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The recent research findings concerning syndromes of muscle wasting, malnutrition, and inflammation in individuals with chronic kidney disease (CKD) or acute kidney injury (AKI) have led to a need for new terminology. To address this need, the International Society of Renal Nutrition and Metabolism (ISRNM) convened an expert panel to review and develop standard terminologies and definitions related to wasting, cachexia, malnutrition, and inflammation in CKD and AKI. The ISRNM expert panel recommends the term 'protein-energy wasting' for loss of body protein mass and fuel reserves. 'Kidney disease wasting' refers to the occurrence of protein-energy wasting in CKD or AKI regardless of the cause. Cachexia is a severe form of protein-energy wasting that occurs infrequently in kidney disease. Protein-energy wasting is diagnosed if three characteristics are present (low serum levels of albumin, transthyretin, or cholesterol), reduced body mass (low or reduced body or fat mass or weight loss with reduced intake of protein and energy), and reduced muscle mass (muscle wasting or sarcopenia, reduced mid-arm muscle circumference). The kidney disease wasting is divided into two main categories of CKD- and AKI-associated protein-energy wasting. Measures of chronic inflammation or other developing tests can be useful clues for the existence of protein-energy wasting but do not define protein-energy wasting. Clinical staging and potential treatment strategies for protein-energy wasting are to be developed in the future.

Anna Machowska,1 Mark Dominik Alscher,2 Satyanarayana Reddy Vanga,3 Michael Koch,4 Michael Aarup,5 Abdul Rashid Qureshi,1 Bengt Lindholm,1 Peter A Rutherford6 1Division of Renal Medicine and Baxter Novum, Department of Clinical Science, Intervention, and Technology, Karolinska Institutet, Stockholm, Sweden; 2Division of Nephrology, Department of Internal Medicine, Robert-Bosch-Krankenhaus, Stuttgart, Germany; 3Department of Renal Medicine, University Hospital of North Staffordshire, Stoke-on-Trent, Staffordshire, UK; 4Center of Nephrology, Nephrologisches Zentrum, Mettmann, Germany; 5Department of Nephrology, Odense University Hospital, Odense, Denmark; 6Baxter Healthcare SA, Zurich, Switzerland Objectives: Unplanned dialysis start (UPS) leads to worse clinical outcomes than planned start, and only a minority of patients ever receive education on this topic and are able to make a modality choice, particularly for home dialysis. This study aimed to determine the predictive factors for patients receiving education, making a decision, and receiving their preferred modality choice in UPS patients following a UPS educational program (UPS-EP). Methods: The Offering Patients Therapy Options in Unplanned Start (OPTiONS) study examined the impact of the implementation of a specific UPS-EP, including decision support tools and pathway improvement on dialysis modality choice. Linear regression models were used to examine the factors predicting three key steps: referral and receipt of UPS-EP, modality decision making, and actual delivery of preferred modality choice. A simple economic assessment was performed to examine the potential benefit of implementing UPS-EP in terms of dialysis costs. Results: The majority of UPS patients could receive UPS-EP (214/270 patients) and were able to make a decision (177/214), although not all patients received their preferred choice (159/177). Regression analysis demonstrated that the initial dialysis modality was a predictive factor for referral and receipt of UPS-EP and modality decision making. In contrast, age was a predictor for referral and receipt of UPS-EP only, and comorbidity was not a predictor for any step, except for myocardial infarction, which was a weak predictor for lower likelihood of receiving preferred modality. Country practices predicted UPS-EP receipt and decision making. Economic analysis demonstrated the potential benefit of UPS-EP implementation because dialysis modality costs were associated with modality distribution driven by patient preference. Conclusion: Education and decision support can allow UPS patients to understand their options and choose dialysis modality, and attention needs to be focused on ensuring equity of access to educational programs, especially for the elderly. Physician practice and culture across units/countries is an important predictor of UPS patient management and modality choice independent of patient-related factors. Additional work is required to understand and improve patient pathways to ensure that modality preference is enacted. There appears to be a cost benefit of delivering education, supporting choice, and ensuring that the choice is enacted in UPS patients. Keywords: chronic kidney disease, dialysis, patient education, unplanned dialysis start, decision-making process

Cleto Alvarez-Aguilar,1–3 Alfonso Rafael Alvarez-Paredes,2 Bengt Lindholm,4 Peter Stenvinkel,4 Elvia García-López,4 Oliva Mejía-Rodríguez,5 Joel Edmundo López-Meza,6 Dante Amato,7 Ramon Paniagua8 1Hospital General Regional N°1, Instituto Mexicano del Seguro Social (IMSS), Morelia, 2Facultad de Ciencias Médicas y Biológicas "Dr. Ignacio Chávez" Universidad Michoacana de San Nicolás de Hidalgo (UMSNH), Morelia, Michoacán, 3División de Estudios Superiores, Universidad Nacional Autónoma de México (UNAM), México DF, México; 4Department of Clinical Science Intervention and Technology, Karolinska Institutet, Stockholm, Sweden; 5Coordinación Delegacional de Investigación en Salud, IMSS, Morelia, 6Centro Multidisciplinario de Estudios en Biotecnología (CMEB), UMSNH, Morelia, Michoacán, 7Facultad de Estudios Superiores Iztacala, UNAM, Tlalnepantla, 8Unidad de Investigación en Enfermedades Nefrológicas, Hospital de Especialidades, CMN Siglo XXI, IMSS, México DF, México Background: A reduction of dopaminergic (DAergic) activity with increased prolactin levels has been found in obese and hypertensive patients, suggesting its involvement as a pathophysiological mechanism promoting hypertension. Similarly, leptin action increasing sympathetic activity has been proposed to be involved in mechanisms of hypertension. The aim of this study was to analyze the effects of DA, norepinephrine (NE), and prolactin on leptin release and leptin gene (OB) expression in adipocytes from obese and hypertensive patients. Methods: Leptin release and OB gene expression were analyzed in cultured adipocytes from 16 obese and hypertensive patients treated with DA (0.001, 0.01, 0.1, and 1.0 µmol/L), NE (1.0 µmol/L), insulin (0.1 µmol/L), and prolactin (1.0 µmol/L), and from five nonobese and normotensive controls treated with DA (1 µmol/L), NE (1 µmol/L), insulin (0.1 µmol/L), and prolactin (1.0 µmol/L). Results: A dose-related reduction of leptin release and OB gene messenger ribonucleic acid expression under different doses of DA was observed in adipocytes from obese hypertensive patients. Whereas prolactin treatment elicited a significant increase of both leptin release and OB gene expression, NE reduced these parameters. Although similar effects of DA and NE were observed in adipocytes from controls, baseline values in controls were reduced to 20% of the value in adipocytes from obese hypertensive patients. Conclusion: These results suggest that DAergic deficiency contributes to metabolic disorders linked to hyperleptinemia in obese and hypertensive patients. Keywords: dopamine, leptin, cultured adipocytes, obesity, hypertension

Hepatitis C (HCV) is not an uncommon feature in hemodialysis (HD) patients and may be a cause of systemic inflammation. Plasma cytokine interleukin-6 (IL-6) is mainly produced by circulating and peripheral cells and induces the hepatic synthesis of C-reactive protein (CRP), which is the main acute phase reactant. The aim of this study was to investigate the influence of HCV on two markers of systemic inflammation, serum CRP and IL-6, in HD patients. The study included 118 HD patients (47% males, age 47 ± 13 years, 9% diabetics) who had been treated by standard HD for at least 6 months. The patients were divided into two groups depending on the presence (HCV+) or absence (HCV-) of serum antibodies against HCV. Serum albumin (S-Alb), plasma high sensitivity CRP (hsCRP), IL-6, and alanine aminotransferase (ALT) were measured and the values were compared with those for 22 healthy controls. Median hsCRP and IL-6 values and hsCRP/IL-6 ratio were: 3.5 vs 2.1 mg/l, P < 0.05; 4.3 vs 0.9 pg/ml, P < 0.0001, and 0.8 vs 2.7, P < 0.0001, for patients and controls, respectively. Age, gender, S-Alb, IL-6 and hsCRP did not differ between the HCV+ and HCV- patients. However, HCV+ patients had higher ALT (29 ± 21 vs 21 ± 25 IU/l) and had been on HD for a longer time (6.1 ± 3.0 vs 4.0 ± 2.0 years, P < 0.0001). Moreover, HCV+ patients had a significantly lower median hsCRP/IL-6 ratio (0.7 vs 0.9, P < 0.05) compared to the HCV- group. The lower hsCRP/IL-6 ratio in HCV+ patients than in HCV- patients suggests that hsCRP may be a less useful marker of inflammation in HCV+ patients and that a different cut-off value for hsCRP for this population of patients on HD may be required to define inflammation.

The process of water reabsorption from the peritoneal cavity into the surrounding tissue substantially decreases the net ultrafiltration in patients on peritoneal dialysis. The goal of this study was to propose a mathematical model based on data from clinical studies and animal experiments to describe the changes in absorption rate, interstitial hydrostatic pressure, and tissue hydration caused by increased intraperitoneal pressure after the initiation of peritoneal dialysis. The model describes water transport through a deformable, porous tissue after infusion of isotonic solution into the peritoneal cavity. Blood capillary and lymphatic vessels are assumed to be uniformly distributed within the tissue. Starling's law is applied for a description of fluid transport through the capillary wall, and the transport within the interstitium is modeled by Darcy's law. Transport parameters such as interstitial fluid volume ratio, tissue hydraulic conductance, and lymphatic absorption in the tissue are dependent on local interstitial pressure. Numerical simulations show the strong dependence of fluid absorption and tissue hydration on the values of intraperitoneal pressure. Our results predict that in the steady state only ~20-40% of the fluid that flows into the tissue from the peritoneal cavity is absorbed by the lymphatics situated in the tissue, whereas the larger (60-80%) part of the fluid is absorbed by the blood capillaries. water absorption; tissue transport; hydrostatic pressure; peritoneal dialysis