Changes in hormones after apneic hypoxia/hypercapnia - An investigation in voluntary apnea divers.

BACKGROUND: Prolonged apnea is characterized by hypoxia/hypercapnia. Hypoxia can be associated with hormonal dysfunction. We raised the question as to whether steroid hormonal and gonadotropin levels could be influenced by short-term hypoxia/hypercapnia in a model of dry apnea in trained apnea divers. METHODS: Adrenal, sex steroid and pituitary hormones were measured in ten trained voluntary apnea divers before, immediately after, 0.5 h and 4 h after a maximal breath-hold. Apnea was carried out under dry conditions. RESULTS: Corticosterone, progesterone, cortisol, 17-OH-progesterone, dehydroepiandrosterone and androstenedione showed a significant continuous increase with a maximum at 0.5 h after apnea, followed by a decrease back to or below baseline at 4 h after apnea. Testosterone, estradiol, cortisone and dihydrotestosterone showed a decrease 4 h after apnea. Dehydroepiandrosteronesulfate, luteinizing hormone (LH) and follicle stimulating hormone (FSH) showed no significant changes. CONCLUSION: Even a single apnea resulted in two different patterns of hormone response to apnea, with increased adrenal and reduced sex steroid levels, while LH/FSH showed no clear kinetic reaction. Apnea divers might be a suitable clinical model for hypoxic disease.

Antihormone treatment differentially regulates PSA secretion, PSMA expression and 68Ga-PSMA uptake in LNCaP cells.

BACKGROUND: In recent years, a variety of innovative therapeutics for castration-resistant prostate cancer have been developed, including novel anti-androgenic drugs, such as abiraterone or VPC-13566. Therapeutic monitoring of these pharmaceuticals is performed either by measuring PSA levels in serum or by imaging. PET using PSMA ligands labeled with Fluor-18 or Gallium-68 is the most sensitive and specific imaging modality for detection of metastases in advanced prostate cancer. To date, it remains unclear how PSMA expression is modulated by anti-hormonal treatment and how it correlates with PSA secretion. METHODS: We analyzed modulation of PSMA-mRNA and protein expression, 68Ga-PSMA uptake and regulation of PSA secretion by abiraterone or VPC-13566 in LNCaP cells in vitro. RESULTS: We found that abiraterone and VPC-13566 upregulate PSMA protein and mRNA expression but block PSA secretion in LNCaP cells. Both anti-androgens also enhanced 68Ga-PSMA uptake normalized by the number of cells, whereas abiraterone and VPC-13566 reduced 68Ga-PSMA uptake in total LNCaP monolayers treated due to cell death. CONCLUSION: Our data indicate that PSA secretion and PSMA expression are differentially regulated upon anti-androgen treatment. This finding might be important for the interpretation of 68Ga-PSMA PET images in monitoring therapies with abiraterone and VPC-13566 in prostate cancer patients, but needs to be validated in vivo.

Switching tenofovir disoproxil fumarate to tenofovir alafenamide in a real life setting: what are the implications?

OBJECTIVES: Development of novel antiretrovirals aims at reducing long-term toxicities. Tenofovir disoproxil fumarate (TDF) has been associated with potential nephrotoxicity. The aim of our study was to assess the impact of switching from TDF to tenofovir alafenamide (TAF) on functional nephropathy and lipid parameters in a real-life setting. METHODS: We retrospectively analysed data from 347 HIV-infected patients switching from a TDF- to a TAF-containing regimen between April and December 2016. Sociodemographic, clinical and laboratory data were collected at TDF-to-TAF switch, and at 3 and 6 months thereafter. Proteinuria and albuminuria were classified according to Kidney Diseases Improving Global Outcomes (KDIGO) guidelines. RESULTS: At time of switch, moderately and severely increased proteinuria was detected in 32% and 8% of patients, respectively; however, urine dipstick analysis was negative in 84% and 42%, respectively. Moderately and severely increased albuminuria was found in 17% and 3% of patients, respectively. In patients with a urinary protein-to-creatinine ratio (UPCR) ≥ 150 mg/g, the mean value declined from 416 mg/g at baseline to 272 mg/g (P < 0.001) and 242 mg/g (P < 0.001) after 3 and 6 months, respectively. Patients with an albumin-to-creatinine ratio (UACR) ≥ 30 mg/g showed no significant decrease of albuminuria. Mean total cholesterol increased from 187 mg/dL at baseline to 202 (P < 0.001) and 208 mg/dL (P < 0.001) at 3 and 6 months, respectively, and mean low-density lipoprotein (LDL) cholesterol increased from 114 mg/dL at baseline to 124 (P < 0.001) and 128 mg/dL (P < 0.001), respectively. As mean high-density lipoprotein (HDL) cholesterol increased from 50 mg/dL at baseline to 54 (P < 0.001) and 57 mg/dL (P < 0.001) at 3 and 6 months, respectively, the LDL:HDL ratio remained stable. CONCLUSIONS: In an aging HIV-infected cohort, proteinuria and albuminuria were common findings and were underdiagnosed via urine dipstick. Our real-life data suggest that laboratory markers of moderately/severely increased proteinuria improved after TDF-to-TAF-switch. Lipid profiles were not aggravated. Long-term follow-up is needed to determine the clinical benefit of the TDF-to-TAF switch.

Cardiovascular magnetic resonance assessment of acute cardiovascular effects of voluntary apnoea in elite divers.

BACKGROUND: Prolonged breath holding results in hypoxemia and hypercapnia. Compensatory mechanisms help maintain adequate oxygen supply to hypoxia sensitive organs, but burden the cardiovascular system. The aim was to investigate human compensatory mechanisms and their effects on the cardiovascular system with regard to cardiac function and morphology, blood flow redistribution, serum biomarkers of the adrenergic system and myocardial injury markers following prolonged apnoea. METHODS: Seventeen elite apnoea divers performed maximal breath-hold during cardiovascular magnetic resonance imaging (CMR). Two breath-hold sessions were performed to assess (1) cardiac function, myocardial tissue properties and (2) blood flow. In between CMR sessions, a head MRI was performed for the assessment of signs of silent brain ischemia. Urine and blood samples were analysed prior to and up to 4 h after the first breath-hold. RESULTS: Mean breath-hold time was 297 ± 52 s. Left ventricular (LV) end-systolic, end-diastolic, and stroke volume increased significantly (p < 0.05). Peripheral oxygen saturation, LV ejection fraction, LV fractional shortening, and heart rate decreased significantly (p < 0.05). Blood distribution was diverted to cerebral regions with no significant changes in the descending aorta. Catecholamine levels, high-sensitivity cardiac troponin, and NT-pro-BNP levels increased significantly, but did not reach pathological levels. CONCLUSION: Compensatory effects of prolonged apnoea substantially burden the cardiovascular system. CMR tissue characterisation did not reveal acute myocardial injury, indicating that the resulting cardiovascular stress does not exceed compensatory physiological limits in healthy subjects. However, these compensatory mechanisms could overly tax those limits in subjects with pre-existing cardiac disease. For divers interested in competetive apnoea diving, a comprehensive medical exam with a special focus on the cardiovascular system may be warranted. TRIAL REGISTRATION: This prospective single-centre study was approved by the institutional ethics committee review board. It was retrospectively registered under ClinicalTrials.gov (Trial registration: NCT02280226 . Registered 29 October 2014).

Parenteral trace element provision: recent clinical research and practical conclusions.

The aim of this systematic review (PubMed, www.ncbi.nlm.nih.gov/pubmed and Cochrane, www.cochrane.org; last entry 31 December 2014) was to present data from recent clinical studies investigating parenteral trace element provision in adult patients and to draw conclusions for clinical practice. Important physiological functions in human metabolism are known for nine trace elements: selenium, zinc, copper, manganese, chromium, iron, molybdenum, iodine and fluoride. Lack of, or an insufficient supply of, these trace elements in nutrition therapy over a prolonged period is associated with trace element deprivation, which may lead to a deterioration of existing clinical symptoms and/or the development of characteristic malnutrition syndromes. Therefore, all parenteral nutrition prescriptions should include a daily dose of trace elements. To avoid trace element deprivation or imbalances, physiological doses are recommended.

Pulmonary hypertension in HIV infection: a prospective echocardiographic study.

OBJECTIVES: While idiopathic pulmonary arterial hypertension (PAH) is a rare disease, it is seen more frequently in patients with HIV infection. The aim of this study was to evaluate the prevalence of pulmonary hypertension (PH) in patients with HIV infection by echocardiographic screening. METHODS: Echocardiography and N-terminal of the prohormone brain natriuretic peptide measurement were used to examine the prevalence of PH prospectively in HIV-positive patients (n = 374) during routine follow-up visits for HIV disease. RESULTS: In echocardiographic screening, PH was detected in a total of 23 of 374 HIV-infected patients (6.1%). Of these, three patients (13%) presented with symptoms of dyspnoea and fatigue, and diagnosis of PAH was confirmed by right heart catheterization. Patients with systolic pulmonary artery pressure (sPAP) > 30 mmHg were more likely to be female, to have a history of injecting drug use and to originate from high-prevalence countries (HPCs). CONCLUSIONS: Echocardiographic screening detected PH in a substantial proportion of HIV-positive patients. Female gender, a history of injecting drug use and HPC origin were associated with a higher prevalence of HIV-associated PH. The relevance and long-term outcome of these findings need to be validated in follow-up studies, which are ongoing.

Oxygen saturation in pulse oximetry in hemoglobin anomalies.

Pulse oximetry is an essential diagnostic method in pediatric emergency medicine and pediatric intensive care. However, if undetected hemoglobin anomalies are the underlying cause measurements of low oxygen saturation can be interpreted incorrectly or may lead to unnecessary examinations. In 2 recently discovered hemoglobin anomalies, Hb Bonn and Hb Venusberg, this resulted in extensive and repeat cardiopulmonary examinations. This review aims to provide an overview of hemoglobin anomalies causing low oxygen saturation.We describe the methods required for differential diagnosis of hemoglobin anomalies, such as hemoglobin electrophoresis, High Performance Liquid Chromatography, hemoglobin gene sequencing and spectral photometry, and the difficulties with the interpretation of results. Furthermore, with a review of the literature we provide an extensive overview of hemoglobin anomalies which result in low oxygen saturation measurement in pulse oximetry. With the examples of Hb Bonn, a novel hemoglobin mutation of the proximal α1-globin, which results in false low pulse oximetry measurements of oxygen saturation, and Hb Venusberg, a low oxygen-affine hemoglobin mutation of the ß-globin, we highlight the difficulties arising from the respective case histories.In pediatric medicine, hemoglobin anomalies must be included in the diagnosis as a possible underlying cause of low oxygen saturation in case of ambiguous or conflicting pulse oximetry findings.

Evaluation of 2 hematology analyzers in body fluid mode versus flow cytometry immunophenotyping of mainly neurosurgical cerebrospinal fluid samples.

BACKGROUND: For CSF analysis, exact knowledge of the type and amount of cells is essential, especially for detection of infection or bleeding. The chamber count has been the current reference method to date, yet it is problematic due to its subjectivity depending on the examiner's skill and experience. Therefore, as a reference method, we used an impulse cytophotometric measurement with Epics XL owing to its improved objectify ability and compared this method to the measurement of CSF samples performed with the ADVIA 2120 and XE-5000. MATERIAL AND METHODS: 101 CSF samples were measured with the ADVIA 2120, XE-5000, and Epics XL. For impulse cytophotometric measurement, CD235a was used for identification of erythrocytes; CD45 for the entire leukocyte population; CD56, CD16 and CD14 for monocytes; CD3, CD4 and CD19 for lymphocytes;and CD13, CD15 and CD33 for neutrophile granulocytes. RESULTS: Regarding leukocyte measurements, a strong correlation was obtained between Epics XL and XE-5000 (r = 0.990), with the correlation between Epics XL and ADVIA 2120 not as strong (r = 0.538). This finding is due to the fact that with blood-stained CSF samples (erythrocytes >1,500/µl), no valid results were produced by the ADVIA 2120. In measurements of blood-free CSF samples, correlations between Epics XL, XE-5000, and ADVIA 2120 were almost identical (r = 0.985 and r = 0.964). The same applies to the correlation between polymorphonuclear and mononuclear cells (range 0.920-0.972). In erythrocyte measurements, the correlation between XE-5000 and ADVIA 2120 was excellent (r = 0.945). Impulse cytophotometric measurement of erythrocytes with CD 238 antibodies did not appear to be functional. CONCLUSION: In the measurement of leukocytes in CSF with the ADVIA 2120, no valid results could be obtained in blood-stained CSF samples (erythrocytes >1,500/µl). In blood-free CSF samples (erythrocytes <1,500/µl), measurements of leukocytes, and polymorphonuclear and mononuclear cells performed with the ADVIA 2120 and XE-5000 produced almost identical good results. Determination of CSF cells with the XE-5000 is presently the best automated method for counting leukocytes of blood-stained CSF.

Lipid, lipoprotein and apolipoprotein profiles in European adolescents and its associations with gender, biological maturity and body fat--the HELENA Study.

BACKGROUND/OBJECTIVES: To provide a detailed lipid profile of a European adolescent population considering age, gender, biological maturity, body mass index (BMI), fat mass (FM) and percentage body fat (BF). SUBJECTS/METHODS: Within Healthy Lifestyle in Europe by Nutrition in Adolescence (HELENA), a cross-sectional study was conducted to determine fasting serum concentrations of lipids, lipoproteins and apolipoproteins in 1076 adolescents aged 12.5-17.49 years from ten European centres. RESULTS: All serum lipid concentrations were significantly higher in girls than in boys. In boys, age was negatively correlated with high-density lipoprotein (HDL)-cholesterol and total cholesterol (TC), and positively associated with triacylglycerides (TAG) (P < 0.01) whereas no significant associations were observed in girls. Biological maturity was negatively associated with TC, HDL-, low-density lipoprotein (LDL)- and non-HDL cholesterol in boys (all P<0.05) and negatively correlated with HDL-cholesterol in girls (P<0.05). BMI, FM and BF were significantly correlated with HDL-cholesterol, LDL-cholesterol, non-HDL cholesterol, apolipoprotein (apo) A1, apoB and TAG in both boys and girls. CONCLUSIONS: The lipid profile in adolescents is strongly determined by gender. Biological maturity, FM and percentage BF contribute to the variance in lipid concentrations and should be considered in future evaluations of lipid status.

The plant sterol brassicasterol as additional CSF biomarker in Alzheimer's disease.

OBJECTIVE: Plant sterols (sitosterol, campesterol, stigmasterol and brassicasterol) are solely dietary-derivable sterols that are structurally very similar to cholesterol. In contrast to peripheral cholesterol, plant sterols can cross the blood-brain barrier and accumulate within mammalian brain. As an impaired function of the cerebrospinal fluid (CSF)-blood barrier is linked to neurodegenerative disorders, i.e. Alzheimer's disease (AD), we investigated whether this results in altered plant sterol concentrations in CSF. METHOD: Applying gas chromatography/mass spectrometry analysis, plant sterol concentrations were measured in plasma and CSF of patients with AD (n = 67) and controls (n = 29). Age, gender, plasma-to-CSF albumin ratio, CSF Aß(42) , CSF pTau, APOE4 genotype, and serum creatinine were applied as covariates in the statistical analysis for individual plant sterols in order to compare plasma and CSF plant sterol concentrations between patients with AD and controls. RESULTS: Albumin quotient was a consistent predictor in CSF for cholesterol and methyl plant sterols campesterol and brassicasterol. Comparison of lipid parameters per diagnosis based on relevant predictors revealed significantly lower concentrations of brassicasterol (P < 0.001) in CSF of patients with AD. Binary logistic regression analysis revealed that brassicasterol improved the predictive value when added to pTau and Aß42 in a biomarker model. CONCLUSION: Brassicasterol might be a relevant additional biomarker in AD.

[Evaluation of folate substitution in women with epilepsy. Determination of erythrocyte folic acid concentrations]. / Folsäuresubstitution bei Frauen mit Epilepsie. Evaluation des Substitutionseffektes durch intraerythrozytäre Folsäurebestimmung.

Insufficient maternal folate concentrations appear to be a fetal risk factor for neural tube defects (NTD). Erythrocyte folate concentrations are widely accepted as an indicator of tissue folate storage. We retrospectively evaluated erythrocyte folate concentrations to examine if a recommended daily dosage of 5 mg folic acid is sufficient to balance the impact of antiepileptic drugs (AED) on folate metabolism in women with epilepsy. Data of 48 women (mean age 30.3 years) with idiopathic epilepsy with generalized seizures (n=12) or symptomatic epilepsy with focal seizures (n=36) were available, 43 women submitted to further analysis and 30 women received AED monotherapy. Duration of folic acid supplementation varied between 0.5 and 12 months. The daily dosage of folic acid ranged from 0.4 to 15 mg and 32 women received 5 mg/day. Erythrocyte folate concentrations ranged from 282 to 1596 ng/ml (mean 780 ng/ml). In 29 out of the 32 women (90.6%) on 5 mg folic acid per day, red cell folate was ≥400 ng/ml. In previous studies the risk for NTD was estimated to be 0.8‰ if red cell folate was ≥400 ng/ml. Our results suggest that 5 mg/day folic acid as preconception supplementation in women with epilepsy is effective to balance the impact of AEDs on folate metabolism in women with epilepsy.

Sampling and processing of fresh blood samples within a European multicenter nutritional study: evaluation of biomarker stability during transport and storage.

INTRODUCTION: Analysis of several biological markers improves the quality and physiologic comprehension of data obtained in epidemiological nutritional studies. AIM: To develop a methodology that guarantees the centralized analysis and quality assurance of the most relevant blood parameters from fresh blood samples in adolescents in a European multicenter study. MATERIALS AND METHODS: Stability of selected nutrients and biomarkers (vitamins, fatty acids, iron metabolism and immunological parameters) chosen with respect to time and temperature of sample transport and storage was evaluated as part of the pilot study of the Healthy Lifestyle in Europe by Nutrition in Adolescence (HELENA) project. RESULTS: Routine biochemistry and iron status parameters included in the HELENA Cross-Sectional Study (CSS) protocol could be analyzed within 24 h from fresh blood samples without any stability problems (coefficient of variation (CV)<5%, P<0.05). However, stability tests for lymphocyte subpopulations, vitamin C and fatty acids showed that they are very unstable at room temperature without any treatment. Therefore, a special handling for these samples was developed. Vitamin C was stabilized with metaphosphoric acid and transported under cooled conditions (CV 4.4%, recovery rate >93%, P>0.05). According to the results, a specific methodology and transport system were developed to collect blood samples at schools in 10 European cities and to send them to the centralized laboratory (IEL, Bonn, Germany). To guarantee good clinical practice, the field workers were instructed in a training workshop and a manual of operation was developed. CONCLUSION: The handling and transport system for fresh blood samples developed for the European multicenter study HELENA is adequate for the final part of the HELENA-CSS and will provide, for the first time, reference values for several biological markers in European adolescents.

Beta-trace protein-based equations for calculation of GFR in renal transplant recipients.

Recently, we showed that serum beta-trace protein (BTP) is an alternative marker of glomerular filtration rate (GFR) in renal transplant recipients (RTR). We have now developed three BTP-based GFR formulae derived by multiple regression analyses from the patients who had participated in that study. Currently, we validated the diagnostic performance of these BTP-formulae in 102 consecutive RTR who underwent a technetium diethylenetriamine pentaacetic acid (DTPA) clearance for GFR measurement in comparison to the re-expressed Modification of Diet in Renal Disease (MDRD) equation and a recently proposed BTP-based equation (referred to as 'White equation'). The best-performing BTP formula was found to be: GFR = 89.85 x BTP(-0.5541)x urea(-0.3018). This equation estimated true GFR virtually without bias (+0.43 mL/min/1.73 m(2), not significant [NS]), while a small, but significant, overestimation was seen for the MDRD formula (+3.43 mL/min/1.73 m(2), p = 0.003). Precision and accuracies within 50% of true GFR (93.1% and 88.2%, respectively) tended to be higher for the BTP formula, but the differences did not reach significance. The White equation overestimated the true GFR by 9.43 mL/min/1.73 m(2)(p = 0.001), and was inferior with respect to precision and 50% accuracy (79.4%). BTP-based GFR calculations are reliable, and may serve as an alternative to the re-expressed MDRD equation.

Osteoporosis in haemophilia - an underestimated comorbidity?

A relationship between haemophilia and osteoporosis has been suggested, leading to the initiative for a larger study assessing this issue. Bone mineral density (BMD) was measured by osteodensitometry using dual energy X-ray absorptiometry (DEXA) in 62 male patients with severe haemophilia A; mean age 41 +/- 13.1 years, mean body mass index (BMI) 23.5 +/- 3.6 kg m(-2). Using the clinical score suggested by the World Federation of Hemophilia, all patients were assessed to determine the severity of their arthropathy. A reduced BMD defined as osteopenia and osteoporosis by World Health Organization criteria was detected in 27/62 (43.5%) and 16/62 (25.8%) patients, respectively. Fifty-five of sixty-two (88.7%) patients suffered from haemophilic arthropathy. An increased number of affected joints and/or an increased severity were associated with lower BMD in the neck of femur. Pronounced muscle atrophy and loss of joint movement were also associated with low BMD. Furthermore, hepatitis C, low BMI and age were found to be additional risk factors for reduced BMD in the haemophiliac. Our data shows that in haemophilic patients osteoporosis represents a frequent concomitant observation. The main cause for reduced bone mass in the haemophiliac is most probably the haemophilic arthropathy being typically associated with chronic pain and loss of joint function subsequently leading to inactivity. Further studies including control groups are necessary to elucidate the impact of comorbidities such as hepatitis C or HIV on the development of osteoporosis in the haemophiliac.

Cystatin C-based calculation of glomerular filtration rate in kidney transplant recipients.

Cystatin C (Cys C) has been shown to be an alternative marker of renal function. However, estimation of the glomerular filtration rate (GFR) based on Cys C has received little attention. Recently, several Cys C-based equations were developed in different patient cohorts. To date, the benefit of a Cys C-based GFR calculation in patients after renal transplantation (RTx) remains to be elucidated. We compared the diagnostic accuracy of three Cys C-based formulae (Larsson, Hoek, Filler which used an immunonephelometric method) with the results of the Modification of Diet in Renal Disease (MDRD) formula. GFR was measured by means of technetium-diethylenetriamine pentaacetic acid ((99m)Tc-DTPA) clearance in 108 consecutive patients after RTx. Correlation coefficients of all calculated GFR estimates with the true GFR were high but did not differ significantly from one another (0.83-0.87). The MDRD and Filler equations overestimated GFR significantly, whereas the Larsson equation significantly underestimated GFR. Bias of the Hoek formula was negligible. Precision of the Hoek (8.9 ml/min/1.73 m(2)) and Larsson equations (9.6 ml/min/1.73 m(2)) were significantly better than MDRD equations (11.4 ml/min/1.73 m(2); P< or =0.035 each). Accuracy within 30% of real GFR was 67.0 and 65.1% for the MDRD and Filler formulae, and 77.1% for the Larsson and Hoek formulae, respectively. Accuracy within 50% of true GFR for the Hoek formula (97.2%) was better than for the MDRD equations (85.3%). Cys C-based formulae may provide a better diagnostic performance than creatinine-based equations in GFR calculation after RTx.

NT-pro-BNP in obstructive sleep apnea syndrome is decreased by nasal continuous positive airway pressure.

OBJECTIVE: The aim of this study was to evaluate the impact of obstructive sleep apnea syndrome (OSAS) on B-type natriuretic peptide (BNP) and to determine the effect of nasal continuous positive airway pressure (nCPAP) treatment on BNP levels. BACKGROUND: Increased sympathetic activity, repetitive rises in blood pressure, and apnea-induced wall stress may contribute as a trigger to release BNP in OSAS. However, there is uncertainty about whether OSAS affects BNP and whether application of nasal continuous positive airway pressure (nCPAP) ventilation affects release of BNP. PATIENTS AND METHODS: A prospective study in 69 consecutive patients with suspected sleep disordered breathing referred to our sleep laboratory was conducted. OSAS was confirmed in 26 normotensive and 34 hypertensive patients and ruled out in nine normotensive patients (controls) by polysomnography (PSG). RESULTS: Baseline N-terminal fragment of BNP prohormone (NT-pro-BNP) did not differ significantly between OSAS patients (hypertensive: mean +/-SEM 60.8+/-9.9 pg/ml, normotensive: 43.2+/-6.8 pg/ml) and controls (36.5+/-8.5 pg/ml). Application of CPAP resulted in a significant decrease of NT-pro-BNP in hypertensive (60.8+/-9.9 pg/ml to 47.6+/-7.4 pg/ml, p=0.023) and normotensive OSAS (43.2+/-6.8 pg/ml to 29.6+/-5.3 pg/ml, p=0.0002). In contrast, controls showed no significant differences in NT-pro-BNP after a second PSG (36.5+/-8.5 pg/ml to 40.7+/-12.3 pg/ml, p=0.597). CONCLUSIONS: Normotensive and hypertensive OSAS was not associated with a significant elevation of NT-pro-BNP. Application of nCPAP decreased NT-pro-BNP levels significantly in normotensive and, in particular, hypertensive OSAS. These findings may provide further evidence of the potential for nCPAP to improve cardiovascular comorbidity and co-mortality in OSAS and sleep disordered breathing, in general.

Calculation of glomerular filtration rate based on cystatin C in cirrhotic patients.

BACKGROUND: Plasma creatinine and creatinine clearance are of limited value for the estimation of renal function in cirrhotics. In these patients, cystatin C (Cys C) has been proposed as an alternative marker of glomerular filtration rate (GFR) and Cys C-based equations for calculation of GFR have been developed in non-cirrhotic patient cohorts. METHODS: We retrospectively analyzed correlation, bias, precision and accuracy of two Cys C-based formulae (Larsson and Hoek) for GFR estimation in comparison with two creatinine-based equations (Cockroft & Gault and MDRD). The Cys C was determined by an immunonephelometric method. The GFR was measured by means of inulin clearance in 44 consecutive patients with liver cirrhosis. RESULTS: On average, inulin clearance was 28.3 (95% CI: 29.2-41.3 ml/min/1.73 m2). Creatinine as well as Cys C-based equations overestimated the true GFR by 105-154%. However, Cys C-based equations showed significantly lower bias and higher precision than the creatinine-based formulae. Correlation and accuracy tended to be better with the Hoek and Larsson equation than with the Cockroft & Gault or MDRD formulae. Hoek and Larsson equations showed a similar diagnostic performance in all statistical procedures. CONCLUSION: Our data suggest a significant improvement of GFR estimation in liver cirrhotics by means of the Cys C-based Hoek and Larsson formulae. However, all estimates remain a crude approximation of true GFR and thus cannot replace gold standard methods.

Non-functioning pituitary adenomas: endocrinological and clinical outcome after transsphenoidal and transcranial surgery.

AIM: To study improvement of anterior pituitary function after transsphenoidal and transcranial surgery of non-functioning (NF) pituitary macro- and microadenomas. METHODS: We retrospectively examined 155 patients with NF adenomas preoperatively and 3 months, 1 year and 2 years postoperatively. 130 patients harboured a macroadenoma, 109 underwent transsphenoidal (group one), 21 transcranial surgery (group two). 25 patients presented a microadenoma (transsphenoidal surgery, group three). Endocrine studies included basal serum levels and dynamic testing of anterior pituitary partial function. Clinical symptoms and hormone replacement therapy were documented. RESULTS: Preoperatively, in group one, two and three, somatotropic function was impaired in 85, 90 and 80 %, gonadotropic in 61, 57 and 24 %, corticotropic in 31, 38 and 28 %, thyreotropic in 32, 38 and 12 % and lactotropic in 22, 38 and 32 % cases, respectively. Pituitary functions did not improve significantly after transsphenoidal or transcranial surgery. Presurgically, 63, 62 and 0 % patients complained about visual impairments, 60, 48 and 40 % about headache, 53, 24 and 36 % about fatigue and 28, 33 and 20 % about disturbance of cycle or potency. After transsphenoidal surgery, impaired vision, headache and fatigue improved within 3 months; after transcranial surgery, only headache improved. Preoperatively, pituitary malfunctions were treated adequately. Postsurgically, more patients received adrenal and thyroid hormone substitution, less patients received sex hormones than examinations proved necessary. CONCLUSION: Anterior pituitary function of NF adenoma patients did not improve significantly after transsphenoidal or transcranial surgery. After transsphenoidal surgery, most clinical symptoms normalised within 3 months. In some of the patients, substitution was not optimally adjusted to hormonal impairments.

Effect of propranolol and depot lanreotide SR on postprandial and circadian portal haemodynamics in cirrhosis.

BACKGROUND: Long-acting somatostatin analogues have been suggested as an alternative to propranolol for the prevention of variceal rebleeding. AIM: To compare the effectiveness of lanreotide SR, a new depot formulation injected once-weekly, and propranolol in reducing circadian portal blood flow (PVF) and meal-stimulated hepatic venous pressure gradient (HVPG) in patients with liver cirrhosis. METHODS: Patients were randomized to receive either lanreotide SR intramuscularly (30 mg once weekly, n=12) or propranolol (n=12) orally. Hemodynamic measurements were performed on day 0 and on day 21 after a 3-week period of drug administration, while patients received three standard oral liquid test meals. On each study day 27 PVF measurements were performed over 24 h and eight measurements of HVPG during the first postprandial period. RESULTS: Propranolol was more effective than lanreotide SR in reducing baseline HVPG (-21.9 vs. -13.6%, P=0.04) and meal-stimulated HVPG (-16.6 vs. -3.8%, P=0.04). Propranolol reduced circadian PVF significantly by 9.3% (P=0.03) but not lanreotide SR. CONCLUSIONS: Long-term treatment with propranolol reduced baseline and postprandial HVPG and circadian PVF, while lanreotide SR did not. The results of our study do not encourage clinical testing of lanreotide SR 30 mg for the prevention of variceal haemorrhage.

Cystatin C as an endogenous marker of glomerular filtration rate in renal transplant patients.

BACKGROUND: Serum creatinine is the most common endogenous marker used to estimate the glomerular filtration rate (GFR). However, creatinine depends considerably on muscle mass, and its tubular secretion increases, especially in chronic renal failure. Cystatin C is a 13-kD protease inhibitor which is produced by all nucleated cells and is independent of muscle mass and sex. Cystatin C is eliminated by glomerular filtration and metabolized by proximal tubular cells. Its measurement has been proposed as an alternative and more sensitive marker of GFR than creatinine in patients with slight to moderately decreased GFR. METHODS: We investigated serum cystatin C levels in comparison with creatinine as a single measurement for estimation of GFR in 173 patients after renal transplantation. GFR was calculated as creatinine clearance according to standard equations. RESULTS: Serum creatinine correlated well with cystatin C (r = 0.84; p < 0.0001). No significant differences were obtained for the comparison of the linear correlation of 1/creatinine with creatinine clearance (r = 0.77; p < 0.0001) and for the linear correlation of 1/cystatin C with creatinine clearance (r = 0.73; p < 0.0001). However, we found a significant advantage of cystatin C in detecting a clinical relevant reduction of kidney function (GFR <70 ml/min; p = 0.0047, McNemar test). CONCLUSION: Cystatin C is an alternative marker for the assessment of GFR in renal allograft recipients that may be superior to creatinine.