Hyperphosphatemia has been associated with higher mortality risk in CKD 5 patients receiving dialysis. Here, we determined the association between the use of single and combined phosphate-binding agents and survival in 6797 patients of the COSMOS study: a 3-year follow-up, multicenter, open-cohort, observational prospective study carried out in 227 dialysis centers from 20 European countries. Patient phosphate-binding agent prescriptions (time-varying) and the case-mix–adjusted facility percentage of phosphate-binding agent prescriptions (instrumental variable) were used as predictors of the relative all-cause and cardiovascular mortality using Cox proportional hazard regression models. Three different multivariate models that included up to 24 variables were used for adjustments. After multivariate analysis, patients prescribed phosphate-binding agents showed a 29 and 22% lower all-cause and cardiovascular mortality risk, respectively. The survival advantage of phosphate-binding agent prescription remained statistically significant after propensity score matching analysis. A decrease of 8% in the relative risk of mortality was found for every 10% increase in the case-mix–adjusted facility prescription of phosphate-binding agents. All single and combined therapies with phosphate-binding agents, except aluminum salts, showed a beneficial association with survival. The findings made in the present association study need to be confirmed by randomized controlled trials to prove the observed beneficial effect of phosphate-binding agents on mortality.

Chronic kidney disease–mineral and bone disorders (CKD–MBD) are important complications of CKD5D patients that are associated with mortality. COSMOS is a multicentre, open cohort, prospective, observational 3-year study carried out in haemodialysis patients from 20 European countries during 2005–07. The present article describes the main characteristics of the European dialysis population, the current practice for the prevention, diagnosis and treatment of secondary hyperparathyroidism and the differences across different European regions. The haemodialysis population in Europe is an aged population (mean age 64.8 ± 14.2 years) with a high prevalence of diabetes (29.5%) and cardiovascular disease (76.0%), and 28.7% of patients have been on haemodialysis more than 5 years. Patients from the former Eastern countries are younger (59.3 ± 14.3 versus 66.0 ± 13.9), having a lower proportion of diabetics (24.1 versus 30.7%). There were relevant differences in the frequency of measurement of the main CKD–MBD biochemical parameters [Ca, P and parathyroid hormone (PTH)] and the Eastern countries showed a poorer control of these biochemical parameters (K/DOQI and K/DIGO targets). Overall, 48.0% of the haemodialysis patients received active vitamin D treatment. Calcitriol use doubled that of alfacalcidiol in the Mediterranean countries, whereas the opposite was found in the non-Mediterranean countries. The criteria followed to perform parathyroidectomy were different across Europe. In the Mediterranean countries, the level of serum PTH considered to perform parathyroidectomy was higher than in non-Mediterranean countries; as a result, in the latter, more parathyroidectomies were performed in the year previous to inclusion to COSMOS. The COSMOS baseline results show important differences across Europe in the management of CKD–MBD.

Summary: Background and Objectives: A high body mass index (BMI) is associated with lower mortality in patients undergoing hemodialysis. Short-term weight gains and losses are also related to lower and higher mortality risk, respectively. The implications of weight gain or loss may, however, differ between obese individuals and their nonobese counterparts. Design, Setting, Participants, & Measurements: The Current Management of Secondary Hyperparathyroidism: A Multicenter Observational Study (COSMOS) is an observational study including 6797 European hemodialysis patients recruited between February 2005 and July 2007, with prospective data collection every 6 months for 3 years. Time-dependent Cox proportional hazard regressions assessed the effect of BMI and weight changes on mortality. Analyses were performed after patient stratification according to their starting BMI. Results: Among 6296 patients with complete data, 1643 died. At study entry, 42% of patients had a normal weight (BMI, 20–25 kg/m²), 11% were underweight, 31% were overweight, and 16% were obese (BMI ≥30 kg/m²). Weight loss or gain (1% of body weight) was strongly associated with higher rates of mortality or survival, respectively. After stratification by BMI categories, this was true in nonobese categories and especially in underweight patients. In obese patients, however, the association between weight loss and mortality was attenuated (hazard ratio, 1.28 [95% confidence interval (CI), 0.74 to 2.14]), and no survival benefit of gaining weight was seen (hazard ratio, 0.98 [95% CI, 0.59 to 1.62]). Conclusions: Assuming that these weight changes were unintentional, our study brings attention to rapid weight variations as a clinical sign of health monitoring in hemodialysis patients. In addition, a patient’s BMI modifies the strength of the association between weight changes with mortality.

Introduction: Chronic kidney disease (CKD) and osteoporosis are important health problems. There is an interrelationship between osteoporosis and CKD. Bone densitometry is the “gold” standard in the diagnosis of osteoporosis. Unfortunately, there are some problems with the interpretation of bone densitometry in CKD patients. The goal of this study was to determine bone mineral density (BMD) in CKD patients, to assess the difference between genders and different sites of bone densitometry correlation between BMD and laboratory parameters, and to assess the most optimal measuring site. Methods: We studied 134 hemodialysis (HD) patients (62 females, 72 males). The mean age was 56.4 ± 12.4 years and the mean duration of HD was 54.4 ± 60 months. BMD of the lumbar spine (posterior–anterior projection and lateral projection), hip (femoral neck, trochanter, intertrochanter, total femur, the Ward's Triangle), and forearm (ultradistal (UD), middistal (MID), distal third portion, and total forearm) was measured using dual X-ray absorptiometry (DXA) (Hologic Delphi apparatus). Values were expressed as BMD, T-score, and Z-score. Results: Females had lower values of BMD in all measurement points. There were no significant differences in T- and Z-scores of forearm between males and females. Age was in a positive correlation with lumbar spine BMD in males and females. There was a negative correlation with neck and forearm BMD in both groups. Serum parathyroid hormone (PTH) was also in negative correlation with hip and forearm BMD in both groups. The best correlation of BMD in different sites was between forearm and neck. Conclusion: BMD data in CKD patients should be interpreted with caution and appendicular skeletal sites should be included in the evaluation.

Green nephrology, also often called sustainable nephrology, has become a field of interest in our discipline in recent years. Although several reviews have been published, comparatively few original articles have appeared, witnessing interest but also lack of original data. Greater awareness of the effect nephrology has on the planet, including, but not limited to its carbon footprint, is needed to promote education and research on these issues. Increasing awareness entails increasing knowledge at various levels, and it is for this reason that we are presenting this review focusing on educational activities that have been and could further be undertaken to spread knowledge of these topics. We start from a description of the various approaches to green nephrology: technical, mainly focused on dialysis, clinical, encompassing medical and nonmedical treatments in all CKD phases, and comprehensive, embedding kidney care in the society. We further summarize what is known and the fundamental needs and problems we presently face in reducing dialysis carbon-print, optimizing the pathways of care, avoiding futility in clinical work and research, and implementing lifestyle interventions and education. We further acknowledge the lack of data on lifecycle of items and procedures, including commonly used drugs, and identify research needs at various levels. We finally discuss some examples of educational programs on green nephrology that are already available at various levels, from medical schools (an educational game), to medical meetings (healthy eating and reduction of plastic and paper waste), and daily clinical practice, in which teaching passes also through examples (personalizing dialysis and adapting schedules to each patient). Finally, we identify some barriers that educational approaches may offer ways to overcome, to promote effective, targeted interventions that will make us advance on the road to reduce nephrology's carbon footprint.