Introduction: Despite recognized geographic and sex-based differences in hemoglobin in the general population, these factors are typically ignored in patients with chronic kidney disease (CKD) in... Show moreIntroduction: Despite recognized geographic and sex-based differences in hemoglobin in the general population, these factors are typically ignored in patients with chronic kidney disease (CKD) in whom a single therapeutic range for hemoglobin is recommended. We sought to compare the distribution of hemoglobin across international nondialysis CKD populations and evaluate predictors of hemoglobin.Methods: In this cross-sectional study, hemoglobin distribution was evaluated in each cohort overall and stratified by sex and estimated glomerular filtration rate (eGFR). Relationships between candidate predictors and hemoglobin were assessed from linear regression models in each cohort. Estimates were subsequently pooled in a random effects model.Results: A total of 58,613 participants from 21 adult cohorts (median eGFR range of 17-49 ml/min) and 3 pediatric cohorts (median eGFR range of 26-45 ml/min) were included with broad geographic representation. Hemoglobin values varied substantially among the cohorts, overall and within eGFR categories, with particularly low mean hemoglobin observed in women from Asian and African cohorts. Across the eGFR range, women had a lower hemoglobin compared to men, even at an eGFR of 15 ml/min (mean difference 5.3 g/l, 95% confidence interval [CI] 3.7-6.9). Lower eGFR, female sex, older age, lower body mass index, and diabetic kidney disease were all independent predictors of a lower hemoglobin value; however, this only explained a minority of variance (R-2 7%-44% across cohorts).Conclusion: There are substantial regional differences in hemoglobin distribution among individuals with CKD, and the majority of variance is unexplained by demographics, eGFR, or comorbidities. These findings call for a renewed interest in improving our understanding of hemoglobin determinants in specific CKD populations. Show less
European Reference Networks (ERNs) were founded on the principle that many rare disease (RD) issues are pan-European and any single Member State cannot solve them alone. In 2021, ERNs are already... Show moreEuropean Reference Networks (ERNs) were founded on the principle that many rare disease (RD) issues are pan-European and any single Member State cannot solve them alone. In 2021, ERNs are already in the deployment stage; however, their day-to-day functioning and realization of their potential are still severely hampered by many challenges, including issues in governance and regulation, lack of legal status, insufficient and unsustainable funding, lack of ERN integration into national systems, endangered collaboration with UK RD experts due to Brexit, insufficient exploitation of ERN potential in RD research, underappreciation of highly qualified human resources, problems with the involvement of patient representatives, and still unclear place of ERNs in the overall European RD and digital ecosystem. Bold and innovative solutions that must be taken to solve these challenges inevitably involve pan-European collaboration across several sectors and among multistakeholder RD communities and in many cases crucially rely on the constructive dialogue and coherent, united decisions of national and European authorities that are based on common EU values. Importantly, unresolved challenges may have a strong impact on the further sustainability of ERNs and their ability to realize full potential in addressing huge unmet needs of RD patients and their families. Show less
