Protective effects of physical activity on mental health outcomes during the COVID-19 pandemic.

The COVID-19 pandemic has been linked with increased reports of depression, anxiety, and stress. Stay-at-home directives during the pandemic-imposed lifestyle changes, including eating and sedentary behaviors that can further undermine mental health outcomes. Physical activity is a vital component for metabolic health, as well as for mental health by serving as an active coping strategy to manage stress and promote resilience. Global reports of increased sedentary leisure behaviors have been associated with feelings of depression and anxiety, but it unclear whether the relationship between physical activity and depression or anxiety persists over time. In this longitudinal study, we investigated (i) whether physical activity at the onset of the pandemic was related to feelings of depression or anxiety over time and (ii) whether this relationship was mediated by stress appraisals during the pandemic. We surveyed 319 adults living in Canada or the United States to assess physical activity, stress appraisals, and mental health outcomes at two time points over a 6-month period. We found a reduction in leisure-time physical activity that was linked to subsequent feelings of depression. Furthermore, individuals with lower levels of physical activity were more likely to appraise their COVID-19 situation to be uncontrollable at pandemic onset and as the pandemic continued. Stress appraisals of threat and uncontrollability were also positively related to feelings of depression. Modelling these three factors together showed that appraising a situation as uncontrollable mediated the relationship between initial physical activity and subsequent depressive feelings. Although correlational, these data highlight the protective role of leisure-time physical activity against worsened mental health outcomes during periods of prolonged stress.

Spatial distribution of beta-klotho mRNA in the mouse hypothalamus, hippocampal region, subiculum, and amygdala.

Beta-klotho (KLB) is a coreceptor required for endocrine fibroblast growth factor (FGF) 15/19 and FGF21 signaling in the brain. Klb is prominent within the hypothalamus, which is consistent with its metabolic functions, but diverse roles for Klb are now emerging. Central Klb expression is low but discrete and may govern FGF-targeted sites. However, given its low expression, it is unclear if Klb mRNA is more widespread. We performed in situ hybridization to label Klb mRNA to generate spatial maps capturing the distribution and levels of Klb within the mouse hypothalamus, hippocampal region, subiculum, and amygdala. Semiquantitative analysis revealed that Klb-labeled cells may express low, medium, or high levels of Klb mRNA. Hypothalamic Klb hybridization was heterogeneous and varied rostrocaudally within the same region. Most Klb-labeled cells were found in the lateral hypothalamic zone, but the periventricular hypothalamic region, including the suprachiasmatic nucleus, contained the greatest proportion of cells expressing medium or high Klb levels. We also found heterogeneous Klb hybridization in the amygdala and subiculum, where Klb was especially distinct within the central amygdalar nucleus and ventral subiculum, respectively. By contrast, Klb-labeled cells in the hippocampal region only expressed low levels of Klb and were typically found in the pyramidal layer of Ammon's horn or dentate gyrus. The Klb-labeled regions identified in this study are consistent with reported roles of Klb in metabolism, taste preference, and neuroprotection. However, additional identified sites, including within the hypothalamus and amygdala, may suggest novel roles for FGF15/19 or FGF21 signaling.

Piece of Cake: Coping with COVID-19.

To limit the spread of coronavirus disease 2019 (COVID-19), many individuals were instructed to stay at home, and teleworking became commonplace. Meanwhile, many others were laid off or worked reduced hours, and some front line workers were required to work longer hours. Concurrently, a surge in reports of "pandemic baking" suggested a cascade effect on eating behaviors, which may be an inadvertent strategy to cope with stress. We conducted an online survey of people living in Canada or the United States (N = 680) to assess how employment change may have been experienced as stressful and linked to a shift in food choices. Regression models suggested that reduced hours and being laid off were associated with greater stress appraisals, avoidant- and emotion-focused coping responses, and negative affect. In turn, negative affect was associated with eating to cope and unhealthy snack choices, like salty or sweet treats. Our study emphasizes that under stressful conditions, such as those experienced during the COVID-19 pandemic, some coping strategies may contribute to the greater vulnerability to downstream effects, particularly those relating to eating choices and nutritional balances.