Dose requirements among hemodialysis patients treated with darbepoetin-alpha or epoetin-beta.

BACKGROUND/AIMS: In a cohort of hemodialysis patients, we evaluated the hypothesis that weekly administration of intravenous (IV) darbepoetin-alpha (DA) was associated with lower total erythropoiesis-stimulating agent (ESA) requirements as compared to a regimen of multiple subcutaneous (SC) doses per week of epoetin-beta (EB). METHODS: We studied 1,159 hemodialysis patients who were treated exclusively with either IV DA or SC EB across a network of Portuguese clinics during 2004. Linear regression was used to assess the adjusted relationship between the ESA regimen and weekly ESA requirements over the period of observation. Generalized estimating equations were applied in order to model the population average effects of the correlated mean weekly ESA dose for each individual. We also calculated propensity scores for the receipt of DA and assessed the relationship between ESA type and dose requirement within each quintile of the score. RESULTS: The adjusted dose of IV DA, when expressed as a proportion of the dose used in EB-treated patients, did not differ from the dose administered to EB recipients (0.961, 95% CI 0.904, 1.021). A similar relationship was observed within each propensity score quintile. CONCLUSIONS: Hemodialysis patients who received IV DA had dose requirements that were similar to their counterparts who were treated with SC EB. A once-weekly dosing regimen and avoidance of SC administration enhance the attractiveness of DA as an alternative to traditional ESAs. The potential for unmeasured confounding, restriction to a population that was treated with a single ESA preparation and application of a 200 IU:1 mug EB:DA dose conversion are important limitations of this study.

Diastolic function in several stages of chronic kidney disease in patients with autosomal dominant polycystic kidney disease: a tissue Doppler imaging study.

BACKGROUND: This study evaluates the prevalence of diastolic dysfunction (DD) in several stages of chronic kidney disease (CKD) in patients with autosomal dominant polycystic kidney disease (ADPKD). METHODS: 107 ADPKD patients performed echocardiographic and Doppler studies and a tissue Doppler imaging (TDI) study. Patients were divided in three groups: group 1, 57 patients with CKD stage I, group 2, 37 patients in stages II and III, and group 3, 13 patients with CKD stages IV and V (not on dialysis). RESULTS: In transmitral Doppler, 1 patient in group 1 compared to 5 in group 2, and 4 in group 3 exhibited DD (p < 0.005); moreover, E/A ratio decreases progressively from group 1 to 3 (p < 0.0001). In TDI, DD was observed in 8 patients in group 1, 17 in group 2, and 8 in group 3 had DD (p < 0.001). Em velocity, the best TDI parameter for DD, correlated with age, renal function and blood pressure. When adjusted for age, increased left ventricular mass index and decreased renal function were independent risk factors of DD. CONCLUSIONS: DD occurred progressively as renal function deteriorates in patients with ADPKD and this effect is independently related to age and blood pressure.

Ambulatory blood pressure measurement in young normotensive patients with autosomal dominant polycystic kidney disease.

INTRODUCTION: Autosomal dominant polycystic kidney disease (ADPKD) is the most common genetic disorder causing chronic kidney disease in adults. Hypertension occurs early and frequently precedes the development of renal failure. It has been shown that clinically normotensive young adults with ADPKD exhibit increased left ventricular mass and left ventricular mass index (LVMI), which contributes to the increased cardiovascular risk in these patients. We set out to investigate whether normotensive patients have a prehypertensive state that could account for their increased LVMI. METHODS: Patients with ADPKD followed as outpatients were selected if they were aged between 21-30 years, were normotensive (office and sporadic blood pressure < 140/90 without medication), and had normal renal function (GFR > 90 ml/min). Normotensive controls aged between 21-30 years were selected, all with normal renal ultrasound, serum creatinine, dipstick analysis and microalbuminuria /creatinine ratio. Patients and controls underwent 24-hour ambulatory blood pressure measurement (ABPM) according to the local protocol. RESULTS: Systolic (124.7 +/- 7.6 vs. 115.2 +/- 6.9; p < 0.0001), diastolic (77.3 +/- 6.3 vs. 70.5 +/- 3.9; p < 0.0001) and mean (92.7 +/- 8.5 vs. 85.7 +/- < 0.001) 24-hour blood pressure was significantly higher in patients with ADPKD compared to controls. Statistically significant differences were also found when daytime and night-time periods were analyzed separately. Hypertension on ABPM was diagnosed in 6 patients but differences in the ABPM profile persisted even when these patients were excluded from the analysis. CONCLUSION: In young adults with ADPKD there is a prehypertensive state that can be detected using ABPM.

Fungal peritonitis in peritoneal dialysis patients: Is previous antibiotic therapy an essential condition?

The aim of this study was to analyse the clinical and microbiological features of fungal peritonitis, in chronic peritoneal dialysis patients, focusing on non-traditional risk factors for this feared complication. From 2001 to 2004, five episodes of fungal peritonitis were diagnosed in five different patients, accounting for 4.5% of all peritonitis cases seen during this period. Candida spp. were the most frequent isolates. In all cases, peritoneal dialysis catheter removal and switching to haemodialysis were necessary. In these five cases of fungal peritonitis only one was preceded by antibiotic use, within the previous 3 months, the classical risk factor for fungal peritonitis. Identifying predisposing factors usually not taken into account, may lead to an early diagnosis and to a better understanding of fungal peritonitis pathogenesis.

Hypertension in autosomal dominant polycystic kidney disease: observational study in 207 patients with a mean follow-up of 107 months.

INTRODUCTION AND OBJECTIVES: Autosomal dominant polycystic kidney disease (ADPKD) is one of the most common hereditary diseases in adults. ADPKD is a frequent cause of 4 secondary hypertension and, conversely, hypertension is a common manifestation of ADPKD and, more importantly, one of the few that are treatable. Given the autosomal dominant nature of the disease and the fact that it is easy to diagnose with a renal scan, ADPKD patients can be diagnosed early at a pre-symptomatic stage, and hypertension can be detected and treated. The main purpose of this article is to report our experience in the long-term follow-up of patients with ADPKD, with particular emphasis on hypertension. METHODS: A retrospective analysis was made of 532 patients observed in our outpatient clinic due to renal cysts over the last 17 years, of whom 383 were diagnosed with ADPKD according to Ravine's criteria. Patients were followed-up as outpatients on a yearly basis, or more frequently if necessary. Data on demography and clinical findings were analyzed with particular emphasis on blood pressure control, number and type of antihypertensive drugs, and left ventricular mass index (LVMI). RESULTS: At the beginning of follow-up 56% of the patients, including 30.7% of the young adults aged 20 to 34 years, were hypertensive. Focusing on 207 patients observed in 2006, with a mean follow-up of 107 +/- 66 months, a significant decrease in systolic and diastolic blood pressure was observed between the first and last observations. Of a subgroup of 115 patients who were normotensive at the initial observation, 50% became hypertensive by the age of 40. During follow-up, only eleven had a cardiovascular event such as angina, myocardial infarction, stroke or peripheral artery disease (rate 0.006 events/patient-year). LVMI correlated with age, renal function and systolic and diastolic blood pressure, but only age was an independent risk factor for increased left ventricular mass. CONCLUSION: Hypertension is a common complication in ADPKD patients. Early diagnosis and follow-up at a pre-symptomatic stage of the disease are important since this enables early initiation of antihypertensive therapy, which could reduce the rate of cardiovascular events in this population.

Tissue Doppler imaging in the evaluation of left ventricular function in young adults with autosomal dominant polycystic kidney disease.

BACKGROUND: Hypertension and increased left ventricular mass index (LVMI) have been reported in patients with early stages of autosomal dominant polycystic kidney disease (ADPKD). Whether these abnormalities are associated with diastolic dysfunction in this stage remains to be established. The aim of the study is to evaluate diastolic function in young normotensive patients with ADPKD by using tissue Doppler imaging (TDI), the most sensitive method available to date. METHODS: Thirty-two young clinically normotensive patients aged 21 to 30 years were compared with 23 controls with similar ages. Ambulatory blood pressure measurement (ABPM) was performed to confirm normal blood pressure. Subsequently, patients and controls underwent echocardiography using transmitral Doppler and TDI. RESULTS: LVMI was greater in patients with ADPKD than controls (89.3 +/- 17.7 versus 77.6 +/- 15.9 g/m2; P < 0.02). No significant differences were found in transmitral Doppler and TDI results. When ABPMs were taken into account, 11 patients had mild hypertension and showed increased LVMI and decreased early diastolic peak velocity (E wave: 67.0 +/- 12.0 cm/s in hypertensive patients with ADPKD versus 81.4 +/- 3.3 cm/s in normotensive patients with ADPKD versus 79.3 +/- 2.9 cm/s in controls; P < 0.04) and decreased TDI peak early diastolic annular velocity (11.6 +/- 2.8 cm/s in hypertensive patients with ADPKD versus 13.2 +/- 1.6 cm/s in normotensive patients with ADPKD versus 13.4 +/- 1.6 in controls; P < 0.05). CONCLUSION: Diastolic dysfunction is not a prominent sign in young normotensive patients with ADPKD.

[Metabolic evaluation of recurrent idiopathic calcium stone disease in Portugal]. / Avaliação metabólica da litíase cálcica idiopática recorrente em Portugal.

BACKGROUND: Idiopathic calcium stone disease is the most frequent type of nephrolithiasis in industrialised countries. Several metabolic, environmental and genetic factors have described and may be involved in its pathogenesis. This study was designed to evaluate the factors that contribute to idiopathic calcium stone disease in Portugal. METHODS: To characterise the Portuguese population with idiopathic recurrent calcium stone disease, a population of 87 consecutive idiopathic recurrent calcium stone formers (IRCSF) was evaluated over a 5-year period. The results were compared with a control group of 45 healthy subjects (HS) from the same population, with similar age and gender distribution. RESULTS: No difference was observed in the distribution of affected individual according to gender (47 females and 40 males). A familial history of nephrolithiasis was present in 35.6%. Significantly higher urinary calcium and lower urinary citrate were observed in IRCSF group when compared with HS group. Individual analysis revealed urinary abnormalities in 78 of 87 IRCSF (89.7%). Hyperoxaluria was the most frequent abnormality, observed in 40.2% of the patients, hyperuricosuria in 33.3%, hypercalciuria in 24.1%, hypocitraturia in 23.0%, low urine volume in 19.5% and hypomagnesiuria in 8%. No difference was observed in the distribution of urinary risk factors according to gender or presence of familial antecedents of nephrolithiasis. A positive correlation was observed between urinary sodium and calcium in hypercalciuric patients. CONCLUSIONS: Among the studied population, idiopathic calcium nephrolithiasis affected both genders equally. Metabolic evaluation permits the identification of urine abnormalities in most of these patients. Hyperoxaluria, hypercalciuria, hypocitraturia and hyperuricosuria appeared as important pathogenic factors in IRCSF. Urine volume was not different between groups. Dietary factors may be involved in the observed urine abnormalities and need to be further evaluated.

[Paraquat intoxication]. / Intoxicação por paraquat.

Paraquat, widely used as a contact herbicide is, in some environments (meanly rural), the principal mean of suicide. Commercially known as Gramoxone, it was sintetyzed for the first time in 1882 and its herbicide properties were not discovered until 1955. The authors made a literature review and describe the historic perspective, physicochemical properties, clinic aspects, prognosis factors and treatment and, finally, propose a therapeutic approach having always in mind the capital importance of the early beginning of general treatment of intoxication cases.