Case-Finding for Sarcopenia in Community-Dwelling Older Adults: Comparison of Mini Sarcopenia Risk Assessment with SARC-F and SARC-CalF

BACKGROUND

We compared the diagnostic performance of the short five-item and full seven-item Mini Sarcopenia Risk Assessment Questionnaire (MSRA-5 and MSRA-7) against the Strength, Assistance walking, Rise from a chair, Climb stairs, and Falls (SARC-F) and SARC-F with calf circumference (SARC-CalF) scales for sarcopenia in healthy community-dwelling older adults.

METHODS

We conducted a post-hoc cross-sectional secondary data analysis of a prospective cohort study, using data from 230 older adults (mean age 67.2±7.4 years, 92% Chinese, and 73% female) from the "Longitudinal Assessment of Biomarkers for characterization of early Sarcopenia and Osteosarcopenic Obesity in predicting frailty and functional decline in community-dwelling Asian older adults Study" (GeriLABS-2) conducted between December 2017 and March 2019 in Singapore. We performed receiver operating characteristic curve analysis to ascertain the area under the curve (AUC) for sarcopenia diagnosis using the Asian Working Group for Sarcopenia 2019 consensus criteria. We applied the Delong method to compare the AUCs of the four instruments.

RESULTS

The MSRA-5 and MSRA-7 demonstrated poor diagnostic performance (AUC of 0.511, 95% confidence interval [CI] 0.433-0.589 and AUC of 0.526, 95% CI 0.445-0.606, respectively), compared to that in SARC-CalF (AUC of 0.739, 95% CI 0.671-0.808) and SARC-F (AUC of 0.564, 95% CI 0.591-0.636). The SARC-CalF demonstrated significantly superior discriminatory ability compared to that in the SARC-F, MSRA-5, and MSRA-7 (all p<0.01). The MSRA-5 demonstrated lower sensitivity (0.464) and specificity (0.597) than in the SARC-CalF (0.661 and 0.738, respectively), whereas the MSRA-7 had higher specificity (0.887) and lower sensitivity (0.145).

CONCLUSION

Conclusions: The poor diagnostic performances of the MSRA-5 and MSRA-7 in our study suggest limitations of self-reported questionnaires for assessing general and dietary risk factors for sarcopenia in healthy and culturally diverse community-dwelling older adults. Studies in different populations are needed to ascertain the utility of the MSRA for the community detection of sarcopenia.

SARC-F and modified versions using arm and calf circumference: Diagnostic performance for sarcopenia screening and the impact of obesity

AIM

SARC-F is limited by low sensitivity for sarcopenia identification. As surrogates of muscle mass, mid-arm circumference (MAC) and/or calf circumference have been proposed as additions to SARC-F to enhance sarcopenia identification. The aim of this study was to evaluate the diagnostic performance of SARC-F, SARC-CalF, SARC-F + MAC, and SARC-CalF + MAC in sarcopenia detection, and to assess the impact of obesity on their diagnostic performance.

METHODS

We studied 230 healthy non-frail community-dwelling older adults age >50 years. We performed receiver operating characteristic curve analysis for SARC-F, SARC-CalF, SARC-F + MAC and SARC-CalF + MAC against sarcopenia diagnosed by the Asian Working Group for Sarcopenia (AWGS) 2019 as the reference standard. Obesity was defined by high waist circumference (men ≥90 cm, women ≥80 cm). We performed subgroup analysis to compare between obese and non-obese groups.

RESULTS

The prevalence of sarcopenia was 27.0% by AWGS 2019. SARC-CalF + MAC had the best diagnostic performance (area under the curve [AUC] 0.74, 95% confidence interval [CI] 0.67-0.81; sensitivity 66.1%; specificity 69.1%), followed by SARC-CalF (AUC 0.70, 95% CI 0.62-0.78; sensitivity 21.0%; specificity 95.8%). SARC-F (AUC 0.57, 95% CI 0.49-0.66; sensitivity 0%; specificity 100%) performed significantly worsethan its modified versions (P < 0.05). There was higher accuracy of sarcopenia identification in obese compared with non-obese groups for SARC-F + MAC (AUC 0.75, 95% CI 0.65-0.85 vs. 0.58, 95% CI 0.46-0.70) and SARC-CalF + MAC (AUC 0.75, 95% CI 0.66-0.85 vs. 0.70, 95% CI 0.59-0.81).

CONCLUSIONS

The addition of arm circumference to SARC-CalF confers better diagnostic accuracy for sarcopenia identification, especially in the obese group. Thus, MAC may complement SARC-CalF for community screening of sarcopenia amongst healthy community-dwelling older adults by increasing sensitivity for the detection of sarcopenic obesity. Geriatr Gerontol Int 2024; 24: 182-188.

Yubi-Wakka Test for Sarcopenia Screening in the Community: Comparative Agreement, Diagnostic Performance and Validity with Calf Circumference Measurements

BACKGROUND

Screening tools such as calf circumference (CC) and Yubi-wakka (finger-ring) test have been recognized as effective tools by Asian Working Group for Sarcopenia 2019 (AWGS'19) for sarcopenia screening but their comparative agreement, diagnostic performance and validity are unclear.

OBJECTIVES

This study aims to determine: (i)agreement between calf and finger-ring circumference, (ii)diagnostic performance for low muscle mass and AWGS'19 sarcopenia diagnosis, (iii)correlation with muscle mass, strength, and physical performance, and (iv)association with frailty, life space mobility and physical activity.

METHODS

We studied 187 healthy community-dwelling older adults (mean age=66.8+7.0years) from the GERILABS-2 study. CC was measured via (i) both calves in sitting and standing positions, and (ii) Yubi-wakka test by encircling the thickest part of the non-dominant calf with index fingers and thumbs of both hands. We performed Cohen's kappa to check for agreement, area under receiver operating characteristic curve (AUC) to compare diagnostic performance, partial correlations adjusted for age and gender to compare convergent validity, and logistic regression to determine predictive validity for outcome measures.

RESULTS

Sarcopenia prevalence was 24.0% (AWGS'19). Yubi-wakka identified 16.6% of participants as screen-positive ("smaller"), showing moderate agreement only with non-dominant sitting CC measurements (k=0.421,p<0.001) and having lower diagnostic performance in determining low muscle mass (AUC=0.591 vs 0.855-0.870,p<0.001; sensitivity=57.1% vs 75.5-90.8%; specificity=58.4% vs 70.8-80.9%) and sarcopenia diagnosis (AUC=0.581 vs 0.788-0.818,p<0.001; sensitivity=55.6% vs 57.5-71.8%; specificity=74.4% vs 75.6-88.9%) compared to CC measurements. Yubi-wakka correlated significantly with muscle mass, grip strength and knee extension but not physical performance. When adjusted for age, gender and hypertension, Yubi-wakka was significantly associated with frailty (OR=3.96,95%CI:1.09-14.38), life space mobility (OR=2.38,95%CI:1.08-5.24) and physical activity (OR=2.50,95%CI:1.07-5.86).

DISCUSSION AND CONCLUSIONS

Yubi-wakka provides a self-administered, low-cost and practicable community screening tool for sarcopenia. Our study affirmed the convergent and predictive validity of Yubi-wakka, albeit with lower sensitivity and specificity in diagnostic performance compared to CC measurements.

Frailty Screening and Detection of Geriatric Syndromes in Acute Inpatient Care: Impact on Hospital Length of Stay and 30-Day Readmissions

BACKGROUND

Frailty is prevalent in acute care and is associated with negative outcomes. While a comprehensive geriatric assessment to identify geriatric syndromes is recommended after identifying frailty, more evidence is needed to support this approach in the inpatient setting. This study examined the association between frailty and geriatric syndromes and their impact on outcomes in acutely admitted older adults.

METHODS

A total of 733 individuals aged ≥65 years admitted to the General Surgery Service of a tertiary hospital were assessed for frailty using the Clinical Frailty Scale (CFS) and for geriatric syndromes using routine nursing admission assessments, including cognitive impairment, falls, incontinence, malnutrition, and poor oral health. Multinomial logistic regression and Cox regression were used to evaluate the associations between frailty and geriatric syndromes and their concomitant impact on hospital length of stay (LOS) and 30-day readmissions.

RESULTS

Greater frailty severity was associated with an increased likelihood of geriatric syndromes. Individuals categorized as CFS 4-6 and CFS 7-8 with concomitant geriatric syndromes had 29% and 35% increased risks of a longer LOS, respectively. CFS 4-6 was significantly associated with functional decline (relative risk ratio =1.46; 95% confidence interval [CI], 1.03-2.07) and 30-day readmission (hazare ratio=1.78; 95% CI, 1.04-3.04), whereas these associations were not significant for CFS 7-8.

CONCLUSION

Geriatric syndromes in frail individuals can be identified from routine nursing assessments and represent a potential approach for targeted interventions following frailty identification. Tailored interventions may be necessary to achieve optimal outcomes at different stages of frailty. Further research is required to evaluate interventions for older adults with frailty in a wider hospital context.

Bridging Radiotherapy Prior to Chimeric Antigen Receptor T-Cell Therapy for B-Cell Lymphomas: An ILROG Multi-Institutional Study

PURPOSE/OBJECTIVE(S)

To report an ILROG multi-institutional analysis of bridging radiotherapy (BRT) prior to CD19-targeting chimeric antigen receptor T-cell (CAR T) therapy for relapsed/refractory aggressive B-cell lymphomas (BCL).

MATERIALS/METHODS

Weretrospectively reviewed 115 patients (pts) with diffuse large BCL (n = 101, 88%), primary mediastinal BCL (n = 11, 10%), mantle cell lymphoma (n = 2, 2%), and T-cell/histiocyte rich large BCL (n = 1, 1%) who received BRT prior to commercial CAR T from 2018-2020 across 6 institutions. BRT toxicities were graded per CTCAE v5.0, cytokine release syndrome (CRS) per ASTCT, and immune effector cell-associated neurotoxicity syndrome (ICANS) per either ASTCT or CTCAE v5.0. Progression-free survival (PFS) and overall survival (OS), measured from CAR T infusion, were estimated using the Kaplan-Meier method. PFS was modeled using Cox regression with stepwise variable selection.

RESULTS

BRTwas given prior to axicabtagene ciloleucel (axi-cel; n = 82, 71%), tisagenlecleucel (tisa-cel; n = 31, 27%), or brexucabtagene autoleucel (n = 2, 2%). Median age was 62 years with median of two prior lines of therapy. Most pts had advanced stage III/IV disease at leukapheresis (n = 87, 76%), elevated pre-leukapheresis LDH (n = 73, 63%), and bulky disease (n = 55, 50%) (1 lesion ≥7.5 cm). 78 pts (68%) had extranodal disease, 12 (10%) had central nervous system (CNS) involvement, and 36 (31%) had bone involvement. Systemic bridging therapy was given to 42 pts (37%). Median intervals from leukapheresis to BRT start and from BRT completion to CAR T infusion were 5 days (IQR -6, 11) and 12 days (IQR 9, 23), respectively. BRT was delivered to 163 total sites; most commonly the abdomen/pelvis (n = 58, 50%), head/neck (n = 34, 30%), thorax (n = 20, 17%), extremity/soft tissue (n = 20, 17%), and CNS (n = 13, 11%). Median biologically effective dose was 31.3 Gy (IQR 24, 39). Most common regimen was 30 Gy in 10 fractions (n = 27, 17%). 40 pts (35%) received comprehensive BRT (to all active lesions). There were no grade ≥3 BRT toxicities. Grade ≥3 CRS occurred in 9 pts (8%), including 8/82 (10%) after axi-cel and 1/31 (3%) after tisa-cel. Grade ≥3 ICANS occurred in 23 pts (20%), including 22/82 (27%) after axi-cel and 1/31 (3%) after tisa-cel. Median follow up was 26.9 months. 1- and 2-year OS rates were 60% and 49%. 1- and 2-year PFS rates were 41% and 35%. Comprehensive BRT associated with superior PFS (HR 0.34, 95% CI 0.19-0.62, p<0.001) in a multivariable model with age ≥60, ECOG ≥2, advanced stage, CNS disease, pre-leukapheresis LDH, and axi-cel.

CONCLUSION

In this multi-institutional study, pts receiving BRT prior to CAR T therapy for BCL frequently had bulky disease yet experienced favorable PFS and OS. There were no serious toxicities attributable to BRT, and the rates of CRS and ICANS are comparable to those after CAR T alone. Comprehensive BRT associated with superior PFS.

Diagnosis and outcomes of cachexia in Asia: Working Consensus Report from the Asian Working Group for Cachexia

Chronic diseases often lead to metabolic disorders, causing anabolic resistance and increased energy consumption, which result in cachexia. Cachexia, in turn, can lead to major clinical consequences such as impaired quality of life, shortened life expectancy, and increased healthcare expenditure. Existing international diagnostic criteria for cachexia employ thresholds derived from Western populations, which may not apply to Asians due to differing body compositions. To address this issue, the Asian Working Group for Cachexia (AWGC) was initiated. The AWGC comprises experts in cachexia research and clinical practice from various Asian countries and aims to develop a consensus on diagnostic criteria and significant clinical outcomes for cachexia in Asia. The AWGC, composed of experts in cachexia research and clinical practice from several Asian countries, undertook three-round Delphi surveys and five meetings to reach a consensus. Discussions were held on etiological diseases, essential diagnostic items for cachexia, including subjective and objective symptoms and biomarkers, and significant clinical outcomes. The consensus highlighted the importance of multiple diagnostic factors for cachexia, including chronic diseases, either or both weight loss or low body mass index, and at least one of the following: anorexia, decreased grip strength (<28 kg in men and <18 kg in women), or elevated C-reactive protein levels (>5 mg/L [0.5 mg/dL]). The AWGC proposed a significant weight change of 2% or more over a 3-6 month period and suggested a tentative cut-off value of 21 kg/m2 for low body mass index in diagnosing cachexia. Critical clinical outcomes were determined to be mortality, quality of life as assessed by tools such as EQ-5D or the Functional Assessment of Anorexia/Cachexia Therapy, and functional status as measured by the Clinical Frailty Scale or Barthel Index, with significant emphasis on patient-reported outcomes. The AWGC consensus offers a comprehensive definition and user-friendly diagnostic criteria for cachexia, tailored specifically for Asian populations. This consensus is set to stimulate future research and enhance the multidisciplinary approach to managing cachexia. With plans to develop further guidelines for the optimal treatment, prevention, and care of cachexia in Asians, the AWGC criteria are expected to drive research across chronic co-morbidities and cancer in Asia, leading to future refinement of diagnostic criteria.

Aerosol generation with the use of positive pressure ventilation via supraglottic airway devices: an observational study

The amount of aerosol generation associated with the use of positive pressure ventilation via a supraglottic airway device has not been quantified. We conducted a two-group, two-centre, prospective cohort study in which we recruited 21 low-risk adult patients scheduled for elective surgery under general anaesthesia with second-generation supraglottic airway devices. An optical particle sizer and an isokinetic sampling probe were used to record particle concentrations per second at different size distributions (0.3-10 μm) during use as well as baseline levels during two common activities (conversation and coughing). There was a median (IQR [range]) peak increase of 2.8 (1.5-4.5 [1-28.1]) and 4.1 (2.0-7.1 [1-18.2]) times background concentrations during SAD insertion and removal. Most of the particles generated during supraglottic airway insertion (85.0%) and removal (85.3%) were < 3 μm diameter. Median (IQR [range]) aerosol concentration generated by insertion (1.1 (0.6-5.1 [0.2-22.3]) particles.cm^-3 ) and removal (2.1 (0.5-3.0 [0.1-18.9]) particles.cm^-3 ) of SADs were significantly lower than those produced during continuous talking (44.5 (28.3-70.5 [2.0-134.5]) particles.cm^-3 ) and coughing (141.0 (98.3-202.8 [4.0-296.5]) particles.cm^-3 ) (p < 0.001). The aerosol levels produced were similar with the two devices. The proportion of easily inhaled and small particles (<1 μm) produced during insertion (57.5%) and removal (57.5%) was much lower than during talking (99.1%) and coughing (99.6%). These results suggest that the use of supraglottic airway devices in low-risk patients, even with positive pressure ventilation, generates fewer aerosols than speaking and coughing in awake patients.

The global syndemic of metabolic diseases in the young adult population: a consortium from the Global Burden of Disease 2000-2019

Funding Acknowledgements

Type of funding sources: None.

Background

A large proportion of premature deaths are related to metabolic diseases in the young adult population. We examined the global trends and mortality of metabolic diseases using estimates from the Global Burden of Diseases, Injuries and Risk Factors Study (GBD) 2019 in individuals aged below 40 years.

Methods

From 2000-2019, global estimates of prevalence, deaths, and disability-adjusted life years (DALYs) were described for metabolic diseases (type 2 diabetes mellitus [T2DM], hypertension, non-alcoholic fatty liver disease [NAFLD]). Global estimates were limited to mortality and DALYs for risk factors (hyperlipidemia and obesity). Subgroup analyses were performed based on sex, geographical regions and Socio-Demographic Index (SDI). Age-standardized prevalence, death, and DALYs were presented per 100,000 population with 95% uncertainty intervals (UI).

Findings

The prevalence for all metabolic diseases increased from 2000-2019, with the most pronounced increase in males and high SDI countries. In 2019, the highest age-standardised death rates were observed in hypertension (133·88 [121·25-155·73]; males, 160·13 [138·91-180·79]; females, 119·66 [102·33-136·86]), followed by obesity (62·59 [39·92-89·13]; males, 66·55 [39·76-97·21]; females, 58·14 [38·53-81·39]), hyperlipidemia (56·51 [41·83-73·62]; males, 67·33 [50·78-86·43]; females, 46·50 [32·70-62·38]), T2DM (18·49 [17·18-19·66]; males, 19·94 [18·50-21·32]; females, 17·30 [15·62-18·70]) and NAFLD (2·09 [1·61-2·60]; males, 2·38 [1·82-3·02]; females, 1·82 [1·41-2·27]). Similarly, obesity (1932·54 [1276·61-2639·74]) had the highest age-standardised DALYs, followed by hypertension (2885·57 [2580·75-3201·05]), hyperlipidemia (1207·15 [975·07-1461·11]), T2DM (801·55 [670·58-954·43]) and NAFLD (53·33 [40·73-68·29]). Mortality rates decreased over time in hyperlipidemia (-60%), hypertension (-47%), NAFLD (-31%) and T2DM (-20%), but not in obesity (107% increase). The highest metabolic-related mortality was observed in the Eastern Mediterranean and low SDI countries.

Conclusion

The growing prevalence of metabolic diseases, increasing obesity-related mortality trends, and the sex-regional-socioeconomic disparities evident in young adulthood, present the concerning global burden of metabolic diseases now and in the years ahead.

Association of Oral Health with Frailty, Malnutrition Risk and Functional Decline in Hospitalized Older Adults: A Cross-Sectional Study

BACKGROUND

Poor oral health is known to be associated with adverse outcomes, but the frequency and impact of poor oral health on older adults in the acute inpatient setting has been less well studied.

OBJECTIVES

We examined the association between oral health, frailty, nutrition and functional decline in hospitalized older adults.

DESIGN

Retrospective cross-sectional study.

SETTING AND PARTICIPANTS

We included data from 465 inpatients (mean age 79.2±8.3 years) admitted acutely to a tertiary hospital.

METHODS

We evaluated oral health using the Revised Oral Assessment Guide (ROAG), frailty using the Clinical Frailty Scale (CFS), malnutrition risk using the Nutritional Screening Tool (NST) and functional status using a modified Katz Activities of Daily Living (ADL) scale. We examined cross-sectional associations of oral health with frailty, malnutrition risk and functional decline on admission, followed by multivariate logistic regression models evaluating the association between poor oral health and the aforementioned outcomes.

RESULTS

343 (73.8%), 100 (21.5%) and 22 (4.7%) were classified as low, moderate and high risk on the ROAG, respectively. Poorer oral health was associated with greater severity of frailty, functional decline on admission and malnutrition risk. Abnormalities in ROAG domains of voice changes, swallowing difficulty, xerostomia, lips and tongue appearance were more frequently present at greater severity of frailty. Poor oral health was associated with frailty [odds ratio (OR): 1.76, 95% confidence interval (CI) 1.05-2.97; P=0.034]; malnutrition risk [OR: 2.76, 95% CI 1.46-5.19, P=0.002] and functional decline [OR: 1.62, 95% CI 1.01-2.59, P=0.046].

CONCLUSIONS

Poor oral health is significantly associated with frailty, malnutrition risk and functional decline in older inpatients. Oral health evaluation, as part of a comprehensive geriatric assessment may be a target for interventions to improve outcomes. Further research including longitudinal outcomes and effectiveness of specific interventions targeted at oral health are warranted in older adults in the inpatient setting.

Validating the Centre of Excellence on Longevity Self-AdMinistered (CESAM) Questionnaire: An Online Self-Reported Tool for Frailty Assessment of Older Adults

OBJECTIVES

Subjective health measures are often used to assess frailty, but the validity of self-reported online tools to identify frailty remains to be established. We aimed to assess concurrent, known-groups, convergent and predictive validity of the Centre of Excellence on Longevity Self-AdMinistered (CESAM) questionnaire for frailty assessment of older adults in an outpatient setting.

DESIGN

Cross-sectional analysis of 120 participants.

SETTING AND PARTICIPANTS

Participants of age ≥65 were recruited from an outpatient geriatric clinic. Individuals who had severe neurological, cognitive, or motor deficits were excluded.

METHODS

We assessed concurrent validity with area under receiver operating characteristic curve (AUC) against the Frailty Index (FI) and Clinical Frailty Scale (CFS). We analyzed known-groups validity between CESAM scores with frailty status (CFS and FI), Modified Barthel Index (MBI), and modified Chinese Mini-Mental State Examination (mCMMSE) using 1-way analysis of variance. We evaluated convergent validity using correlations with MBI, the Lawton index, mCMMSE, and Geriatric Depression Scale (GDS). Associations between CESAM-identified frailty for clinician-diagnosed geriatric syndromes, and health-related quality of life (HRQoL) was analyzed using regression analysis.

RESULTS

The CESAM questionnaire demonstrated excellent diagnostic performance for frailty using FI ≥0.25 (AUC = 0.88; 95% CI: 0.82-0.94; P < .001) and CFS ≥4 (AUC = 0.78; 95% CI: 0.68-0.88; P < .001). CESAM scores increased significantly with increasing frailty (both CFS and FI), lower MBI, and lower mCMMSE scores (all P < .001), indicating concurrent validity. The moderate-good correlation of CESAM scores with MBI (r = -0.61; P < 0.001), Lawton Index (r = -0.54; P < .001), mCMMSE (r = -0.53; P < .001) and GDS (r = 0.58; P < .001) supports convergent validity. Using a cutoff of ≥8 for frailty identification, CESAM-identified frailty was associated with cognitive impairment (OR = 3.7; 95% CI: 1.7-8.2; P = .001) depression (OR = 4.0; 95% CI: 1.7-9.6; P = .002), falls (OR = 3.1; 95% CI: 1.2-8.2; P = .021) and poorer HRQoL (β = -0.1; 95% CI: -0.2 to -0.02; P = .017).

CONCLUSION AND IMPLICATIONS

Our results support the validity of an online self-reported tool to identify frailty and geriatric syndromes in an outpatient setting, an approach that is potentially applicable for remote screening of frailty.

Calf Circumference Measurement Protocols for Sarcopenia Screening: Differences in Agreement, Convergent Validity and Diagnostic Performance

Background

Although recommended by the Asian Working Group for Sarcopenia 2019 consensus (AWGS’19) as a screening tool for sarcopenia, there remains no consensus regarding the position (sitting, standing) or laterality (right, left) for the measurement of calf circumference (CC). This study aimed to determine the agreement between CC measurements, correlations with muscle mass and function, and diagnostic performance for sarcopenia screening.

Methods

We studied 176 healthy community-dwelling older adults (mean age, 66.8±7.1 years) from the GERILABS-2 study. CC was measured using non-elastic tape in four ways: left and right sides in the sitting and standing positions. Sarcopenia was diagnosed using the AWGS’19 criteria. We produced Bland-Altman plots to assess the agreement, partial correlations for muscle mass and function to compare convergent validity, and area under the receiver operating characteristic curve (AUC) to compare diagnostic performance.

Results

The prevalence rate of sarcopenia was 17.4%. Sitting CC was larger than standing regardless of laterality (right 35.31±2.95 cm vs. 34.61±2.74 cm; left 35.37±2.96 cm vs. 34.70±2.83 cm; both p<0.001), consistent with the systematic bias on Bland-Altman plots showing the overestimation of sitting over standing measurements (right bias=0.70 cm; 95% confidence interval [CI], -0.48–1.88; left bias=0.67 cm, 95% CI, -0.35–1.68). After adjusting for age and sex, CC was significantly correlated with appendicular skeletal mass, hand grip strength, knee extension, gait speed, chair stand, and short physical performance battery. Although right-sided CC measurements had better diagnostic performance (AUC=0.817), the difference was not statistically significant compared to the other positions (p>0.05). The optimal cutoff was <34 cm for all measurements, except for the left standing position (cutoff <35 cm).

Conclusion

Standing CC measurements are recommended for sarcopenia screening in community-dwelling older adults because of their good agreement without systematic bias, convergent validity, and diagnostic performance.

Self-reported Frailty Screening Tools: Comparing Construct Validity of the Frailty Phenotype Questionnaire and FRAIL

OBJECTIVES

We examined the construct validity of 2 self-reported frailty questionnaires, the Frailty Phenotype Questionnaire (FPQ) and FRAIL, against the Cardiovascular Health Study frailty phenotype (CHS-FP).

DESIGN

Cross-sectional data analysis of longitudinal prospective cohort study.

SETTINGS AND PARTICIPANTS

We included data from 230 older adults (mean age: 67.2 ± 7.4 years) from the "Longitudinal Assessment of Biomarkers for characterization of early Sarcopenia and Osteosarcopenic Obesity in predicting frailty and functional decline in community-dwelling Asian older adults Study" (GeriLABS 2) recruited between December 2017 and March 2019.

METHODS

We compared area under receiver operating characteristic curves (AUC), agreement, correlation, and predictive validity against outcome measures (Short Physical Performance Battery, 5 times repeat chair stand [RCS-5], Frenchay activities index, International Physical Activity Questionnaire, life-space assessment, Social Functioning Scale 8 [SFS-8], EuroQol-5 dimensions [utility value]) using logistic regression adjusted for age, gender, and vascular risk factors. We examined concurrent validity across robust versus prefrail/frail for inflammatory blood biomarkers (tumor necrosis factor receptor 1 and C-reactive protein [CRP]) and dual-energy x-ray absorptiometry body composition (bone mineral density (BMD); appendicular lean mass index [ALMI], and fat mass index [FMI]).

RESULTS

Prevalence of prefrail/frail was 25.7%, 14.8%, and 48.3% for FPQ, FRAIL, and CHS-FP, respectively. Compared with FRAIL, FPQ had better diagnostic performance (AUC = 0.617 vs 0.531, P = .002; sensitivity = 37.8% vs 18.0%; specificity = 85.6% vs 88.2%) and agreement (AC1-Stat = 0.303 vs 0.197). FPQ showed good predictive validity (RCS-5: odds ratio [OR] 2.38; 95% CI: 1.17-4.86; International Physical Activity Questionnaire: OR 3.62; 95% CI:1.78-7.34; SFS-8: OR 2.11; 95% CI: 1.64-5.89 vs FRAIL: all P > .05). Only FRAIL showed concurrent validity for CRP, compared with both FPQ and FRAIL for TNF-R1. FRAIL showed better concurrent validity for BMD, FMI, and possibly ALMI, unlike FPQ (all P > .05).

CONCLUSIONS AND IMPLICATIONS

Our results support complementary validity of FPQ and FRAIL in independent community-dwelling older adults. FPQ has increased case detection sensitivity with good predictive validity, whereas FRAIL demonstrates concurrent validity for inflammation and body composition. With better diagnostic performance and validity for blood biomarkers and clinical outcomes, FPQ has utility for early frailty detection in the community setting.

Social Frailty and Executive Function: Association with Geriatric Syndromes, Life Space and Quality of Life in Healthy Community-Dwelling Older Adults

BACKGROUND

Despite emerging evidence about the association between social frailty and cognitive impairment, little is known about the role of executive function in this interplay, and whether the co-existence of social frailty and cognitive impairment predisposes to adverse health outcomes in healthy community-dwelling older adults.

OBJECTIVES

We aim to examine independent associations between social frailty with the MMSE and FAB, and to determine if having both social frailty and cognitive impairment is associated with worse health outcomes than either or neither condition.

METHODS

We studied 229 cognitively intact and functionally independent community-dwelling older adults (mean age= 67.2±7.43). Outcome measures comprise physical activity; physical performance and frailty; geriatric syndromes; life space and quality of life. We compared Chinese Mini Mental State Examination (CMMSE) and Chinese Frontal Assessment Battery (FAB) scores across the socially non-frail, socially pre-frail and socially frail. Participants were further recategorized into three subgroups (neither, either or both) based on presence of social frailty and cognitive impairment. Cognitive impairment was defined as a score below the educational adjusted cut-offs in either CMMSE or FAB. We performed logistic regression adjusted for significant covariates and mood to examine association with outcomes across the three subgroups.

RESULTS

Compared with CMMSE, Chinese FAB scores significantly decreased across the social frailty spectrum (p<0.001), suggesting strong association between executive function with social frailty. We derived three subgroups relative to relationship with socially frailty and executive dysfunction: (i) Neither, N=140(61.1%), (ii) Either, N=79(34.5%), and (iii) Both, N=10(4.4%). Compared with neither or either subgroups, having both social frailty and executive dysfunction was associated with anorexia (OR=4.79, 95% CI= 1.04-22.02), near falls and falls (OR= 5.23, 95% CI= 1.10-24.90), lower life-space mobility (odds ratio, OR=9.80, 95% CI=2.07-46.31) and poorer quality of life (OR= 13.2, 95% CI= 2.38-73.4).

CONCLUSION

Our results explicated the association of executive dysfunction with social frailty, and their synergistic relationship independent of mood with geriatric syndromes, decreased life space and poorer quality of life. In light of the current COVID-19 pandemic, the association between social frailty and executive dysfunction merits further study as a possible target for early intervention in relatively healthy older adults.

Cognitive assessment by telemedicine: reliability and agreement between face-to-face and remote videoconference-based cognitive tests in older adults attending a memory clinic

Background

The coronavirus disease 2019 (COVID-19) pandemic has spurred the rapid adoption of telemedicine. However, the reproducibility of face-to-face (F2F) versus remote videoconference-based cognitive testing remains to be established. We assessed the reliability and agreement between F2F and remote administrations of the Abbreviated Mental Test (AMT), modified version of the Chinese Mini-Mental State Examination (mCMMSE), and Chinese Frontal Assessment Battery (CFAB) in older adults attending a memory clinic.

Methods

The participants underwent F2F followed by remote videoconference-based assessment by the same assessor within 3 weeks. Reliability was evaluated using intraclass correlation coefficients (ICC; two-way mixed, absolute agreement), the mean difference between remote and F2F-based assessments using paired-sample t-tests, and agreement using Bland-Altman plots.

Results

Fifty-six subjects (mean age, 76±5.4 years; 74% mild; 19% moderate dementia) completed the AMT and mCMMSE, of which 30 completed the CFAB. Good reliability was noted based on the ICC values—AMT: ICC=0.80, 95% confidence interval [CI] 0.68–0.88; mCMMSE: ICC=0.80, 95% CI 0.63–0.88; CFAB: ICC=0.82, 95% CI 0.66–0.91. However, remote AMT and mCMMSE scores were higher compared to F2F—mean difference (i.e., remote minus F2F): AMT 0.3±1.1, p=0.03; mCMMSE 1.3±2.9, p=0.001. Significant differences were observed in the orientation and recall items of the mCMMSE and the similarities and conflicting instructions of CFAB. Bland–Altman plots indicated wide 95% limits of agreement (AMT -1.9 to 2.6; mCMMSE -4.3 to 6.9; CFAB -3.0 to 3.8), exceeding the a priori-defined levels of error.

Conclusion

While the remote and F2F cognitive assessments demonstrated good overall reliability, the test scores were higher when performed remotely compared to F2F. The discrepancies in agreement warrant attention to patient selection and environment optimization for the successful adaptation of telemedicine for cognitive assessment.

The effect of light intensity on the body weight, keel bone quality, tibia bone strength, and mortality of brown and white feathered egg-strain pullets reared in perchery systems

The development of the musculoskeletal system is influenced by bird activity, which can be impacted by light intensity (L). The objective of this study was to determine the effect of L on the growth and bone health of Lohmann Brown-Lite (LB) and Lohmann LSL-Lite (LW) pullets. Three L treatments (10, 30 or 50 lux, provided by white LED lights) were used in a Randomized Complete Block Design in 2 repeated trials. LB and LW (n = 1,800 per strain [S]) were randomly assigned to floor pens (50 pullets per pen; 12 pen replicates per L × S) within 6 light-tight rooms from 0 to 16 wk. Each pen contained 4 parallel perches and a ramp. Data collected include cumulative mortality, BW at 0, 8, and 16 wk, and uniformity, keel bone damage (KBD; deviations, fractures), breast muscle weight, and tibiae bone strength at 16 wk. Tibiae bone resistance to mechanical stress was assessed using a three-point-bending test. The effect of L, S, and their interactions were analyzed using Proc Mixed (SAS 9.4) and differences were considered significant when P < 0.05. L did not affect BW, KBD, or mortality. An interaction between L and S was observed for bone stress (bone strength relative to bone size), however, in general, LW pullets had greater resistance to bone stress (peak noted at 30 lux) than LB (peak at 50 lux). LB pullets were heavier than LW at 8 and 16 wk. There were no S differences on KBD from palpated or dissected keel bones. LB pullets had higher breast muscle weight and heavier tibiae than LW, however relative to BW, LW had a higher percentage of breast muscle and a longer and thicker tibiae than LB. LW had higher mortality during the first wk but there was no relationship to L. Conclusively, the results suggest that L, within a range of 10 to 50 lux, does not affect pullet BW or KBD, however S may affect both parameters, as well as bone strength.

Letter to the Editor: Obesity Definition for Muscle Outcomes in Sarcopenic Obesity: Utility of Waist Circumference Revisited

Sarcopenic obesity (SO) is defined as the concomitant presence of sarcopenia and obesity (1). Studies have employed different obesity definitions to understand the relation of SO to cardiometabolic outcomes, with more recent studies examining muscle-related outcomes (2, 3). The leading candidates amongst obesity definitions are waist circumference (WC), percentage fat mass (FM%), and fat mass index (FMI). The last two measures are derived from dual energy X-ray absorptiometry (DXA) or bioelectrical impedance (BIA), and adjust for fat quantity irrespective of distribution (4).

Grip Strength Criterion Matters: Impact of Average Versus Maximum Handgrip Strength on Sarcopenia Prevalence and Predictive Validity for Low Physical Performance

IMPORTANCE

Muscle strength has been elevated to the forefront of sarcopenia diagnosis, with handgrip strength the preferred measure. Extant handgrip protocols adopt different handgrip strength (HGS) criteria. Paucity of direct comparison studies assessing the impact of HGS criterion on prevalence of sarcopenia and predictive validity on physical performance contributes to the lack of standardisation of HGS criteria in sarcopenia diagnosis.

OBJECTIVES

Our study aims to compare the effect of average (HGSave) versus maximum (HGSmax) HGS criterion on: (1) prevalence of low HGS and sarcopenia; and (2) association with physical performance at baseline and at 2 years.

METHODS

We recruited 200 community dwelling, cognitively intact, and functionally independent older adults. Muscle strength, physical performance measures, cognitive tests and nutritional assessments were performed. Short Physical Performance Battery (SPPB) was administered at baseline and at 2 years. We compared HGSave and HGSmax to assess the prevalence of low HGS and sarcopenia. Univariate analysis was performed comparing baseline characteristics between low and normal groups for each HGS criterion. Significantly different variables were included in logistic regression analysis to examine association of low HGS and SPPB at baseline. Predictive validity of low HGS for SPPB<10 at 2 years was examined by performing logistic regression analysis for HGSave and HGSmax.

RESULTS

The prevalence of low HGS and sarcopenia incorporating HGSave criterion is 40% and 33% respectively, whereas that of HGSmax criterion is 21% and 19.5% respectively. There is moderate agreement between the 2 HGS criteria for sarcopenia diagnosis (kappa=0.604) and poorer agreement for low HGS (kappa=0.570). There was no significant association with baseline SPPB for both HGS criteria. At 2 years, only low HGSmax was significantly associated with low SPPB (adjusted OR 3.91, 95% CI 1.24 - 12.33).

CONCLUSION

Our study demonstrates that HGS criteria matters in diagnosis of sarcopenia and we support extant HGS protocols using HGSmax criterion in view of better predictive validity for poor physical performance.

Disentangling the Relationship between Frailty and Intrinsic Capacity in Healthy Community-Dwelling Older Adults: A Cluster Analysis

BACKGROUND

Frailty and intrinsic capacity (IC) are distinct but interrelated constructs. Uncertainty remains regarding how they are related and interact to influence health outcomes. We aim to understand the relationship between frailty and IC by identifying subgroups based on frailty criteria and IC domains and studying one-year outcomes.

METHODS

We studied 200 independent community-dwelling older adults (mean age 67.9±7.9 years, Modified Barthel Index (MBI) score 99±2.6). Frailty was defined by modified Fried criteria. Scores (range: 0-2) were assigned to individual IC domains (cognition, psychological, locomotion, and vitality) to yield a total IC score of 8. To identify subgroups, two-step cluster analysis was performed with age, frailty and IC domains. Cluster associations with one-year outcomes (frailty, muscle strength (grip strength, repeated chair stand test), physical performance (gait speed, Short Physical Performance Battery), function (MBI) and quality-of-life (EuroQol (EQ)-5D)) were examined using multiple linear regression adjusted for age, gender and education.

RESULTS

Three distinct clusters were identified - Cluster 1: High IC/Robust (N=74, 37%); Cluster 2: Intermediate IC/Prefrail (N=73, 36.5%); and Cluster 3: Low IC/Prefrail-Frail (53, 26.5%). Comparing between clusters, IC domains, cognition, depressive symptoms, nutrition, strength and physical performance were least impaired in Cluster 1, intermediate in Cluster 2 and most impaired in Cluster 3. At one year, the proportion transitioning to frailty or remaining frail was highest in Cluster 3 compared to Cluster 2 and Cluster 1 (39% vs 6.9% vs 2.8%, P<0.001). Compared to Cluster 1, Cluster 3 experienced greatest declines in grip strength (β=-4.1, P<.001), MBI (β=-1.24, P=0.045) and EQ-5D utility scores (β=-0.053, P=0.005), with Cluster 2 intermediate between Cluster 1 and Cluster 3.

CONCLUSIONS

Amongst independent community-dwelling older adults, IC is complementary to frailty measures through better risk-profiling of one-year outcomes amongst prefrail individuals into intermediate and high-risk groups. The intermediate group merits follow-up to ascertain longer-term prognosis.

Nutrition Mediates the Relationship between Osteosarcopenia and Frailty: A Pathway Analysis

Osteosarcopenia is associated with increased risk of adverse outcomes such as falls and fractures. Its association with frailty is less well-described, particularly in independent community-dwelling older adults. Although nutrition plays a crucial role in maintaining bone and muscle health, the complex relationship between osteosarcopenia and nutrition in the pathogenesis of frailty remains to be elucidated. In this cross-sectional analysis of 230 independent, community-dwelling individuals (mean age 67.2 ± 7.4 years), we examined the associations between osteosarcopenia with nutritional status and frailty, and the mediating role of nutrition in the association between osteosarcopenia and frailty. Osteosarcopenia was defined as fulfilling both the Asian Working Group for Sarcopenia 2019 consensus definition (low relative appendicular skeletal muscle mass adjusted for height, in the presence of either of either low handgrip strength or slow gait speed) and T-score ≤ -2.5 SD on bone mineral densitometry. We assessed frailty using the modified Fried criteria and nutrition using the Mini-Nutritional Assessment. We performed multiple linear regression, followed by pathway analysis to ascertain whether nutrition mediates the relationship between osteosarcopenia and frailty. Our study population comprised: 27 (11.7%) osteosarcopenic, 35 (15.2%) sarcopenic, 36 (15.7%) osteoporotic and 132 (57.4%) normal (neither osteosarcopenic, sarcopenic nor osteoporotic). Osteosarcopenia (β = 1.1, 95% CI 0.86-1.4) and sarcopenia (β = 1.1, 95% CI 0.90-1.4) were significantly associated with frailty, but not osteoporosis. Nutrition mediated the association between osteosarcopenia and frailty (indirect effect estimate 0.09, bootstrap 95% CI 0.01-0.22). In conclusion, osteosarcopenia is associated with frailty and poorer nutritional status, with nutrition mediating the association between osteosarcopenia and frailty. Our findings support early nutritional assessment and intervention in osteosarcopenia to mitigate the risk of frailty.

The Simplified Nutritional Appetite Questionnaire (SNAQ) as a Screening Tool for Risk of Malnutrition: Optimal Cutoff, Factor Structure, and Validation in Healthy Community-Dwelling Older Adults

Malnutrition is an independent marker of adverse outcomes in older adults. While the Simplified Nutritional Appetite Questionnaire (SNAQ) for anorexia has been validated as a nutritional screening tool, its optimal cutoff and validity in healthy older adults is unclear. This study aims to determine the optimal cutoff for SNAQ in healthy community-dwelling older adults, and to examine its factor structure and validity. We studied 230 community-dwelling older adults (mean age 67.2 years) who were nonfrail (defined by Fatigue, Resistance, Ambulation, Illnesses & Loss (FRAIL) criteria). When compared against the risk of malnutrition using the Mini Nutritional Assessment (MNA), the optimal cutoff for SNAQ was ≤15 (area under receiver operating characteristic (ROC) curve: 0.706, sensitivity: 69.2%, specificity: 61.3%). Using exploratory factor analysis, we found a two-factor structure (Factor 1: Appetite Perception; Factor 2: Satiety and Intake) which accounted for 61.5% variance. SNAQ showed good convergent, discriminant and concurrent validity. In logistic regression adjusted for age, gender, education and MNA, SNAQ ≤15 was significantly associated with social frailty, unlike SNAQ ≤4 (odds ratio (OR) 1.99, p = 0.025 vs. OR 1.05, p = 0.890). Our study validates a higher cutoff of ≤15 to increase sensitivity of SNAQ for anorexia detection as a marker of malnutrition risk in healthy community-dwelling older adults, and explicates a novel two-factor structure which warrants further research.

Muscle Strength Definitions Matter: Prevalence of Sarcopenia and Predictive Validity for Adverse Outcomes Using the European Working Group on Sarcopenia in Older People 2 (EWGSOP2) Criteria

BACKGROUND

EWGSOP2 criteria for sarcopenia recommends the use of either handgrip strength (GS) or 5-times repeated chair stand test (RCS) as a muscle strength measure. We aim to compare the impact of different muscle strength definitions on sarcopenia prevalence and predictive validity for 2-year outcomes, using the EWGSOP2 clinical algorithm.

METHODS

We studied 200 community-dwelling older adults, comparing sarcopenia prevalence using three muscle strength definitions: 1) maximum GS (Asian Working Group cutoffs); 2) RCS-1 (standard cutoff >15s); and 3) RCS-2 (ROC-derived cutoff >12.5s). Two-year outcomes include: 1) Incident frailty (modified Fried criteria); 2) Physical performance [Short Physical Performance Battery (SPPB) score <10]; and 3) Quality of life [EuroQol-5 dimension (EQ-5D) <25th percentile]. We performed logistic regression on 2-year outcomes adjusted for age, gender, cognition and mood.

RESULTS

Prevalence of confirmed sarcopenia was 14.5%, 4% and 9% for GS, RCS-1 and RCS-2 respectively. For 2-year outcomes (N=183), RCS-2 predicted incident frailty (OR: 5.7, 95% CI 1.4-22.8, p=0.013), low SPPB (OR: 4.4, 95% CI 1.4-13.1, p=0.009), and trended towards predicting low QOL (OR: 2.1, 95% CI 0.9-4.9, p=0.095). In contrast, GS and RCS-1 did not predict frailty nor low QOL, but predicted low SPPB only (GS: OR 3.8, 95% CI 1.3-10.6, p=0.01; RCS-1: OR: 8.8, 95% CI 2.2-35.0, p=0.002).

CONCLUSIONS

Sarcopenia prevalence varies with muscle strength definitions, with GS being significantly higher vis-à-vis RCS definitions. Our results also support the use of population-specific over standard cutoffs for RCS to obtain intermediate estimates of sarcopenia prevalence and the best predictive validity for two-year outcomes.

Validating a Standardised Approach in Administration of the Clinical Frailty Scale in Hospitalised Older Adults

Introduction: We developed a Clinical Frailty Scale algorithm (CFS-A) to minimise inter-rater variability and to facilitate wider application across clinical settings. We compared the agreement, diagnostic performance and predictive utility of CFS-A against standard CFS. Materials and Methods: We retrospectively analysed data of 210 hospitalised older adults (mean age, 89.4 years). Two independent raters assessed frailty using CFS-A. Agreement between CFS-A raters and with previously completed CFS was determined using Cohen’s Kappa. Area under receiver operator characteristic curves (AUC) for both measures were compared against the Frailty Index (FI). Independent associations between these measures and adverse outcomes were examined using logistic regression. Results: Frailty prevalence were 81% in CFS and 96% in CFS-A. Inter-rater agreement between CFS-A raters was excellent (kappa 0.90, P <0.001) and there was moderate agreement between CFS-A and standard CFS (kappa 0.42, P <0.001). We found no difference in AUC against FI between CFS (0.91; 95% CI, 0.86-0.95) and CFS-A (0.89; 95% CI, 0.84-0.95; P <0.001). Both CFS (OR, 3.59; 95% CI, 2.28-5.67; P <0.001) and CFS-A (OR, 4.31; 95% CI, 2.41-7.69; P <0.001) were good predictors of mortality at 12 months. Similarly, CFS (OR, 2.59; 95% CI, 1.81-3.69; P <0.001) and CFS-A (OR, 3.58; 95% CI, 2.13-6.02; P <0.001) were also good predictors of institutionalisation and/or mortality after adjusting for age, sex and illness severity. Conclusion: Our study corroborated the results on inter-rater reliability, diagnostic performance and predictive validity of CFS-A which has the potential for consistent and efficient administration of CFS in acute care settings. Key words: Assessment, Frailty, Geriatric, Inpatient, Risk

Validating a Standardised Approach in Administration of the Clinical Frailty Scale in Hospitalised Older Adults

INTRODUCTION

We developed a Clinical Frailty Scale algorithm (CFS-A) to minimise inter-rater variability and to facilitate wider application across clinical settings. We compared the agreement, diagnostic performance and predictive utility of CFS-A against standard CFS.

MATERIALS AND METHODS

We retrospectively analysed data of 210 hospitalised older adults (mean age, 89.4 years). Two independent raters assessed frailty using CFS-A. Agreement between CFS-A raters and with previously completed CFS was determined using Cohen's Kappa. Area under receiver operator characteristic curves (AUC) for both measures were compared against the Frailty Index (FI). Independent associations between these measures and adverse outcomes were examined using logistic regression.

RESULTS

Frailty prevalence were 81% in CFS and 96% in CFS-A. Inter-rater agreement between CFS-A raters was excellent (kappa 0.90, P <0.001) and there was moderate agreement between CFS-A and standard CFS (kappa 0.42, P <0.001). We found no difference in AUC against FI between CFS (0.91; 95% CI, 0.86-0.95) and CFS-A (0.89; 95% CI, 0.84-0.95; P <0.001). Both CFS (OR, 3.59; 95% CI, 2.28-5.67; P <0.001) and CFS-A (OR, 4.31; 95% CI, 2.41-7.69; P <0.001) were good predictors of mortality at 12 months. Similarly, CFS (OR, 2.59; 95% CI, 1.81-3.69; P <0.001) and CFS-A (OR, 3.58; 95% CI, 2.13-6.02; P <0.001) were also good predictors of institutionalisation and/or mortality after adjusting for age, sex and illness severity.

CONCLUSION

Our study corroborated the results on inter-rater reliability, diagnostic performance and predictive validity of CFS-A which has the potential for consistent and efficient administration of CFS in acute care settings.

Serum Myostatin and IGF-1 as Gender-Specific Biomarkers of Frailty and Low Muscle Mass in Community-Dwelling Older Adults

OBJECTIVES

(i) To investigate serum myostatin (absolute and normalized for total body lean mass (TBLM)) and IGF-1 as biomarkers of frailty and low relative appendicular skeletal muscle mass (RASM) in older adults, and; (ii) to examine gender differences in the association of serum myostatin and IGF-1 levels with frailty and low RASM.

DESIGN

Cross-sectional study.

SETTING

The "Longitudinal Assessment of Biomarkers for characterization of early Sarcopenia and predicting frailty and functional decline in community-dwelling Asian older adults Study" (GERI-LABS) study in Singapore.

PARTICIPANTS

200 subjects aged 50 years and older residing in the community.

MEASUREMENTS

Frailty was assessed using the modified Fried criteria. Low RASM was defined using cutoffs for height-adjusted appendicular skeletal muscle mass measured by dual-energy X-ray absorptiometry as recommended by the Asian Working Group for Sarcopenia. Comorbidities, cognitive and functional performance, physical activity and nutritional status were assessed. Blood samples collected included serum myostatin, insulin-like growth factor 1 (IGF-1) and markers of inflammation (total white cell count, CRP, IL-6 and TNFaR1). Subjects were classified into 4 groups: Frail/Prefrail with low RASM (Frail/Low RASM), Frail/Prefrail with normal RASM (Frail/Normal RASM), Robust with low RASM (Robust/Low RASM) and Robust with normal RASM (Robust/Normal RASM).

RESULTS

63 (32%) subjects were classified as Frail/Low RASM, 53 (27%) Frail/Normal RASM, 28 (14%) Robust/Low RASM and 56 (28%) Robust/Normal RASM respectively. Frail/Low RASM subjects were older and had lower BMI compared to Frail/Normal RASM and robust subjects. Mean (SE) normalized myostatin levels were higher in Frail/Low RASM compared to Frail/Normal RASM subjects (1.0 (0.04) versus 0.84 (0.05) ng/ml/kg, P=0.01). Median (IQR) IGF-1 level was lower amongst Frail/Low RASM subjects compared to Frail/Normal RASM subjects (102.3, (77.7, 102.5) vs 119.7 (82.7, 146.0) ng/ml, P=0.046). No differences in myostatin or IGF-1 were observed among robust individuals with or without low muscle mass. In adjusted multinomial logistic regression models with Robust/Normal RASM as the reference group, myostatin (P=0.05) and IGF-1 (P=0.043) were associated with Frail/Low RASM status in the whole cohort. When stratified by gender, myostatin was significantly associated with Frail/Low RASM status in men only (P=0.03). In women, serum IGF-1 was associated with Frail/Low RASM status (P=0.046), but not myostatin (P=0.53).

CONCLUSION

Serum myostatin, normalized for TBLM in men and IGF-1 in women are potential biomarkers for frail individuals with low RASM, and may identify a target group for intervention.

High protein copy number is required to suppress stochasticity in the cyanobacterial circadian clock

Circadian clocks generate reliable ~24-h rhythms despite being based on stochastic biochemical reactions. The circadian clock in Synechococcus elongatus uses a post-translational oscillator that cycles deterministically in a test tube. Because the volume of a single bacterial cell is much smaller than a macroscopic reaction, we asked how clocks in single cells function reliably. Here, we show that S. elongatus cells must express many thousands of copies of Kai proteins to effectively suppress timing errors. Stochastic modeling shows that this requirement stems from noise amplification in the post-translational feedback loop that sustains oscillations. The much smaller cyanobacterium Prochlorococcus expresses only hundreds of Kai protein copies and has a simpler, hourglass-like Kai system. We show that this timer strategy can outperform a free-running clock if internal noise is significant. This conclusion has implications for clock evolution and synthetic oscillator design, and it suggests hourglass-like behavior may be widespread in microbes.

Circadian clocks must maintain their fidelity despite stochasticity arising from finite protein copy numbers. Here, the authors show that a small cyanobacterium relies on an environmentally driven timer likely because its low protein copy numbers cannot support an accurate free-running clock.

IGFBPL1 Regulates Axon Growth through IGF-1-mediated Signaling Cascades

Activation of axonal growth program is a critical step in successful optic nerve regeneration following injury. Yet the molecular mechanisms that orchestrate this developmental transition are not fully understood. Here we identified a novel regulator, insulin-like growth factor binding protein-like 1 (IGFBPL1), for the growth of retinal ganglion cell (RGC) axons. Expression of IGFBPL1 correlates with RGC axon growth in development, and acute knockdown of IGFBPL1 with shRNA or IGFBPL1 knockout in vivo impaired RGC axon growth. In contrast, administration of IGFBPL1 promoted axon growth. Moreover, IGFBPL1 bound to insulin-like growth factor 1 (IGF-1) and subsequently induced calcium signaling and mammalian target of rapamycin (mTOR) phosphorylation to stimulate axon elongation. Blockage of IGF-1 signaling abolished IGFBPL1-mediated axon growth, and vice versa, IGF-1 required the presence of IGFBPL1 to promote RGC axon growth. These data reveal a novel element in the control of RGC axon growth and suggest an unknown signaling loop in the regulation of the pleiotropic functions of IGF-1. They suggest new therapeutic target for promoting optic nerve and axon regeneration and repair of the central nervous system.

Biophysical clocks face a trade-off between internal and external noise resistance

Many organisms use free running circadian clocks to anticipate the day night cycle. However, others organisms use simple stimulus-response strategies ('hourglass clocks') and it is not clear when such strategies are sufficient or even preferable to free running clocks. Here, we find that free running clocks, such as those found in the cyanobacterium Synechococcus elongatus and humans, can efficiently project out light intensity fluctuations due to weather patterns ('external noise') by exploiting their limit cycle attractor. However, such limit cycles are necessarily vulnerable to 'internal noise'. Hence, at sufficiently high internal noise, point attractor-based 'hourglass' clocks, such as those found in a smaller cyanobacterium with low protein copy number, Prochlorococcus marinus, can outperform free running clocks. By interpolating between these two regimes in a diverse range of oscillators drawn from across biology, we demonstrate biochemical clock architectures that are best suited to different relative strengths of external and internal noise.

Costs of Clock-Environment Misalignment in Individual Cyanobacterial Cells

Circadian rhythms are endogenously generated daily oscillations in physiology that are found in all kingdoms of life. Experimental studies have shown that the fitness of Synechococcus elongatus, a photosynthetic microorganism, is severely affected in non-24-h environments. However, it has been difficult to study the effects of clock-environment mismatch on cellular physiology because such measurements require a precise determination of both clock state and growth rate in the same cell. Here, we designed a microscopy platform that allows us to expose cyanobacterial cells to pulses of light and dark while quantitatively measuring their growth, division rate, and circadian clock state over many days. Our measurements reveal that decreased fitness can result from a catastrophic growth arrest caused by unexpected darkness in a small subset of cells with incorrect clock times corresponding to the subjective morning. We find that the clock generates rhythms in the instantaneous growth rate of the cell, and that the time of darkness vulnerability coincides with the time of most rapid growth. Thus, the clock mediates a fundamental trade-off between growth and starvation tolerance in cycling environments. By measuring the response of the circadian rhythm to dark pulses of varying lengths, we constrain a mathematical model of a population's fitness under arbitrary light/dark schedules. This model predicts that the circadian clock is only advantageous in highly regular cycling environments with frequencies sufficiently close to the natural frequency of the clock.

Outcomes of a multimodal cognitive and physical rehabilitation program for persons with mild dementia and their caregivers: a goal-oriented approach

Background

Nonpharmacological interventions such as exercise and cognitive rehabilitation programs have shown promise in reducing the impact of dementia on the individual and the caregiver. In this study, we examine the effect of a multimodal cognitive and physical rehabilitation program for persons with mild dementia and their caregivers using conventional measures of cognition, behavior, quality of life (QoL), and caregiver burden together with goal attainment scaling (GAS), an individualized outcome measure.

Methods

Goals were set at baseline, and GAS score was calculated at the end of the program. Participants were also assessed with the Chinese Mini-Mental State Examination, functional and behavioral scales (Barthel Index), Instrumental Activities of Daily Living, Neuropsychiatric Inventory Questionnaire, QoL, and caregiver burden using EuroQol-five dimension questionnaire and Zarit Burden Interview (ZBI). Differences in median scores postintervention were obtained. Further analysis of caregiver burden was undertaken utilizing the multidimensional classification of burden on the ZBI.

Results

Thirty-four (61.8%) patients were assessed to have met their goals (GAS score≥50). Mean (standard deviation) GAS score was 48.6 (6.5). Cognition goals were set in only 20.6%, followed by goals to improve engagement and socialization; reduce caregiver stress; and improve physical function, behavior, and mood. Median scores in the cognitive, functional, and QoL measures did not differ significantly pre- and postintervention. The intervention had a positive impact on role strain, a unique dimension of caregiver burden.

Conclusion

This study provides evidence that a multimodal approach combining physical exercise and cognitive rehabilitation improves goal attainment and caregiver burden in individuals and caregivers of persons with mild dementia.