Association Between Serum β2 -Microglobulin Levels and Prevalent and Incident Physical Frailty in Community-Dwelling Older Women

Current strategies for senescence treatment: Focused on theranostic performance of nanomaterials

Age-related diseases imposed heavy burdens to the healthcare systems globally, while cell senescence served as one fundamental molecular/cellular basis for these diseases. How to tackle the senescence-relevant problems is a hotspot for biomedical research. In this review article, the hallmarks and molecular pathways of cell senescence were firstly discussed, followed by the introduction of the current anti-senescence strategies, including senolytics and senomorphics. With suitable physical or chemical properties, multiple types of nanomaterials were used successfully in senescence therapeutics, as well as senescence detection. Based on the accumulating knowledges for senescence, the rules of how to use these nanoplatforms more efficiently against senescence were also summarized, including but not limited to surface modification, material-cargo interactions, factor responsiveness etc. The comparison of these "senescence-selective" nanoplatforms to other treatment options (prodrugs, ADCs, PROTACs, CART etc.) was also given. Learning from the past, nanotechnology can add more choice for treating age-related diseases, and provide more (diagnostic) information to further our understanding of senescence process.

Health-related quality of life and DNA methylation-based aging biomarkers among survivors of childhood cancer

BACKGROUND

Childhood cancer survivors are at high risk for morbidity and mortality and poor patient-reported outcomes, typically health-related quality of life (HRQOL). However, associations between DNA methylation-based aging biomarkers and HRQOL have not been evaluated.

METHODS

DNA methylation was generated with Infinium EPIC BeadChip on blood-derived DNA (median for age at blood draw = 34.5 years, range = 18.5-66.6 years), and HRQOL was assessed with age at survey (mean = 32.3 years, range = 18.4-64.5 years) from 2206 survivors in the St Jude Lifetime Cohort. DNA methylation-based aging biomarkers, including epigenetic age using multiple clocks (eg, GrimAge) and others (eg, DNAmB2M: beta-2-microglobulin; DNAmADM: adrenomedullin), were derived from the DNAm Age Calculator (https://dnamage.genetics.ucla.edu). HRQOL was assessed using the Medical Outcomes Study 36-Item Short-Form Health Survey to capture 8 domains and physical and mental component summaries. General linear models evaluated associations between HRQOL and epigenetic age acceleration (EAA; eg, EAA_GrimAge) or other age-adjusted DNA methylation-based biomarkers (eg, ageadj_DNAmB2M) after adjusting for age at blood draw, sex, cancer treatments, and DNA methylation-based surrogate for smoking pack-years. All P values were 2-sided.

RESULTS

Worse HRQOL was associated with greater EAA_GrimAge (physical component summaries: β = -0.18 years, 95% confidence interval [CI] = -0.251 to -0.11 years; P = 1.85 × 10-5; and 4 individual HRQOL domains), followed by ageadj_DNAmB2M (physical component summaries: β = -0.08 years, 95% CI = -0.124 to -0.037 years; P = .003; and 3 individual HRQOL domains) and ageadj_DNAmADM (physical component summaries: β = -0.082 years, 95% CI = -0.125 to -0.039 years; P = .002; and 2 HRQOL domains). EAA_Hannum (Hannum clock) was not associated with any HRQOL.

CONCLUSIONS

Overall and domain-specific measures of HRQOL are associated with DNA methylation measures of biological aging. Future longitudinal studies should test biological aging as a potential mechanism underlying the association between poor HRQOL and increased risk of clinically assessed adverse health outcomes.

Metabolic clues to aging: exploring the role of circulating metabolites in frailty, sarcopenia and vascular aging related traits and diseases

Background: Physical weakness and cardiovascular risk increase significantly with age, but the underlying biological mechanisms remain largely unknown. This study aims to reveal the causal effect of circulating metabolites on frailty, sarcopenia and vascular aging related traits and diseases through a two-sample Mendelian Randomization (MR) analysis. Methods: Exposures were 486 metabolites analyzed in a genome-wide association study (GWAS), while outcomes included frailty, sarcopenia, arterial stiffness, atherosclerosis, peripheral vascular disease (PAD) and aortic aneurysm. Primary causal estimates were calculated using the inverse-variance weighted (IVW) method. Methods including MR Egger, weighted median, Q-test, and leave-one-out analysis were used for the sensitive analysis. Results: A total of 125 suggestive causative associations between metabolites and outcomes were identified. Seven strong causal links were ultimately identified between six metabolites (kynurenine, pentadecanoate (15:0), 1-arachidonoylglycerophosphocholine, androsterone sulfate, glycine and mannose) and three diseases (sarcopenia, PAD and atherosclerosis). Besides, metabolic pathway analysis identified 13 significant metabolic pathways in 6 age-related diseases. Furthermore, the metabolite-gene interaction networks were constructed. Conclusion: Our research suggested new evidence of the relationship between identified metabolites and 6 age-related diseases, which may hold promise as valuable biomarkers.

Glomerular filtration rate by different measures and albuminuria are associated with risk of frailty: the Rugao Longitudinal Ageing Study

BACKGROUND AND AIM

A decreased estimated glomerular filtration rate (eGFR) is associated with frailty, but the association between kidney function and frailty using multidimensional assessments has not been entirely examined. We aimed to investigate whether albuminuria and the eGFR using different biomarkers were associated with frailty.

METHODS

A total of 1830 older adults were included. Kidney function was assessed by the eGFR (based on combined creatinine-cystatin C [eGFR_cr-cys]) and β₂-microglobulin [eGFR_B2M]) and urine albumin-creatinine ratio (UACR). Frailty was measured by the Fried phenotype (FP) and frailty index (FI). Logistic regression models were used to investigate cross-sectional and longitudinal associations of baseline kidney measures with prevalent and incident frailty.

RESULTS

At baseline, kidney function was associated with prevalent frailty. During the 2-year follow-up, a decreased eGFR (per 10 units) was associated with an increased risk of incident frailty using the FP (eGFR_cr-cys: OR 1.18, 95% CI 1.03-1.35; eGFR_B2M: OR 1.14, 95% CI 1.02-1.29, respectively) and FI (eGFR_B2M: OR 1.18, 95% CI 1.04-1.65). An increased logUACR was associated with a higher risk of incident frailty using the FP (OR 1.18, 95% CI 1.03-1.35). Additionally, individuals with chronic kidney disease (CKD) had a higher risk of incident frailty using the FP (eGFR_cr-cys: OR 2.13, 95% CI 1.28-3.47; eGFR_B2M: OR 1.58, 95% CI 1.10-2.29, respectively) and FI (eGFR_cr-cys: OR 1.97, 95% CI 1.15-3.32; eGFR_B2M: OR 1.51, 95% CI 1.03-2.24, respectively).

CONCLUSION

Kidney function decline and CKD were associated with an increased risk of prevalent and incident frailty in older adults. Physicians should pay more attention to monitoring frailty status in older adults with CKD, even in those with kidney function decline.

The Role of Blood-Derived Factors in Protection and Regeneration of Aged Tissues

Tissue regeneration substantially relies on the functionality of tissue-resident endogenous adult stem cell populations. However, during aging, a progressive decline in organ function and regenerative capacities impedes endogenous repair processes. Especially the adult human heart is considered as an organ with generally low regenerative capacities. Interestingly, beneficial effects of systemic factors carried by young blood have been described in diverse organs including the heart, brain and skeletal muscle of the murine system. Thus, the interest in young blood or blood components as potential therapeutic agents to target age-associated malignancies led to a wide range of preclinical and clinical research. However, the translation of promising results from the murine to the human system remains difficult. Likewise, the establishment of adequate cellular models could help to study the effects of human blood plasma on the regeneration of human tissues and particularly the heart. Facing this challenge, this review describes the current knowledge of blood plasma-mediated protection and regeneration of aging tissues. The current status of preclinical and clinical research examining blood borne factors that act in stem cell-based tissue maintenance and regeneration is summarized. Further, examples of cellular model systems for a more detailed examination of selected regulatory pathways are presented.

The impact of uremic toxins on Alzheimer's disease

Alzheimer's disease (AD) is the most common type of dementia, pathologically characterized by accumulation of senile plaques and neurofibrillary tangles. Chronic kidney disease (CKD) is highly prevalent in elderly population closely associated with occurrence of dementia. Recent epidemiological and experimental studies suggest a potential association of CKD with AD. Both diseases share a panel of identical risk factors, such as type 2 diabetes; and hypertension. However, the relationship between CKD and AD is unclear. Lower clearance of a panel of uremic toxin including cystatin-C, guanidine, and adiponectin due to CKD is implied to contribute to AD pathogenesis. In this review we summarize the current evidence from epidemiological, experimental and clinical studies on the potential contribution of uremic toxins to AD pathogenesis. We describe outstanding questions and propose an outlook on the link between uremic toxins and AD.

Factors associated with frailty transition at different follow-up intervals: A scoping review

Frailty is a dynamic process. Identifying the factors associated with frailty transition may increase the opportunities for success in interventions for frailty. This scoping review, following Arksey and O'Malley's methodological framework, aimed to identify the factors associated with frailty transition and the rate of frailty transition among community-dwelling older people. A literature search was conducted. Among the included studies, 5, 13, and 3 involved follow-up intervals of 2-3 years (short term), 4-6 years (intermediate term), and >6 years (long term), respectively. Reportedly, life course characteristics, diseases, and psychological factors were related to frailty transitions at all follow-up intervals. Physical factors were related to frailty transition at both short and intermediate follow-up intervals, while social factors were related to frailty transition at intermediate follow-up intervals. The rate of improvement in frailty seemed to decrease, and that of worsening seemed to increase when the follow-up intervals lengthened.

Development of a cognitive function marker based on D-amino acid proportions using new chiral tandem LC-MS/MS systems

The incidence of dementia, a clinical symptom characterized by severe cognitive decline, is increasing worldwide. Predictive biomarkers are therefore required for early identification and management. D-amino acids in the brain contribute to cognitive function and are suggested as useful biomarkers for diagnosing dementia risk. To clarify their relationship with human cognitive decline, we developed an identification method of chiral metabolomics for detecting slight differences in chiral amino acid amounts. Chiral tandem liquid chromatography-tandem mass spectrometry systems were applied for sensitive and selective amino acid species along with chiral species determination based on anion and zwitterion exchange mechanisms. In a comprehensive health cohort (cross-sectional study), we measured blood chiral amino acid levels from 305 women (65–80 years old) classified into Control, Mild-cognitive-Impairment (MCI), and Dementia groups using the Mini-Mental State Examination. MCI exhibited higher D-Pro (D-Pro/(D-Pro + L-Pro)) proportion vs the Control group, suggesting this proportion as a useful biomarker for MCI. Biomarker accuracy was improved in combination with D-Ser proportion. Receiver operating characteristics analysis of the Control vs. MCI proportion obtained area under the curve (0.80) with 70% sensitivity and 84% specificity at the optimal cutoff value (0.30). Thus, dementia monitoring can be improved by including trace D-amino acids measurements.

Risk Factors of Progression to Frailty: Findings from the Singapore Longitudinal Ageing Study

OBJECTIVES

To investigate risk factors of incident physical frailty.

DESIGN

A population-based observational longitudinal study.

SETTING

Community-dwelling elderly with age 55 years and above recruited from 2009 through 2011 in the second wave Singapore Longitudinal Ageing Study-2 (SLAS-2) were followed up 3-5 years later.

PARTICIPANTS

A total of 1297 participants, mean age of 65.6 ±0.19, who were free of physical frailty.

MEASUREMENTS

Incident frailty defined by three or more criteria of the physical phenotype used in the Cardiovascular Health Study was determined at follow-up. Potential risk factors assessed at baseline included demographic, socioeconomic, medical, psychological factors, and biochemical markers.

RESULTS

A total of 204 (15.7%) participants, including 81 (10.87%) of the robust and 123 (22.28%) of the prefrail transited to frailty at follow-up. Age, no education, MMSE score, diabetes, prediabetes and diabetes, arthritis, ≥5 medications, fair and poor self-rated health, moderate to high nutritional risk (NSI ≥3), Hb (g/dL), CRP (mg/L), low B12, low folate, albumin (g/L), low total cholesterol, adjusted for sex, age and education, were significantly associated (p<0.05) with incident frailty. In stepwise selection models, age (year) (OR=1.07, 95%CI=1.03-1.10, p<0.001), albumin (g/L) (OR=0.85, 95%CI=0.77-0.94, p=0.002), MMSE score (OR=0.88, 95%CI=0.78-0.98, p=0.02), low folate (OR=3.72, 95%CI=1.17-11.86, p=0.03, and previous hospitalization (OR=2.26, 95%CI=1.01-5.04,p=0.05) were significantly associated with incident frailty.

CONCLUSIONS

The study revealed multiple modifiable risk factors, especially related to poor nutrition, for which preventive measures and early management could potentially halt or delay the development of frailty.

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

Metabolic syndrome (MetS) predisposes older adults to the development of frailty. However, previous studies have not explored factors that may influence the association between MetS and the risk of frailty in this population. Community-dwelling older adults (≥65 years of age) were prospectively identified and enrolled between 2013 and 2016. MetS and frailty were defined based on the American Association of Clinical Endocrinologists and Study of Osteoporotic Fractures criteria, respectively. Multiple logistic regression with frailty/prefrailty as the dependent variable was used to examine the relationship between MetS and frailty/prefrailty, supplemented by subgroup analyses of the influence of aging and chronic kidney disease (CKD). Among 2862 elderly (73.4 ± 6.7 years), 17.5% and 17.3%, respectively, had MetS and frailty/prefrailty, among whom 74 (2.6%) and 420 (14.7%) had frailty and prefrailty. The presence of MetS (odds ratio [OR] 2.53, p < 0.001), higher age (OR 1.05, p < 0.001), and CKD (OR 1.42, p = 0.006) were associated with a significantly higher risk of frailty/prefrailty. Furthermore, among those ≥80 years of age, the association between MetS and frailty/prefrailty disappeared (p = 0.329). Among those with CKD, the presence of MetS was significantly associated with a progressively higher risk of frailty/prefrailty (for stage 3 or higher and for stage 3b or higher, OR 6.4 and 12.4, p < 0.001 and = 0.009, respectively). In conclusion, aging and CKD modified the association between MetS and frailty. These findings may assist in devising case-specific care plans for elderly with MetS by refocusing our attention on those at high risk of developing frailty/prefrailty.

Global Incidence of Frailty and Prefrailty Among Community-Dwelling Older Adults: A Systematic Review and Meta-analysis

IMPORTANCE

Frailty is a common geriatric syndrome of significant public health importance, yet there is limited understanding of the risk of frailty development at a population level.

OBJECTIVE

To estimate the global incidence of frailty and prefrailty among community-dwelling adults 60 years or older.

DATA SOURCES

MEDLINE, Embase, PsycINFO, Web of Science, CINAHL Plus, and AMED (Allied and Complementary Medicine Database) were searched from inception to January 2019 without language restrictions using combinations of the keywords frailty, older adults, and incidence. The reference lists of eligible studies were hand searched.

STUDY SELECTION

In the systematic review, 2 authors undertook the search, article screening, and study selection. Cohort studies that reported or had sufficient data to compute incidence of frailty or prefrailty among community-dwelling adults 60 years or older at baseline were eligible.

DATA EXTRACTION AND SYNTHESIS

The methodological quality of included studies was assessed using The Joanna Briggs Institute's Critical Appraisal Checklist for Prevalence and Incidence Studies. Meta-analysis was conducted using a random-effects (DerSimonian and Laird) model.

MAIN OUTCOMES AND MEASURES

Incidence of frailty (defined as new cases of frailty among robust or prefrail individuals) and incidence of prefrailty (defined as new cases of prefrailty among robust individuals), both over a specified duration.

RESULTS

Of 15 176 retrieved references, 46 observational studies involving 120 805 nonfrail (robust or prefrail) participants from 28 countries were included in this systematic review. Among the nonfrail individuals who survived a median follow-up of 3.0 (range, 1.0-11.7) years, 13.6% (13 678 of 100 313) became frail, with the pooled incidence rate being 43.4 (95% CI, 37.3-50.4; I2 = 98.5%) cases per 1000 person-years. The incidence of frailty was significantly higher in prefrail individuals than robust individuals (pooled incidence rates, 62.7 [95% CI, 49.2-79.8; I2 = 97.8%] vs 12.0 [95% CI, 8.2-17.5; I2 = 94.9%] cases per 1000 person-years, respectively; P for difference < .001). Among robust individuals in 21 studies who survived a median follow-up of 2.5 (range, 1.0-10.0) years, 30.9% (9974 of 32 268) became prefrail, with the pooled incidence rate being 150.6 (95% CI, 123.3-184.1; I2 = 98.9%) cases per 1000 person-years. The frailty and prefrailty incidence rates were significantly higher in women than men (frailty: 44.8 [95% CI, 36.7-61.3; I2 = 97.9%] vs 24.3 [95% CI, 19.6-30.1; I2 = 8.94%] cases per 1000 person-years; prefrailty: 173.2 [95% CI, 87.9-341.2; I2 = 99.1%] vs 129.0 [95% CI, 73.8-225.0; I2 = 98.5%] cases per 1000 person-years). The incidence rates varied by diagnostic criteria and country income level. The frailty and prefrailty incidence rates were significantly reduced when accounting for the risk of death.

CONCLUSIONS AND RELEVANCE

Results of this study suggest that community-dwelling older adults are prone to developing frailty. Increased awareness of the factors that confer high risk of frailty in this population subgroup is vital to inform the design of interventions to prevent frailty and to minimize its consequences.

Transitions between frailty states among community-dwelling older people: A systematic review and meta-analysis

Frailty is a well-established risk factor for adverse health outcomes. However, comparatively little is known about the dynamic nature of frailty and the extent to which it can improve. The purposes of this study were to systematically search for studies examining frailty transitions over time among community-dwelling older people, and to synthesise pooled frailty transitions rates. Four electronic databases (Medline, Embase, PsycINFO and CINAHL) were searched in July 2018. Inclusion criteria were: prospective design, community-dwelling older people with mean age>60, using 5-item frailty phenotype criteria to define three states: robust, prefrail and frail and the numbers of participants with 9 frailty transition patterns based on frailty status at baseline and follow-up. Exclusion criteria were: selected populations, using fewer than 5 frailty phenotype criteria. Two investigators independently screened 504 studies for eligibility and identified 16 studies for this review. Data were extracted by the two investigators independently. Pooled rates of frailty transition patterns were calculated by random-effects meta-analysis. Among 42,775 community-dwelling older people from 16 studies with a mean follow-up of 3.9 years (range: 1-10 years), 13.7% (95%CI = 11.7-15.8%) improved, 29.1% (95%CI = 25.9-32.5%) worsened and 56.5% (95%CI = 54.2-58.8%) maintained the same frailty status. Among those who were robust at baseline, pooled rates of remaining robust or transitioning to prefrail and frail were 54.0% (95%CI = 48.8-59.1%), 40.6% (95%CI = 36.7-44.7%) and 4.5% (95%CI = 3.2-6.1%), respectively. Among those who were prefrail at baseline, corresponding rates to robust, prefrail and frail were 23.1% (95%CI = 18.8-27.6%), 58.2% (95%CI = 55.6-60.7%) and 18.2% (95%CI = 14.9-21.7%), respectively. Among those who were frail at baseline, pooled rates of transitioning to robust, prefrail and remaining frail were 3.3% (95%CI = 1.6-5.5%), 40.3% (95%CI = 34.6-46.1%) and 54.5% (95%CI = 47.6-61.3%), respectively. Stratified and meta-regression analyses showed age, gender and follow-up period were associated with frailty transition patterns. Older people make dynamic changes in their frailty status. Given that while one quarter of prefrail older people improved to robust only 3% of frail older people did, early interventions should be considered.

Association of multidimensional comorbidities with survival, toxicity, and unplanned hospitalizations in older adults with metastatic colorectal cancer treated with chemotherapy

BACKGROUND

Studies of older patients with colorectal cancer(CRC) have found inconsistent results about the correlation of various comorbidities with overall survival(OS) and treatment tolerance. To refine our understanding, we evaluated this correlation using the Cumulative Illness Rating Scale-Geriatric(CIRS-G) and heat maps to identify subgroups with the highest impact.

METHODS

We retrospectively reviewed 153 patients aged 65 years and older with stage IV CRC undergoing chemotherapy. We calculated CIRS-G scores, and a Total Risk Score(TRS) derived from a previous heat map study. The association between CIRS-G scores/TRS and OS, unplanned hospitalizations, and chemotoxicity was examined by the Cox proportional hazards model.

RESULTS

Median age was 71 years. Median MAX2 score of chemotherapies was 0.134(0.025-0.231). The most common comorbidities were vascular(79.8%), eye/ear/nose/throat(68%), and respiratory disease(52.4%). Median OS was 25.1 months(95% confidence interval: 21.2-27.6). In univariate analysis, ECOG PS ≥ 2(HR 1.86(1.1-3.17), p = 0.019), poorly differentiated histology(HR 2.03(1.27-3.25), p = 0.003), primary site(rectum vs colon)(HR 0.58 (0.34-0.98), p = 0.04), age at diagnosis(HR per 5y 1.20 (1.04-1.39), p = 0.012), and number of CIRS-G grade 4 comorbidities(HR 1.86 (1.1-3.17), p = 0.019) were associated with OS. In multivariate analysis, the number of CIRS-G grade 4 comorbidities lost significance, although it retained it in the subgroup of patients with colon cancer. Conversely, the TRS was associated with OS in patients with rectal cancer. No association of comorbidity with unplanned hospitalization or chemotoxicity was observed.

CONCLUSIONS

In older adults with metastatic CRC, the number of CIRS-G grade 4 comorbidities was associated with worse OS but no specific CIRS-G category was independently associated with OS, unplanned hospitalization, or toxicities.

Association between serum β2-microglobulin levels and frailty in an elderly Chinese population: results from RuLAS

OBJECTIVE

To examine the association between serum β2-microglobulin (B2M) levels and frailty in an elderly Chinese population.

DESIGN

A population-based cohort study.

SETTING AND PARTICIPANTS

We used data on 1,663 elderly participants (aged 70-84 years) from the aging arm of the Rugao Longevity and Ageing study, a population-based observational two-arm cohort study conducted in Rugao, China.

MEASUREMENTS

The serum B2M was measured with chemiluminescence immunoassay by a technician in the biochemistry laboratory of the Rugao People's Hospital. Information on the frailty index and phenotype was collected.

RESULTS

The mean B2M levels and frailty index were 1.8 mg/L and 0.16, respectively; 188 (11.3%) participants were classified as frail (frailty phenotype). For a standard deviation increase in B2M, the adjusted odds ratio for frailty phenotype was 1.20 (95% CI: 1.05, 1.39; P=0.009) and the standardized coefficient for frailty index was 0.07 (95% CI: 0.02, 0.11; P=0.004). Relative to the lowest quartile, the highest B2M quartile had a greater risk of prevalent frailty with adjusted odds ratios of 1.68 (95% CI: 1.04, 2.71; P=0.034) for frailty phenotype and 1.51 (95% CI: 1.01, 2.27; P=0.044) for frailty index (≥0.25). In addition, estimated glomerular filtration rate (based on B2M) or chronic kidney disease (estimated glomerular filtration rate <60 mL/min/1.73 m²) was significantly associated with frailty phenotype and index.

CONCLUSION

B2M was significantly associated with both frailty phenotype and index in elderly Chinese population. The findings underscore the promising kidney relevant biomarkers for identifying vulnerable elderly Chinese population.