[Nutritional and Functional assessment of peritoneal dialysis patients in the clinical practice: Report from MITO-DP Group]. / Valutazione Nutrizionale e Funzionale dei pazienti in dialisi peritoneale nella pratica clinica: l'esperienza del Gruppo Medico-Infermieristico Toscano di Dialisi Peritoneale (M.I.TO.-DP).

Nutritional abnormalities and physical inactivity are risk factors of increased morbidity and mortality in patients with ESRD. Identify and define malnutrition, in particular protein-energy depletion (PEW), is an important task in the management of renal patients. The aim of this multicenter observational study was to implement the assessment of nutritional status and functional capacity in patients on peritoneal dialysis, including tests and validated methods which are relatively easy to apply in daily clinical practice. The study includes all the 133 prevalent patients (80 m, 53 f, age 65 14 years), in peritoneal dialysis treatment (vintage 26 19 months) in 9 centers in Tuscany. We performed anthropometry, bioimpedance (BIA), clinical biochemistry, evaluation of habitual physical activity (RAPA tests) and performance (Sit-To-Stand test), appetite-evaluation questionnaire, and indices including the Malnutrition Inflammation Score (MIS), Geriatric Nutrition Risk Index (GNRI), Charlson comorbidity index, Barthel and Karnowsky index. The latter showed a condition of dependence in 7.2% and 19.7% of cases, respectively. Poor appetite was recorded in 48.2%. The majority of patients fell within the overweight / obesity range (51%) with waist circumference values associated with increased cardiovascular risk in 51% of males and 60% of females. At the BIA analysis, a BCMI <8 kg/m2 was detected in 39% of patients; an estimated protein intake <1.0 g / kg/d was found in 59% of cases; 34% of patients had serum albumin <3.5 g / dl; control of acidosis was good (bicarbonate 25.4 3.8 mM) but hyperphosphatemia was present in 64.6% of patients. A condition of sedentary or light physical activity was reported by 65.1% of patients, vigorous activity only by 11.9%. The 86.5% of patients able to perform the Sit-to-stand test reported a lower than the reference values for age and sex. A diagnosis of PEW was possible in 8% of our series, while a MIS score> 11, indicative of PEW, took place in 12.7% of cases. The values of the MIS correlated directly with age and the degree of comorbidity and inversely with the sit-to-stand test, RAPA tests and appetite level. The data in this study show that single tests indicative of malnutrition disorders are frequent to be found in our series of peritoneal dialysis patients. However, a diagnosis of PEW is quite infrequent. A large percentage of patients are overweight with increased abdominal adiposity, and reduced cell mass and protein intake below recommended levels; the level of habitual physical activity is low, and the level of physical capability is scarce. Therefore it is conceivable a nutritional counseling intervention to increase the intake of proteins, limiting the phosphorus and (when indicated) energy intake and to stimulating spontaneous physical activity or arranging assisted programs for functional rehabilitation. Close monitoring of the nutritional status and implementation of programs of adapted physical activity should have a prominent role in the clinical management of patients on peritoneal dialysis.

Quantitative ultrasound in the assessment of skeletal status in uremic patients.

Renal osteodystrophy (ROD) can be characterized by both high (HT) and low (LT) bone turnover states. Although bone biopsy remains the "gold standard" to diagnose ROD, noninvasive tools for the diagnosis and follow-up of such bone disease are desirable. Recently, ultrasound (US) techniques, proposed to assess skeletal status, have been shown to be correlated not only with bone density but also with bone quality. We have investigated 98 patients on chronic hemodyalisis (HD) and 98 healthy, sex- and age-matched subjects. Amplitude-dependent speed of sound (AD-SOS) and ultrasound bone profile score (UBPS) at phalanxes and speed of sound (SOS), broadband ultrasound attenuation (BUA), and a quantitative ultrasound index (QUI/stiffness) at the heel were performed in both groups. In all subjects intact parathyroid hormone (PTH), total alkaline phosphatase (T-ALP), bone isoenzyme alkaline phosphatase (B-ALP), and carboxy-terminal telopeptide of type I collagen (ICTP) were assessed. All US parameters were significantly lower in the hemodialysis group than in control subjects. Moreover, among US parameters only AD-SOS and UBPS showed a significant correlation with PTH, T-ALP, and B-ALP. Dialytic age showed a modest, but significant correlation only with US parameters at the phalanxes. On the basis of bone biochemical markers, we considered a group with high and a group with normal to low bone turnover. AD-SOS and UBPS, but not SOS, BUA, and stiffness were significantly (p < 0.01) lower in the high bone turnover than in low bone turnover group. Furthermore, in the high bone turnover group, parameters of the US phalanxes strongly correlated with B-ALP. Our results seem to demonstrate that US parameters are a useful tool in the assessment of skeletal status in patients on maintenance dialysis.

Uremia, dialysis and aluminium.

Few studies have dealt with assaying aluminium levels in different tissues of uremic patients; so far a comparison has never been made between its accumulation in the various tissues of uremic patients and controls. Aluminium levels were determined in the following biological samples: 1) 111 serum samples from hemodialysis patients and 55 serum samples from normal subjects; 2) 47 urine samples from the same dialysis patients and 45 from the controls; autopsy tissue specimens (blood, bile, brain, rib, cartilage, cranium, lung, spleen, kidney, aorta, vena cava, liver, muscle) from 12 deceased dialysis patients undergoing post-mortem diagnosis and 10 autopsy cases in which death was not associated with uremia. In living subjects, both serum and urinary levels of aluminium are significantly higher in hemodialysis patients than in controls; a significant positive correlation was found between serum and urinary levels of aluminium. In autopsy specimens, aluminium levels were higher in the dialysis group than controls for all tissues; the differences were statistically significant except in heart and urine. Tissue concentrations of aluminium in the two groups were then analysed separately both in uremic patients and controls. The highest values found in dialysis cases were in the bile, followed by blood, urine and lung; levels in the other tissues were considerably lower. In controls, the distribution was somewhat different, due to much lower levels in the liver and bile with respect to dialysis cases. Again we found surprisingly high levels in the lung. The results show that aluminium storage in uremic patients occurs in all organs and tissues, albeit to different degrees.

Mechanisms of acid-base homeostasis in acetate and bicarbonate dialysis, lactate hemofiltration and hemodiafiltration.

The different mechanisms of acidosis buffering were investigated in 15 RDT patients dialyzed in cross-over with four depurative techniques: acetate dialysis (AD), bicarbonate dialysis (BD), lactate hemofiltration (LHF) and hemodiafiltration (HDF) with acetate bath and lactate reinfusion fluid. Blood pH, bicarbonate, blood gases, intraerythrocytic pH - on red cell hemolisates - anion gap, L-lactate, pyruvate, adenosinmonophosphate (ADP) and 2-3 Diphosphoglycerate (2-3 DPG) levels were evaluated. During AD the intradialytic buffering is initially achieved by the CO2 fall and later by the acetate metabolism and an important bicarbonate shift from the intra to the extracellular space. A physiological compensation is obtained during BD with bicarbonate administration and a mild ventilatory response to the pCO2 increase. In LHF the massive lactate administration, with plasma levels of 7 mmol/l, strongly alters the Central Nervous System elettroneutrality inducing a hyperventilatory response with a purely pulmonary acidosis buffering. Furthermore the lactate/pyruvate ratio rose as high as 40:1 with ADP increase and cellular energy depletion. In HDF several different mechanisms are associated: the CO2 fixation, the acetate muscular metabolism, the intra-extracellular bicarbonate shift with the pulmonary response driven by lactate Central Nervous System penetration.

Effect of increasing doses of lisinopril on proteinuria of normotensive patients with IgA nephropathy and normal renal function.

The antiproteinuric effect of angiotensin converting enzyme (ACE) inhibition in patients with renal disease is well known, but the results of clinical studies appear to vary considerably from a partial decrease to a fall of 100% in urinary protein excretion. This may have been due to the use of different doses of ACE inhibitor, different renal pathology and non-standardized sodium intake. In 16 proteinuric patients with biopsy-proven IgA nephropathy, with normal renal function and blood pressure, maintained at controlled sodium intake < or = 80 mEqII, the efficacy of increasing doses of the ACE inhibitor lisinopril was studied. The lisinopril doses were 5, 10, 15 and 20 mg, administered for 4 weeks. Between each dose increment a placebo period of 3 weeks was interposed. Proteinuria stepwise decreased from the control period by 39%, 44%, 61% and 67% with lisinopril at 5, 10, 15 and 20 mg, respectively. The blood pressure decreased by 22% with lisinopril 5 mg; a similar fall was observed with the dose increment. Although the glomerular filtration rate remained unchanged, the renal plasma flow increased by 21%, 26%, 24% and 28% and the filtration fraction increased by 28% mean. The ACE plasma levels decreased by 33%, 64%, 76% and 83%. A close correlation was found between an increase in lisinopril dosage and the fall in urinary protein excretion (r = 0.88, p < 0.001). The antiproteinuric effect of lisinopril is dose-related and may be attributable to some extent to the fall in systemic (and intraglomerular) blood pressure, but it is best attributed to the modification of glomerular sieving function.(ABSTRACT TRUNCATED AT 250 WORDS)