Prevalence risk of sarcopenia in older Brazilian adults during the pandemic: A cross-sectional analysis of the Remobilize Study

Pleiotropic effects on Sarcopenia subphenotypes point to potential molecular markers for the disease

Sarcopenia is a progressive age-related muscle disease characterized by low muscle strength, quantity and quality, and low physical performance. The clinical overlap between these subphenotypes (reduction in muscle strength, quantity and quality, and physical performance) was evidenced, but the genetic overlap is still poorly investigated. Herein, we investigated whether there is a genetic overlap amongst sarcopenia subphenotypes in the search for more effective molecular markers for this disease. For that, a Bioinformatics approach was used to identify and characterize pleiotropic effects at the genome, loci and gene levels using Genome-wide association study results. As a result, a high genetic correlation was identified between gait speed and muscle strength (rG=0.5358, p=3.39 × 10-8). Using a Pleiotropy-informed conditional and conjunctional false discovery rate method we identified two pleiotropic loci for muscle strength and gait speed, one of them was nearby the gene PHACTR1. Moreover, 11 pleiotropic loci and 25 genes were identified for muscle mass and muscle strength. Lastly, using a gene-based GWAS approach three candidate genes were identified in the overlap of the three Sarcopenia subphenotypes: FTO, RPS10 and CALCR. The current study provides evidence of genetic overlap and pleiotropy among sarcopenia subphenotypes and highlights novel candidate genes and molecular markers associated with the risk of sarcopenia.

Risk of sarcopenia and mobility of older adults during the COVID-19 pandemic: the longitudinal data from the REMOBILIZE study

BACKGROUND

We assessed whether clinical, functional and behavioral factors were associated with the decrease in mobility trajectories reported in older people at risk of sarcopenia (RS) and without risk of sarcopenia (NRS) during COVID-19 pandemic.

METHODS

We prospectively analyzed mobility trajectories reported in older adults with RS and NRS over 16-month follow-up (Remobilize study). The self-perceived risk of sarcopenia and mobility were assessed using the SARC-F and the Life-Space Assessment (LSA) tools, respectively. Gender, age, comorbidities, pain, functional limitation, physical activity (time spent in walking; min/week), and sitting time (ST; hours/day) were assessed. We used a multilevel model to determine changes in mobility between groups and over time.

RESULTS

Mobility was lower in RS than in NRS. Older people at RS, who were women, aged 70-79 years and 80 years or older, inactive, and with moderate to severe functional limitation experienced reduced mobility trajectories reported over the pandemic. For older people at NRS, trajectories with reduce mobility reported were experienced by women with comorbidities, for those with insufficient walking time and aged 70-79 years; aged 70-79 years and with ST between 5 and 7 hours/day; for those with insufficient walking time and increased ST; and for those with pain and increased ST.

CONCLUSION

Mobility trajectories reported in older people at risk of sarcopenia were negatively influenced by insufficient level of physical inactivity and pre-existing moderate to severe functional limitation. Health and social interventions should be target to avoid mobility limitation during and after the COVID-19 pandemic.

The association between sedentary behaviour and sarcopenia in older adults: a systematic review and meta-analysis

BACKGROUND

Sedentary behaviour is considered to contribute to sarcopenia when combined with physical inactivity. Whether sedentary behaviour is independently associated with sarcopenia remains controversial. The aim of this study is to explore the association between sedentary behaviour and sarcopenia in older adults in community and long-term care facility settings.

METHODS

Eight electronic databases including MEDLINE, PsycINFO, Wanfang were searched from inception until August 2023. The review included cross-sectional and longitudinal studies concerning the association between sedentary behaviour and sarcopenia among participants over 60 years old. Evidence was pooled by both random-effects meta-analysis and narrative synthesis. Subgroup analyses explored variation according to adjustment of physical activity, settings, and measurements of sedentary behaviour and sarcopenia. Quality assessment for individual studies was performed with the Joanna Briggs Institute (JBI) Critical Appraisal Checklist.

RESULTS

Seventeen articles (16 cross-sectional studies and 1 longitudinal study) of 25,788 participants from community or long-term care facility settings were included. The overall quality of the included studies was rated high. Meta-analysis of 14 cross-sectional studies showed that sedentary behaviour was independently positively associated with sarcopenia: pooled odd ratio 1.36 (95% confidence interval, 1.18-1.58). The independent positive association remained in subgroup analyses by adjustment of physical activity, settings, and measurements of sedentary behaviour and sarcopenia. The narrative analysis corroborated the findings of the meta-analysis and provided additional evidence suggesting that interruptions in sedentary periods were linked to a decreased likelihood of developing sarcopenia.

CONCLUSIONS

The findings support the hypothesis that sedentary behaviour is independently positively associated with sarcopenia in older adults, providing vital indications for the development of strategies to prevent sarcopenia.

SYSTEMATIC REVIEW REGISTRATION

The systematic review protocol has been registered with the PROSPERO database (CRD42022311399).