Advanced Age and Chronic Kidney Disease Modify the Association Between Metabolic Syndrome and Frailty Among Community-Dwelling Elderly

Genetic insights into the risk of frailty on metabolic syndrome and its components: Bidirectional Mendelian randomization study

BACKGROUND AND AIMS

Previous studies have shown that frailty and metabolic syndrome (Mets) share common pathophysiological mechanisms. However, whether the observed association reflects causality requires clarification. We performed a bidirectional Mendelian randomization study to investigate the causal relationship between frailty, Mets, and their individual components.

METHODS AND RESULTS

Summary-level data from GWAS to identify genetic variants associated with frailty, Mets, and its components among individuals of European ancestry. Inverse variance weighting was utilized as the main method. Using bidirectional Mendelian randomization analysis, we found that the risk of frailty was causally associated with an increased risk of MetS (OR: 2.092, 95%CI: 1.564-2.799) and its components, including waist circumference (OR: 1.349, 95 % CI: 1.181-1.541), hypertension (OR: 1.099, 95 % CI: 1.075-1.125), triglycerides (OR: 1.297, 95 % CI: 1.179-1.428). Conversely, the risk of MetS was causally associated with an increased risk of frailty (OR: 1.048; 95 % CI: 1.024-1.073). however, when removing SNPs assocaited with BMI at the loci significance level and performed MVMR, Mets and frailty were not associated.

CONCLUSION

These findings suggest a bidirectional causal relationship between frailty and MetS, indicating that genetic factors contributing to frailty also increase the risk of MetS and its components, and vice versa. Furthermore, BMI-related SNPs may act as effect modifiers in the association between MetS and frailty. These insights into the shared pathophysiology of frailty and MetS have implications for the prevention and treatment strategies in elderly individuals with MetS.

The prevalence of frailty among patients with metabolic syndrome: a systematic review and meta-analysis

BACKGROUND

Growing evidence shows that metabolic syndrome and frailty are significantly associated. Screening and assessing frailty in patients with metabolic syndrome is important to help improve their clinical outcomes and quality of life. Therefore, understanding the prevalence of frailty in patients with metabolic syndrome is the first critical step, however, the prevalence reported in the literature varies widely.

AIM

To pool the overall prevalence of frailty among patients with metabolic syndrome.

DESIGN

Systematic review and meta-analysis.

METHODS

The Cochrane Library, PubMed, Web of Science, Embase, APA PsycINFO, Scopus, CINAHL Complete, CNKI, Wan Fang, SinoMed, and VIP databases were searched from the inception to March 6, 2024. Statistical analysis was performed using STATA15 software. The prevalence was pooled using the random-effects model. The sources of heterogeneity were investigated by using meta-regression and subgroup analyses.

RESULTS

A total of 22 original studies published between 2007 and 2023 were included in this systematic review and meta-analysis, involving 19,921 metabolic syndrome patients. The prevalence of frailty and pre-frailty among patients with metabolic syndrome was 20% (95% CI: 16% to 25%, I2 = 99.44%) and 45% (95% CI: 36% to 53%, I2 = 99.20%). Subgroup analyses revealed differences in prevalence by frailty instruments, geographic regions, study settings, publication years, study quality, study design, and different components of metabolic syndrome.

CONCLUSIONS

This systematic review and meta-analysis showed the high prevalence of frailty and pre-frailty in patients with metabolic syndrome. In the future, more high-quality longitudinal studies and exploration of other potential demographic characteristics that may influence frailty are needed to understand more information on frailty in patients with metabolic syndrome.

The intersection of frailty and metabolism

On average, aging is associated with unfavorable changes in cellular metabolism, which are the processes involved in the storage and expenditure of energy. However, metabolic dysregulation may not occur to the same extent in all older individuals as people age at different rates. Those who are aging rapidly are at increased risk of adverse health outcomes and are said to be "frail." Here, we explore the links between frailty and metabolism, including metabolic contributors and consequences of frailty. We examine how metabolic diseases may modify the degree of frailty in old age and suggest that frailty may predispose toward metabolic disease. Metabolic interventions that can mitigate the degree of frailty in people are reviewed. New treatment strategies developed in animal models that are poised for translation to humans are also considered. We suggest that maintaining a youthful metabolism into older age may be protective against frailty.

Aortic arch calcification increases major adverse cardiac event risk, modifiable by echocardiographic left ventricular hypertrophy, in end-stage kidney disease patients

Background

The factors affecting cardiovascular risk associated with vascular calcification in patients with chronic kidney disease are less well addressed. Distinct risk factors may contribute synergistically to this elevated cardiovascular risk in this population.

Objectives

We aimed to determine whether echocardiographic left ventricular hypertrophy (LVH) affects the risk of major adverse cardiac events (MACE) associated with vascular calcification in end-stage kidney disease (ESKD) patients.

Methods

In this retrospective cohort study, ESKD patients underwent chest radiography and echocardiography to assess aortic arch calcification (AoAC) and LVH, respectively, and were classified into three groups accordingly: non-to-mild AoAC without LVH, non-to-mild AoAC with LVH, and moderate-to-severe AoAC. The risks of MACE, cardiovascular mortality, and overall mortality were assessed using Cox proportional hazard analysis.

Results

Of the 283 enrolled ESKD patients, 44 (15.5%) had non-to-mild AoAC without LVH, 117 (41.3%) had non-to-mild AoAC with LVH, and 122 (43.1%) had moderate-to-severe AoAC. After 34.1 months, 107 (37.8%) participants developed MACE, including 6 (13.6%), 40 (34.2%), and 61 (50%) from each respective group. Those with moderate-to-severe AoAC (Hazard ratio, 3.72; 95% confidence interval, 1.58-8.73) had a significantly higher risk of MACE than did those with non-to-mild AoAC without LVH or with non-to-mild AoAC and LVH (Hazard ratio, 2.73; 95% confidence interval, 1.16-6.46). A similar trend was observed for cardiovascular and overall mortality.

Conclusion

Echocardiographic LVH could modify the risk of adverse cardiovascular events associated with vascular calcification in ESKD patients. Interventions aiming to ameliorate both morbidities might be translated into a lower MACE risk in this population.

Vascular frailty, a proposal for new frailty type: A narrative review

Frailty is the incremental accumulation of minute defects that progressively impair health and performance. Frailty is commonly observed in older adults; however, secondary frailty may also occur in patients with metabolic disorders or major organ failure. In addition to physical frailty, several distinct types of frailty have been identified, including oral, cognitive, and social frailty, each of which is of practical importance. This nomenclature suggests that detailed descriptions of frailty can potentially advance relevant researches. In this narrative review, we first summarize the clinical value and plausible biological origin of frailty, as well as how to appropriately assess it using physical frailty phenotypes and frailty indexes. In the second part, we discuss the issue of vascular tissue as a relatively underappreciated organ whose pathologies contribute to the development of physical frailty. Moreover, when vascular tissue undergoes degeneration, it exhibits vulnerability to subtle injuries and manifests a unique phenotype amenable to clinical assessment prior to or accompanying physical frailty development. Finally, we propose that vascular frailty, based on an extensive set of experimental and clinical evidence, can be considered a new frailty type that requires our attention. We also outline potential methods for the operationalization of vascular frailty. Further studies are required to validate our claim and sharpen the spectrum of this degenerative phenotype.

The association between metabolic syndrome and presence of frailty: a systematic review and meta-analysis

BACKGROUND

Frailty represents a progressive deterioration in multi-system of the body and could increase vulnerability to stressors. Recently, several studies found that metabolic syndrome was significantly associated with frailty and emphasized its role in assessing and preventing frailty. However, these conclusions are controversial. We conducted this systematic review and meta-analysis to evaluate the association between metabolic syndrome and frailty.

METHODS

Databases including Pubmed, Embase, Web of Science, CINAHL Complete, China National Knowledge Infrastructure (CNKI) and Wanfang Data Knowledge Service Platform were searched for studies on the association between metabolic syndrome and frailty, from inception to 17th June 2022. Two researchers independently screened the literature, extracted the data and evaluated the quality. Stata/SE 15.0 software was used to perform the statistical analysis.

RESULTS

Eleven studies were included in this review and eight studies were included in the meta-analysis, involving one prospective cohort studies and ten cross-sectional studies with 12,640 participants. The pooled results indicated that metabolic syndrome was significantly associated with frailty (OR = 1.82, 95% CI = 1.46-2.27) with a low heterogeneity (I² = 32.1%), and there were significant associations between MetS and weakness (OR = 1.35, 95% CI = 1.15-1.58, I² = 0.0%), slow gait speed (OR = 1.80, 95% CI = 1.51-2.14, I² = 93.4%), weight loss (OR = 1.77, 95% CI = 1.36-2.29, I² = 0.0%) and decreased physical activity (OR = 1.87, 95% CI = 1.49-2.35, I² = 39.7%).

CONCLUSIONS

The findings of this systematic review and meta-analysis suggested that metabolic syndrome could be significantly associated with the presence of frailly. Future studies need to further consider the effects of measurement tools, age and specific disease status in this association. Furthermore, the casual relationship between them is to be determined.

The Relationship between Metabolic Syndrome and Frailty in Older People: A Systematic Review and Meta-Analysis

AIMS

Both metabolic syndrome (MetS) and frailty are associated with increased all-cause mortality, yet the complex interplay between these two conditions has not adequately been elucidated. We aim to analyse the relationship between MetS and frailty through a systematic review of the literature with meta-analyses.

METHODS

A literature search was conducted via MEDLINE and EMBASE. Studies were included if validated frameworks for defining frailty and MetS (presence of at least 3 out of the five constitutive components: abdominal obesity, high fasting blood glucose, hypertension, hypertriglyceridaemia, and low high-density lipoprotein level) were utilised, in addition to the inclusion of participants aged 60 or older.

RESULTS

Eleven studies were included, all observational. All were in community-dwelling older people, 9 cross-sectional and 2 longitudinal. Most of the studies used Fried's frailty phenotype. The prevalence of frailty ranged from 0.9% to 14.8% in population-based studies and 35.6% in the outpatient clinic setting. The prevalence of MetS was also higher in the outpatient clinic setting at 47.5%, compared to 17.5-41.0% in the community-dwelling populations. The meta-analysis of 11 studies showed that MetS was associated with an increased risk of frailty (pooled OR 1.73, 95% CI, 1.41-2.13).

CONCLUSION

This systematic review and meta-analysis suggest that frailty was more prevalent in older people with MetS compared to older people without MetS. The study findings suggest the importance of frailty screening in older people with MetS and a distinct role of managing MetS in preventing frailty in older people.

Low glycaemic state increases risk of frailty and functional decline in older people with type 2 diabetes mellitus - Evidence from a systematic review

AIMS

To explore risk of frailty and functional decline associated with low glycaemia in older people with type 2 diabetes.

METHODS

Systematic review.

RESULTS

11 studies included. Six studies investigated risk of frailty or physical decline with hypoglycaemia. Hypoglycaemia increased risk of incident frailty (HR 1.60, 95% CI 1.14 to 2.42) in one study and risk of fractures in four studies (2.24, 1.56 to 3.21, 1.24, 1.13 to 1.37, 1.94, 1.67 to 2.24 and 1.71, 1.35 to 2.16 respectively). In sixth study, hypoglycaemia associated with dependency (P < 0.001). Five studies explored association of low blood glucose/HbA1c with frailty. One study showed that mean blood glucose decreased with increasing frailty (p = 0.003). Two studies reported that HbA1c inversely correlated with clinical frailty scale (r = -0.31, p < 0.01) and HbA1c < 6.9% increased risk of frailty (HR, 1.41 95% CI 1.12 to 1.78) respectively. Last two studies showed that HbA1c < 6.5% associated with risk of any fracture (HR 1.08, 95% CI 1.06 to 1.11) and HbA1c < 6.0% associated with increased risk of care need (3.45, 1.02 to 11.6) respectively.

CONCLUSIONS

Low glycaemia increases risk of frailty and functional decline in older people with type 2 diabetes. Management should minimise incidence of low glycaemia in these patients.

Uremic Toxins and Frailty in Patients with Chronic Kidney Disease: A Molecular Insight

The accumulation of uremic toxins (UTs) is a prototypical manifestation of uremic milieu that follows renal function decline (chronic kidney disease, CKD). Frailty as a potential outcome-relevant indicator is also prevalent in CKD. The intertwined relationship between uremic toxins, including small/large solutes (phosphate, asymmetric dimethylarginine) and protein-bound ones like indoxyl sulfate (IS) and p-cresyl sulfate (pCS), and frailty pathogenesis has been documented recently. Uremic toxins were shown in vitro and in vivo to induce noxious effects on many organ systems and likely influenced frailty development through their effects on multiple preceding events and companions of frailty, such as sarcopenia/muscle wasting, cognitive impairment/cognitive frailty, osteoporosis/osteodystrophy, vascular calcification, and cardiopulmonary deconditioning. These organ-specific effects may be mediated through different molecular mechanisms or signal pathways such as peroxisome proliferator-activated receptor γ coactivator 1-α (PGC-1α), mitogen-activated protein kinase (MAPK) signaling, aryl hydrocarbon receptor (AhR)/nuclear factor-κB (NF-κB), nuclear factor erythroid 2-related factor 2 (Nrf2), heme oxygenase-1 (HO-1), Runt-related transcription factor 2 (RUNX2), bone morphogenic protein 2 (BMP2), osterix, Notch signaling, autophagy effectors, microRNAs, and reactive oxygen species induction. Anecdotal clinical studies also suggest that frailty may further accelerate renal function decline, thereby augmenting the accumulation of UTs in affected individuals. Judging from these threads of evidence, management strategies aiming for uremic toxin reduction may be a promising approach for frailty amelioration in patients with CKD. Uremic toxin lowering strategies may bear the potential of improving patients’ outcomes and restoring their quality of life, through frailty attenuation. Pathogenic molecule-targeted therapeutics potentially disconnect the association between uremic toxins and frailty, additionally serving as an outcome-modifying approach in the future.

Vascular Calcification as an Underrecognized Risk Factor for Frailty in 1783 Community-Dwelling Elderly Individuals

Background Vascular calcification (VC) is associated with high morbidity and mortality among older adults, a population that exhibits a higher tendency for developing frailty at the same time. Whether VC serves as a risk factor for the development of frailty in this population remains unclear. Methods and Results We analyzed a prospectively assembled cohort of community-dwelling older adults between 2014 and 2017 (n=1783). Frailty and prefrailty were determined on the basis of the Study of Osteoporotic Fractures criteria, and VC was measured using semiquantitative aortic arch calcification (AAC) and abdominal aortic calcification scoring. We conducted multiple logistic regression with prefrailty or frailty as the dependent variable, incorporating sociodemographic profiles, comorbidities, medications, laboratory data, AAC status/severity, and other geriatric phenotypes. Among all participants, 327 (18.3%) exhibited either prefrailty (15.3%) or frailty (3.1%), and 648 (36.3%) exhibited AAC. After adjusting for multiple confounders, we found that AAC incidence was associated with a substantially higher probability of prefrailty or frailty (odds ratio [OR], 11.9; 95% CI, 7.9-15.4), with a dose-responsive relationship (OR for older adults with AAC categories 1, 2, and 3 was 9.3, 13.6, and 52.5, respectively). Similar association was observed for older adults with abdominal aortic calcification (OR, 5.0; 95% CI, 1.3-19.5), and might be replicable in another cohort of patients with end-stage renal disease. Conclusions Severity of VC exhibited a linear positive relationship with frailty in older adults. Our findings suggest that a prompt diagnosis and potential management of VC may assist in risk mitigation for patients with frailty.

Elevated Red Cell Distribution Width Is Independently Associated With a Higher Frailty Risk Among 2,932 Community-Dwelling Older Adults

Background: Older adults are at an increased risk of frailty, but laboratory surrogates for identifying frailty in this population remain controversial and clinicians frequently encounter difficulty during frailty screening. We examined whether having a high red cell distribution width (RDW) was associated with an increased probability of frailty in older adults.

Methods: We prospectively included community-dwelling older adults between 2013 and 2016 from a single institute, with their clinical features/laboratory parameters documented. We used the Study of Osteoporotic Fractures index (malnutrition, poor physical performance, and fatigue) to delineate frailty, and harnessed multiple logistic regression to investigate whether having a high RDW (≥ 15.7%) was associated with an increased risk of having frailty among these participants.

Results: A total of 2,932 older adults (mean 73.5 ± 6.7 years; 44.6% male) were included, among whom 113 (3.9%) and 76 (2.6%) had a high RDW and presented frailty, respectively. Older adults with a high RDW were more likely to be frail (p = 0.002) and had more positive SOF items than those with normal RDW levels (p = 0.013). Those with a high RDW exhibited a significantly higher risk of having frailty (odds ratio [OR] 2.689, 95% confidence interval [CI] 1.184–6.109) compared to those without. Sensitivity analyses using RDW as a continuous variable similarly showed that RDW levels were positively associated with frailty risk (OR 1.223 per 1% RDW higher).

Conclusions: In older adults, higher RDW can be regarded as a frailty indicator, and the readiness in RDW assessment supports its screening utility.

Hypoglycemic episodes are associated with an increased risk of incident frailty among new onset diabetic patients

AIMS

Patients with diabetes mellitus (DM) are at risk for developing frailty due to the complex interplay between different cardiometabolic factors. We examined whether hypoglycemia could independently increase frailty risk besides these factors.

METHODS

From the Longitudinal Cohort of Diabetic Patients, 210,254 patients with new onset DM between 2004 and 2011 were identified, among whom 2119 non-frail patients had at least 1 hypoglycemic episode within 3 years of DM diagnosis. They were propensity score-matched to 8432 non-frail ones without hypoglycemia throughout the study period. Both groups were followed up longitudinally for incident physical frailty according to a modified FRAIL scale (Fatigue, Resistance, Ambulation, Illness, and Loss of weight). We analyzed the risk of frailty (primary) and mortality (secondary outcome) introduced by hypoglycemia, adjusted for known risk factors of frailty.

RESULTS

The mean age of patients (46.2% male) was 65.9 ± 14 years; diabetic patients with hypoglycemia had significantly higher comorbidity burden than those without. After 2.68 years, 172 (1.6%) patients with hypoglycemia developed incident frailty, representing a 60% higher risk (hazard ratio [HR] 1.599, 95% confidence interval [CI] 1.14-2.42). After adjusting for other risk factors, those with hypoglycemia had a significantly higher risk of frailty than those without (HR 1.443, 95% CI 1.01-2.05). Additionally, the mortality of those with hypoglycemia was 2-fold higher than those without, and the risk persisted despite confounder adjustment (HR 1.462, 95% CI 1.3-1.65).

CONCLUSION

In this population-based cohort, hypoglycemic episodes among diabetic patients increased the risk of incident frailty and mortality.