Prognostic interplay of kidney function with sarcopenia, anemia, disability and cognitive impairment. The GLISTEN study

Biomarkers of chronic kidney disease in older individuals: navigating complexity in diagnosis

Chronic kidney disease (CKD) in older individuals is a matter of growing concern in the field of public health across the globe. Indeed, prevalence of kidney function impairment increases with advancing age and is often exacerbated by age-induced modifications of kidney function, presence of chronic diseases such as diabetes, hypertension, and cardiovascular disorders, and increased burden related to frailty, cognitive impairment and sarcopenia. Accurate assessment of CKD in older individuals is crucial for timely intervention and management and relies heavily on biomarkers for disease diagnosis and monitoring. However, the interpretation of these biomarkers in older patients may be complex due to interplays between CKD, aging, chronic diseases and geriatric syndromes. Biomarkers such as serum creatinine, estimated glomerular filtration rate (eGFR), and albuminuria can be significantly altered by systemic inflammation, metabolic changes, and medication use commonly seen in this population. To overcome the limitations of traditional biomarkers, several innovative proteins have been investigated as potential, in this review we aimed at consolidating the existing data concerning the geriatric aspects of CKD, describing the challenges and considerations in using traditional and innovative biomarkers to assess CKD in older patients, highlighting the need for integration of the clinical context to improve biomarkers' accuracy.

Chronic kidney disease and functional impairment in a longitudinal study of older adults in China

OBJECTIVES

To examine the associations of chronic kidney disease (CKD) with dynamic functional impairment among older Chinese adults.

DESIGN

This was a prospective longitudinal study.

SETTING

Data were derived from the Chinese Longitudinal Healthy Longevity Study.

PARTICIPANTS

All adults aged ≥60 years were potentially eligible. This study included 2970 participants.

PRIMARY OUTCOME MEASURES

CKD was defined as an estimated glomerular filtration rate <60 mL/min/1.73 m2. Functional performances included instrumental activities of daily living (IADL) and basic activities of daily living (BADL), which were measured using six daily activities, including eating, dressing, transferring, using the toilet, bathing and continence, and eight daily activities, including visiting neighbours, shopping, cooking, washing clothes, walking 1 km, lifting 5 kg, crouching and standing up three times and taking public transportation, respectively.

RESULTS

This study included 2970 participants, including 988 (33.60%) participants with CKD. Participants with CKD had higher IADL scores than those without CKD (β=0.895, 95% CI: 0.761 to 1.029). Furthermore, there was a significant linear trend in the association of CKD severity with the IADL score (p<0.001). Similarly, CKD was significantly associated with higher BADL scores (β=0.067, 95% CI: 0.017 to 0.118). However, only participants with moderate and advanced CKD had a higher BADL score (β=0.088 and 0.152, 95% CI: 0.006 to 0.171 and 0.019 to 0.286, respectively).

CONCLUSIONS

CKD was associated with worse functional impairment. Furthermore, there was a significant linear trend in the association of the severity of CKD with the IADL score. However, only participants with moderate and advanced CKD had higher BADL scores.

Disentangling the Complexity of Nutrition, Frailty and Gut Microbial Pathways during Aging: A Focus on Hippuric Acid

Hippuric acid (HA) is a metabolite resulting from the hepatic glycine conjugation of benzoic acid (BA) or from the gut bacterial metabolism of phenylalanine. BA is generally produced by gut microbial metabolic pathways after the ingestion of foods of vegetal origin rich in polyphenolic compounds, namely, chlorogenic acids or epicatechins. It can also be present in foods, either naturally or artificially added as a preservative. The plasma and urine HA levels have been used in nutritional research for estimating the habitual fruit and vegetable intake, especially in children and in patients with metabolic diseases. HA has also been proposed as a biomarker of aging, since its levels in the plasma and urine can be influenced by the presence of several age-related conditions, including frailty, sarcopenia and cognitive impairment. Subjects with physical frailty generally exhibit reduced plasma and urine levels of HA, despite the fact that HA excretion tends to increase with aging. Conversely, subjects with chronic kidney disease exhibit reduced HA clearance, with HA retention that may exert toxic effects on the circulation, brain and kidneys. With regard to older patients with frailty and multimorbidity, interpreting the HA levels in the plasma and urine may result particularly challenging because HA is at the crossroads between diet, gut microbiota, liver and kidney function. Although these considerations may not make HA the ideal biomarker of aging trajectories, the study of its metabolism and clearance in older subjects may provide valuable information for disentangling the complex interaction between diet, gut microbiota, frailty and multimorbidity.

Impact of anthropometric factors on outcomes in atrial fibrillation patients: analysis on 10 220 patients from the European Society of Cardiology (ESC)-European Heart Rhythm Association (EHRA) EurObservational Research Programme on Atrial Fibrillation (EORP-AF) general long-term registry

AIM

To investigate the association of anthropometric parameters [height, weight, body mass index (BMI), body surface area (BSA), and lean body mass (LBM)] with outcomes in atrial fibrillation (AF).

METHODS AND RESULTS

Ten-thousand two-hundred twenty patients were enrolled [40.3% females, median age 70 (62-77) years, followed for 728 (interquartile range 653-745) days]. Sex-specific tertiles were considered for the five anthropometric variables. At the end of follow-up, survival free from all-cause death was worse in the lowest tertiles for all the anthropometric variables analyzed. On multivariable Cox regression analysis, an independent association with all-cause death was found for the lowest vs. middle tertile when body weight (hazard ratio [HR] 1.66, 95%CI 1.23-2.23), BMI (HR 1.65, 95%CI 1.23-2.21), and BSA (HR 1.49, 95%CI 1.11-2.01) were analysed in female sex, as well as for body weight in male patients (HR 1.61, 95%CI 1.25-2.07). Conversely, the risk of MACE was lower for the highest tertile (vs. middle tertile) of BSA and LBM in males and for the highest tertile of weight and BSA in female patients. A higher occurrence of haemorrhagic events was found for female patients in the lowest tertile of height [odds ratio (OR) 1.90, 95%CI 1.23-2.94] and LBM (OR 2.13, 95%CI 1.40-3.26).

CONCLUSIONS

In AF patients height, weight, BMI, BSA, and LBM were associated with clinical outcomes, with all-cause death being higher for patients presenting lower values of these variables, i.e. in the lowest tertiles of distribution. The anthropometric variables independently associated with other outcomes were also different between male and female subjects.

The relevance of geriatric assessments on the association between chronic kidney disease stages and mortality among older people: a secondary analysis of a multicentre cohort study

Background

age-adapted definition of chronic kidney disease (CKD) does not take individual risk factors into account. We aimed at investigating whether functional impairments influence CKD stage at which mortality increases among older people.

Methods

our series consisted of 2,372 outpatients aged 75 years or more enrolled in a multicentre international prospective cohort study. The study outcome was 24-month mortality. Kidney function was assessed by estimated glomerular filtration rate (eGFR) and albumin-to-creatinine ratio (ACR). Geriatric assessments included handgrip strength, short physical performance battery (SPPB), cognitive impairment, dependency in basic activities of daily living (BADL) and risk of malnutrition. Analysis was carried out by Cox regression, before and after stratification by individual functional impairments. Survival trees including kidney function and functional impairments were also investigated, and their predictivity assessed by C-index.

Results

overall, mortality was found to increase starting from eGFR = 30–44.9 ml/min/1.73 m² (hazard ratio [HR] = 3.28, 95% confidence interval [CI] = 1.81–5.95) to ACR = 30–300 mg/g (HR = 1.96, 95%CI = 1.23–3.10). However, in survival trees, an increased risk of mortality was observed among patients with impaired handgrip and eGFR = 45–59.9 ml/min/1.73 m², as well as patients with ACR < 30 mg/g and impaired handgrip and SPPB. Survival tree leaf node membership had greater predictive accuracy (C-index = 0.81, 95%CI = 0.78–0.84 for the eGFR survival tree and C-index = 0.77, 95%CI = 0.71–0.81 for the ACR survival tree) in comparison with that of individual measures of kidney function.

Conclusions

physical performance helps to identify a proportion of patients at an increased risk of mortality despite a mild–moderate impairment in kidney function and improves predictive accuracy of individual measures of kidney function.

Chronic Kidney Disease with Mild and Mild to Moderate Reduction in Renal Function and Long-Term Recurrences of Atrial Fibrillation after Pulmonary Vein Cryoballoon Ablation

The aim of this research was to evaluate if patients with chronic kidney disease (CKD) and mild or mild to moderate depression of renal function have an increased risk of atrial fibrillation (AF) recurrences after cryoballoon (CB) ablation. We performed a retrospective analysis of AF patients undergoing pulmonary vein isolation (PVI) by CB. The cohort was divided according to the KDIGO CKD-EPI classification into a (1) normal, (2) mildly decreased, or (3) mild to moderate reduction in estimated glomerular filtration rate (eGFR). Freedom from AF recurrences was the primary endpoint. A total of 1971 patients were included (60 ± 10 years, 29.0% females, 73.6% paroxysmal AF) in the study. Acute success and complication rates were 99.2% and 3.7%, respectively, with no significant differences among the three groups. After a follow-up of 24 months, AF recurrences were higher in the mildly and mild to moderate CKD groups compared to the normal kidney function group (23.4% vs. 28.3% vs. 33.5%, p < 0.05). Mild to moderate CKD was an independent predictor of AF recurrences after the blanking period (hazard ratio:1.38, 95% CI 1.02−1.86, p = 0.037). In conclusion, a multicenter analysis of AF patients treated with cryoablation revealed mild to moderate reductions in renal functions were associated with a higher risk of AF recurrences. Conversely, the procedural success and complication rates were similar in patients with normal, mildly reduced, or mild to moderate reduction in eGFR.