The epidemiology of hypertension and its associated risk factors in the city of Debrecen, Hungary.

The purpose of this work was to estimate the prevalence of hypertension and cardiovascular risk factors and its association with sociodemographic, behavioural and lifestyle characteristics among the adult population of the city of Debrecen, Hungary.A cross-sectional study was conducted in 1996. Amongst 21 800 inhabitants aged 30-65 y risk screening for cardiovascular disease (CVD) was estimated by a questionnaire that included sociodemographic, lifestyle characteristics, family history of CVD and results of self-reported data of body weight, height and blood pressure. Of the total of 19 961 surveyed sample, 37.02% were considered to be hypertensive, 53.73% were overweight, 32.18% were current smokers and 58.85% were physically inactive. Hypertensives were older than normotensives (50.81+/-9.01 vs 44.78+/-8.97 y, P<0.001). The prevalence of various risk factors amongst hypertensives as compared to normotensives were overweight (68.49 vs 45.06%, P<0.0001), current smoking (28.38 vs 34.41%, P<0.0001), physical inactivity (64.78 vs 55.36%, P<0.001), and high alcohol consumption (1.91 vs 1.06%, P<0.01). Of the hypertensives 37.11% were on drug therapy. Of those on therapy, only 17.03% had normal blood pressure. Being overweight and having low physical activity was positively associated with hypertension (OR=2.25, CI=2.11-2.40) and (OR=1.26, CI=1.15-1.38). Manual work, a family history of CVD, low education, and the male gender were also associated with hypertension and more CVD risk factors. These findings illustrate a very high prevalence of hypertension and CVD risk factors in Debrecen, indicating the importance of the need for more effective prevention programmes and control of hypertension in Hungary.

Inhibition of the superoxide anion release and hydrogen peroxide formation in PMNLs by flavonolignans.

The mixture of flavonolignans [Legalon: silybin (2a), isosilybin (3), silydianin (4) and silychristin (5)] and derivatives of silybin (2b-d) were assessed for their inhibitory activity on the oxidative burst of PMA-stimulated human PMNLs. The inhibitory effect of flavonolignans on O(2)(-) release were compared with that of vitamin E (1). The flavonolignans tested exhibited the following order in inhibition of O(2)(-) release by PMA-stimulated PMNLs: 5,7,4"- trimethylsilybin (2c) approximately vitamin E (1) > Legalon >or= peracetylsilybin (2b) > silybin (2a) > peracetyl-5,7,4"-trimethylsilybin (2d). The flavonolignans inhibited not only the O(2)(-) release, but also the H(2)O(2) formation in PMA-stimulated PMNLs. The inhibitory capacity of flavonolignans on H(2)O(2) formation was similar to their inhibitory capacity on O(2)(-) release. These data suggest that the flavonolignans have antioxidant properties on the PMNL oxidative burst. The fact that the trimethyl derivative of silybin (2c) has a greater inhibitory effect than silybin itself suggests that the efficacy of the antioxidant properties is dependent on the lipophilicity of the molecules. This is underlined by the fact that peracetylation of all of the hydroxyl groups in silybin resulted in a total loss of the antioxidant activity of the molecule. In summary, flavonolignans inhibit the oxidative burst of PMNLs, and this inhibitory effect depends on the chemical structure of the flavonolignans.

Gemfibrozil increases paraoxonase activity in type 2 diabetic patients. A new hypothesis of the beneficial action of fibrates?

OBJECTIVE: The constellation of elevated triglycerides and decreased high-density lipoprotein is recognised as a risk factor for CAD and constitutes the major dyslipidemia in type 2 diabetes. The high-density lipoprotein associated paraoxonase activity can inhibit low-density lipoprotein oxidation and has an antiatherogenic effect. To determine the effect of gemfibrozil on the dyslipidemia and serum paraoxonase activity in patients with type 2 diabetes. MATERIAL AND METHODS: Fifty-six type 2 diabetic patients with associated hypertriglyceridemia were involved. They were investigated for the effect of twice daily 600 mg of gemfibrozil on serum cholesterol, triglycerides, apolipoproteins, fibrinogen level, body mass index and glycated hemoglobin. Serum paraoxonase activity was measured spectrophotometrically. RESULTS: After three months, it was observed that under the effect of gemfibrozil, serum triglyceride level was significantly decreased (from median: 3.46 mmol/l quartiles: q1=2.92 q3=5.28 to median 2.20 mmol/l quartiles: q1=1.79 q3=3.65; p<0.001) while protective high-density lipoprotein (from 1.02 +/- 0.22 mmol/l to 1.13 +/- 0.28 mmol/l; p=0.05) and apolipoprotein A(1) (from 1.56 +/- 0.33 g/l to 1.72 +/- 0.29; p<0.01) levels were significantly increased. Serum paraoxonase activity was found to be significantly increased (from median: 100.2 U/l quartiles: q1=60.1 q3=152.7 to median 118.7 U/l quartiles: q1=80.1 q3=171.0; p<0.001) after gemfibrozil treatment. The total cholesterol, low-density lipoprotein, apolipoprotein B, lipoprotein (a), glycated hemoglobin and fibrinogen levels were not significantly changed during the three-month treatment period. The standardized paraoxonase activity for HDL and apo A(1) were not significantly changed. Paraoxonase activity did not correlate with the concentration of glycohemoglobin and the duration of diabetes. CONCLUSION: Twice daily administration of 600 mg of gemfibrozil is effective in type 2 diabetic patients with associated hypertriglyceridemia. It favorably lowers lipid levels, and improves antioxidant status by increasing serum paraoxonase activity.

[Epidemiology of hypertension in adolescence and factors influencing blood pressure]. / A serdülókori hypertonia epidemiológiája és a vérnyomást befolyásoló tényezók.

The authors summarize the determining and influencing factors of adolescent hypertension. An overview of the definition and prevalence of hypertension in adolescence is given and the predictive role of the adolescent hypertension on the incidence of adult cardiovascular diseases is pointed out. According to the previous literature data, adult hypertension is more frequent in those people who have had hypertension in their adolescence. There are no widely used, population-based nomograms of adolescent hypertensives available. According to the opinion of the authors, a population-based hypertension screening program would help in delineating the factors influencing adolescent blood pressure, and the most frequent risk factors for hypertension in Hungary. With the follow-up and appropriate treatment of the hypertensives the reduction of target-organ damages may be possible.

Which parameters affect cytosolic free calcium in polymorphonuclear leukocytes of haemodialysis patients?

BACKGROUND: Cytosolic free calcium ([Ca(2+)](i)) is an important second messenger during stimulation in a wide variety of cells, including polymorphonuclear leukocytes (PMNs). Its mobilization in PMNs is altered in various diseases such as atherosclerosis and ageing. In chronic haemodialysis (HD) patients, both atherosclerosis and accelerated ageing are well known. Therefore [Ca(2+)](i) in resting PMNs of HD patients was determined along with certain parameters which might affect it, such as recombinant human erythropoietin (rHuEpo) treatment, calcium-phosphate balance, and biocompatibility of dialysis membranes. METHODS: PMNs were separated by density centrifugation and [Ca(2+)](i) was determined by spectrofluorimetry using Quin 2/AM fluorescent dye. Laboratory parameters were determined by standard methods in clinical chemistry. RESULTS: It was found that [Ca(2+)](i) in resting PMNs of HD patients not undergoing rHuEpo therapy was higher than that of controls. After 12-weeks of rHuEpo therapy, [Ca(2+)](i) decreased to near normal level. The role of erythropoiesis in normalization of [Ca(2+)](i) in resting PMNs was supported by PMN [Ca(2+)](i) which was elevated in patients who had low haemoglobin (<100 g/l) or haematocrit (<0.30) values. In some patients, including those receiving rHuEpo treatment, [Ca(2+)](i) remained high, suggesting a role for other parameters in increasing [Ca(2+)](i). One possible parameter might be the disturbed calcium-phosphate metabolism of chronic renal failure, because we found a strong correlation between [Ca(2+)](i) and plasma iPTH levels in HD patients (r=0.743, P<0.001). [Ca(2+)](i) was also elevated in PMNs of those patients who had either low plasma calcium or high plasma phosphate levels. PMN [Ca(2+)](i) of HD patients correlated positively with the duration of HD (r=0.671, P<0.001). However, there was no correlation between [Ca(2+)](i) and patient age. The dialysis procedure itself also transiently increased PMN [Ca(2+)](i) HD patients, independently of the type of dialysis membrane. CONCLUSION: PMN [Ca(2+)](i) is modulated by various parameters in HD patients, including the degree of anaemia, disturbances of calcium metabolism, and duration of dialysis treatment. The elevated [Ca(2+)](i) of resting PMNs might contribute to altered functions in these cells.

Vitamin E, lipid profile, and peroxidation in hemodialysis patients.

BACKGROUND: Hypertriglyceridemia, lipid peroxidation, and abnormalities of the plasma fatty acid (PUFA) profile may be important risk factors for the atherosclerotic cardiovascular disease in hemodialysis (HD) patients. METHODS: We investigated how these factors are affected by vitamin E supplementation carried out by oral administration (clinical study 1) and dialysis with vitamin E-modified dialyzers (clinical study 2). RESULTS: In the HD patients, conditions of relative vitamin E deficiency were observed [lowered vitamin E/triglyceride (TG) ratio] in the presence of high levels of thiobarbituric acid reactants (TBARs) and decreased levels of the polyunsaturated fraction of PUFAs paired with an increased amount of monounsaturated ones (MUFA). In both studies, vitamin E supplementation significantly increased the levels of vitamin E in the plasma without affecting TG levels and provided a partial correction of TBAR levels. Of note was the relative increase in the PUFA fraction, which gave solid proof of an anti(per)oxidant effect of vitamin E supplementation in HD patients. Vitamin E supplementation was also observed to increase plasma levels of reduced glutathione and NOx (NO2 + NO3). CONCLUSION: The results suggest that vitamin E supplementation may be an effective accessory therapy to combat oxidative stress-lowering lipid peroxidation in HD patients.

[Results and complications of parathyroidectomy in secondary hyperparathyroidism]. / Szekunder hyperparathyreosis miatt végzett parathyroidectomiák eredményessége és szövódményei.

Retrospective study was performed to measure the results of parathyroidectomy in patients with secondary hyperparathyroidism. From 1987 to 2000, 48 patients underwent surgery for secondary hyperparathyroidism. There were 30 of 48 patients on haemodialysis treatment, and 11 patients were in pre-dialysis stage. Parathyroidectomy was performed after successful kidney transplantation in 4 cases. Indication of the surgery was extremely elevated serum level of parathyroid hormone (at least 10 fold elevation), which was resistant for the conservative medical therapy. Subtotal parathyroidectomy (3 1/2) was performed in 30 patients. Five patients underwent total parathyroidectomy and autotransplantation. Only 2 or 3 parathyroid glands have been removed in 13 patients. Haematoma occurred in 3 cases after parathyroidectomy. Recurrent nerve injury or septic complication did not occur. Two patients died in the early postoperative period due to cardiac failure. Tetania was noted in 2 patients after surgery. Permanent postoperative hypocalcaemia (over 6 months) occurred in 3 cases. Persistent hyperparathyroidism was diagnosed in 5 patients. In these patients 2 parathyroid glands were removed during the primary operation. Recurrent hyperparathyroidism was detected in 2 patients. Subtotal parathyroidectomy was carried out in these cases previously. At the reoperation for persistent and recurrent hyperparathyroidism, total parathyroidectomy and autotransplantation was performed. Serum alkaline phosphatase level and serum parathyroid hormone value decreased after surgery, except those patients with persistent hyperparathyroidism. Bone pain decreased in 96% of the cases and pruritus decreased in 92% of the patients after parathyroidectomy. Soft tissue calcification showed improvement in 45% of cases. In conclusion, the subtotal parathyroidectomy or total parathyroidectomy with autotransplantation cause a rapid decrease of PTH level and the improvement of the clinical symptoms in patients with medical treatment resistant secondary hyperparathyroidism. Persistent hyperparathyroidism occurs in those cases when inadequate parathyroidectomy was performed.

Prevalence of iodine deficiency and goitre during pregnancy in east Hungary.

OBJECTIVE: To assess the iodine nutritional status and the prevalence of goitre during pregnancy in a region of Hungary that appeared to be iodine sufficient in previous studies. DESIGN: A cross-sectional voluntary screening study was organized in which 313 pregnant women participated. METHODS: Urine iodine concentration and the volume of the thyroid gland were measured in every woman. In the presence of low urinary iodine concentrations, goitre, or both, thyroid function tests were performed. RESULTS: Iodine deficiency was found in 57.1% of the pregnant women, and was severe in 15.6%. The volume of the thyroid gland was enlarged in 19.2% of individuals. Nodular goitre was found in 17 women (5.4%). The frequency of goitre and the mean thyroid volume were increased in the group of iodine-deficient women. In the 89 cases of iodine deficiency or goitre, thyrotrophin concentrations were in the normal range; however, the free triiodothyronine:free throxine ratio was increased in 97% of them, indicating that the thyroid gland was in a stimulated state in these individuals. CONCLUSIONS: Iodine deficiency with high prevalence of goitre was recognized among pregnant women in an area that previously appeared to be iodine sufficient. An unexpected mild iodine deficiency was also noted in the non-pregnant control group. Reassessment and continuous monitoring of iodine nutritional status is warranted even in populations that are apparently considered to be 'at no risk' of iodine deficiency, especially in pregnant women. Regular administration of iodine, starting at preconception or in early pregnancy and continuing during the period of nursing, is recommended in these regions.

Prevalence of cardiovascular risk factors of the smokers and non-smokers in the city of Debrecen, Hungary.

The aim of our study was to compare the major cardiovascular disease (CVD) risk factors of smokers and non-smokers. Risk screening of CVD was estimated by a questionnaire, via interview. Random samples of 20 000 inhabitants of Debrecen, Hungary, aged 30-65 y, took part in the study. 19 922 questionnaires were considered appropriate for further evaluation. 32.2% of the participants (n=6410) were smokers, whose data were compared to those of the 68.8% of non-smokers (n=13 512). There were more male smokers than female (39.3% vs 27.7%), (P<0.001). 36.5% of males and 58.9% of females had not previously smoked regularly (P<0.001). 24.2% of males and only 13.3% of females were able to stop smoking (P<0.001). 8.7% of the participants smoked more than 20 cigarettes per day (14.8% of males, 5.0% of females), (P<0.001). Smokers were younger, with a mean age of 43.4 y vs 47.1 y for non-smokers (P<0.01). The ex-smokers and non-smokers had a higher body mass index than light, moderate and heavy smokers (26. 75+/-4.1 kg/m2 and 26.09+/-4.3 kg/m2 vs 24.87+/-3.9 kg/m2 and 24. 89+/-4.2 kg/m2 and 25.32+/-4.3 kg/m2, respectively), (P<0.001). The results of the last measured blood pressures did not differ between the two groups. 94.8% of smokers and 93.6% of non-smokers did not perform any regular leisure time exercises (P<0.01). 39.8% of smokers regularly ate fatty food, in comparison to 28.0% of non-smokers (P<0.001). 30.6% of smokers vs 28.6% of non-smokers were factory workers while 69.4% of smokers vs 71.4% of non-smokers did sedentary jobs (P<0.001). 2.3% of smokers vs 0.9% of non-smokers admitted regular consumption of alcohol (P<0.001). Amongst the parents and brothers/sisters of smokers the prevalence of heart attack was higher 19.7% vs 18.7%, than for those of non-smokers (P<0. 05). We observed an accumulation of cardiovascular risk factors in the case of smokers, which indicates the higher susceptibility of smokers to CVD.

Ferriporphyrins and endothelium: a 2-edged sword-promotion of oxidation and induction of cytoprotectants.

Heme arginate infusions blunt the symptoms of patients with acute intermittent porphyria without evidence of the vascular or thrombotic side effects reported for hematin. To provide a rationale for heme arginate's safety, the present study examined the effects of various ferriporphyrins to sensitize human endothelial cells to free radical injury and to induce heme oxygenase and ferritin expression. Heme arginate, unlike hematin, did not amplify oxidant-induced cytotoxicity mediated by hydrogen peroxide (5.3 +/- 2.4 versus 62.3 +/- 5.3% (51)Cr release, P <.0001) or by activated neutrophils (14.4 +/- 2.9 versus 41.1 +/- 6.0%, P <.0001). Nevertheless, heme arginate efficiently entered endothelial cells similarly to hematin, since both markedly induced heme oxygenase mRNA (more than 20-fold increase) and enzyme activity. Even with efficient permeation, endothelial cell ferritin content was only minimally increased by heme arginate compared with a 10-fold induction by hematin; presumably less free iron was derived from heme arginate despite up-regulation of heme oxygenase. Hematin is potentially vasculopathic by its marked catalysis of oxidation of low-density lipoprotein (LDL) to endothelial-toxic moieties. Heme arginate was significantly less catalytic. Heme arginate-conditioned LDL was less than half as cytotoxic to endothelial cells as hematin-conditioned LDL (P <.004). It is concluded that heme arginate may be less vasculotoxic than hematin since it is an effective heme oxygenase gene regulator but a less efficient free-radical catalyst.

[Nil nocere! Phytotherapy causing nephropathy]. / "Nil nocere!"--fitoterápia által okozott nephropathia.

The summary draws attention to the nephropathy caused by "Chinese tea", with all its attendant risks that lead to organ damage. Available data from the literature describe more than 100 women who, at various times, underwent long-term slimming courses by taking two types of Chinese tea containing tablets, namely, Stefania tetranda and Magnolia officinalis. The nephropathy is characterized by severe anemia, tubular proteinuria, histologically chronic ischaemic, interstitial nephritis, accelerated decline in kidney function, and epithelial cell dysplasia of the urinary tract, with consequent inclination towards malignant transformation. The clinical and histological picture resembles that of the Balkan nephropathy. Apart from all these a proportion of the patients may develop aorta insufficiency. The author emphasises the hazards in one of the branches of alternative medicine, fitotherapy, and their prevention.

[Hypophosphatemic oncogenic osteomalacia]. / Hypophosphataemiával járó onkogén osteomalacia.

The first case of oncogen osteomalacia in Hungary is reported, to draw the attention of the medical profession to it and to present the new data about its pathomechanism. Pathological hip fracture caused by hypophosphataemic osteomalacia due to isolated renal phosphate wasting was found in a previously healthy 19 years old sportsman. In spite of daily 1.5 micrograms calcitriol treatment and phosphate supplementation, hypophosphataemia persisted for 13 years and he needed regular indometacin medication for his bone pain. During that time an 1.5 cm gingival tumour was found and radically removed. The serum phosphate level returned to normal in a few hours after the operation (preoperative 0.51, after 2, 4 and 8 hours 0.61, 0.68 and 0.79 mmol/l respectively), and remained normal without calcitriol. The histological examination showed epulis with fibroblast and vascular cell proliferation, which has never been previously reported in connection with oncogenic osteomalacia. The pain resolved after 3 months and the bone density became normal in one year. Oncogenic osteomalacia must be considered in every case presenting with atypical hypophosphataemic osteomalacia. Careful dental examination is needed also in the course of search for the underlying tumour. Every tumour-like growth, even the common epulis, has to be operated radically and serum phosphate monitored in the postoperative period in all such cases.

Serum paraoxonase activity changes in uremic and kidney-transplanted patients.

Serum paraoxonase (PON) is a high-density lipoprotein (HDL)-associated hydrolase, which inhibits low-density lipoprotein oxidation. Uremic and kidney-transplanted patients have an increased risk of atherosclerosis, to which an increased lipoprotein oxidation may contribute. The aim of our study was to determine whether the PON activity or phenotype is altered in uremic and kidney-transplanted patients, and to compare the values with those of healthy controls. 117 uremic patients on long-term hemodialysis treatment, 115 renal-transplanted patients, and 110 healthy controls were involved in the study. The PON activity was significantly reduced in the uremic patients compared to controls (PON 101.36+/-30. 12 vs. control 188.05+/-58.96 U/ml; p < 0.001), while in kidney-transplanted patients the values were almost identical to those of controls (PON 161.5+/-35.39 U/ml). The different immunosuppressive drug combinations did not influence PON activity. To assess whether the altered PON activity was due to a decrease HDL level, we standardized the enzyme activity for the HDL concentration (PON/HDL ratio). We found that the standardized enzyme activity was lower in the uremic (102.7+/-54.8) and kidney-transplanted patients (144.5+/-32.7) when compared to controls (194.5+/-94.5; p < 0.001). The phenotypic distribution of PON in uremic, renal transplant and control patients are as follows: AA 66.67, 56.48 and 66.67%; AB 31. 62, 33.3 and 26.67%; BB 1.71, 10.19 and 6.67%. We conclude that the decreased PON/HDL and PON/apoA-1 ratios may lead to a reduction in the antioxidant capacity of HDL, which might contribute to the accelerated development of atherosclerosis in uremic and kidney-transplanted patients.

Disturbed LDL and scavenger receptor functions in monocytes from chronic haemodialysed patients.

BACKGROUND: The most frequent complication in patients with end-stage renal failure on chronic haemodialysis (HD) treatment is atherosclerosis, i.e. the different forms of heart and vascular diseases. The complete disorder of serum lipid and lipoprotein patterns is well demonstrated, whereas our knowledge about the low-density lipoprotein (LDL) and scavenger receptor expression and function are poorly understood. METHODS: In our current work, LDL and scavenger receptor expression and functions were simultaneously studied in monocytes obtained from 15 healthy male control subjects and from 11 chronic HD male patients applied with (125)I-labelled LDL, isolated from healthy volunteers. To study the scavenger LDL receptors, labelled acetylated LDL (acLDL) was used. RESULTS: LDL binding to the monocytes of the HD-group was found to be decreased in comparison to that of the controls. As a result, the 50 microg LDL protein-induced inhibition of endogenous cholesterol synthesis was also diminished. In contrast, acLDL binding was greatly increased, though it could trigger only a low apoE synthesis. Consequently the number of cholesterol inclusions in monocytes was increased. CONCLUSIONS: The disturbed expression and function of LDL and scavenger receptors both may play significant roles in pathogenesis of cardiovascular complications in chronic HD patients. Based on our present results, it can be assumed that dysfunction of scavenger receptors is at the centre of cardiovascular complications of HD patients with renal failure.

The role of technetium-99m methoxyisobutylisonitrile scintigraphy in the differential diagnosis of cold thyroid nodules.

Various diagnostic techniques have been successfully used in the clinical management of cold nodules; however, the decision on whether to employ surgery or a conservative treatment is not always easy. This study was designed to appraise the diagnostic value of technetium-99m methoxyisobutylisonitrile (MIBI) scintigraphy in the assessment of cold nodules detected using (99m)Tc-pertechnetate. Fifty-two patients were included in the study. All had already been selected for surgery, based on their clinical and laboratory findings, including fine-needle aspiration biopsy. The total number of cold nodules on (99m)Tc-pertechnetate scans was 59. The thyroid scan was performed 20-40 min after i.v. injection of 400 MBq of (99m)Tc-MIBI. Uptake of MIBI in thyroid nodules was compared with that in the surrounding normal thyroid tissue, and a score of between 0 and 3 was assigned to each nodule as follows: 0, cold; 1, decreased; 2, equal; 3, hot. Definitive histology revealed nodular goitre in 24 cases, adenoma in 19, thyroiditis in 1, differentiated cancer in 12, medullary cancer in 2, and anaplastic cancer in 1. None of the degenerative nodules were hot on MIBI scan, while the adenomas showed a variety of MIBI imaging patterns, most frequently the score 3 pattern. In the diagnosis of differentiated thyroid cancer the sensitivities of score 3 and score 2+3 MIBI uptake patterns were 83% (10/12) and 100%, respectively. The score 3 MIBI uptake pattern had a specificity of 100% and a positive predictive value of 100% with respect to thyroid (benign and malignant) neoplastic diseases, whereas a specificity of 72% and a positive predictive value of 43% were observed in the detection of differentiated cancer. After a cold nodule had been detected using (99m)Tc-pertechnetate, a second scan with high MIBI uptake increased by 7.8 times the probability that this nodule would be a differentiated cancer. In conclusion, (99m)Tc-MIBI scintigraphy is a useful method in the differential diagnosis of cold thyroid nodules if the primary aim is to differentiate degenerative from neoplastic diseases rather than to differentiate benign from malignant nodules. High MIBI uptake considerably increases the probability of a differentiated thyroid cancer and facilitates immediate surgical removal, while decreased uptake actually excludes it. We suggest a combination of fine-needle aspiration biopsy and MIBI scan as a routine diagnostic approach to cold thyroid nodules.

QT dispersion in patients with end-stage renal failure and during hemodialysis.

Interlead variability of the QT interval in surface electrocardiogram (ECG), i.e., QT dispersion, reflects regional differences in ventricular recovery time, and it has been linked to the occurrence of malignant arrhythmias in different cardiac diseases. The purpose of the study was to assess the effect of hemodialysis on QT and corrected QT (QTc) interval and dispersion in chronic hemodialyzed patients. Data of 34 nondiabetic patients (male/female = 21/13; mean age, 54 +/- 15 yr) on chronic hemodialysis were studied. Polysulfone capillaries and bicarbonate dialysate containing (in mEq/L) 135 Na+, 2.0 K+, 1.5 Ca2+, and 1.0 Mg2+ were used. Simultaneous 12-lead ECG were recorded before and after hemodialysis in a standard setting. The QT intervals for each lead were measured manually on enlarged (x3) ECG by one observer using calipers. Each QT interval was corrected for patient heart rate: QTc = QT/square root of RR (in milliseconds [ms]). The average cycle intervals were 853 +/- 152 ms predialysis and 830 +/- 173 ms postdialysis; the difference was not significant. The maximal QT interval changed significantly from 449 +/- 43 to 469 +/- 41 ms (P < 0.01). The corrected maximal QT interval increased significantly from 482 +/- 42 to 519 +/- 33 ms (P < 0.01). The QT dispersion changed from 56 +/- 15 to 85 +/- 12 ms (P < 0.001) and the corrected QT interval dispersion from 62 +/- 18 to 95 +/- 17 ms (P < 0.001). During hemodialysis, the serum potassium and phosphate levels decreased from 5.5 +/- 0.8 to 3.9 +/- 0.5 (mM) and from 2.3 +/- 0.5 to 1.6 +/- 0.4 (mM), respectively, whereas calcium increased from 2.2 +/- 0.23 to 2.5 +/- 0.22 (mM). It is concluded that hemodialysis increases the QT and QTc interval and QT and QTc dispersion in patients with end-stage renal failure. Thus, it may be stated that the nonhomogeneity of regional ventricular repolarization increases during hemodialysis. Measurement of QT and QTc dispersion is a simple bedside method that can be used for analyzing ventricular repolarization during hemodialysis.

[Effect of hemodialysis on QT dispersion in chronic uremia]. / A hemodialízis hatása a QT diszperzióra krónikus uraemiás betegekben.

Interlead variability of the QT interval in surface 12-lead ECG (i.e. QT dispersion) reflects regional differences in ventricular recovery time and it has been linked to the occurrence of malignant arrhythmias in different cardiac diseases. The purpose of the study was to assess the effect of hemodialysis on QT dispersion in chronic hemodialyzed patients. The data of 34 patients (Male/Female = 21/13, mean age 54 +/- 15 years) on chronic hemodialysis were studied. Simultaneous 12 lead ECGs were recorded pre- and post-hemodialysis in a standard setting. The QT intervals for each lead were measured manually by one observer. Each QT interval was corrected for patient's heart rate: QTc = QT/square route of RR (sec). The maximal QT interval changed from 449 +/- 43 to 469 +/- 41 ms (p < 0.01). The maximal QTc interval increased from 482 +/- 42 to 519 +/- 33 ms (p < 0.01). The QT dispersion changed rom 56 +/- 15 to 85 +/- 12 ms (p < 0.001), and the QTc interval from 62 +/- 18 to 95 +/- 17 ms (p < 0.001). During hemodialysis the serum potassium and phosphate decreased from 5.5 +/- 0.8 to 3.9 +/- 0.5 (p < 0.001), and from 2.3 +/- 0.5 to 1.6 +/- 0.4, respectively, whereas calcium level increased from 2.2 +/- 0.23 to 2.5 +/- 0.22 (p < 0.001). It can be concluded that the hemodialysis increased the inhomogeneity of regional ventricular repolarization. Measurement of QT and QTc dispersion by a cheap and simple bedside method could predict the increased myocardial inhomogeneity in dialyzed patients.

The serum paraoxonase activity in patients with chronic renal failure and hyperlipidemia.

Human serum paraoxonase is physically associated with an apolipoprotein (Apo-A1) and clusterin-containing high-density lipoprotein (HDL) and prevents low-density lipoprotein from lipid peroxidation. The aim of our study was to determine whether paraoxonase activity or phenotype is altered in patients with chronic renal failure and in hyperlipidemic subjects without renal insufficiency and to compare the values with those of healthy controls. We investigated the serum paraoxonase activity and polymorphism in 119 hemodialyzed uremic patients, 107 patients with primary hyperlipoproteinemia, and in 110 healthy control subjects. The serum paraoxonase activity was significantly decreased both in hyperlipidemic (p < 0.01) and uremic patients (p < 0.001) as compared with controls. On comparison, the serum paraoxonase activity was significantly lower (p < 0.001) in uremic than in hyperlipoproteinemic patients. The HDL and Apo-A1 levels were as follows: uremic < hyperlipidemic < control. To assess whether the observed reduction in paraoxonase activity was due to HDL and Apo-A1 level decreases, we standardized the enzyme activity for HDL and Apo-A1 concentrations. We found that the standardized paraoxonase activity (paraoxonase/HDL ratio) was also lower in the uremic patients (103.3 +/- 69.5) as compared with hyperlipidemic patients (137.64 +/- 81.0) and controls (194.45 +/- 94.45). The standardized values for Apo-A1 showed a similar tendency: paraoxonase/Apo-A1 ratio in uremic patients 89.64 +/- 47.8, in hyperlipidemic patients 128.12 +/- 69.83, and in controls 161.40 +/- 47.35. The phenotypic distribution of paraoxonase (AA, AB, BB) did not change significantly in the patient groups. These results suggest that HDL concentration and phenotypic distribution of paraoxonase may not be the only determining factors, but that other as yet undetermined factors could be involved in the enzyme activity changes.