Chronic kidney disease and the aging population

Estimated glomerular filtration rate in clinical practice: Consensus positioning of the Brazilian Society of Nephrology (SBN) and Brazilian Society of Clinical Pathology and Laboratory Medicine (SBPC/ML)

Chronic kidney disease (CKD) represents one of today's main public health problems. Serum creatinine measurement and estimation of the glomerular filtration rate (GFR) are the main tools for evaluating renal function. There are several equations to estimate GFR, and CKD-EPI equation (Chronic Kidney Disease - Epidemiology) is the most recommended one. There are still some controversies regarding serum creatinine measurement and GFR estimation, since several factors can interfere in this process. An important recent change was the removal of the correction for race from the equations for estimating GFR, which overestimated kidney function, and consequently delayed the implementation of treatments such as dialysis and kidney transplantation. In this consensus document from the Brazilian Societies of Nephrology and Clinical Pathology and Laboratory Medicine, the main concepts related to the assessment of renal function are reviewed, as well as possible existing controversies and recommendations for estimating GFR in clinical practice.

Characteristics and Effectiveness of Dedicated Care Programs for Patients Starting Dialysis: A Systematic Review

BACKGROUND

Dedicated care programs that provide increased support to patients starting dialysis are increasingly being used to reduce the risk of complications. The objectives of this systematic review were to determine the characteristics of existing programs and their effect on patient outcomes.

METHODS

We searched Embase, MEDLINE, Web of Science, Cochrane CENTRAL, and CINAHL from database inception to November 20, 2019 for English-language studies that evaluated dedicated care programs for adults starting maintenance dialysis in the inpatient or outpatient setting. Any study design was eligible, but we required the presence of a control group and prespecified patient outcomes. We extracted data describing the nature of the interventions, their components, and the reported benefits.

RESULTS

The literature search yielded 12,681 studies. We evaluated 66 full texts and included 11 studies (n=6812 intervention patients); eight of the studies evaluated hemodialysis programs. All studies were observational, and there were no randomized controlled trials. The most common interventions included patient education (n=11) and case management (n=5), with nurses involved in nine programs. The most common outcomes were mortality (n=8) and vascular access (n=4), with only three studies reporting on the uptake of home dialysis and none on transplantation. We identified four high-quality studies that combined patient education and case management; in these programs, the relative reduction in 90-day mortality ranged from 22% (95% CI, -3% to 41%) to 49% (95% CI, 33% to 61%). Pooled analysis was not possible due to study heterogeneity.

CONCLUSIONS

Few studies have evaluated dedicated care programs for patients starting dialysis, especially their effect on home dialysis and transplantation. Whereas multidisciplinary care models that combine patient education with case management appear to be promising, additional prospective studies that involve patients in their design and execution are needed before widespread implementation of these resource-intensive programs.

Kidney supportive care: an update of the current state of the art of palliative care in CKD patients

Chronic kidney disease (CKD) has become a public health burden worldwide for its increasing incidence and prevalence, high impact on the health related quality of life (HRQoL) and life expectancy, and high personal and social cost. Patients with advanced CKD, in dialysis or not, suffer a burden from symptoms very similar to other chronic diseases and have a life span not superior to many malignancies. Accordingly, in recent years, renal palliative care has been recommended to be integrated in the traditional care delivered to this population. This research provides an updated overview on renal palliative care from the relevant literature.

Chronic Kidney Disease among Middle-Aged and Elderly Population: A cross-sectional screening in a Hospital Camp in Varanasi, India

Chronic kidney disease (CKD) is no longer considered just a health burden, but a major health priority owing to its high treatment costs and poor outcome. The lack of community-based screening programs has led to the detection of CKD patients at advanced stages. This study aims to estimate the prevalence of CKD and patterns of known risk factors among the general population (middle-aged and elderly) attending a screening camp in a community-based setting. The study participants constituted a part of the general population of Varanasi (aged ≥45 years) who volunteered in a screening camp that was organized as part of the World Kidney Day Initiative at Opal Hospital. Information on age, sex, height, weight, smoking and drug history, history of diabetes, hypertension, and family history of kidney disease was extensively interrogated, while laboratory investigations such as urinalysis and serum creatinine levels were recorded. More than three-fifths of the participants were middle-aged adults (i.e., 45-64 years) and the remaining 34.8% were elderly population, i.e., ≥65 years. The overall prevalence of CKD in the 198 studied participants was 29.3%. Higher number of participants (40.6%) of elderly population had CKD (P = 0.011). The serum creatinine, albuminuria, and estimated glomerular filtration rate levels were strongly associated with CKD (P <0.05). Our study suggests that elderly individuals are at risk with higher serum creatinine levels and would benefit from early detection of CKD to prevent disease progression and associated morbidity and mortality.

Prevalence of kidney damage in Chinese elderly: a large-scale population-based study

BACKGROUND

In China, both population aging and kidney damage has become emerging public health challenges. Despite the number of elders is huge, data on kidney damage in this population are scarce. The present study aimed to describe the prevalence of kidney damage among older adults in Wuhan, China.

METHODS

To describe the prevalence of kidney damage among Chinese elderly, the health screening data of 350,881 adults older than 65 years in Wuhan, China were collected and analyzed. Kidney damage was defined as eGFR less than 60 mL/min per 1·73 m2 or the presence of proteinuria. Decreased renal function was defined as an eGFR < 60 mL/min/1.73 m2. Proteinuria was defined as urine protein ≥1+ and without urine WBC or nitrite positive. The associated risk factors of eGFR decline and kidney damage were analyzed by multivariate logistic regression.

RESULTS

The age-standardized prevalence of kidney damage, decreased renal function and proteinuria was 17.2, 13.5 and 5.3%. Among the patients, up to 74.4% was stage 3. The prevalence of kidney damage and eGFR decline were higher in suburbs than in urban (18.3% vs 16.0 and 14.6% vs 12.4%). Factors independently associated with kidney damage were age, female, BMI, abdominal circumference, hypertension, diabetes, stroke and coronary heart disease.

CONCLUSIONS

Kidney damage has become an important public health problem in Chinese elderly. More attention should be paid to elderly lived in suburbs or rural area in our further work.

Usefulness of ambulatory blood pressure monitoring in chronic kidney disease: The moroccan experience

Among patients with chronic kidney disease (CKD), hypertension (HTN) is very common and widely recognized to accelerate the progression of CKD and increase the risk for cardiovascular events. Accumulated data indicate that ambulatory blood pressure monitoring (ABPM) is better in detecting HTN than office blood pressure (BP) measurement. The goal of this study is to describe the ABPM characteristics in a group of CKD and hypertensive patients. A transversal study was conducted over a period of six months, to evaluate the ABPM patterns among a group of hypertensive patients with CKD (Group 1) and compared the data with a control group (Group 2). ABPM was performed with measurement rate every 15 min during daytime and 30 min at night. Nondipping BP patterns were defined as the absence of fall in nocturnal systolic and diastolic BP >10% of daytime values. Masked HTN was defined as controlled office BP (<140/90 mm Hg) with an elevated overall average BP by 24-h ABPM (>125/75 mm Hg), and white-coat HTN was defined as association of elevated BP readings (>140/90 mm Hg) in a clinical setting and normal 24-h average BP levels (<130/80 mm Hg). Fifty patients were included in each group. HTN was much longer in duration among hypertensive patients with CKD and frequently associated with obesity, dyslipidemia, and diabetes (64% vs. 39.60%). Positive proteinuria was present in 82% of CKD patients with HTN. CKD patients with HTN received more antihypertensive drugs than Group 2 patients. HTN was much more uncontrolled among CKD patients (60% vs. 24%), more serious with higher daytime and nighttime SBP, and loss of physiologic dipping during nighttime BP measurement (80%). Out-of-office BP monitoring by ABPM may improve the assessment and the successful management of HTN in patients with CKD. Standardized definitions for the diagnosis of masked and white-coat HTN would facilitate research.

The Potential Impact of Public Health Interventions in Preventing Kidney Disease

The years of life lost and years lived with disability resulting from chronic kidney disease (CKD) increased globally by 90% and 49.5%, respectively, between 1990 and 2013. In addition to the traditional factors, infections, low birthweight, environmental factors, and low socioeconomic status contribute to the CKD burden in low- and middle-income countries. System-level challenges such as poor appreciation of the burden, insufficient human resources, high health care costs, poor referral pathways, unreliable health information systems, and inadequate medicine supply pose barriers to CKD control. In this article, we present evidence that the CKD burden in low- and middle-income countries is related to system-wide issues, which could be reduced effectively using innovative, affordable, and scalable interventions. A multipronged approach is required including improving socioeconomic determinants of health, enabling the environment for healthy decision making, and sustainable interventions. Innovative approaches include promoting healthy behaviors, counseling, and education in primary care, task-sharing between physicians and nonphysicians, using technology to train nonphysicians to screen, diagnose, refer, follow-up, and educate patients, and ensuring quality. Stronger political will and system-level change are needed to prevent and manage CKD if the sustainable development goals of reducing premature mortality from noncommunicable diseases by 2030 are to be attained.

Diminished stress resistance and defective adaptive homeostasis in age-related diseases

Adaptive homeostasis is defined as the transient expansion or contraction of the homeostatic range following exposure to subtoxic, non-damaging, signaling molecules or events, or the removal or cessation of such molecules or events (Mol. Aspects Med. (2016) 49, 1-7). Adaptive homeostasis allows us to transiently adapt (and then de-adapt) to fluctuating levels of internal and external stressors. The ability to cope with transient changes in internal and external environmental stress, however, diminishes with age. Declining adaptive homeostasis may make older people more susceptible to many diseases. Chronic oxidative stress and defective protein homeostasis (proteostasis) are two major factors associated with the etiology of age-related disorders. In the present paper, we review the contribution of impaired responses to oxidative stress and defective adaptive homeostasis in the development of age-associated diseases.

A dual agonist of farnesoid X receptor (FXR) and the G protein-coupled receptor TGR5, INT-767, reverses age-related kidney disease in mice

Even in healthy individuals, renal function gradually declines during aging. However, an observed variation in the rate of this decline has raised the possibility of slowing or delaying age-related kidney disease. One of the most successful interventional measures that slows down and delays age-related kidney disease is caloric restriction. We undertook the present studies to search for potential factors that are regulated by caloric restriction and act as caloric restriction mimetics. Based on our prior studies with the bile acid-activated nuclear hormone receptor farnesoid X receptor (FXR) and G protein-coupled membrane receptor TGR5 that demonstrated beneficial effects of FXR and TGR5 activation in the kidney, we reasoned that FXR and TGR5 could be excellent candidates. We therefore determined the effects of aging and caloric restriction on the expression of FXR and TGR5 in the kidney. We found that FXR and TGR5 expression levels are decreased in the aging kidney and that caloric restriction prevents these age-related decreases. Interestingly, in long-lived Ames dwarf mice, renal FXR and TGR5 expression levels were also increased. A 2-month treatment of 22-month-old C57BL/6J mice with the FXR-TGR5 dual agonist INT-767 induced caloric restriction-like effects and reversed age-related increases in proteinuria, podocyte injury, fibronectin accumulation, TGF-β expression, and, most notably, age-related impairments in mitochondrial biogenesis and mitochondrial function. Furthermore, in podocytes cultured in serum obtained from old mice, INT-767 prevented the increases in the proinflammatory markers TNF-α, toll-like receptor 2 (TLR2), and TLR4. In summary, our results indicate that FXR and TGR5 may play an important role in modulation of age-related kidney disease.

Effects of childbirth on podocyturia in women with normotensive, uncomplicated pregnancies

Changes in hemodynamics and blood pressure occur shortly before and after childbirth regardless of the mode of delivery. This study aimed to test the hypothesis that parturition induces a temporal increase in podocyturia monitored by podocyte-specific protein podocin mRNA expression levels (Pod-mRNA). A total of 105 urine specimens, consisting of 43 and 62 from 18 and 20 otherwise healthy women with vaginal delivery (VD) and elective cesarean delivery (ECS), respectively, were studied. Determination of urine protein and creatinine (Cr) concentrations and quantitative analyses of Pod-mRNA, nephrin mRNA (Nep-mRNA), synaptopodin mRNA (Syn-mRNA), and aquaporin 2 mRNA expression were performed using RT-PCR in pelleted urine samples. Levels of mRNA expression were corrected by urine Cr concentration. Podocyturia increased significantly, concomitant with a significantly decreased Nep:Pod-mRNA ratio (NPR) in the urine, collected immediately before or after childbirth regardless of the delivery mode compared with urine collected before commencement of labor or on postpartum day 3 or later. Podocyturia was significantly negatively correlated with NPR [correlation coefficient (r) = -0.614/-0.750 for VD/ECS women, respectively], as well as the Syn:Pod-mRNA ratio. Systolic blood pressure exceeded 140 mmHg during labor in 50% of VD women, and mean arterial pressure was significantly positively correlated with podocyturia during labor in VD women (r = 0.733). Thus parturition induces a transient increase in urine podocytes with reduced Nep- and Syn-mRNA expressions. Glomerular podocytes with reduced Nep- and Syn-mRNA levels were suggested to be likely to detach from the glomerular basement membrane around childbirth.

The role of laboratory testing in detection and classification of chronic kidney disease: national recommendations

Chronic kidney disease (CKD) is a common clinical condition with significant adverse consequences for the patient and it is recognized as a significant public health problem. The role of laboratory medicine in diagnosis and management of CKD is of great importance: the diagnosis and staging are based on estimation of glomerular filtration rate (eGFR) and assessment of albuminuria (or proteinuria). Therefore, the joint working group of the Croatian society of medical biochemistry and laboratory medicine and Croatian chamber of medical biochemists for laboratory diagnostics in CKD issued this national recommendation regarding laboratory diagnostics of CKD.
Key factors for laboratories implementing the national guidelines for the diagnosis and management of CKD are:
1. Ensure good communication between laboratory professionals and clinicians, such as nephrologists or specialists in general/family medicine,
2. Ensure all patients are provided with the same availability of laboratory diagnostics,
3. Ensure creatinine assays are traceable to isotope dilution mass spectrometry (IDMS) method and have minimal bias and acceptable imprecision,
4. Select the appropriate GFR estimating formula. Recommended equation is the 2009 Chronic Kidney Disease Epidemiology Collaboration (CKD - EPI) equation,
5. In reporting the key laboratory tests (creatinine, eGFR, urine albumin-to-creatinine ratio, urine protein-to-creatinine ratio) use the appropriate reporting units,
6. Provide adequate information on limitations of creatinine measurement.
The manuscript has been organized to identify critical points in laboratory tests used in basic laboratory diagnostics of CKD and is based on the Kidney Disease: Improving Global Outcomes (KDIGO) 2012 Clinical Practice Guideline for the Evaluation and Management of Chronic Kidney Disease.

Alteration of podocyte phenotype in the urine of women with preeclampsia

Podocyte injury has been suggested to induce phenotypic alteration of glomerular podocytes and accelerate the detachment of podocytes from the glomeruli resulting in podocyturia. However, it is not clear whether podocyte phenotypic alteration occurs in the urine of women with preeclampsia (PE). Seventy-seven and 116 pelleted urine samples from 38 and 18 women at various stages of normal and PE pregnancies, respectively underwent quantitative analysis of podocyte-specific or associated protein mRNA expression, including podocin, nephrin, and synaptopodin using RT-PCR. Significant proteinuria in pregnancy (SPIP) is defined as protein:creatinine ratio (P/Cr, mg/mg) ≥0.27 in the urine supernatant. All three urine-pellet mRNAs expression levels were significantly positively correlated with P/Cr levels, suggesting that podocyturia increased with proteinuria. The podocin:nephrin mRNA ratio (PNR) and synaptopodin:nephrin mRNA ratio (SNR) increased significantly with increasing P/Cr, while the podocin:synaptopodin mRNA ratio (PSR) did not change significantly according to P/Cr, resulting in significantly higher PNR and SNR, but not PSR levels, in urine from PE women with than without SPIP. The PNR, SNR, and PSR in urine from PE women before onset of SPIP were comparable to those from controls. Thus, nephrin mRNA expression was reduced in the podocytes recovered from PE women.

Predictors of a Rapid Decline of Renal Function in Patients with Chronic Kidney Disease Referred to a Nephrology Outpatient Clinic: A Longitudinal Study

Background. Predicting the progression of kidney failure in patients with chronic kidney disease is difficult. The aim of this study was to assess the predictors of rapid kidney decline in a cohort of patients referred to a single outpatient nephrology clinic. Design. Longitudinal, prospective cohort study with a median follow-up of 3.39 years. Methods. Data were obtained from 306 patients with chronic renal failure based on serum creatinine-estimated glomerular filtration rate (eGFRcreat) < 90 mL/min/1.73 m2. After excluding patients who died (n=30) and those who developed end-stage renal failure (n=6), 270 patients were included. This population was grouped according to the rate of kidney function decline. Rapid kidney function decline was defined as an annual eGFRcreat loss > 4 mL/min/1.73 m2. We recorded nonfatal cardiovascular events at baseline and during follow-up in addition to biochemical parameters. Results. The mean loss in renal function was 1.22 mL/min/1.73 m2 per year. The mean age was 75 ± 8.8 years old, and the mean baseline eGFRcreat was 42 ± 14 mL/min/1.73 m2. Almost one-fourth of the sample (23.3% [63 patients]) suffered a rapid decline in renal function. In a logistic regression model with rapid decline as the outcome, baseline characteristics, lower serum albumin (OR: 0.313, 95% CI: 0.114–0.859), previous cardiovascular disease (OR: 1.903 95% CI: 1.028–3.523), and higher proteinuria (g/24 h) (OR: 1.817 CI 95%: 1.213–2.723) were the main predictors of rapid kidney decline. On multivariate analysis, including baseline and follow-up data, we obtained similar adjusted associations of rapid kidney decline with baseline serum albumin and proteinuria. The follow-up time was also shorter in the group with rapid rates of decline in renal function. Conclusion. Renal function remained stable in the majority of our population. Previous cardiovascular disease and cardiovascular incidents, lower serum albumin, and higher proteinuria at baseline were the main predictors of rapid kidney decline in our population.

Anticipated increase in the number of patients who require dialysis treatment among the aging population of Japan

The aging population is anticipated to have a large impact on the number of incident dialysis patients, as the risk of end-stage kidney disease increases with age. This study aimed to examine trends in the sex- and age-specific incidence rates of dialysis between 2008 and 2012, and to assess the impact of population aging on the number of incident dialysis patients over the next decade in Japan. Incidence was calculated using published data and Japan's population statistics. The 2012 incidence was extrapolated, and projected future demographic changes within the Japanese population were used to estimate the number of incident dialysis patients in 2020 and 2025. As a general trend, the sex- and age-specific incidence rates of dialysis decreased gradually between 2008 and 2012, except among men aged ≥80 years. The total number of incident dialysis patients was projected to increase by 12.8% from 36 590 in 2012 to 41 270 in 2025. Greater increases were observed in the oldest age group (≥85 years). In 2025, the number of incident dialysis patients in this group was projected to increase by 92.6% in men and 62.2% in women. This study shows the number of patients who initiate dialysis treatment is projected to increase over the next decade in Japan due to aging of the population. Effective strategies are needed to offset the challenges faced by the aging population, with a particular focus on octogenarians and older, given the notable proportion of patients requiring dialysis treatment in the future.

Renal transplantation in elderly patients. How to select the candidates to the waiting list?

Today, old age does not represent a formal contraindication to kidney transplantation. Rather, there is evidence that in elderly patients renal transplantation offers longer life expectancy and better quality of life in comparison with dialysis. Yet, the results of renal transplantation in recipients older than 65years are inferior to those observed in younger adults, death with functioning graft representing a major cause of failure. Therefore, the selection of aged patients is of paramount importance. Apart from the routine clinical and biological investigations, three aspects have been relatively neglected by the transplant community and may require a careful analysis in elderly candidates to transplantation: the presence and degree of frailty, the presence of comorbidities and the adherence to prescriptions. Although there are rapid and simple tests for assessing the degree of frailty in the elderly, there is no clear cut-off value to decide whether a patient should be accepted or not. With advanced age the prevalence and severity of cardiovascular events and other diseases tend to increase. The use of combined age-comorbidity indices may be helpful to identify patients at high risk of mortality. Another critical point is the poor unintentional adherence to treatment, often caused by forgetfulness and mild cognitive impairment. These drawbacks may be further enhanced by a high number of pills to take and by changes in the dosage or type of prescriptions. A careful screening of the presence and degree of frailty, comorbidity and poor compliance to treatment is highly recommended before admitting older candidates to the waiting list for transplantation.