebrospinal fluid (CSF) catecholamines were measured in normotensive patients and in patients with mild to moderate essential hypertension. CSF-norepinephrine (NE) concentrations were 50% lower in the normotensive individuals (127 ± 28 vs. 240 ± 23 pg/m1) (P<0.01). In hypertensive patients, CSF-NE was inversely related to age (r =-0.68; P<0.01) and directly related to plasma NE (r = 0.61; P<0.05). Clonidine (450 mcg/day for 2 weeks) significantly reduced CSF-NE (?40%) in hypertensive patients. In addition, it decreased blood pressure, plasma and urinary NE. Urinary VMA was not affected by clonidine. No correlation was observed between clonidine effects on BP and on plasma or CSF catecholamines. This study indicates that patients with essential hypertension have elevated levels of CSF-NE which are reduced after treatment with clonidine. The elevation of CSF-NE suggests that central (spinal?) noradrenergic activity may be increased in patients with mild to moderate essential hypertension, and that can be reduced by treatment with clonidine.     

Isolation of a plasma protein observed in patients with essential hypertension

Daily progesterone administration (1.33 mg/kg body weight) to immature rabbits brought about an initial increase in the uterine content of uteroglobin which, however, subsided when progesterone treatment was continued for 10 days. During this treatment period progesterone did not lose its own uterine receptors nor did it lose its inhibitory effect on the accumulation of occupied nuclear estrogen receptors. Since immature rabbits were used, the decrease of uteroglobin concentration cannot be explained by inhibitory effects of endogenous estrogens. The results suggest that termination of uteroglobin secretion may be a selective and inherent effect of progesterone itself.     

Protein C and plasma serine protease inhibitors in patients with essential hypertension]

Plasma protein C and serine protease inhibitors together with some other hemostasis parameters have been determined in 60 patients with essential hypertension. Significant decrease in protein C and alpha 2-antiplasmin levels, increased fibrinogen, fibrinopeptide A, WF: Ag, plasminogen, and prolongation of euglobulin fibrinolysis time have been observed. Results indicate hypercoagulability and fibrinolysis defect in hypertensive patients.     

Plasma leptin levels strongly correlate with plasma renin activity in patients with essential hypertension.

Previous studies demonstrated elevated plasma leptin and angiotensinogen (PRA) levels in essential hypertension. However, a few studies investigated the relationship between leptin and angiotensinogen levels in both lean and overweight/ obese hypertensives. The aim of the present study was therefore to examine the relationship between blood pressure, leptin and plasma renin activity in normotensives and in both lean and overweight/obese patients with essential hypertension. Two groups of subjects who were carefully matched for age, gender, waist:hip ratio and body mass index (BMI) were studied: 28 normotensives (NT) (age: 40.1+/-9.1 years old, BMI: 28.1+/-3.6 kg/m2, male/female: 18/10) and 33 newly diagnosed mild to moderate essential hypertensives (EHT) (age: 38.9+/-10 years old, BMI: 27.9+/-4.8 kg/m2, male/female: 22/11). No significant differences in age, gender, waist:hip ratio, fasting blood glucose and BMI were detected between EHT and NT groups. However, systolic and diastolic pressures, mean arterial blood pressures, plasma leptin levels and PRA were significantly higher in EHT group than in NT group (P = 0.001). Plasma leptin levels were strongly correlated with BMI in EHT (r=0.67, P = 0.001) and NT groups (r=0.44, P = 0.001). Plasma leptin levels were correlated with plasma PRA levels in both EHT and NT groups (r = 0.66 and r = 0.44; both P < 0.05, respectively). There was no correlation between leptin or PRA and systolic, diastolic pressures, or mean arterial blood pressures. Furthermore, the patients were divided as lean (n=16) and overweight/obese (n = 17) and compared with BMI-matched controls. In both subgroups, plasma leptin and PRA levels were also higher than those of controls. Our results showed that elevated plasma leptin and PRA are associated with hypertension in both lean and overweight/obese hypertensives. Moreover, plasma leptin was significantly correlated with plasma angiotensinogen levels. These findings suggest that adipose mass is an important determinant of blood pressure, although the mechanism is not clear.     

Effect of somatostatin on plasma renin activity and blood pressure in patients with essential hypertension

The effects of somatostatin on plasma renin activity (PRA) and blood pressure were evaluated in patients with essential hypertension (EH) and in normotensive subjects. All subjects examined were hospitalized and placed on a diet containing 7-8 g/day sodium chloride and received an intravenous infusion of somatostatin (500 microgram/20 ml of saline, for 60 min) in the basal condition. During somatostatin infusion, the mean blood pressure (MBP) remained unaffected in all patients with EH and the normotensive subjects, while the PRA decreased slightly in the EH group. When the patients with EH were classified according to their renin levels (low, normal and high), parallel significant decreases in MBP and PRA were found only in the high renin group during the somatostatin infusion. No significant change in MBP and PRA was observed in the other groups including the normotensive subjects. To assess the activity of synthetic somatostatin, the plasma levels of growth hormone (GH) and cyclic AMP were measured. These levels were lowered significantly during the infusion and the GH levels showed a rebound 15 min after cessation of the infusion. The cyclic AMP returned to the basal levels, but no rebound was observed. The above data indicate that the fall in blood pressure in the high renin group in the basal condition was probably due in part to reduced renin release by somatostatin, and the maintenance of high blood pressure especially in high renin EH.     

哈萨克族原发性高血压患者血浆EPCsCD34+水平及其相关性研究

目的:探讨血浆内皮祖细胞(EPCs)CD34+水平与新疆哈萨克族(哈族)原发性高血压病患者血压、血脂、血糖、肥胖等的相关性.方法:选取新疆哈族原发性高血压患者87为观察组,哈族健康对照组79例,测量血压(BP)、身高、体重、腰围(WC)、臀围(HC),抽取空腹静脉血测定血糖(FPG)、总胆固醇(TC)、甘油三酯(TG)、高密度脂蛋白胆固醇(HDL-C)、低密度脂蛋白胆固醇(LDL-C),计算体重指数(BMI)腰臀比(WHR).结果:①原发性高血压组血浆EPCs CD34+水平明显低于对照组(p<0.01)②原发性高血压组血浆EPCs CD34+水平与收缩压、舒张压、总胆固醇、甘油三酯、低密度脂蛋白胆固醇、血糖、体重指数呈显著负相关.对照组血浆EPCs CD34+水平与收缩压、舒张压、总胆固醇、甘油三酯、体重指数呈负相关.③多元回归分析显示在原发性高血压组中收缩压、甘油三酯是影响血浆EPCs CD34+水平的独立因素,在对照组中总胆固醇、体重指数是影响血浆EPCs CD34+水平水平的独立因素.结论:哈族原发性高血压患者血浆EPCs CD34+水平与血压水平存在一定的相关性.     

Application of plasma lipidomics in studying the response of patients with essential hypertension to antihypertensive drug therapy

Hypertension is a key risk factor in the progression of cardiovascular disease (CVD). Dyslipidemia, a strong predictor of CVD, frequently coexists with hypertension. Therefore, the control of hypertension and dyslipidemia may help reduce CVD morbidity and mortality. In the present study, the therapeutic effects of antihypertensive agents on blood pressure control and plasma lipid metabolism were evaluated. The plasma lipid profiles of patients with treated (n = 25) or untreated (n = 30) essential hypertension as well as of subjects with normotension (n = 28) were analyzed using liquid chromatography mass spectrometry. Principal component analysis of the lipidomics data revealed distinct clusters among studied subjects across three human populations. Phosphatidylcholines and triacylglycerols (TG) dominated the pattern of hypertension-influenced plasma lipid metabolism. Discriminatory lipid metabolites were analyzed using one-way analysis of variance followed by a post hoc multiple comparison correction. TG lipid class was significantly increased by 49.0% (p < 0.001) in hypertensive vs. normotensive groups while tended to decrease (-21.2%, p = 0.054) in hypertensive patients after treatment. Total cholesteryl esters were significantly decreased by -16.9% (p < 0.001) in hypertensive patients after treatment. In particular, a large number of individual neutral lipid species were significantly elevated in hypertensive subjects but significantly decreased after treatment with antihypertensive agents. The present study applied, for the first time, a systems biology based lipidomics approach to investigate differentiation among plasma lipid metabolism of patients with treated/untreated essential hypertension and subjects with normotension. Our results demonstrate that antihypertensive medications to lower blood pressure of hypertensive patients to target levels produced moderate plasma lipid metabolism improvement of patients with hypertension.     

Peripheral glucose metabolism in patients with essential hypertension.

The present study was designed to determine the effect of essential hypertension on peripheral glucose metabolism during the postabsorptive state and after an oral glucose challenge. Ten normal subjects and nine patients with essential hypertension were studied after an overnight fast (12-14 h) and for 3 h after the ingestion of 75 g of glucose. Peripheral glucose metabolism was analyzed by the forearm technique to estimate muscle exchange of substrate combined with indirect calorimetry. Decreased forearm glucose uptake was observed in hypertensive patients compared to normal subjects (4.9+/-0.6 vs. 8.6+/-0.5 mmol x 100 ml forearm(-1) x 3 h(-1)) with diminished nonoxidative glucose metabolism (2.7+/-0.5 vs. 6.9+/-0.6 mmol x 100 ml forearm(-1) x 3 h(-1)). Muscle glucose oxidation did not differ significantly between groups. Both serum free fatty acid levels and lipid oxidation rates were similar in the normal subjects and the hypertensive patients, and declined in a similar fashion after glucose ingestion. Basal serum insulin levels did not differ significantly between normal and hypertensive patients, whereas the insulinemic response to glucose load was greater among the patients with essential hypertension. These data show that insulin resistance occurring in patients with essential hypertension is accompanied by impaired muscle glucose uptake and nonoxidative metabolism.     

Increased activity of the platelet-activating factor acetylhydrolase in plasma low density lipoprotein from patients with essential hypertension

We have measured activity of platelet-activating factor (PAF) acetylhydrolase, an enzyme that specifically inactivates PAF, in plasma from patients with essential hypertension and healthy controls. The average activities in 34 patients and 22 controls were 113 +/- 60 and 79 +/- 32 nmol/ml/min, respectively, and the difference was significant (p less than 0.05). Approximately three fourths of the total plasma activity was recovered in LDL, with the remainder in HDL; and there was a significant difference in the activity associated with the LDL between patients and controls. The relative distribution of the activity among lipoproteins was almost equal in the two groups, and there was no difference in plasma lipids or apoproteins between them. In patients there was a tendency for plasma PAF acetylhydrolase activity to increase with the length of the history of hypertension. Further studies are needed to distinguish between a number of reasons for increased levels of plasma PAF acetylhydrolase in essential hypertension.     

Influence of antihypertensive treatment with perindopril, pindolol or felodipinon plasma leptin concentration in patients with essential hypertension.

Leptin - produced predominantly by adipocytes - is presumably also involved in pathogenesis of essential hypertension (EH). In the present study, we addressed the question whether and to what extent antihypertensive monotherapy does influence leptinemia in patients with mild or moderate EH. Forty-two EH patients were enrolled in this randomized, open-labeled study. In all subjects, plasma concentrations of leptin, insulin, glucose, cholesterol, triglycerides and creatinine were estimated twice - before and one month after initiation of monotherapy with perindopril, pindolol or felodipin, respectively. Plasma leptin concentration, in the afternoon and midnight, was significantly higher in patients with essential hypertension than in normotensive healthy subjects (p < 0.01). Therapy with perindopril or felodipin did not influence the daily profile of leptinemia or insulinemia, respectively. However, pindolol monotherapy showed a marked (p < 0.01) suppressive effect on the daily profile of leptinemia, but did not influence insulinemia. Conclusions: First, patients with essential hypertension are characterized by higher plasma leptin levels as compared with normotensive healthy subjects; second, suppressive effect of pindolol on leptinemia may be of pathophysiological relevance in the course of weight gain during beta-blocker therapy.     

高血压患者心电图左心室高电压和左心室肥厚与血压的关系

目的:探讨原发性高血压患者常规心电图检测左心室高电压和左心室肥厚与血压的关系.方法:回顾分析我科2009年1月～2009年12月门诊及住院就医的各期原发性高血压患者92例临床资料,并与同期76例健康体检者对比.结果:高血压组心电图对左心室肥厚的检出率为15.22%,明显高于对照组,有统计学差异(x2=19.07,P<0.01);高血压组心电图对左心室高电压的检出率为20.65%,明显高于对照组,有统计学差异(x2=4.23,P<0.05).高血压组左心室肥厚率随着病情的加重逐渐加重,各级之间相比差异有统计学意义(P<0.01).左心室高电压情况各级之间相比差异亦有统计学意义(P<0.01),但与病情无明显的相关性.结论:心电图监测左心室肥厚和左心室高电压,简便易行,高血压患者应定期复查心电图,发现异常,积极降压等治疗.