Associations between inflammatory markers and muscle strength in older adults according to the presence or absence of obesity.

BACKGROUND: We investigated the association between inflammatory markers and muscle strength in older adults according to the presence or absence of obesity. Dynapenia is the age-related decline in muscle strength and results in negative outcomes to older adults. Accordingly, obesity is more prevalent throughout aging and is associated with comorbidities, such as type 2 diabetes, dyslipidemia and cardiovascular diseases. Both dynapenia and obesity are strongly linked to chronic inflammation, sharing common signaling pathways. METHODS: We recruited 247 older adults aged 60 or older and collected sociodemographic, anthropometric and metabolic data. Dynapenia was diagnosed according to the European Working Group on Sarcopenia in Older People 2 (EWGSOP2) criteria. Circulating inflammatory cytokines were measured in plasma using a multiplex panel kit. Anthropometric, sociodemographic, lipid profile, and fasting blood glucose were also assessed. RESULTS: Dynapenic participants were predominantly males (74.4%), had insufficiently active lifestyle and higher IL-10 plasma levels (0.95 pg/mL; 0.40-2.12). The prevalence of obesity was higher among non-dynapenic participants (45.3%; 95% CI, 37.7-53). In dynapenic older adults, obesity was predominant in males (53.6%) and subjects with normal muscle strength had higher serum levels of TNF-ß (0.63 pg/mL; 0.30-1.30) and lower hand-grip strength (24 kg; 20.00-28.00). Using a multivariate quantile regression analysis, we found a strong and negative association between IL-10 and muscle strength. CONCLUSIONS: This study can help to understand the association of inflammation, obesity and muscle strength to promote interventions in order to avoid or delay the negative outcomes associated with dynapenia and sarcopenia in older adults.

ADAM10 plasma levels predict worsening in cognition of older adults: a 3-year follow-up study.

BACKGROUND: Blood-based biomarkers for Alzheimer's disease (AD) are highly needed in clinic practice. So far, the gold standards for AD diagnosis are brain neuroimaging and beta-amyloid peptide, total tau, and phosphorylated tau in cerebrospinal fluid (CSF); however, they are not attractive for large-scale screening. Blood-based biomarkers allow an initial large-scale screening of patients under suspicion that could later be tested for the already established CSF biomarkers. To this regard, in this study, we evaluated whether plasma ADAM10 levels would be predictors of declines in cognition in community-dwelling older adults after a 3-year period follow-up. METHODS: This was a 3-year longitudinal cohort study that included 219 community-dwelling older adults. Sociodemographic, clinical, lifestyle, depressive symptoms (GDS), and cognitive data (Mini-Mental State Examination, MMSE; Clock Drawing test, CDT) were gathered. The measurement of ADAM10 plasma levels was performed using a sandwich ELISA kit. Bivariate comparisons between groups were performed using Wilcoxon-Mann-Whitney for continuous data and Pearson's chi-square tests with Yates continuity correction for categorical data. Longitudinal analyzes of changes in the MMSE scores were performed using linear mixed-effects modeling. RESULTS: Baseline MMSE scores and ADAM10 levels were significantly associated with MMSE scores on the follow-up assessment. When analyzing the interaction with time, normal MMSE scores and the ADAM10 plasma levels at baseline presented a significant and independent negative association with MMSE score values on the follow-up assessment. The analyses also showed that the predictive effect of ADAM10 plasma levels on decreasing MMSE scores on follow-up seems to be more pronounced in participants with normal MMSE, when compared with those with altered MMSE scores at baseline. CONCLUSIONS: Considering that ADAM10 increase in plasma is detected as soon as in mild cognitive impairment (MCI) patients, the results presented here may support the complementary clinical use of this biomarker, in addition to the classical AD biomarkers. Taken together, these results provide the first direct evidence that changes in ADAM10 plasma levels are predictors of cognitive worsening in older adults. Moreover, this work can shed light on the study of blood biomarkers for AD and contribute to the advancement of the area.