Haemodynamic frailty - A risk factor for acute kidney injury in the elderly

Age and Hypertension Synergize With Dehydration to Cause Renal Frailty in Rats and Predispose Them to Intrinsic Acute Kidney Injury

Acute kidney frailty (AKF) is a condition of increased susceptibility to acute kidney injury (AKI), an abrupt impairment of renal excretory function potentially leading to severe complications. Prevention of AKI relies on the recognition of risk factors contributing to AKF. At the population level, dehydration constitutes a predisposing factor for AKI. However, renal frailty may be context-specific, with variations among patients in the types of damage and the distinct pathological mechanisms. In this regard, we studied the combined effect of dehydration with other factors on renal homeostasis, such as increasing age and hypertension. AKF status was studied in rats bearing risk factors individually and in combination and was evaluated as the level of AKI induced by a triggering dose of cisplatin, which is known to be mildly nephrotoxic for young, healthy rats. AKI was assessed through parameters of renal function (including creatinine, urea, creatinine clearance, proteinuria, and fractional excretion of sodium) and histopathology of renal tissue specimens. The hydration status was measured by bioelectric impedance and other techniques. Water deprivation induces a dehydration state characterized by reductions in body weight and urinary flow and increases in hematocrit and plasma and urine osmolality. Bioelectric impedance showed a net loss of body water after water deprivation with no relevant changes in body mass distribution. Dehydration is not sufficient to predispose young control rats to intrinsic AKI. However, the combination of dehydration with advanced age or hypertension induces AKF evidenced by a magnified response of renal dysfunction (reduced filtration and tubular function) and tubular necrosis caused by low-dose cisplatin treatment. This study highlights the relevance of addressing AKF as a premorbid condition providing prophylactic opportunities and shows that dehydration differentially predisposes to prerenal and intrinsic AKI.

Association between estimated pulse wave velocity and in-hospital mortality of patients with acute kidney injury: a retrospective cohort analysis of the MIMIC-IV database

BACKGROUND

Estimated pulse wave velocity (ePWV) has been found to be an independent predictor of cardiovascular mortality and kidney injury, which can be estimated noninvasively. This study aimed to investigate the association between ePWV and in-hospital mortality in critically ill patients with acute kidney injury (AKI).

METHODS

This study included 5960 patients with AKI from the Medical Information Mart for Intensive Care IV (MIMIC-IV) database. The low and high ePWV groups were compared using a Kaplan-Meier survival curve to evaluate the differences in survival status. Cox proportional hazards models were used to explore the association between ePWV and in-hospital mortality in critically ill patients with AKI. To further examine the dose-response relationship, we used a restricted cubic spline (RCS) model. Stratification analyses were conducted to investigate the effect of ePWV on hospital mortality across various subgroups.

RESULTS

Survival analysis indicated that patients with high ePWV had a lower survival rate than those with low ePWV. Following adjustment, high ePWV demonstrated a statistically significant association with an increased risk of in-hospital mortality among AKI patients (HR = 1.53, 95% CI = 1.36-1.71, p < 0.001). Analysis using the RCS model confirmed a linear increase in the risk of hospital mortality as the ePWV values increased (P for nonlinearity = 0.602).

CONCLUSIONS

A high ePWV was significantly associated with an increased risk of in-hospital mortality among patients with AKI. Furthermore, ePWV was an independent predictor of in-hospital mortality in critically ill patients with AKI.

Nutritional considerations with antiobesity medications

The improved efficacy and generally favorable safety profile of recently approved and emerging antiobesity medications (AOMs), which result in an average weight reduction of ≥15%, represent significant advancement in the treatment of obesity. This narrative review aims to provide practical evidence-based recommendations for nutritional assessment, management, and monitoring of patients treated with AOMs. Prior to treatment, clinicians can identify preexisting nutritional risk factors and counsel their patients on recommended intakes of protein, dietary fiber, micronutrients, and fluids. During treatment with AOMs, ongoing monitoring can facilitate early recognition and management of gastrointestinal symptoms or inadequate nutrient or fluid intake. Attention should also be paid to other factors that can impact response to treatment and quality of life, such as physical activity and social and emotional health. In the context of treatment with AOMs, clinicians can play an active role in supporting their patients with obesity to improve their health and well-being and promote optimal nutritional and medical outcomes.

Frailty and In-Hospital Outcomes for Management of Cardiogenic Shock without Acute Myocardial Infarction

(1) Background: Cardiogenic shock (CS) is associated with high morbidity and mortality. Frailty and cardiovascular diseases are intertwined, commonly sharing risk factors and exhibiting bidirectional relationships. The relationship of frailty and non-acute myocardial infarction with cardiogenic shock (non-AMI-CS) is poorly described. (2) Methods: We retrospectively analyzed the National Inpatient Sample from 2016 to 2020 and identified all hospitalizations for non-AMI-CS. We classified them into frail and non-frail groups according to the hospital frailty risk score cut-off of 5 and compared in-hospital outcomes. (3) Results: A total of 503,780 hospitalizations for non-AMI-CS were identified. Most hospitalizations involved frail adults (80.0%). Those with frailty had higher odds of in-hospital mortality (adjusted odds ratio [aOR] 2.11, 95% confidence interval [CI] 2.03-2.20, p < 0.001), do-not-resuscitate status, and discharge to a skilled nursing facility compared with those without frailty. They also had higher odds of in-hospital adverse events, such as acute kidney injury, delirium, and longer length of stay. Importantly, non-AMI-CS hospitalizations in the frail group had lower use of mechanical circulatory support but not rates of cardiac transplantation. (4) Conclusions: Frailty is highly prevalent among non-AMI-CS hospitalizations. Those accompanied by frailty are often associated with increased rates of morbidity and mortality compared to those without frailty.

Anemia and Its Connections to Inflammation in Older Adults: A Review

Anemia is a common hematological disorder that affects 12% of the community-dwelling population, 40% of hospitalized patients, and 47% of nursing home residents. Our understanding of the impact of inflammation on iron metabolism and erythropoiesis is still lacking. In older adults, anemia can be divided into nutritional deficiency anemia, bleeding anemia, and unexplained anemia. The last type of anemia might be caused by reduced erythropoietin (EPO) activity, progressive EPO resistance of bone marrow erythroid progenitors, and the chronic subclinical pro-inflammatory state. Overall, one-third of older patients with anemia demonstrate a nutritional deficiency, one-third have a chronic subclinical pro-inflammatory state and chronic kidney disease, and one-third suffer from anemia of unknown etiology. Understanding anemia's pathophysiology in people aged 65 and over is crucial because it contributes to frailty, falls, cognitive decline, decreased functional ability, and higher mortality risk. Inflammation produces adverse effects on the cells of the hematological system. These effects include iron deficiency (hypoferremia), reduced EPO production, and the elevated phagocytosis of erythrocytes by hepatic and splenic macrophages. Additionally, inflammation causes enhanced eryptosis due to oxidative stress in the circulation. Identifying mechanisms behind age-related inflammation is essential for a better understanding and preventing anemia in older adults.

Pathophysiology of Acute Kidney Frailty

Acute kidney frailty is a premorbid condition of diminished renal functional reserve that predisposes to acute kidney injury; this condition results from subclinical wear or distortion of renal homeostatic responses that protect the renal excretory function. Knowledge of its pathophysiological basis is critical for the development of diagnostic and therapeutic strategies that allow for prophylactic intervention and disease prevention.

Is It Time to Integrate Frailty Assessment in Onconephrology?

Simple Summary

There are an increasing number of older people living with kidney cancer and/or cancer and kidney disease worldwide, sparking a wider discussion on the impact of frailty and the clinical significance of conducting frailty assessments for this patient population. We provide an update on the current evidence related to frailty assessment in onconephrology and identify areas where further research efforts are anticipated to address knowledge gaps within this topic.

Abstract

Onconephrology has emerged as a novel sub-specialty of nephrology dedicated to the intersection between the kidney and cancer. This intersection is broad and includes a number of important areas of focus, including concurrent chronic kidney disease (CKD) and cancer, acute kidney complications of cancer, and cancer-treatment-induced nephrotoxicity. The importance of onconephrology is even more evident when considering the global growth in the population of older adults, many of whom are living with some degree of frailty. Furthermore, a considerable proportion of older adults have CKD (some of whom eventually progress to kidney failure) and are at high risk of developing solid tumour and hematologic malignancies. Specific to kidney disease, the association between frailty status and kidney disease has been explored in depth, and tools to capture frailty can be used to guide the management and prognostication of older adults living with kidney failure. Whilst there is emerging data regarding the assessment and impact of frailty in onconephrology, there remains a relative paucity of knowledge within this topic. In this article, we evaluate the definition and operationalization of frailty and discuss the significance of frailty within onconephrology. We review evidence on current approaches to assessing frailty in onconephrology and discuss potential developments and future directions regarding the utilization of frailty in this patient population. A greater awareness of the intersections and interactions between frailty and onconephrology and further efforts to integrate frailty assessment in onconephrology to optimize the delivery of realistic and goal-directed management strategies for patients is needed.

Associations between greenness and kidney disease in Massachusetts: The US Medicare longitudinal cohort study

BACKGROUND

Recent studies have identified the association of environmental stressors with reduced kidney function and the development of kidney disease. While residential greenness has been linked to many health benefits, the association between residential greenness and the development of kidney disease is not clear. We aimed to investigate the association between residential greenness and the development of kidney disease.

METHODS

We performed a longitudinal population-based cohort study including all fee-for-service Medicare Part A beneficiaries (aged 65 years or older) in Massachusetts (2000-2016). We assessed greenness with the annual average Enhanced Vegetation Index (EVI) based on residential ZIP codes of beneficiaries. We applied Cox-equivalent Poisson models to estimate the association between EVI and first hospital admission for total kidney disease, chronic kidney disease (CKD), and acute kidney injury (AKI), separately.

RESULTS

Data for 1,462,949 beneficiaries who resided in a total of 644 ZIP codes were analyzed. The total person-years of follow-up for total kidney disease, CKD, and AKI were 9.8, 10.9, and 10.8 million person-years, respectively. For a 0.1 increase in annual EVI, the hazard ratios (HRs) were 0.95 (95% CI: 0.93 to 0.97) for the first hospital admission for total kidney disease, and the association was more prominent for AKI (HR: 0.94 with 95% CI: 0.92 to 0.97) than CKD (HR: 0.98 with 95% CI: 0.95-1.01]). The estimated effects of EVI on kidney disease were generally more evident in White beneficiaries and those residing in metropolitan areas compared to the overall population.

CONCLUSIONS

This study found that higher levels of annual residential greenness were associated with a lower risk of the first hospital admission for kidney diseases. Results are consistent with the hypothesis that higher residential greenness benefits kidney patients.

Dehydration risk factors and outcomes in older people in rural areas

Objective: To determine the risk factors for dehydration in elderly people in one of Elbehira Governorate’s villages.

Methods: A descriptive correlational design was utilized in this study. The study was conducted at Elnemaria village, Markaz Abo Elmatamir, Elbehira Governorate, Egypt. Data were collected using 3 tools: a structured interviewing questionnaire, a dehydration knowledge questionnaire, and a dehydration risk appraisal checklist.

Results: The study found that 29.5% of the participants were aged between 65 and 70. Males constituted 51% of the study participants. The majority of the study participants regularly took anti-acids, anti-inflammatory drugs, and diuretics. Among the elderlies comprising the respondents, 40% had a low level of knowledge regarding dehydration. More than half of the study subjects were at moderate risk for dehydration.

Conclusions: The study showed that half of the participants had diabetes and a medium level of information about dehydration. The study also showed in general that the elderly in the village are exposed to a moderate dehydration rate, and there is also a strong relationship between taking different types of medication and the occurrence of dehydration.

Diagnosis of Cardiac Surgery-Associated Acute Kidney Injury: State of the Art and Perspectives

Diagnosis of cardiac surgery-associated acute kidney injury (CSA-AKI), a syndrome of sudden renal dysfunction occurring in the immediate post-operative period, is still sub-optimal. Standard CSA-AKI diagnosis is performed according to the international criteria for AKI diagnosis, afflicted with insufficient sensitivity, specificity, and prognostic capacity. In this article, we describe the limitations of current diagnostic procedures and of the so-called injury biomarkers and analyze new strategies under development for a conceptually enhanced diagnosis of CSA-AKI. Specifically, early pathophysiological diagnosis and patient stratification based on the underlying mechanisms of disease are presented as ongoing developments. This new approach should be underpinned by process-specific biomarkers including, but not limited to, glomerular filtration rate (GFR) to other functions of renal excretion causing GFR-independent hydro-electrolytic and acid-based disorders. In addition, biomarker-based strategies for the assessment of AKI evolution and prognosis are also discussed. Finally, special focus is devoted to the novel concept of pre-emptive diagnosis of acquired risk of AKI, a premorbid condition of renal frailty providing interesting prophylactic opportunities to prevent disease through diagnosis-guided personalized patient handling. Indeed, a new strategy of risk assessment complementing the traditional scores based on the computing of risk factors is advanced. The new strategy pinpoints the assessment of the status of the primary mechanisms of renal function regulation on which the impact of risk factors converges, namely renal hemodynamics and tubular competence, to generate a composite and personalized estimation of individual risk.

The effects of exercise on kidney injury: the role of SIRT1

In patients with kidney injury, muscle mass and strength decrease with altered muscle protein synthesis and degradation along with complications such as inflammation and low physical activity. A treatment strategy to maintain muscle metabolism in kidney injury is important. One of the proposed strategies in this regard is exercise, which in addition to inducing muscle hypertrophy, reducing plasma creatinine and urea and decreasing the severity of tubal injuries, can boost immune function and has anti-inflammatory effects. One of the molecules that have been considered as a target in the treatment of many diseases is silent information regulator 1 (SIRT1). Exercise increases the expression of SIRT1 and improves its activity. Therefore, studies that examined the effect of exercise on kidney injury considering the role of SIRT1 in this effect were reviewed to determine the direction of kidney injury research in future regarding to its prevalence, especially following diabetes, and lack of definitive treatment. In this review, we found that SIRT1 can be one of renoprotective target pathways of exercise. However, further studies are needed to determine the role of SIRT1 in different kidney injuries following exercise according to the type and severity of exercise, and the type of kidney injury.

Postoperative Dehydration Is Associated with Frailty and Decreased Survival in Older Patients with Hip Fracture

BACKGROUND

Hyperosmolar dehydration (HD) is a risk factor for severe complications in hip fracture in older patients. However, evidence for recommending screening of dehydration is insufficient and its relation with frailty and mortality is unclear. We tested the hypothesis that postoperative HD is associated with frailty and increased mortality.

METHODS

We recruited 625 older (>65 years) patients surgically treated for hip fracture and co-managed by an orthogeriatric team over one year in 2017. Pre- and postoperative HD (serum osmolarity > 300 mmol/L) was diagnosed. Frailty and associated mortality risk were assessed by the Multidimensional Prognostic Index (MPI).

RESULTS

The prevalence of preoperative HD was 20.4%. Compared with no-HD, MPI was similar in HD patients despite higher (p < 0.05) prevalence of polypharmacy, arterial hypertension, diabetes, chronic kidney disease and heart failure. After surgery the incidence of HD decreased to 16.5%, but increased (p = 0.003) in the MPI high-risk subgroup. Postoperative HD was associated with more complications and was an independent determinant of adjusted hospital length of stay (LOS) and of 60- to 365-days mortality.

CONCLUSIONS

Older frail patients with hip fracture are prone to developing postoperative HD, which independently predicts prolonged hospital LOS and mortality. Systematically screening older patients for frailty and dehydration is advisable to customize hydration management in high-risk individuals.