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Objectives: To identify frailty trajectories and examine its association with allostatic load (AL) and mediating effect of physical activity (PA). Methods: This study included 8,082 adults from the English Longitudinal Study of Aging over Waves 4–9. AL was calculated by 14 biological indicators, and a 53-item frailty index was used to evaluate frailty. Frailty trajectories were classified by group-based trajectory modeling, and the mediated effect of PA was tested by causal mediation analysis. Results: Four frailty trajectories were identified: "Robustness" (n = 4,437, 54.9%), "Incident prefrailty" (n = 2,061, 25.5%), "Prefrailty to frailty" (n = 1,136, 14.1%), and "Frailty to severe frailty" (n = 448, 5.5%). High baseline AL was associated with increased odds of "Incident prefrailty," "Prefrailty to frailty," and "Frailty to severe frailty" trajectories. PA demonstrated significant mediated effects in aforementioned associations. Conclusions: AL is significantly associated with the onset and progression of frailty, and such associations are partially mediated by PA. [ABSTRACT FROM AUTHOR]

Background and purpose: This prospective observational study aimed to investigate the occurrence of avascular necrosis (AVN) of the femoral head in COVID-19 patients through MRI scans. The study examined the patterns of AVN in 110 individuals who had undergone conventional COVID-19 therapy and reported hip discomfort. This study highlights the importance of considering AVN as a potential complication of COVID-19 therapy, particularly in younger patients who experience hip discomfort. Methods: Individuals who had corticosteroid treatment for COVID-19 and experienced hip discomfort during 6 months between January 2022 and August 2022 were included in this study, and an MRI scan was done to observe changes in the hip joint. Results: The results were classified using the Ficat and Arlet classification system. The analysis revealed that AVN was not present in 91.81% of cases. However, Stage I AVN was detected in 4.54% of cases, Stage II AVN in 2.72% of cases, and Stage III AVN in 1.1% of cases. No cases of Stage IV AVN were observed. Conclusions: The study concludes that AVN occurred in 6% of individuals who underwent conventional therapy for COVID-19 and experienced hip discomfort. In these settings (post COVID-19), normal MRI results were more typical, and mild AVN (Stage I) was a frequent finding in MRI scans that were positive. [ABSTRACT FROM AUTHOR]

Introduction: Routine blood factors can be economical and easily accessible candidates for sarcopenia screening and monitoring. The associations between sarcopenia and routine blood factors remain unclear. This study aimed to examine sarcopenia and blood factor associations based on a nation-wide cohort in China. Methods: A total of 1,307 participants and 17 routine blood indices were selected from two waves (year 2011 and year 2015) of the China Health and Retirement Longitudinal Study (CHARLS). The diagnosis of sarcopenia was based on the criteria proposed by the Asian Working Group for Sarcopenia (AWGS 2019). Generalized mixed-effects models were performed for association analyses. A logistic regression (LR) model was conducted to examine the predictive power of identifying significant blood factors for sarcopenia. Results: A higher sarcopenia risk was cross-sectionally associated with elevated blood concentrations of high-sensitivity C-reactive protein (hsCRP) (OR = 1.030, 95% CI [1.007, 1.053]), glycated hemoglobin (HbA1c) (OR = 1.407, 95% CI [1.126, 1.758]) and blood urea nitrogen (BUN) (OR = 1.044, 95% CI [1.002, 1.089]), and a decreased level of glucose (OR = 0.988, 95% CI [0.979, 0.997]). A higher baseline hsCRP value (OR = 1.034, 95% CI [1.029, 1.039]) and a greater over time change in hsCRP within 4 years (OR = 1.034, 95% CI [1.029, 1.039]) were associated with a higher sarcopenia risk. A higher BUN baseline value was related to a decreased sarcopenia risk over time (OR = 0.981, 95% CI [0.976, 0.986]), while a greater over time changes in BUN (OR = 1.034, 95% CI [1.029, 1.040]) and a smaller over time change in glucose (OR = 0.992, 95% CI [0.984, 0.999]) within 4 years were also related to a higher sarcopenia risk. LR based on significant blood factors (i.e., hsCRP, HbA1c, BUN, and glucose), and sarcopenia status in year 2015 yielded an area under the curve of 0.859 (95% CI: 0.836–0.882). Conclusion: Routine blood factors involved in inflammation, protein metabolism, and glucose metabolism are significantly associated with sarcopenia. In clinical practice, plasma hsCRP, BUN, blood sugar levels, sex, age, marital status, height, and weight might be helpful for sarcopenia evaluation and monitoring. [ABSTRACT FROM AUTHOR]

To develop a risk assessment scale for pathological scarring and validate its psychometric properties. This was a methodological study. Researchers developed the scale based on a literature review, qualitative study and Delphi expert consultation. Subsequently, 409 patients participated in the study to test the psychometric properties of the scale. We evaluated construct validity, content validity, internal consistency reliability, and interrater reliability. The researchers developed a scale consisting of three dimensions and 12 items. Factor analysis extracted a total of four common factors that accounted for 62.22% of the total variance. The results revealed that the item‐content validity index (I‐CVI) ranged from 0.67 to 1, while the scale‐content validity index (S‐CVI) was 0.82. Internal consistency reliability: Cronbach's α of the items ranged from 0.67 to 0.76, while Cronbach's α of the whole scale was 0.74. Interrater reliability: the Kappa number was 0.73. The final scale showed adequate construct validity, content validity, and reliability. It is appropriate for use in research and clinical practice settings to identify patients with a risk of pathological scarring. Further study is needed to confirm the scale's validity and reliability in other settings and populations. [ABSTRACT FROM AUTHOR]

The plant architecture of higher plants is regulated through environmental and genetic factors, as well as phytohormones. Phytohormones play a critical role in regulating shoot branching. We determined the branching phenotype of D16 and N99-6, the content of strigolactones, the genetic expression level, and the interaction between auxin and strigolactones. We found that the branching development of the two soybean varieties under shading was significantly slower than that under normal light. The average branch length of N99-6 decreased by 40.9% after shading; however, the branch length of D16 was not significantly affected. Meanwhile, the branch formation rate in D16 was significantly higher than in N99-6. In addition, after shading treatment, the content of strigolactones in D16 and N99-6 axillary buds increased significantly, and the expression of phytochrome genes, PhyA and PhyB, showed opposite changes. However, strigolactone synthesis gene GmMAX4 and signal transduction gene GmMAX2 expression levels of D16 were lower than those of N99-6 after 24 h of shading. In addition, the application of strigolactone inhibitor TIS108 and auxin inhibitor NPA to soybean had no significant effect on the branch phenotype. The expression of the GmMAX2 gene was significantly up-regulated after the external application of the auxin analog, and the expression of auxin transporter gene GmPINI was significantly down-regulated after external application of the strigolactone analog under shade. In this study, we investigated the adverse effect of shade on soybean branching development, which may be due to the interaction of strigolactones with auxins. [ABSTRACT FROM AUTHOR]

Aim: This study aims to explore nursing emergency management system under public health emergencies. Design: A descriptive qualitative study. Method: Semi‐structured interviews were conducted during March–November 2020 with 11 nursing emergency management administrators from 11 COVID‐19 designated hospitals and infectious disease hospitals under four administrative divisions in China, who were recruited through convenience and purposive sampling. Interviews were audio‐recorded and transcribed. Data were analysed with Braun and Clarke's inductive thematic analysis. The study adhered to the Consolidated Criteria for Reporting Qualitative Research. Results: Three main themes emerged from data analysis: (1) Five core elements of nursing emergency management system: Structure, Staff, System, Setting, and Supply (5S); (2) Four phases of nursing emergency management system: Reduction, Readiness, Response and Recovery (4R); and (3) operational process of nursing emergency management system (5S*4R). The findings generated a conceptual model of a nursing emergency management system. Public Contribution: This study provides a theoretical basis for nursing emergency management system for public health emergencies in the future. Nurse administrators could refer to this model to either review or develop their system and develop viable interventions to prepare for future public health emergencies. [ABSTRACT FROM AUTHOR]

Our aim was to explore the possibility of using machine learning (ML) in predicting the onset and trajectories of depressive symptom in home-based older adults over a 7-year period. Depressive symptom data (collected in the year 2011, 2013, 2015 and 2018) of home-based older Chinese (n = 2650) recruited in the China Health and Retirement Longitudinal Study (CHARLS) were included in the current analysis. The latent class growth modeling (LCGM) and growth mixture modeling (GMM) were used to classify different trajectory classes. Based on the identified trajectory patterns, three ML classification algorithms (i.e. gradient boosting decision tree, support vector machine and random forest) were evaluated with a 10-fold cross-validation procedure and a metric of the area under the receiver operating characteristic curve (AUC). Four trajectories were identified for the depressive symptoms: no symptoms (63.9%), depressive symptoms onset {incident increasing symptoms [new-onset increasing (16.8%)], chronic symptoms [slowly decreasing (12.5%), persistent high (6.8%)]}. Among the analyzed baseline variables, the 10-item Center for Epidemiologic Studies Depression Scale (CESD-10) score, cognition, sleep time, self-reported memory were the top five important predictors across all trajectories. The mean AUCs of the three predictive models had a range from 0.661 to 0.892. ML techniques can be robust in predicting depressive symptom onset and trajectories over a 7-year period with easily accessible sociodemographic and health information. Supplemental data for this article is available online at http://dx.doi.org/10.1080/13607863.2022.2031868 [ABSTRACT FROM AUTHOR]

Background Growth differentiation factor 15 (GDF15) has been associated with several age-related disorders, but its associations with functional abilities in community-dwelling older adults are not well studied. Methods The study was a secondary analysis of 1 096 community-dwelling older adults (aged 69–94 years) recruited from the Multidomain Alzheimer's Preventive Trial. Plasma GDF15 was measured 1 year after participants' enrollment. Annual data of physical performance (grip strength and Short Physical Performance Battery [SPPB]) and global cognitive functions (Mini-Mental State Examination [MMSE] and a composite cognitive score) were measured for 4 years. Adjusted mixed-effects linear models were performed for cross-sectional and longitudinal association analyses. Results A higher GDF15 was cross-sectionally associated with a weaker grip strength (β = −1.1E−03, 95% CI [−2.0E−03, −1.5E−04]), a lower SPPB score (β = −3.1E−04, 95% CI [−5.4E−04, −9.0E−05]), and worse cognitive functions (β = −2.4E−04, 95% CI [−3.3E−04, −1.6E−04] for composite cognitive score; β = −4.0E−04, 95% CI [−6.4E−04, −1.6E−04] for MMSE). Participants with higher GDF15 demonstrated greater longitudinal declines in SPPB (β = −1.0E−04, 95% CI [−1.7E−04, −2.0E−05]) and composite cognitive score (β = −2.0E−05, 95% CI [−4.0E−05, −3.6E−06]). The optimal initial GDF15 cutoff values for identifying participants with minimal clinically significant decline after 1 year were 2 189 pg/mL for SPPB (AUC: 0.580) and 2 330 pg/mL for composite cognitive score (AUC: 0.587). Conclusions Plasma GDF15 is cross-sectionally and longitudinally associated with lower-limb physical performance and global cognitive function in older adults. Circulating GDF15 alone has a limited capacity of discriminating older adults who will develop clinically significant functional declines. Clinical Trial Registration NCT00672685 [ABSTRACT FROM AUTHOR]

Aim: The purpose of this review was to evaluate the content, validity and reliability of patient‐reported questionnaires on patient participation in patient safety. Background: Patient participation in patient safety is one of the key strategies that are increasingly regarded as a critical intervention to improve the quality of safety care. Evaluation: A systematic review was conducted according to Preferred Reporting Items for Systematic Reviews and Meta‐Analyses (PRISMA) guidelines. The content, reliability and validity of patient‐reported questionnaires on patient participation in patient safety were assessed. Key issues: Twenty‐seven studies were included for data extraction and synthesis. The questionnaire contents most commonly used to describe patient participation in patient safety were 'attitudes and perceptions', 'experience', 'information and feedback' and 'willingness'. Internal consistency was evaluated for 17 questionnaires, and test–retest reliability was tested for four questionnaires. Content validity was assessed among all included questionnaires, and structural validity was evaluated for 12 questionnaires. Conclusions: Future research targeting the different safety issues is still indispensable for developing patient‐reported questionnaires with great psychometric quality in validity, reliability, feasibility and usability in patient participation in patient safety. Implications for Nursing Management: Clinical nurses should consider the internal consistency, test–retest reliability, content validity and structural validity of the questionnaires that have been positively appraised for methodological quality before use. [ABSTRACT FROM AUTHOR]

The Grading of Recommendations, Assessment, Development, and Evaluation (GRADE) approach was developed to assess the certainty (or quality) of evidence and strength of recommendations in guidelines and endorsed internationally as a standard. Some guidelines had been developed to promote pressure injury prevention. We explored whether and to what extent the development of pressure injury prevention guidelines had followed or been informed by the GRADE approach. If this approach was not used, we examined which other methods were used instead. A cross-sectional study of pressure injury prevention guidelines was conducted. PubMed, Embase, CINAHL, and Chinese databases as well as guideline repositories and websites of professional bodies were searched for guidelines from 1990 to 2020. The grading systems of the certainty (or quality) of evidence and strength of recommendations of included guidelines were extracted. For the GRADE approach guidelines, compliance was assessed with the GRADE application criteria. Twenty guidelines were identified. Among them, four guidelines (20%) indicated the use of the GRADE approach. The compliance rate ranged from 33.3%–94.4%. Other approaches, such as the Scottish Intercollegiate Guidelines Network (SIGN) approach, were also used. The GRADE approach is rarely followed and inconsistently applied in pressure injury prevention guidelines. Other systems, such as the SIGN approach, are being used despite being outdated or inconsistent. Strategies for further uptake and appropriate application of the GRADE approach among guideline developers are needed in the future. • Inconsistency and variability was observed in the grading systems in PI prevention guidelines. • The GRADE approach was rarely used and inconsistently followed. • Some unified grading systems such as the GRADE approach should be encouraged in the development of guidelines. [ABSTRACT FROM AUTHOR]

One major issue that challenges person re-identification (Re-ID) is the ubiquitous occlusion over the captured persons. There are two main challenges for the occluded person Re-ID problem, $i.e.$ , the interference of noise during feature matching and the loss of pedestrian information brought by the occlusions. In this paper, we propose a new approach called Feature Recovery Transformer (FRT) to address the two challenges simultaneously, which mainly consists of visibility graph matching and feature recovery transformer. To reduce the interference of the noise during feature matching, we mainly focus on visible regions that appear in both images and develop a visibility graph to calculate the similarity. In terms of the second challenge, based on the developed graph similarity, for each query image, we propose a recovery transformer that exploits the feature sets of its $k$ -nearest neighbors in the gallery to recover the complete features. Extensive experiments across different person Re-ID datasets, including occluded, partial and holistic datasets, demonstrate the effectiveness of FRT. Specifically, FRT significantly outperforms state-of-the-art results by at least 6.2% Rank- 1 accuracy and 7.2% mAP scores on the challenging Occluded-Duke dataset. [ABSTRACT FROM AUTHOR]

Background: Comparisons between high intensity interval training (HIIT) and continuous training (CT) regarding improvements of adolescents' cardiac function are scarce and the preferred intensity for cardiac improvement with restricted myocardial damage remains unknown. This study conducted a 4-weeks training in male adolescent rats under moderate (MI) or high intensity (HI) HIIT and CT programs, aiming to discover and compare exercise-induced myocardial adaptations towards these two training methods. Methods: 39 male adolescent Sprague-Dawley rats (aged 4 weeks) were randomly assigned to high intensity HIIT (HI-HIIT, n = 8), moderate intensity HIIT (MI-HIIT, n = 8), high intensity CT (HI-CT, n = 8), moderate intensity CT (MI-CT, n = 8) and sedentary control (SC, n = 7) groups. Rats in training groups were trained for 4 weeks and echocardiography was performed at baseline and after the final training. Serum creatine kinase myocardial band (CK-MB), cardiac troponin T (cTn-T) and untargeted metabolomics analysis were measured from blood samples collected 24 h after the final training. Results: HIIT groups had greater cardiac output improvement than CT groups while no significant difference was found between the HI-HIIT and the MI-HIIT groups. HI-CT group showed higher serum CK-MB and cTn-T levels compared to MI-HIIT, MI-CT and control groups. Untargeted metabolomics analysis identified eleven HI-HIIT-related metabolites, five MI-HIIT-related metabolites and two HICT-related metabolites. The majority of the identified metabolites were phospholipid-related. Phosphatidylglyceride 18 level was significantly different between the HI-CT and MI-CT groups, and was negatively associated with cTn-T in CT groups. Conclusion: HIIT and CT improve cardiac function of adolescent rats while the HIIT demonstrates better improvement and less myocardial damage. High and moderate training intensities in HIIT exert similar cardiac benefits. HI-CT induced myocardial damage might be associated with serum phospholipids. [ABSTRACT FROM AUTHOR]

Background: Heritability explains 45-82% of muscle mass and strength variation, yet polygenic models for muscle phenotypes in older women are scarce. Therefore, the objective of the present study was to (1) assess if total genotype predisposition score (GPSTOTAL) for a set of polymorphisms differed between older women with low and high muscle mass, and (2) utilise a data-driven GPS (GPSDD) to predict the variance in muscle size and strength-related phenotypes. Methods: In three-hundred 60- to 91-year-old Caucasian women (70.7 ± 5.7 years), skeletal muscle mass, biceps brachii thickness, vastus lateralis anatomical cross-sectional area (VLACSA), hand grip strength (HGS), and elbow flexion (MVCEF) and knee extension (MVCKE) maximum voluntary contraction were measured. Participants were classified as having low muscle mass if the skeletal muscle index (SMI) < 6.76 kg/m2 or relative skeletal muscle mass (%SMMr) < 22.1%. Genotyping was completed for 24 single-nucleotide polymorphisms (SNPs). GPSTOTAL was calculated from 23 SNPs and compared between the low and high muscle mass groups. A GPSDD was performed to identify the association of SNPs with other skeletal muscle phenotypes. Results: There was no significant difference in GPSTOTAL between low and high muscle mass groups, irrespective of classification based on SMI or %SMMr. The GPSDD model, using 23 selected SNPs, revealed that 13 SNPs were associated with at least one skeletal muscle phenotype: HIF1A rs11549465 was associated with four phenotypes and, in descending number of phenotype associations, ACE rs4341 with three; PTK2 rs7460 and CNTFR rs2070802 with two; and MTHFR rs17421511, ACVR1B rs10783485, CNTF rs1800169, MTHFR rs1801131, MTHFR rs1537516, TRHR rs7832552, MSTN rs1805086, COL1A1 rs1800012, and FTO rs9939609 with one phenotype. The GPSDD with age included as a predictor variable explained 1.7% variance of biceps brachii thickness, 12.5% of VLACSA, 19.0% of HGS, 8.2% of MVCEF, and 9.6% of MVCKE. Conclusions: In older women, GPSTOTAL did not differ between low and high muscle mass groups. However, GPSDD was associated with muscle size and strength phenotypes. Further advancement of polygenic models to understand skeletal muscle function during ageing might become useful in targeting interventions towards older adults most likely to lose physical independence. [ABSTRACT FROM AUTHOR]

Background: Plasma amyloid-beta (Aβ), neurofilament light chain (NfL), and progranulin (PGRN) have been related to multiple neurodegenerative conditions that might affect physical performance. The aim of this study was to explore the relationship between these plasma neurodegenerative markers and physical performance among community-dwelling older adults.Methods: Five hundred and seven older adults (aged 76 ± 5 years) previously recruited in the Multidomain Alzheimer's Preventive Trial, and had received blood and physical performance tests, were included in this study. Plasma Aβ (Aβ 42/Aβ 40 ratio), NfL, and PGRN levels were measured. Physical performance was assessed by handgrip strength and the Short Physical Performance Battery (combining gait speed, chair stands, and balance tests). Physical performance measured at the same time point and after the blood tests were used. Mixed-effect linear models were performed with age, sex, allocation to Multidomain Alzheimer's Preventive Trial group, body mass index, and Mini-Mental State Examination score as covariates.Results: The mean values of Aβ 42/Aβ 40 ratio, NfL, and PGRN were 0.11, 84.06 pg/mL, and 45.43 ng/mL, respectively. At the cross-sectional level, higher plasma NfL was associated with a lower Short Physical Performance Battery score (β = -0.004, 95% CI [-0.007, -0.001]). At the longitudinal level, higher PGRN levels were associated with decreasing handgrip strength over time (β = -0.02, 95% CI [-0.04, -0.007]). All the other associations were statistically nonsignificant.Conclusion: Our findings suggest the possibility of using plasma NfL and PGRN as markers of physical performance in older adults. [ABSTRACT FROM AUTHOR]

Neurofilament light chain (NfL) has been associated with cognitive status in multiple neurodegenerative conditions. Studies about plasma NfL and cognitive decline in older adults are still limited. 504 older adults (median age 75 years) who expressed memory complaints were selected from the Multidomain Alzheimer's Preventive Trial (MAPT) and were classified as normal cognition (NC) or mild cognitive impairment (MCI). Cognitive functions were measured as mini mental state examination (MMSE) and composite cognitive score (CCS) over a 4-year period. Plasma NfL was measured at the first or the second year of the MAPT. Mixed-effects linear models were performed to evaluate cross-sectional and longitudinal associations. In the whole population, higher plasma NfL was cross-sectionally associated with lower cognitive functions (MMSE: β = − 0.007, 95% CI [− 0.013, − 0.001]; CCS: β = − 0.003, 95% CI [− 0.006, − 0.001]). In adults with MCI, but not NC, higher plasma NfL was associated with lower CCS at the cross-sectional level (β = − 0.003, 95% CI [− 0.005, − 0.0002]). The upper quartile NfL group further demonstrated more over time decline in CCS (β = − 0.07, 95% CI [− 0.12, − 0.01]) under the MCI status. Plasma NfL can be a promising biomarker of progressive cognition decline in older adults with MCI. [ABSTRACT FROM AUTHOR]

Objective: To explore associations between changes of lower extremity function (LEF) parameters over a 5‐year period and diffusion tensor imaging (DTI) parameters of white matter tracts among community‐dwelling older adults. Design: A secondary analysis on image and physical function data collected from the Multidomain Alzheimer's Preventive Trial (MAPT). Participants: 208 older adults (aged 75 ± 4 years, with spontaneous memory complaint or limited instrumental daily living activity or slow gait speed, 60% female) of the MAPT‐magnetic resonance imaging (MRI) ancillary study. The time interval between a participant's enrolment and MRI scan was on average 110 ± 97 days. Measurements: Forty‐eight white matter tracts (WMTs) were measured. LEF parameters (measured after the MRI scan) were assessed as the short physical performance battery (SPPB) score, gait speed, and chair stands time over a 5‐year period. Mixed‐effects models were performed to explore the associations between baseline DTI values and the progression of LEF parameters. Bonferroni correction was applied for multiple comparison correction. Results: The progression of LEF was associated with 35 baseline DTI parameters from 24 WMTs. Higher baseline DTI parameter values were related to more decreases in SPPB score and gait speed, and greater increases in chair stands time. Bilateral uncinate fasciculus was associated with all LEF parameters. Other WMTs in cingulum, cerebral and cerebellar peduncle, internal capsule, and corpus callosum also showed close connections with LEF changes. Conclusions: Our findings show that DTI parameters of some WMTs are associated with the 5‐year decline in LEF, suggesting that alterations in WMT integrity (evaluated by DTI parameters) might be used to explore potential causes of impaired mobility in older adults when no clear explanations can be found. [ABSTRACT FROM AUTHOR]

Background: Inter‐individual variance in skeletal muscle is closely related to genetic architecture and epigenetic regulation. Studies have examined genetic and epigenetic relationships with characteristics of ageing muscle separately, while no study has combined both genetic and epigenetic profiles in ageing muscle research. The aim of this study was to evaluate the association between combined genetic and methylation scores and skeletal muscle phenotypes in older women. Methods: Forty‐eight older Caucasian women (aged 65–79 years) were included in this study. Biceps brachii thickness and vastus lateralis anatomical cross‐sectional area (ACSAVL) were measured by ultrasonography. Maximum isometric elbow flexion (MVCEF) and knee extension (MVCKE) torques were measured by a customized dynamometer. The muscle‐driven genetic predisposition score (GPSSNP) was calculated based on seven muscle‐related single nucleotide polymorphisms (SNPs). DNA methylation levels of whole blood samples were analysed using Infinium MethylationEPIC BeadChip arrays. The DNA methylation score was calculated as a weighted sum of methylation levels of sarcopenia‐driven CpG sites (MSSAR) or an overall gene‐wise methylation score (MSSNP, the mean methylation level of CpG sites located in muscle‐related genes). Linear regression models were built to study genetic and epigenetic associations with muscle size and strength. Three models were built with both genetic and methylation scores: (1) MSSAR + GPSSNP, (2) MSSNP + GPSSNP, and (3) gene‐wise combined scores which were calculated as the ratio of the SNP score to the mean methylation level of promoters in the corresponding gene. Additional models with only a genetic or methylation score were also built. All models were adjusted for age and BMI. Results: MSSAR was negatively associated with ACSAVL, MVCEF, and MVCKE and explained 10.1%, 35.5%, and 40.1% of the variance, respectively. MSSAR explained more variance in these muscular phenotypes than GPSSNP, MSSNP, and models including both genetic and methylation scores. MSSNP and GPSSNP accounted for less than 8% and 5% of the variance in all muscular phenotypes, respectively. The genotype and methylation level of CNTF was positively related to MVCKE (P = 0.03) and explained 12.2% of the variance. The adjusted R2 and Akaike information criterion showed that models with only a MSSAR performed the best in explaining inter‐individual variance in muscular phenotypes. Conclusions: Our results improve the understanding of inter‐individual variance in muscular characteristics of older women and suggest a possible application of a sarcopenia‐driven methylation score to muscle strength estimation in older women while the combination with a genetic score still needs to be further studied. [ABSTRACT FROM AUTHOR]

Background: Sarcopenia is characterized by progressive decreases in muscle mass, muscle strength, and muscle function with ageing. Although many studies have investigated the mechanisms of sarcopenia, its connection with epigenetic factors, such as DNA methylation, still remains poorly understood. The aim of this study was to explore sarcopenia‐related DNA methylation differences in blood samples between age‐matched sarcopenic and non‐sarcopenic older women. Methods: A sarcopenic group (n = 24) was identified and selected from a set of 247 older Caucasian women (aged 65–80 years) based on cut‐off points of skeletal muscle index at 6.75 kg/m2 and grip strength at 26 kg (the lower quintile of grip strength in the set). A non‐sarcopenic group (n = 24) was created with a similar age distribution as that of the sarcopenic group. DNA methylation patterns of whole blood samples from both groups were analysed using Infinium MethylationEPIC BeadChip arrays. Differentially methylated cytosin–phosphate–guanine sites (dmCpGs) were identified at a P value threshold of 0.01 by comparing methylation levels between the sarcopenic and non‐sarcopenic groups at each CpG site. dmCpG‐related genes were annotated based on Homo sapiens hg19 genome build. The functions of these genes were further examined by GO and KEGG pathway enrichment analysis. Results: The global methylation level of all analysed CpG sites (n = 788 074) showed no significant difference between the sarcopenic and non‐sarcopenic groups (0.812), while the average methylation level of dmCpGs (n = 6258) was significantly lower in the sarcopenic group (0.004). The sarcopenic group had significantly higher methylation levels in TSS200 (the region from transcription start site to 200 nucleotides upstream of the site) and lower methylation levels in gene body and 3'UTR regions. In respect of CpG regions, CpG islands in promoters and some intragenic regions showed greater levels of methylation in the sarcopenic group. dmCpG‐related KEGG pathways were mainly associated with muscle function, actin cytoskeleton regulation, and energy metabolism. Seven genes (HSPB1, PBX4, CNKSR3, ORMDL3, MIR10A, ZNF619, and CRADD) were found with the same methylation direction as previous studies of blood sample methylation during ageing. Fifty‐four genes were shared with previous studies of resistance training. Conclusions: Our results improve understanding of epigenetic mechanisms of sarcopenia by identifying sarcopenia‐related DNA methylation differences in blood samples of older women. These methylation differences suggest underlying alterations of gene expression and pathway function, which can partially explain sarcopenia‐related muscular changes. [ABSTRACT FROM AUTHOR]

Abstract This study aims to identify a genetic predisposition score from a set of candidate gene variants that predicts the response to a one-year exercise intervention. 200 participants (aged 60–83 years) were randomly assigned to a fitness (FIT), whole-body vibration (WBV) and control group. Participants in the exercise (FIT and WBV) groups performed a one-year intervention program. Whole-body skeletal muscle mass (SMM) and isometric knee extension strength (PT IM60 ) were measured before and after the intervention. A set of 170 muscle-related single nucleotide polymorphisms (SNPs) were genotyped. Stepwise regression analysis was applied to select significantly contributing SNPs for baseline and relative change parameters. A data-driven genetic predisposition score (GPS) was calculated by adding up predisposing alleles for each of the phenotypes. GPS was calculated based on 4 to 8 SNPs which were significantly related to the corresponding phenotypes. These SNPs belong to genes that are involved in myoblast differentiation, muscle and bone growth, myofiber contraction, cytokines and DNA methylation. GPS was related to baseline PT IM60 and relative changes of SMM and PT IM60 in the exercise groups, explaining the variance of the corresponding parameter by 3.2%, 14% and 27%, respectively. Adding one increasing allele in the GPS increased baseline PTIM 60 by 4.73 Nm, and exercise-induced relative changes of SMM and PT IM60 by 1.78% and 3.86% respectively. The identified genetic predisposition scores were positively related to baseline knee extension strength and muscle adaptations to exercise in healthy elderly. These findings provide supportive genetic explanations for high and low responders in exercise-induced muscle adaptations. Highlights • Genetic predisposition score is related to knee muscle strength. • Genetic predisposition score can explain exercise-induced adaptation variability. • DNA methylation is suggested to be involved in exercise adaptations. [ABSTRACT FROM AUTHOR]

Obesity may aggravate the effects of sarcopenia on skeletal muscle structure and function in the elderly, but no study has attempted to identify the gene variants associated with sarcopenia in obese women. Therefore, the aims of the present study were to: (1) describe neuromuscular function in sarcopenic and non-sarcopenic women with or without obesity; (2) identify gene variants associated with sarcopenia in older obese women. In 307 Caucasian women (71 ± 6 years, 66.3 ± 11.3 kg), skeletal muscle mass was estimated using bioelectric impedance, and function was tested with a 30 s one-leg standing-balance test. Biceps brachii thickness and vastus lateralis cross-sectional area (VLACSA) were measured with B-mode ultrasonography. Handgrip strength, maximum voluntary contraction elbow flexion (MVCEF), and knee extension torque (MVCKE) were measured by dynamometry, and MVCKE/VLACSA was calculated. Genotyping was performed for 24 single-nucleotide polymorphisms (SNPs), selected based on their previous associations with muscle-related phenotypes. Based on sarcopenia and obesity thresholds, groups were classified as sarcopenic obese, non-sarcopenic obese, sarcopenic non-obese, or non-sarcopenic non-obese. A two-way analysis of covariance was used to assess the main effects of sarcopenia and obesity on muscle-related phenotypes and binary logistic regression was performed for each SNP to investigate associations with sarcopenia in obesity. There were no significant obesity * sarcopenic status interactions for any of the investigated muscle-related phenotypic parameters. Neither sarcopenia nor obesity had a significant effect on biceps brachii thickness, but sarcopenia was associated with lower VLACSA (p = 0.003). Obesity was associated with lower MVCEF (p = 0.032), MVCKE (p = 0.047), and MVCKE/VLACSA (p = 0.012) with no significant effect of sarcopenia. Adjusted for age and height, three SNPs (ACTN3 rs1815739, MTHFR rs1801131, and MTHFR rs1537516) were associated with sarcopenia in obese participants. Sarcopenia was associated with a smaller muscle size, while obesity resulted in a lower muscle quality irrespective of sarcopenia. Three gene variants (ACTN3 rs1815739, MTHFR rs1801131, and MTHFR rs1537516) suspected to affect muscle function, homocysteine metabolism, or DNA methylation, respectively, were associated with sarcopenia in obese elderly women. Understanding the skeletal muscle features affected by sarcopenia and obesity, and identification of genes related to sarcopenia in obese women, may facilitate early detection of individuals at particular risk of sarcopenic obesity. [ABSTRACT FROM AUTHOR]

Although multiple nutrients have shown protective effects with regard to preserving muscle function, the recommended amount of dietary protein and other nutrients profile on older adults for maintenance of high muscle mass is still debatable. The aims of this paper were to: (1) identify dietary differences between older women with low and high relative skeletal muscle mass, and (2) identify the minimal dietary protein intake associated with high relative skeletal muscle mass and test the threshold ability to determine an association with skeletal muscle phenotypes. Older women (n = 281; 70 ± 7 years, 65 ± 14 kg), with both low and high relative skeletal muscle mass groups, completed a food questionnaire. Skeletal muscle mass, fat-free mass (FFM), biceps brachii thickness, vastus lateralis anatomical cross-sectional area (VLACSA), handgrip strength (HGS), maximum elbow flexion torque (MVCEF), maximum knee extension torque (MVCKE), muscle quality (HGS/Body mass), and fat mass were measured. Older women with low relative skeletal muscle mass had a lower daily intake of protein, iodine, polyunsaturated fatty acid (PUFA), Vit E, manganese, milk, fish, nuts and seeds (p < 0.05) compared to women with high relative skeletal muscle mass. The minimum required dietary protein intake for high relative skeletal muscle mass was 1.17 g/kg body mass/day (g/kg/d) (sensitivity: 0.68; specificity: 0.62). Women consuming ≥1.17 g/kg/d had a lower BMI (B = −3.9, p < 0.001) and fat mass (B = −7.8, p < 0.001), and a higher muscle quality (B = 0.06, p < 0.001). The data indicate that to maintain muscle mass and function, older women should consume ≥1.17 g/kg/d dietary protein, through a varied diet including milk, fish and nuts that also contain polyunsaturated fatty acid (PUFA) and micronutrients such as iodine, Vit E and manganese. [ABSTRACT FROM AUTHOR]