Albuminuria, Forgotten No More: Underlining the Emerging Role in CardioRenal Crosstalk.

Kidneys have an amazing ability to adapt to adverse situations, both acute and chronic. In the presence of injury, the kidney is able to activate mechanisms such as autoregulation or glomerular hyperfiltration to maintain the glomerular filtration rate (GFR). While these adaptive mechanisms can occur in physiological situations such as pregnancy or high protein intake, they can also occur as an early manifestation of diseases such as diabetes mellitus or as an adaptive response to nephron loss. Although over-activation of these mechanisms can lead to intraglomerular hypertension and albuminuria, other associated mechanisms related to the activation of inflammasome pathways, including endothelial and tubular damage, and the hemodynamic effects of increased activity of the renin-angiotensin-aldosterone system, among others, are recognized pathways for the development of albuminuria. While the role of albuminuria in the progression of chronic kidney disease (CKD) is well known, there is increasing evidence of its negative association with cardiovascular events. For example, the presence of albuminuria is associated with an increased likelihood of developing heart failure (HF), even in patients with normal GFR, and the role of albuminuria in atherosclerosis has recently been described. Albuminuria is associated with adverse outcomes such as mortality and HF hospitalization. On the other hand, it is increasingly known that the systemic effects of congestion are mainly preceded by increased central venous pressure and transmitted retrogradely to organs such as the liver or kidney. With regard to the latter, a new entity called congestive nephropathy is emerging, in which increased renal venous pressure can lead to albuminuria. Fortunately, the presence of albuminuria is modifiable and new treatments are now available to reverse this common risk factor in the cardiorenal interaction.

Vitamin D and Chronic Kidney Disease Association with Mineral and Bone Disorder: An Appraisal of Tangled Guidelines.

Chronic kidney disease (CKD) is a highly prevalent condition worldwide in which the kidneys lose many abilities, such as the regulation of vitamin D (VD) metabolism. Moreover, people with CKD are at a higher risk of multifactorial VD deficiency, which has been extensively associated with poor outcomes, including bone disease, cardiovascular disease, and higher mortality. Evidence is abundant in terms of the association of negative outcomes with low levels of VD, but recent studies have lowered previous high expectations regarding the beneficial effects of VD supplementation in the general population. Although controversies still exist, the diagnosis and treatment of VD have not been excluded from nephrology guidelines, and much data still supports VD supplementation in CKD patients. In this narrative review, we briefly summarize evolving controversies and useful clinical approaches, underscoring that the adverse effects of VD derivatives must be balanced against the need for effective prevention of progressive and severe secondary hyperparathyroidism. Guidelines vary, but there seems to be general agreement that VD deficiency should be avoided in CKD patients, and it is likely that one should not wait until severe SHPT is present before cautiously starting VD derivatives. Furthermore, it is emphasized that the goal should not be the complete normalization of parathyroid hormone (PTH) levels. New developments may help us to better define optimal VD and PTH at different CKD stages, but large trials are still needed to confirm that VD and precise control of these and other CKD-MBD biomarkers are unequivocally related to improved hard outcomes in this population.

Prevalence of Protein-Energy Wasting in Dialysis Patients Using a Practical Online Tool to Compare with Other Nutritional Scores: Results of the Nutrendial Study.

This cross-sectional study aims to explore the prevalence of protein-energy wasting (PEW) in dialysis patients in Catalonia, Spain, using a new and practical online tool which enables rapid calculation and comparison with other nutritional scores. METHODS: A web tool (Nutrendial) was created to introduce different variables and automatically calculate PEW, Malnutrition inflammation Score (MIS) and Subjective Global Assessment (SGA) in 1389 patients (88% in haemodialysis (HD)), 12% in peritoneal dialysis (PD) from different regions of Catalonia. RESULTS: A prevalence of 23.3% (26% HD, 10.2% PD) of PEW was found, with a mean MIS score of 6 and SGA score of C in 7% of the patients. ROC analysis showed MIS as the best nutritional score to diagnose PEW (AUC 0.85). Albumin delivered lower diagnostic precision (AUC 0.77) and sensitivity (66%). A cut off point of 7 (86% sensitivity and 75% specificity) for MIS and 3.7 mg/dL for albumin were found to predict the appearance of PEW in this population. SGA B or C showed an 87% sensitivity and 55% specificity to diagnose PEW. Very low nutritional intervention (14%) was recorded with this tool in patients with PEW. CONCLUSIONS: This new online tool facilitated the calculation of PEW, enabling different professionals-including nephrologists, dieticians and nurses-to efficiently obtain insights into the nutritional status of the Catalonian dialysis population and implement the required nutritional interventions. MIS is the score with more sensitivity to diagnose PEW.

Leveraging Data Science for a Personalized Haemodialysis.

BACKGROUND: The 2019 Science for Dialysis Meeting at Bellvitge University Hospital was devoted to the challenges and opportunities posed by the use of data science to facilitate precision and personalized medicine in nephrology, and to describe new approaches and technologies. The meeting included separate sections for issues in data collection and data analysis. As part of data collection, we presented the institutional ARGOS e-health project, which provides a common model for the standardization of clinical practice. We also pay specific attention to the way in which randomized controlled trials offer data that may be critical to decision-making in the real world. The opportunities of open source software (OSS) for data science in clinical practice were also discussed. SUMMARY: Precision medicine aims to provide the right treatment for the right patients at the right time and is deeply connected to data science. Dialysis patients are highly dependent on technology to live, and their treatment generates a huge volume of data that has to be analysed. Data science has emerged as a tool to provide an integrated approach to data collection, storage, cleaning, processing, analysis, and interpretation from potentially large volumes of information. This is meant to be a perspective article about data science based on the experience of the experts invited to the Science for Dialysis Meeting and provides an up-to-date perspective of the potential of data science in kidney disease and dialysis. KEY MESSAGES: Healthcare is quickly becoming data-dependent, and data science is a discipline that holds the promise of contributing to the development of personalized medicine, although nephrology still lags behind in this process. The key idea is to ensure that data will guide medical decisions based on individual patient characteristics rather than on averages over a whole population usually based on randomized controlled trials that excluded kidney disease patients. Furthermore, there is increasing interest in obtaining data about the effectiveness of available treatments in current patient care based on pragmatic clinical trials. The use of data science in this context is becoming increasingly feasible in part thanks to the swift developments in OSS.

Does the obesity survival paradox of dialysis patients differ with age?

BACKGROUND: The obesity paradox of hemodialysis patients (the association between obesity and survival) could be modified by age. We hypothesize that whereas obesity associates with survival in elderly patients, it behaves as a mortality risk marker in younger individuals. METHODS: Retrospective study of 2002-2010 adult incident hemodialysis to analyze the relationship between body mass index (BMI) and annual body weight changes with mortality in different age strata. RESULTS: Included in the study were 6,290 individuals. A progressive decrease in mortality was associated with increasing BMI ranges. Both annual body weight gains and losses were associated with mortality. Similar results were observed in elderly individuals, but in the BMI values of young patients, there were no significant differences in mortality. CONCLUSION: There is a survival benefit with increasing BMI in patients overall. However, while these results persist in patients >65 years, in young people there are no changes in mortality. Patients with the highest inter-annual variability in weight have an increased risk.

The relationship between renal resistive index, arterial stiffness, and atherosclerotic burden: the link between macrocirculation and microcirculation.

The renal resistive index (RRI) measured by Doppler sonography is a marker of microvascular status that can be generalized to the whole of the arterial tree. Its association with large-vessel dysfunction, such as arterial stiffness or the atherosclerotic burden, can help to establish physiopathological associations between macrocirculation and microcirculation. The authors conducted a cross-sectional study of hypertensive patients (n=202) and a healthy control group (n=16). Stiffness parameters, atherosclerotic burden, and determination of the RRI in both kidneys were performed. The average RRI was 0.69±0.08 and was significantly greater in patients with diabetes and chronic kidney disease. Renal resistive index positively correlated with age, creatinine, and albuminuria. Positive correlations were found with arterial stiffness parameters (pulse wave velocity, ambulatory arterial stiffness index, and 24-hour pulse pressure), as well as atherosclerotic burden and endothelial dysfunction measured as asymmetric dimethylarginine in serum. In the multivariate analysis, independent factors for increased RRI were age, renal function, 24-hour diastolic blood pressure, and arterial stiffness. The authors concluded that there is an independent association between renal hemodynamics and arterial stiffness. This, together with the atherosclerotic burden and endothelial dysfunction, suggests that there is a physiopathologic relationship between macrovascular and microvascular impairment.

Doppler ultrasound in the measurement of pulse wave velocity: agreement with the Complior method.

Aortic stiffness is an independent predictor factor for cardiovascular risk. Different methods for determining pulse wave velocity (PWV) are used, among which the most common are mechanical methods such as SphygmoCor or Complior, which require specific devices and are limited by technical difficulty in obtaining measurements. Doppler guided by 2D ultrasound is a good alternative to these methods. We studied 40 patients (29 male, aged 21 to 82 years) comparing the Complior method with Doppler. Agreement of both devices was high (R = 0.91, 0.84-0.95, 95% CI). The reproducibility analysis revealed no intra-nor interobserver differences. Based on these results, we conclude that Doppler ultrasound is a reliable and reproducible alternative to other established methods for the measurement of aortic PWV.

Prevalence of cysts in seminal tract and abnormal semen parameters in patients with autosomal dominant polycystic kidney disease.

BACKGROUND AND OBJECTIVES: Autosomal dominant polycystic kidney disease is a systemic disorder with a wide range of extrarenal involvement. The scope of this study was to analyze the prevalence of seminal cysts and to correlate these findings with the sperm parameters in patients with autosomal dominant polycystic kidney disease. DESIGN, SETTING, PARTICIPANTS, & MEASUREMENTS: A prospective study enrolled 30 adult men with autosomal dominant polycystic kidney disease. Of these 30 patients, 22 agreed to provide a semen sample for analysis, and 28 of 30 agreed to undergo an ultrasound rectal examination. Data obtained from the semen tests and from the ultrasound study were compared. RESULTS: Cysts in the seminal tract were present in 10 (43.47%) of 28 individuals. Twenty of 22 patients showed abnormal semen parameters, with asthenozoospermia as the most common finding. No correlation between ultrasound findings and sperm abnormalities was observed. CONCLUSIONS: The presence of cysts in the seminal tract is remarkably high (43.47%); however, this finding does not correlate with sperm abnormalities, which are also a frequent finding, especially asthenozoospermia. This semen abnormality is probably related to the abnormal function of polycystins. More attention should be paid to reproductive aspects in the initial evaluation of patients with autosomal dominant polycystic kidney disease before their ability to conceive is further impaired by uremia.