[Chronic kidney disease in the elderly patient]

Octogenarians with chronic kidney disease in the nephrology clinic: Progressors vs. non-progressors

Background

The current definition of chronic kidney disease applied to patients over the age of 80 has increased the number of referrals to Nephrology. However not all of these patients may benefit from its assessment. This study aims to analyze the evolution of ≥80 years old patients referred to Nephrology.

Methods

Single-center study including patients ≥80 years old with eGFR <60 mL/min/1,73m2 who were referred to Nephrology consultation for the first time. Clinical and analytical parameters were collected retrospectively 12 months before the visit, and prospectively at baseline, and 12 and 24 months after the initial visit. We divided patients into two groups based on annual eGFR loss: progressors (>5 mL/min/1.73m2) and non-progressors (≤5 mL/min/1,73m2).

Results

A total of 318 patients were included, mean age was 84,9 ± 4 (80-97) years. Baseline serum creatinine was 1,65 ± 0,62 mg/dL, eGRF 35 (28-42) mL/min/1,73, and albumin/creatinine ratio 36 (7-229) mg/g. 55,7% of the patients met the definition of progressor at baseline (initial-progressors), 26,3% were progressors after a 12-month follow-up and 13,4% after 24 months. 21,2% and 11,4% of initial-progressors met this definition at 12 and 24 month follow up. The main risk factor for progression was albuminuria. No relationship was found between the nephrologist intervention and the evolution of renal function among initial non-progressors.

Conclusion

Elderly patients who have stable renal function at the time of referral will continue to have stable renal function over the subsequent 24 months and thus may not need to be referred to a nephrologist.

New mechanisms involved in the development of cardiovascular disease in chronic kidney disease

Chronic kidney disease (CKD) is a pathology with a high worldwide incidence and an upward trend affecting the elderly. When CKD is very advanced, the use of renal replacement therapies is required to prolong its life (dialysis or kidney transplantation). Although dialysis improves many complications of CKD, the disease does not reverse completely. These patients present an increase in oxidative stress, chronic inflammation and the release of extracellular vesicles (EVs), which cause endothelial damage and the development of different cardiovascular diseases (CVD). CKD patients develop premature diseases associated with advanced age, such as CVD. EVs play an essential role in developing CVD in patients with CKD since their number increases in plasma and their content is modified. The EVs of patients with CKD cause endothelial dysfunction, senescence and vascular calcification. In addition, miRNAs free or transported in EVs together with other components carried in these EVs promote endothelial dysfunction, thrombotic and vascular calcification in CKD, among other effects. This review describes the classic factors and focuses on the role of new mechanisms involved in the development of CVD associated with CKD, emphasizing the role of EVs in the development of cardiovascular pathologies in the context of CKD. Moreover, the review summarized the EVs' role as diagnostic and therapeutic tools, acting on EV release or content to avoid the development of CVD in CKD patients.

Impacto das diferentes modalidades de diálise peritoneal automatizada sobre o perfil inflamatório de idosos portadores de doença renal crônica

Resumo Introdução: A doença renal crônica, mais prevalente em idosos, é considerada um problema de saúde pública em todo o mundo. Objetivo: Avaliar o impacto das modalidades de diálise peritoneal automatizada, intermitente e contínua, no perfil inflamatório de idosos renais crônicos. Métodos: Estudo prospectivo, transversal e analítico realizado em uma clínica de diálise em Brasília, com 74 idosos com idade igual ou maior que 60 anos. Os pacientes foram submetidos ao Teste de Equilíbrio Peritoneal rápido, avaliação clínica, coleta de sangue para avaliações bioquímicas e de citocinas, interleucina 6 e fator de crescimento transformador beta 1, e questionário de qualidade de vida (KDQOL-SF36). Foram utilizadas para análise dos dados, associações e correlações com nível de significância de 5%. Resultados: Pacientes na modalidade contínua apresentaram valores séricos do fator de crescimento transformador beta 1 maiores do que os em modalidade intermitente. Estes apresentaram fator de crescimento transformador beta 1 no peritônio, idade e função renal residual maiores do que os em modalidade contínua. A dosagem da interleucina 6 no peritônio foi associada à idade, enquanto a IL-6 sérica foi associada à IL-6 no peritônio, ao tempo em diálise e à idade. Não houve associação entre a modalidade e a presença de diabetes, volemia ou estado nutricional. Ambas as modalidades permitem boa adequação à terapia dialítica. Conclusão: A inflamação na diálise peritoneal automatizada está associada principalmente à baixa função renal residual, à idade avançada e ao maior tempo em terapia, e não à modalidade de diálise realizada.

Impact of different automated peritoneal dialysis modalities on the inflammatory profile of elderly patients with chronic kidney disease

INTRODUCTION

Chronic kidney disease, more prevalent in the elderly, is considered a public health issue worldwide.

OBJECTIVE

To evaluate the impact of automated, peritoneal dialysis modalities, intermittent and continuous, on the inflammatory profile of elderly people with chronic kidney disease.

METHODS

Prospective, cross-sectional and analytical study carried out in a dialysis clinic in Brasília - Brazil, with 74 elderly people aged 60 years or older. The patients underwent rapid Peritoneal Equilibration Test, clinical assessment, blood collection for biochemical and cytokine assessments, interleukin 6 and transforming growth factor beta 1, and answered a quality-of-life questionnaire (KDQOL-SF36). We used a 5% significance level for data analysis, associations and correlations.

RESULTS

Patients in the continuous modality had higher serum values of transforming growth factor beta 1 than those in the intermittent modality, which had higher peritoneal transforming growth factor beta 1, age and residual renal function than those in continuous mode. Interleukin 6 dosage in the peritoneum was associated with age, while serum IL-6 was associated with IL-6 in the peritoneum, time on dialysis and age. There was no association between the modality and the presence of diabetes, blood volume or nutritional status. Both modalities enable good adaptation to the dialysis treatment.

CONCLUSION

Inflammation in automated peritoneal dialysis is mainly associated with low residual renal function, advanced age and longer time on therapy, and not to the type of dialysis performed.

Design and methodology of the chronic kidney disease as a dysmetabolic determinant of disability among older people (CKD-3D) study: a multicenter cohort observational study

Background

Chronic kidney disease (CKD) is a common condition in older people and represents a global health issue since it increases the risk of associated comorbidities and all-cause mortality. Furthermore, older people with reduced renal function might be at higher risk for developing functional limitation and disability. Moreover, the current creatinine-based measures of renal function are influenced by several factors in older population. The aims of the CKD-3D project are to perform an observational study to expand the knowledge about CKD-disability relationship and to investigate the use of novel biomarkers of kidney function.

Methods

An observational, multicenter, prospective cohort study will be conducted in 75 + old patients consecutively admitted to acute care wards of geriatric medicine at participating hospitals. The study planned to enroll 440 patients undergoing clinical and laboratory evaluations at baseline and after 12 months. Face-to-face follow-up at 6 months and telephone follow-up at 3 and 9 months will be carried out. Comprehensive Geriatric Assessment (CGA) and the measurement of Cystatin C, Beta-Trace Protein and Beta2-Microglobulin levels will be included.

Discussion

This study will provide useful information to prevent CKD-related disability by collecting real-life data over 1-year period. The combined approach of CGA and the investigation of innovative existing biomarkers will make it possible to develop new recommendations and guidelines for a patient-centered approach. It is believed that such a study may lead to an improvement of knowledge on CKD in elderly patients and may also have implications in daily clinical practice and in decision-making process.

Plasma Homocysteine Is a Predictive Factor for Accelerated Renal Function Decline and Chronic Kidney Disease in a Community-Dwelling Population

BACKGROUND

Whether elevated plasma total homocysteine (tHcy) is a risk factor for the progression of kidney disease in general population has not been well established. The purpose of this study was to investigate the prognostic properties of plasma tHcy for renal function decrement and early chronic kidney disease (CKD) in community-dwelling populations with normal renal function at baseline.

METHODS

A total of 1,426 participants were enrolled and followed for a median of 4.8 years (interquartile range, 4.5-5.2), and estimated glomerular filtration rate (eGFR) was evaluated. One main outcome was the rapid eGFR decline defined as a decline in eGFR of >3 mL/min per 1.73 m2 per year; the other was the new incidence of CKD.

RESULTS

At the end of follow-up, the incidence of rapid eGFR decline and new-onset CKD was 20.7 and 5.6%, respectively. In multivariate linear regression analysis, age, central pulse pressure, fasting blood glucose, and concentration of tHcy were independent determinants of the change in eGFR. There was a graded association between tHcy quartiles and eGFR decline. Compared with participants with the lowest quartile of tHcy levels, those with the highest quartile had significantly increased risk for rapid eGFR decline (adjusted odds ratio [aOR] = 1.81; 95% confidence interval [CI]: 1.25-2.94) and new onset of CKD (adjusted hazard ratio = 4.29; 95% CI: 1.42-12.99) after adjusting for various confounders. Similarly, significant associations were also found when baseline tHcy was classified as hyperhomocysteinemia (>15 μmol/L) versus normal tHcy level (≤15 μmol/L). However, there was only association between the change in tHcy levels and new occurrence of CKD but not with rapid eGFR decline (aOR = 0.99, p = 0.613).

CONCLUSIONS

In this prospective cohort of individuals from community-based population, elevated plasma tHcy emerged as an independent predictor of renal function decline and incident CKD, which might support selection of at-risk individuals.

Noninvasive central pulse pressure is an independent determinant of renal function

The purpose of this study was to investigate the prognostic properties of different BP measurements for renal function decrement and early chronic kidney disease (CKD) in community-dwelling populations with normal renal function at baseline. A total of 1426 participants were included and followed for a median of 4.8 years (interquartile range, 4.5-5.2), and central hemodynamic profile and estimated glomerular filtration rate (eGFR) were evaluated. One main outcome was the rapid eGFR decline defined as a decline in eGFR of greater than 3 mL/min per 1.73 m² per year; the other was the new incidence of CKD. At the end of follow-up, mean eGFR decreased from 93.39 ± 13.46 mL/min per 1.73 m² to 85.72 ± 14.81 mL/min per 1.73 m² , and the incidence of rapid eGFR decline and CKD were 20.7% and 5.6%, respectively. In multivariate linear regression analysis, central pulse pressure (PP), age, fasting blood glucose, and concentration of homocysteine were independent determinants of the change in renal function. Not only in the prediction of rapid eGFR decline but also in the incident of CKD, baseline central PP was the only BP component that consistently independently associated with both outcomes after adjustment for various confounders. When compared with subjects in the lowest quartile of central PP, those in the highest quartile demonstrated a significantly increased risk of CKD (hazard ratio [HR], 1.57; 95% confidence interval [CI], 1.08-2.96; P = .006). The study showed that central PP emerged as an independent predictor of the decline in renal function.

[Estimated glomerular filtration rate and post-hospital mortality after discharge from an acute care for the elderly unit]

OBJECTIVE

To determine the relationship between estimated glomerular filtration rate (eGFR) and mortality in a retrospective cohort of older adults admitted to an acute care for the elderly (ACE) unit.

MATERIALS AND METHODS

The study included 1,678 patients aged 60 years and over admitted to an AEC, in Cali, Colombia, from 2012 to 2015, and followed- up until 2016. The primary outcome was mortality. Renal function (eGFR) was estimated using Modification of Diet in Renal Disease Study (MDRD-4) equation. The renal function was grouped according to the eGFR (ml/min/1.73m²) as follows: slightly decreased (≥60), moderately decreased (30-59), and severely decreased (<30). Bivariate survival and multivariate Cox regression analyses were performed.

RESULTS

In the univariate analysis, patients with severely decreased eGFR had higher mortality than those with a higher eGFR (P=.046). In the group with severely decreased eGFR, survival was lower in the functionally dependent group (Barthel index [IB]<60) than in the independent group (IB≥60) (log rank test; P=.001). In the multivariate analysis, there was a significant increase in the risk of death in the elderly with severely decreased eGFR (<30) compared with slightly decreased eGFR (≥60) (hazard ratio [HR], 1.44; 95% confidence interval [CI]; 1.02-2.05, P=.039). There was also a significant increase in the risk of death in the dependent elderly compared to the independent ones [HR 1.72; 95% CI; 1.26-2.34, P=.000], those who had the high morbidity (≥4) with low albumin (<3.2g/dL) compared with those with low morbidity (0-3) and high albumin (≥3.2) [HR 1.77; 95% CI; 1.18-2.65, P=.005], and in those with a high (16-102mg/dL) C-reactive protein (CRP) compared with those with low CRP (0-15) [HR 1.42; 95% CI; 1.01-2.01, P=.043].

CONCLUSIONS

The risk of mortality after hospital admission to an AEC unit is greater in patients with eGFR<30. Poor functional status performance, high comorbidity, low plasma albumin, and increased inflammation markers are additional prognostic factors to be taken into account. The improvement in the functional status could improve the survival after hospitalisation.

Usefulness of frailty evaluation for handling chronic kidney disease elderly patients: a review and original proposal

There is interdependence between chronic kidney disease (CKD) and ageing whereby CKD makes ageing more accelerated and pronounced, whereas ageing accelerates chronic nephropathy's progression. Frailty status catalyzes this spiral, with renal and systemic negative consequences, and this condition can currently be documented by applying already validated clinical scores (frailty phenotype) or physical test (gate speed). Although, nephroprevention strategies are similar between young adult and senior CKD patients, standard targets should be adequate to very old and frail elderly individuals. For this purpose, an original algorithm is here proposed to adjust the conventional nephroprevention strategies to the condition of CKD frail patient (more relaxed targets and tighter control), as well as to prescribe anti-frailty interventions to slow patient's functional decline, hospitalization and mortality.

Clinical characteristics and one-year mortality according to admission renal function in patients with a first acute heart failure hospitalization

INTRODUCTION AND OBJECTIVES

Chronic kidney disease is related to poor outcomes in patients with heart failure (HF). Few studies have assessed whether renal function influences one-year mortality risk in patients admitted for the first time for acute HF.

METHODS

We reviewed the medical records of all patients aged >50 years admitted within a two-year period for a first episode of decompensated HF. The sample was divided according to the patients' estimated glomerular filtration rate (eGFR) on admission into three groups (eGFR >60, 30-60 and <30 ml/min/1.73 m²). Index admission and one-year all-cause mortality rates were compared between groups using Cox regression analysis.

RESULTS

A total of 985 patients were included in the study, mean age 78.4±9 years, and with mean admission eGFR of 60.5±26 ml/min/1.73 m². Of these, 516 (52.3%) patients had eGFR <60 ml/min/1.73 m². One-year all-cause mortality was 25.4%, with a significant association between worse eGFR category and mortality (p<0.0001). Cox regression analysis assessing eGFR as a categorical variable confirmed this association (HR 1.378; p=0.030), together with older age (HR 1.066; p<0.001), previous diagnosis of hypertension (HR 0.527; p<0.001), and both lower systolic blood pressure (HR 0.993; p=0.009) and higher serum potassium on admission (HR 1.471; p <0.001).

CONCLUSIONS

Renal impairment is common in HF patients, even at the time of first admission. In this group of HF patients the presence of renal impairment was associated with higher mid-term (one-year) mortality risk.

Senescent Nephropathy: The New Renal Syndrome

Chronic kidney disease (CKD) is a condition characterized by progressive and irreversible deterioration of renal function due to the reduction of nephron mass for a period of at least three months. The prevalence of CKD is roughly 10% in the general population but increases with age, affecting more than one-third of people older than 65. Frailty is a condition usually found in elderly people, characterized by weakness, motility, and balance issues, with a declined ability to resist stressors leading to increased risks of adverse health outcomes including falls, fracture, hospitalization, institutionalization, disability, dependence, dementia, poor quality of life, and death. There is interdependence between CKD and normal ageing whereby CKD makes ageing more accelerated and pronounced (senescence), whereas senescence accelerates chronic nephropathy’s progression. Frailty status catalyzes this spiral, with renal and systemic consequences, phenomenon which can be named senescent nephropathy. In conclusion, senescent nephropathy is a new renal syndrome that should be taken into account, and we must try to handle its appearance and progression not only by applying nephron prevention measurements but also by diagnosis and treating frailty in the CKD population.