Objectives Older adults experienced measurable psychological burden during the COVID-19 pandemic. Although salivary cortisol is widely used as a biomarker of hypothalamic–pituitary–adrenal axis activity, single time-point basal measurements may show inconsistent associations with anxiety. We examined whether afternoon salivary cortisol was cross-sectionally associated with same-day state anxiety in community-dwelling older adults during the COVID-19 pandemic. Methods Community-dwelling adults aged ≥65 years were recruited between May and November 2021 in rural Japan. Afternoon salivary cortisol (15:00–16:00) was measured using enzyme-linked immunosorbent assay from stored samples. State anxiety was assessed using the State–Trait Anxiety Inventory state scale (STAI-State). Multivariable linear regression models were fitted in the overall sample and in exploratory sex-stratified analyses, adjusting for demographic, psychological, cognitive, and COVID-19–related factors. Results The analyses included 76 participants (mean age 80.8 years; 68% female). The mean (standard deviation) STAI-State score was 40.7 (10.5), and median salivary cortisol was 0.13 μg/dL. In adjusted models, salivary cortisol was not associated with STAI-State score in the overall sample or in exploratory sex-stratified analyses. Effect estimates were close to null. Conclusions In this cohort of community-dwelling older adults in Japan during the COVID-19 pandemic, a single afternoon salivary cortisol measurement was not associated with same-day state anxiety. This null finding should be interpreted in the context of the present study design and measurement approach and does not rule out an association between cortisol and anxiety under other conditions.
Population aging has made the maintenance of cognitive function and mental health in older adults a major public health priority. Brain-derived neurotrophic factor (BDNF) and S100 calcium-binding protein B (S100 B) are biomarkers of brain health, reflecting neurotrophic support and neuroinflammatory activity, respectively. The objectives of this study were to examine the association (a) between serum BDNF and S100 B levels and (b) between these biomarkers and cognitive function and depression in community-dwelling older adults. This cross-sectional study included 95 community-dwelling adults aged ≥65 years living in rural Japan. Serum BDNF and S100 B levels were measured using enzyme-linked immunosorbent assays. Cognitive function and depressive symptoms were assessed using four instruments. Spearman's correlation analyses examined associations between the biomarkers and neuropsychological measures. Multiple regression analyses were performed using log10-transformed S100 B as the dependent variable and log10-transformed BDNF, age, sex, education, and BMI as independent variables. Serum BDNF levels were negatively correlated with serum S100 B levels (β = -0.509, p < 0.0001). This association remained significant across adjusted models (all p < 0.0001). Sensitivity analyses yielded consistent results. No associations were observed between serum BDNF or S100 B levels and cognitive function or depression. The inverse relationship between BDNF and S100 B suggests a link between neurotrophic and neuroinflammatory processes. Nursing interventions that enhance BDNF may also affect S100 B level, which may foster brain health in older adults.
Ryuzo Orihashi, Takumi Shiraishi, Toru Murakawa-Hirachi et al.· Biological Research for Nurs...· 0 citations