Elderly Patients in a Large Nephrology Unit: Who Are Our Old, Old-Old and Oldest-Old Patients?

The role of kidney dysfunction in COVID-19 and the influence of age

COVID-19 is strongly influenced by age and comorbidities. Acute kidney injury (AKI) is a frequent finding in COVID-19 patients and seems to be associated to mortality and severity. On the other hand, the role of kidney dysfunction in COVID-19 is still debated. We performed a retrospective study in a cohort of 174 hospitalized COVID-19 patients in Italy from March 3rd to May 21st 2020, to investigate the role of kidney dysfunction on COVID-19 severity and mortality. Moreover, we examined in depth the relationship between kidney function, age, and progression of COVID-19, also using different equations to estimate the glomerular filtration rate (GFR). We performed logistic regressions, while a predictive analysis was made through a machine learning approach. AKI and death occurred respectively in 10.2% and 19.5%, in our population. The major risk factors for mortality in our cohort were age [adjusted HR, 6.2; 95% confidence interval (CI) 1.8-21.4] and AKI [3.36 (1.44-7.87)], while, in these relationships, GFR at baseline mitigated the role of age. The occurrence of AKI was influenced by baseline kidney function, D-dimer, procalcitonin and hypertension. Our predictive analysis for AKI and mortality reached an accuracy of ≥ 94% and ≥ 91%, respectively. Our study scales down the role of kidney function impairment on hospital admission , especially in elderly patients. BIS-1 formula demonstrated a worse performance to predict the outcomes in COVID-19 patients when compared with MDRD and CKD-EPI.

[Long-term physical and psychological consequences of chronic kidney disease]

Aufgrund der verbesserten Behandlungsoptionen können Patient:innen mit chronischen Nierenerkrankungen heute deutlich länger überleben als noch vor 10 Jahren. Das Überleben ist für die Betroffenen jedoch immer mit einem Verlust an Lebensqualität verbunden. In diesem Beitrag wird eine kurze Übersicht über die körperlichen und psychischen Erkrankungsfolgen, Begleiterkrankungen und Therapienebenwirkungen bei chronischen Nierenerkrankungen gegeben. Auf bisher bekannte Auswirkungen der COVID-19-Pandemie wird hingewiesen. Abschließend wird aufgezeigt, wie die Langzeitbehandlung weiterentwickelt werden sollte, um die Lebensqualität der Patient:innen zu erhöhen.

Funktionseinschränkungen der Niere haben aufgrund der Kontamination des Blutes mit harnpflichtigen Substanzen (Urämie) schwere Auswirkungen auf den Gesamtorganismus. Zusätzlich sind die Patient:innen von Nebenwirkungen betroffen, die im Zusammenhang mit der medikamentösen Therapie, Dialyse oder Nierentransplantation auftreten können. Patient:innen und Angehörige sind einer großen psychischen Belastung ausgesetzt. Infektionen mit SARS-CoV‑2 können die Nierenfunktion beeinträchtigen und auch die Prognose einer bereits bestehenden Erkrankung verschlechtern.

Die ganzheitliche Versorgung der Patient:innen mit chronischen Nierenerkrankungen muss neben der medizinischen Versorgung auch die psychologischen und psychosozialen Aspekte berücksichtigen. Nephrologie und Psychonephrologie müssen Hand in Hand weiterentwickelt werden, um die medizinische Versorgung und Lebensqualität der betroffenen Patient:innen zu verbessern.

Nephrologist referrals of elderly CKD patients in Singapore: A cross-sectional study

Background

Chronic kidney disease (CKD) is common in the elderly population. By 2035, approximately one-quarter of Singapore residents are expected to have CKD. Many of these patients are not referred to nephrologists.

Aim

We aimed to compare the characteristics of elderly (≥ 65 years old) patients with stage 3B CKD and above in the referral and non-referral groups.

Design and settings

A cross-sectional study in the primary care organisation National University Polyclinics (NUP), Singapore.

Method

Retrospective data were extracted from the electronic health records of CKD patients (≥ 65 years old) with stage 3B CKD and above.

Results

From 1 January to 31 December 2018, a total of 1,536 patients aged 65 years or older were diagnosed with stage 3B CKD or above (non-referral group =1,179 vs. referral group =357). The mean patient age in the non-referral group (78.3 years) was older than that in the referral group (75.9 years) (P<0.001). Indian elderly patients were referred more compared to their Chinese counterparts (P=0.008). The non-referral group was prescribed significantly less fibrate, statins, insulin, sulfonylureas, dipeptidyl peptidase-4 inhibitors, and antiplatelet than the referral group (P<0.05), but only the difference in fibrates remained significant on subsequent multivariate analysis.

Conclusions

This study demonstrates that there is a considerable number of elderly CKD patients exclusively managed in the primary care setting (n = 1,179) and that referrals primarily depend on demographic factors, namely age and ethnicity, rather than medical determinants of CKD severity or case complexity.

Kidney Function According to Different Equations in Patients Admitted to a Cardiology Unit and Impact on Outcome

Background: This paper aims to evaluate the concordance between the Chronic Kidney Disease Epidemiology Collaboration (CKD-EPI) formula and alternative equations and to assess their predictive power for all-cause mortality in unselected patients discharged alive from a cardiology ward. Methods: We retrospectively included patients admitted to our Cardiology Division independently of their diagnosis. The total population was classified according to Kidney Disease: Improving Global Outcomes (KDIGO) categories, as follows: G1 (estimated glomerular filtration rate (eGFR) ≥90 mL/min/1.73 m²); G2 (eGFR 89–60 mL/min/1.73 m²); G3a (eGFR 59–45 mL/min/1.73 m²); G3b (eGFR 44–30 mL/min/1.73 m²); G4 (eGFR 29–15 mL/min/1.73 m²); G5 (eGFR <15 mL/min/1.73 m²). Cockcroft-Gault (CG), CG adjusted for body surface area (CG-BSA), Modification of Diet in Renal Disease (MDRD), Berlin Initiative Study (BIS-1), and Full Age Spectrum (FAS) equations were also assessed. Results: A total of 806 patients were included. Good agreement was found between the CKD-EPI formula and CG-BSA, MDRD, BIS-1, and FAS equations. In subjects younger than 65 years or aged ≥85 years, CKD-EPI and MDRD showed the highest agreement (Cohen’s kappa (K) 0.881 and 0.588, respectively) while CG showed the lowest. After a median follow-up of 407 days, overall mortality was 8.2%. The risk of death was higher in lower eGFR classes (G3b HR4.35; 95%CI 1.05–17.80; G4 HR7.13; 95%CI 1.63–31.23; G5 HR25.91; 95%CI 6.63–101.21). The discriminant capability of death prediction tested with ROC curves showed the best results for BIS-1 and FAS equations. Conclusion: In our cohort, the concordance between CKD-EPI and other equations decreased with age, with the MDRD formula showing the best agreement in both younger and older patients. Overall, mortality rates increased with the renal function decreasing. In patients aged ≥75 years, the best discriminant capability for death prediction was found for BIS-1 and FAS equations.

Possible Benefits of a Low Protein Diet in Older Patients With CKD at Risk of Malnutrition: A Pilot Randomized Controlled Trial

Background

Current guidelines do not clarify whether older patients with advanced chronic kidney disease (CKD) may benefit of low protein (LP) diet if they are at risk of malnutrition. We compared the effects of normocalorie/normoprotein (NP) and normocalorie/LP diet on nutritional status and metabolic complications related to the progression of kidney damage in these patients.

Methods

This pilot study had an open-label randomized-controlled design (ClinicalTrials.gov Id: NCT05015647). Thirty-five patients were treated for 6 months with two different diets (LP = 17) and (NP = 18). Malnutrition was assessed by the Malnutrition Inflammation Score and International Society of Renal Nutrition and Metabolism criteria. Renal function was assessed by creatinine and cystatin-C-based estimated glomerular filtration rate (eGFR).

Results

At the end of the study, Malnutrition Inflammation Score was improved in both LP and NP groups (respectively: 3 ± 3 vs. 6 ± 1.5, p = 0.020 and 3 ± 2.5 vs. 6 ± 2, p = 0.012), prevalence of protein energy wasting syndrome decreased only in LP. LP group had higher eGFRcys-C (17 ± 6 vs. 12 ± 4 ml/min/1.73 m2; p &lt; 0.05), lower serum urea (105 ± 65 vs. 138 ± 30 mg/dl; p &lt; 0.05) and lower parathormone (68 ± 10 vs. 99 ± 61 ng/L; p &lt; 0.05) than NP. Serum and urinary phosphorous did not change while fibroblast growth factor 23 (FGF23)-intact and FGF23 c-terminal increased in both groups [FGF23-intact in LP: 70 (48; 98) vs. 126 (90; 410) pg/ml, p &lt; 0.01 and in NP: 86 (57; 194) vs. 143 (119; 186) pg/ml, p &lt; 0.01; FGF23 c-terminal in LP: 77 (30.3; 112) vs. 111 (63; 384) RU/ml, p &lt; 0.01 and in NP: 142 (56.6; 175) vs. 157 (76.7; 281) RU/ml, p &lt; 0.01].

Conclusions

LP diet has a favorable impact on nutritional status as much as NP diet with possible greater benefits on the progression of kidney disease and some of its metabolic complications.

Clinical Trial Registration

https://clinicaltrials.gov/ct2/show/NCT05015647, identifier: NCT05015647.

Spontaneously Low Protein Intake in Elderly CKD Patients: Myth or Reality? Analysis of Baseline Protein Intake in a Large Cohort of Patients with Advanced CKD

The recent guidelines on nutritional management of chronic kidney disease (CKD) advise a reduction in protein intake as early as CKD stage 3, regardless of age, to slow kidney function impairment. However, since elderly patients are usually considered as having a spontaneously reduced protein intake, nutritional interventions to reduce protein intake are often considered futile. This study aimed to assess the baseline protein intake of elderly CKD patients referred for nephrology care, and explore the need for dietary evaluations, focusing on the current recommendations for protein restriction in CKD. This is an observational study of CKD patients followed in the unit dedicated to advanced CKD patients in Le Mans, France. Patients with stages 3 to 5 not on dialysis were included. All patients were evaluated by an expert dietician to assess their baseline protein intake, whenever possible on the basis of a 7-days diet journal; when this was not available, dietary recall or analysis of delivered meals was employed. Demographic characteristics, underlying kidney disease, Charlson Comorbidity Index (CCI), Malnutrition-Inflammation Score (MIS), Subjective Global Assessment (SGA) and clinical and laboratory data were recorded. Between 15 November 2017 and 31 December 2020, 436 patients were evaluated in the unit. Their age distribution was as follows: "young": <60 (n = 62), "young-old": 60-69 (n = 74), "old": 70-79 (n = 108), "old-old": 80-89 (n = 140) and "oldest-old": ≥90 (n = 54). The prevalence of vascular nephropathies was higher in patients older than 70 years compared to younger ones, as did CCI and MIS (p < 0.001). Moderate nutritional impairment (SGA: B) was higher in elderly patients, reaching 53.7% at ≥90, while less than 3% of patients in the overall cohort were classified as SGA C (p < 0.001). The median protein intake was higher than the recommended one of 0.8 g/kg/day in all age groups; it was 1.2 g/kg/day in younger patients and 1.0 thereafter (p < 0.001). Patient survival depended significantly on age (p < 0.001) but not on baseline protein intake (p = 0.63), and younger patients were more likely to start dialysis during follow-up (p < 0.001). Over half of the patients, including the old-old and oldest-old, were still on follow-up two years after referral and it was found that survival was only significantly associated with age and comorbidity and was not affected by baseline protein intake. Our study shows that most elderly patients, including old-old and extremely old CKD patients, are spontaneously on diets whose protein content is higher than recommended, and indicates there is a need for nutritional care for this population.