UNLABELLED: 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.

Adrenergic beta-Antagonists↗

PubMedDate not supplied

Effects of neuropeptide Y on appetite.

Neuropeptide Y (NPY) is a polypeptide containing 36 amino acids. Circulating NPY originates predominantly from the sympatho-adrenomedullary nervous system. It has a vasoconstrictive and mitogenic effect on blood vessels and seems to be involved in blood pressure regulation and angiogenesis. NPY is a potent orexigenic agent and is presumed to play a leading role in the regulation of eating behavior. Stimulation of the NPY-ergic arcuate - paraventricular nucleus (ARC-PVN) pathway by exercise, fasting, energy loss (glucosuria) is followed by increased appetite and food intake and increased parasympathetic activity, but suppression of sympathetic activity and energy expenditure. The end result of this process is an increase of energy stores. Activity of the NPY-ergic ARC-PVN pathway is suppressed by leptin - a polypeptide produced by adipocytes. Although functioning of an NPY-leptin feedback was found in rodents, it seems likely that also in man the NPY-leptin axis is involved in the regulation of food intake and energy expenditure.

Animals↗

PubMedDate not supplied

Plasma parathyroid hormone, phosphatemia and vitamin D receptor genotype: are they interrelated?

It is not clear how the rate of bone mineral loss and vitamin D receptor (VDR) Bsml polymorphism in hemodialysed patients are related. We therefore analysed the relationships between indices of calcium-phosphate metabolism in respect to VDR genotype in 180 hemodialysed patients. We measured plasma concentrations of calcium, phosphate, iPTH, 1,25(OH)2D3 and activity of the bone fraction of alkaline phosphatase on the day before dialysis. VDR genotype BB, Bb and bb were found in 39, 84 and 57 patients, respectively. The allele frequency was B 0.45 and b 0.55. Subjects with BB genotype had insignificantly higher plasma levels of phosphate, iPTH and activity of the bone fraction of alkaline phosphatase, but significantly lower (p<0.02) concentrations of 1,25(OH)2D3 [iP (mmol/l): 2.05+/-0.09, 1.98+/-0.06, 1.93+/-0.06; iPTH (pg/ml): 257+/-50, 229+/-24, 219+/-30; AP(BF) (nmol/l/s): 515+/-45, 477+/-27, 457+/-34; 1,25(OH)2D3 (pg/ml): 23.4+/-1.5, 26.2+/-1.0, 29.3+/-1.3, for BB, Bb and bb respectively]. The strongest significant correlation between phosphatemia and iPTH was in the BB subgroup (r=0.343). Moreover, only in this subgroup did phosphatemia significantly contribute to the increase in iPTH, assessed by multiple regression analysis. In conclusion, it seems likely that BB VDR genotype in HD patients contributes to the severity of secondary hyperparathyroidism by a mechanism involving phosphatemia.

Aged↗

PubMedDate not supplied

[The kidneys as an endocrine organ].

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Dihydroxycholecalciferols↗

PubMedDate not supplied

[The effect of treatment with enalapril versus losartan on levels of insulin resistance in patients with essential hypertension].

Insulin resistance and hyperinsulinaemia are presumed to participate in the pathogenesis of essential hypertension (EH). Insulin resistance is characterised by an impaired insulin-mediated glucose uptake. Participation of the renin-angiotensin system in the development of hyperinsulinaemia in EH patients has not been unanimously proven. The present study aimed to asses the influence of antihypertensive therapy with angiotensin converting enzyme inhibitor (ACEI, enalapril = 10 mg/day) (9 male patients) or angiotensin II AT-1 receptor blocker (A II RB = losartan 50 mg/day) (9 male patients) respectively on insulin sensitivity in patients with EH. 3-hours euglycaemic clamp test with constant infusion of insulin (50 mU/m2/min) was performed twice: before and after 8 weeks of therapy with ACEI or A II RB respectively. The control group (CG) consisted of 12 healthy males (clamp test was performed once). Serum insulin concentration (I) was estimated by radioimmunoassay. Glucose disposal rate (M-value = mg/kg/min) and tissue insulin sensitivity (M/I value = mg/kg/min per mU/l) were calculated in subjects of the CG and in patients with EH before and after antihypertensive therapy with ACEI or A II RB, respectively. In CG the M-value (7.38 +/- 0.13) and tissue insulin sensitivity (M/I = = 6.76 +/- 0.19) were significantly higher than in EH before treatment with ACEI (M-value = 5.44 +/- 0.16; M/I = = 4.57 +/- 0.18) or A II RB (M-value = 5.75 +/- 0.21; M/I = 4.77 +/- 0.31), respectively. ACEI therapy was followed by a significant increase of both M (6.82 +/- 0.25) and M/I (5.68 +/- 0.25) values. In contrast to ACEI, treatment with A II RB did not influence neither M (5.75 +/- 0.21) nor M/I (4.79 +/- 0.21) values respectively. In contrast to A II RB, ACEI shows a beneficial effect on insulin sensitivity in EH patients. This effect does not seem to be mediated by an influence on the AT-1 receptor.

Adult↗

PubMedDate not supplied

[Clinical and biochemical picture of primary hyperparathyroidism based on 155 observed cases].

In this study, the biochemical and clinical profile of primary hyperparathyroidism, diagnosed in 155 patients (106 females and 49 males) in the Department of Nephrology of the Silesian University School of Medicine in the years 1972-1998 was analyzed. The mean age of patients was 48.5 +/- 12.8 years. In all cases the diagnosis was confirmed by the pathomorphological examination. In the majority of cases PNP was diagnosed in a phase of advanced organic injuries. The leading clinical finding in these patients was nephrolithiasis. Asymptomatic hypercalcemia was diagnosed only in 9% of cases. In the years 1972-1992 elevated serum total calcium concentration was found in 92.6% while after introduction of routine estimation of ionized calcium concentration in 1993, hypercalcemia was found in all patients. The incidence of hypercalciuria increased significantly in patients diagnosed in the period 1993-1998 while in this same period the incidence of impaired renal function declined significantly. The elevated serum PTH was found in 86% of patients regardless whether C-terminal fragments of PTH or intact PTH-1-84 were assessed. Elevated levels of ionized serum calcium with normal or increased plasma iPTH-1-84 level are the most constant symptoms of primary hyperparathyroidism.

Adult↗

PubMedDate not supplied

Glycemia and insulinemia during intravenous glucose infusion in children.

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Adolescent↗

PubMedDate not supplied

Correlation between left ventricular mass and the resting and post-exercise release of ANP in healthy men.

BACKGROUND: The goal of our study was to assess the impact of left ventricular mass on the resting and post-exercise release of atrial natriuretic peptide (ANP) in healthy young men. MATERIAL AND METHODS: The study involved 36 young men divided into two groups. Group I consisted of 18 healthy untrained men 20-24 years old (mean 22.1). Group II included 18 healthy men aged 22-27 years (mean 23.4 years) who had been taking regular dynamic and static physical exercise for at least 2 years. Echocardiograms were performed in both groups. The thickness of the posterior wall (PW-d), the thickness of the interventricular septum (IV-d), and the left ventricular end-diastole dimension (DdLV) were measured and used to calculate the left ventricular mass. Subsequently, all the patients underwent an exercise test on a cycloergometer. The workload in both groups was 2 Watts/kg at 60 rpm. The anticipated age-adjusted heart rate values at this workload were 170/min in Group I and 155/min in Group II. Blood samples were collected before the exercise test and 1 minute afterwards. The concentrations of ANP and sodium ions and the hematocrit index were measured. RESULTS: In Group I the mean left ventricular mass was 193.1 +/- 51.8 g; in Group II, 248.1 x 91.91 g, which is a statistically significant difference. The resting ANP concentration in Group I was higher than in Group II (24.44 +/- 12.35 pg/ml vs 21.39 +/- 11.03 pg/ml), but the difference was not statistically significant. After exercise there was a significant increase in ANP concentration in both groups: 53.89 +/- 39.98 pg/ml and 47.50 +/- 26.67 pg/ml respectively. There was no correlation between the ANP concentration before and after exercise and the left ventricular mass in either group. There were also no differences between the two groups in resting hematocrit: 48% in Group I and 49.5% in Group II. A significant increase in hematocrit was observed in both groups after exercise. Exertion induced a significant decrease in the plasma sodium concentration in both groups. The ratio of mean plasma ANP concentration at rest to left ventricular mass, corrected according to hematocrit values, was 6.10 in Group I and 4.25 in Group II; after exercise, 14.06 and 9.72 respectively. The ratio of post-exercise increase in ANP concentration to left ventricular mass was 7.6 in Group I and 5.32 in Group II. The average left ventricular mass in Group II, although 30% greater than in Group I, did not exceed 259 g, which is considered the upper limit of normal. Despite this difference the ANP concentration in Group II was ca. 20% lower than in Group II, without cardiac hypertrophy. In both groups a significant increase in ANP concentration was observed when the subjects were exposed to submaximal workload. In Group II, however, the increase was markedly lower. No correlation was found between left ventricular mass at rest and post-exercise ANP release, nor between left ventricular mass and ANP secretion. By contrast, a tendency towards lower ANP release was found in Group II, despite the markedly larger left ventricular mass. CONCLUSIONS: In the evaluation of risk related to left ventricular hypertrophy, both the mass index and cardiac functional efficiency should be taken into account.

Adult↗