Integrated central blood pressure-aortic stiffness risk score for cardiovascular risk stratification in chronic kidney disease.

BACKGROUND AND AIMS: The aim of this study was to develop an integrated central blood pressure-aortic stiffness (ICPS) risk score to predict cardiovascular events. METHODS: It was a retrospective cohort study. A total of 100 chronic kidney disease (CKD) patients on conservative therapy were included. Pulse wave velocity (PWV), central systolic blood pressure (cSBP), and central pulse pressure (cPP) were measured. A score was assigned to tertiles of PWV (0-2), cPP (0-2), and cSBP (0 to the first and second and 1 to the third tertile) based on each parameter's ability to individually predict cardiovascular outcome. The sum of these scores and three ICPS risk categories as predictors were studied. Finally, we compared discrimination of the ICPS risk categories with PWV, cSBP, and cPP. RESULTS: Adjusted for age and sex, patients in high and very high ICPS risk categories had increased cardiovascular risk (HR: 3.52, 95% CI: 1.65-7.49; HR: 7.56, 95% CI: 3.20-17.85, respectively). High and very high ICPS risk categories remained independent predictors in a model adjusted for multiple CV risk factors (HR: 4.58, 95% CI: 1.65-7.49; HR: 8.56, 95% CI: 3.09-23.76, respectively). ICPS risk categories (Harrell's C: 0.723, 95% CI: 0.652-0.795) showed better discrimination than PWV (Harrell's C: 0.659, 95% CI: 0.586-0.732, p = 0.028) and cSBP (Harrell's C: 0.660, 95% CI: 0.584-0.735, p = 0.008) and there has been a tendency of significance in case of cPP (Harrell's C: 0.691, 95% CI: 0.621-0.761, p = 0.170). CONCLUSION: The ICPS score may clinically importantly improve the identification of CKD patients with elevated cardiovascular risk.

The significance of micro- and macrovascular biomarkers on cardiovascular outcome in chronic kidney disease: a prospective cohort study.

Measures of small and large artery dysfunction have not been investigated in a single cohort for the prediction of cardiovascular (CV) events in patients with nondialysed (ND) chronic kidney disease (CKD). This prospective cohort study aimed to determine whether central pulse wave velocity (cPWV), central pulse pressure (CPP) or microvascular post-occlusive reactive hyperaemia area (PORHHA) independently predict CV events and mortality in CKD-ND. A total of 94 stage 1-5 CKD-ND (65.3±13.1 years; estimated glomerular filtration rate 35.3 (22.8-49.4) ml min(-1) per 1.73 m(2)) patients were followed-up for a median of 52 (36-65) months and had baseline cPWV and CPP measured by applanation tonometry and PORHHA by laser Doppler flowmetry. Multiple failure time Cox regression models were used to determine the predictive role of vascular parameters on CV mortality and events. Based on multiple linear regressions, baseline age, diabetes, CV disease, and systolic blood pressure (SBP) were independently related to cPWV (R(2)=0.3), SBP and PORHHA to CPP (R(2)=0.45), whereas CPP was the only parameter independently related to PORHHA (R(2)=0.16, all P<0.05). During follow-up, 41 CV events occurred (14 CV deaths). In univariate analyses, cPWV (1.07 (1.02-1.13) per m s(-1)), CPP (1.04 (1.01-1.07) per mm Hg) and lnPORHHA (0.70 (0.58-0.85) per ln(PU × s)) were all related to the outcome. Baseline diabetes (HR 3.07 (1.65-5.68)), lnFGF23 (fibroblast growth factor-23; 1.86 (1.13-3.06) per RU ml(-1)) and CPP (1.04 (1.01-1.07) per mm Hg) were independent predictors of CV events. The impaired pulsatile component of large arteries (CPP) independently of other vascular markers (cPWV, PORHHA) predicted CV outcomes in CKD-ND. CPP may integrate the information provided by cPWV and PORHHA.

European Society of Hypertension practice guidelines for home blood pressure monitoring.

Self-monitoring of blood pressure by patients at home (home blood pressure monitoring (HBPM)) is being increasingly used in many countries and is well accepted by hypertensive patients. Current hypertension guidelines have endorsed the use of HBPM in clinical practice as a useful adjunct to conventional office measurements. Recently, a detailed consensus document on HBPM was published by the European Society of Hypertension Working Group on Blood Pressure Monitoring. However, in daily practice, briefer documents summarizing the essential recommendations are needed. It is also accepted that the successful implementation of clinical guidelines in routine patient care is dependent on their acceptance by involvement of practising physicians. The present document, which provides concise and updated guidelines on the use of HBPM for practising physicians, was therefore prepared by including the comments and feedback of general practitioners.

Refractory hypertension and sleep apnoea: effect of CPAP on blood pressure and baroreflex.

This study was undertaken to determine whether abolition of obstructive sleep apnoea (OSA) by continuous positive airway pressure (CPAP) could reduce blood pressure (BP) in patients with refractory hypertension. In 11 refractory hypertensive patients with OSA, the acute effects of CPAP on nocturnal BP were studied during sleep and its longer term effects on 24-h ambulatory BP after 2 months. During a single night's application, CPAP abolished OSA and reduced systolic BP in stage 2 sleep from 138.3 +/- 6.8 to 126.0 +/- 6.3 mmHg. There was also a trend towards a reduction in average diastolic BP (from 77.7 +/- 4.5 to 72.9 +/- 4.5). CPAP usage for 2 months was accompanied by an 11.0 +/- 4.4 mmHg reduction in 24-h systolic BP. In addition, both the nocturnal and daytime components of systolic BP fell significantly by 14.4 +/- 4.4 and 9.3 +/- 3.9 mmHg, respectively. Diastolic BP was reduced significantly at night by 7.8 +/- 3.0 mmHg. In patients with refractory hypertension, acute abolition of obstructive sleep apnoea by continuous positive airway pressure reduces nocturnal blood pressure. These data also suggest that continuous positive airway pressure may reduce nocturnal and daytime systolic blood pressure chronically. Randomised trials are needed to confirm the latter results.

Calcium-sensing receptor A986S polymorphism in human rectal cancer.

BACKGROUND AND AIMS: In vivo and in vitro experiments show the protective role of calcium ions (Ca2+) against colorectal cancer. The calcium-sensing receptor (CaSR) detects extracellular Ca2+ concentration. An association between the CaSR A986S polymorphism and serum calcium in healthy adults has been reported. Subjects with AA genotype had lower serum concentrations of Ca2+ than other genotypes. The expression of erbB-2, epidermal growth factor receptor (EGFR), p53, and ras in colorectal cancer has been suggested to have diagnostic and prognostic significance. PATIENTS AND METHODS: We investigated the relationship between the CaSR A986S polymorphism and the expression of erbB-2, EGFR, p53, and ras as well as the UICC stage in 56 patients with rectal cancer. RESULTS: The occurrence of the genotype AA was not different in cancer patients and in 112 controls. In the presence of the coexpression of major oncogenes, patients with genotype AA were in significantly higher UICC stages than in the case of AS genotype. During the follow-up period AA genotype showed a tendency for poor prognosis. CONCLUSIONS: Our observation raises the possibility that genetic alterations of CaSR influence the pathogenesis of rectal cancer.

High prevalence of unrecognized sleep apnoea in drug-resistant hypertension.

OBJECTIVES: To determine the prevalence of obstructive sleep apnoea (OSA) in adult patients with drug-resistant hypertension, a common problem in a tertiary care facility. DESIGN: Cross-sectional study. SETTING: University hypertension clinic. PATIENTS AND METHODS: Adults with drug-resistant hypertension, defined as a clinic blood pressure of > or = 140/90 mmHg, while taking a sensible combination of three or more antihypertensive drugs, titrated to maximally recommended doses. Each of the 41 participants completed an overnight polysomnographic study and all but two had a 24 h ambulatory blood pressure measurement. RESULTS: Prevalence of OSA, defined as an apnoea-hypopnoea index of > or = 10 obstructive events per hour of sleep, was 83% in the 24 men and 17 women studied. Patients were generally late middle-aged (57.2 +/- 1.6 years, mean +/- SE), predominantly white (85%), obese (body mass index, 34.0 +/- 0.9 kg/m2) and taking a mean of 3.6 +/- 0.1 different antihypertensive medications daily. OSA was more prevalent in men than in women (96 versus 65%, P = 0.014) and more severe (mean apnoea-hypopnoea index of 32.2 +/- 4.5 versus 14.0 +/- 3.1 events/h, P = 0.004). There was no gender difference in body mass index or age. Women with OSA were significantly older and had a higher systolic blood pressure, lower diastolic blood pressure, wider pulse pressure and slower heart rate than women without OSA. CONCLUSIONS: The extraordinarily high prevalence of OSA in these patients supports its potential role in the pathogenesis of drug-resistant hypertension, and justifies the undertaking of a randomized controlled trial to corroborate this hypothesis.

Hypertension aggregates in families of kidney stone patients with high urinary excretion of uric acid.

OBJECTIVE: To determine whether kidney stone disease (KSD) and hypertension (HTN) share a common familial component that is determined by a specific urinary biochemical abnormality. DESIGN: Familial aggregation study. PATIENTS: Two hundred and twelve KSD patients, aged 18-50 years, collected a 24-h urine sample to measure the urinary excretion of uric acid, calcium, oxalate, magnesium and citrate, and were interviewed about the occurrence of HTN among first-degree relatives. OUTCOME: Positive family history (FHx) of HTN defined as two or more relatives with HTN, and HTN occurring in the fathers, mothers and siblings. RESULTS: Positive FHx of HTN was significantly associated with increasing urinary excretion of uric acid (P = 0.03) but not with the excretion of the other substances. When the patients were divided into those with and without hyperuricosuria, the adjusted odds ratio (OR) for positive FHx of HTN in a hyperuricosuric KSD patient was 3.8 (95% CI, 1.22-11.66). Separate analysis on the occurrence of HTN in the fathers, mothers and siblings of the probands indicated that hyperuricosuria is positively related to HTN occurring in the siblings of the patients (P < 0.001) but not in the fathers or in the mothers. The adjusted OR for HTN occurring in siblings of hyperuricosuric patients compared with siblings of non-hyperuricosuric patients was 3.8 (2.12-6.67). CONCLUSION: Siblings of KSD patients with hyperuricosuria had a significantly increased prevalence of HTN that could not be accounted for by age, family size, body-mass index and personal history of HTN of the probands. Additional studies need to be undertaken to determine whether this familial clustering has a genetic or environmental origin.

[Comparative study of 24-hour ambulatory blood pressure monitors with standard zero and random zero sphygmomanometers]. / 24 órás ambuláns vérnyomásmonitorozó készülék összehasonlító vizsgálata standard zéró és random zéró vérnyomásmérövel.

The aim of the study was to evaluate the accuracy of the most widespread 24-hour ambulatory blood pressure monitor in Hungary. The test was based on simultaneous measurement on the same arm with the test device and standard zero or random zero sphygmomanometer in 100 patients. The difference between the blood pressure values measured by the test device and by the standard device was calculated in each case, and a relationship between this difference and the actual blood pressure of the patient was analysed. Actual blood pressure was considered as the average of the blood pressure measured by the test and that by the standard device. Regarding the diastolic values, the mean difference between the values obtained by the test device and the standard zero sphygmomanometer was -3.8 +/- 7.55 mm Hg (p > 0.05), and that between the test device and the random zero sphygmomanometer was -0.1 +/- 6.05 mm Hg (p > 0.05). This differences did not reach statistical significance. Regarding the systolic values, the difference showed significant positive correlation with the actual blood pressure level of the patient, meaning that at higher blood pressure values the difference between the data gained by the test and standard device is greater than at lower actual blood pressure levels. Finally, according to the criteria of the British Hypertension Society, our device could be graded "C" both for diastolic and systolic values against the standard zero sphygmomanometer, and "C" for systolic and "B" for diastolic blood pressure against the random zero sphygmomanometer.

Body sodium, atrial natriuretic peptide and blood pressure in diabetes mellitus.

Diabetes mellitus (DM) is frequently associated with hypertension for which an independent pathomechanism has been suggested. We studied 26 patients with insulin-dependent (IDDM) and 18 patients with non-insulin-dependent (NIDDM) uncomplicated DM; all patients were in metabolic balance and none of them had hypertension. Exchangeable body sodium (NaE was estimated by isotope dilution, using appr. 1.1 Mbq 24NA. In a subset of 8 IDDM and 8 NIDDM patients atrial natriuretic peptide (ANP) plasma concentration was determined prior to and after the infusion of 2000 ml physiological saline over 2 hr. NaE was significantly increased both in IDDM and NIDDM patients (104.4 +/- 11.4% and 109.9 +/- 8.0% of the normal value for healthy subjects of identical body surface area; p < 0.05 and < 0.001 resp.). Mean blood pressure (MBP) correlated significantly with NaE in both groups (r = 0.364 and r = 0.520; p < 0.05 and < 0.025, resp.) but not in healthy control subjects (r = 0.112; N.S.). Resting ANP levels were not significantly different in IDDM (34.9 +/- 11.3 pg/ml), NIDDM (42.6 +/- 11.7 pg/ml) or control subjects (40.9 +/- 17.2 pg/ml) however the infusion of saline resulted in a significantly greater increase of plasma ANP in the NIDDM patients (to 82.9 +/- 43.2 pg/ml; P < 0.01) than in the controls (55.6 +/- 23.7 pg/ml; P < 0.01) which was associated with a significantly less increase in sodium excretion (UNAV) in the NIDDM patients (+86% vs. 3170%; P < 0.02) indicating down-regulation of ANP receptors in the kidney of NIDDM patients.(ABSTRACT TRUNCATED AT 250 WORDS)

[The role of exchangeable sodium content of the body in cases of hypertension of various etiology]. / A szervezet kicserélhetö nátrium-tartalmának szerepe különbözö aetiológiájú hypertoniákban.

Measurement of exchangeable sodium by isotope dilution is a relatively simple, reliable method for the determination of body sodium contents, which can be used in the clinical practice without significant health hazard to the patient. When computed to body surface area, the values for exchangeable sodium can be compared in patients of different body build. Exchangeable sodium may be variably increased in different clinical conditions associated with hypertension, thus increased sodium contents of the body is of major importance in the pathogenesis of hypertension caused by all forms of mineralocorticoid excess, and in the majority of patients with chronic renal insufficiency. In several endocrine disorders, e. g., acromegaly, hypothyroidism, increased sodium space does not play any significant part in the pathogenesis of hypertension. In diabetes mellitus, exchangeable sodium may be increased already prior to the development of hypertension, however it is still a matter of debate whether this abnormality is involved in the pathogenesis of hypertension in these patients. It seems now beyond any doubt that body sodium is normal in patients with essential hypertension, including those with the low renin form of the disease; nevertheless, some data indicate that blood pressure may be volume dependent in elderly patients with essential hypertension.

Exchangeable body sodium in normal man: analysis of various frames of reference.

Exchangeable sodium is a reliable measure of body sodium contents. Since fat tissue contains significantly less sodium per unit of weight than other tissues, leanness of an individual may considerably affect exchangeable body sodium. Thus, subjects of different body size can be compared only when body build is considered. To evaluate various frames of reference, we analysed the relationship between exchangeable sodium as determined by isotope dilution and various parameters of body size. Body weight, body height, body surface area, and leanness index correlated significantly with exchangeable sodium, the closest relationship having been obtained with body surface area (r = 0.790; p less than 0.001). When analysing males and females separately (n = 18 and 36, resp.), best parallelism of regression lines was also obtained with body surface area. It is concluded that exchangeable sodium should be referred to unit of body surface area, expressing each individual's value as percent of the normal predicted value calculated from the regression equations y = 1388x + 370 and y = 1554x - 196 for males and females, respectively.