Intra-Individual Cortisol Variability and Low-Grade Inflammation over 10 Years in Older Adults

This study examined the associations between intra-individual variability in, and inter-individual levels of, diurnal cortisol secretion with a marker of low-grade inflammation (i.e., C-Reactive Protein; CRP). Reasoning that greater day-to-day cortisol variability could reflect a dysregulation of the HPA axis, we hypothesized that it would predict higher levels of CRP, above and beyond inter-individual differences in cortisol levels. A 10-year longitudinal study of 130 older adults examined diurnal cortisol secretion on three different days across each of the 6 waves of data collection and levels of CRP during the last 3 waves. Indicators of mean cortisol levels, short-term cortisol variability, and long-term cortisol variability were analyzed. Hierarchical linear modeling showed significant main effects, linking baseline mean cortisol levels, T-ratio = 2.25, p = 0.03, and long-term cortisol variability, T-ratio = 2.63, p = 0.01, with higher CRP values six to ten years after study entry. In addition, a two-way interaction demonstrated that short-term variability in cortisol were associated with higher levels of CRP among individuals who secreted relatively high, T-ratio = 2.68, p = 0.01, but not low, T-ratio = −1.09, p = 0.28, baseline levels of cortisol. Finally, a three-way interaction, T-ratio = 2.24, p = 0.03, suggested that the effect of long-term cortisol variability on CRP became stronger over time among participants who secreted high average levels of cortisol, whereas it became weaker among their counterparts who secreted low average levels of cortisol

Chronic Stress and HPA Axis Dysregulation in Older Adulthood: Protective Effects of Self-Compassion

The aging population is the fastest growing segment of the population. With aging, there is an increase in the number of uncontrollable stressors that arise. Stress is known to have an impact on biological processes (e.g., HPA axis function) and downstream physical health outcomes (e.g., chronic illness). However, the exact pathophysiological patterns of HPA axis dysfunction that arise from chronic stress experiences is vastly understudied. In addition, little is known about psychological factors that promote adaption to stress and reduce the negative consequences of stress on health in old age. This dissertation sought to investigate the impact of stress experiences on older adult’s physical health and the benefits of the psychological trait self-compassion. Study 1 examined how chronic stress levels and changes predicted trajectories of diurnal cortisol (AUC and slope) over 12 years. Results indicated that older adults with high levels of chronic stress were likely to have significantly steeper declines in cortisol levels over the study. In addition, older adults with high and increasing stress levels displayed increasingly flatter cortisol slopes. Study 2 investigated cross-sectional associations between age-related stressors and diurnal cortisol, and whether self-compassion could buffer the impact of stress on cortisol patterns. The results found no association between age-related stress and diurnal cortisol. However, self-compassion moderated the association between age-related stress and cortisol. Specifically, older adults with higher levels of age-related stressors who were more self-compassionate were protected from higher levels of stress-related diurnal cortisol. Study 3 sought to explore the longitudinal health benefits of self-compassion across four years, and whether they vary for older adults in early vs. advanced old age. The results revealed that self-compassion predicted lower levels of daily physical symptoms on average for those in advanced old age (but not early old age). Self-compassion also predicted fewer increases in chronic illness over four years among those in advanced, but not early old age. Overall, this dissertation provides significant contributions to theory and research on stress, aging and health

Self-Compassion, Chronic Age-Related Stressors, and Diurnal Cortisol Secretion in Older Adulthood

Background: Many older adults experience chronic age-related stressors (e.g., life regrets or health problems) that are difficult to control and can disturb cortisol regulation. Self-compassion may buffer adverse effects of these stressful experiences on diurnal cortisol secretion in older adulthood. Purpose: To examine whether self-compassion could benefit older adults’ cortisol secretion in the context of chronic and largely uncontrollable age-related stressors. Methods: 233 community- dwelling older adults reported their levels of self-compassion, age-related stressors (regret intensity, physical health problems, and functional disability), and relevant covariates. Diurnal cortisol was measured over 3 days and the average area-under-the-curve (AUC) and slope were calculated. Results: Higher levels of self-compassion were associated with lower daily cortisol levels among older adults who reported higher levels of regret intensity, physical health problems, or functional disability (βs .28). Conclusions: These results suggest that self- compassion may represent an important personal resource that could protect older adults from stress- related biological disturbances resulting from chronic and uncontrollable stressors

Intra-Individual Cortisol Variability and Low-Grade Inflammation Over 10 Years in Older Adults

Objective: This study examined the associations between intra-individual variability in, and inter-individual levels of, diurnal cortisol secretion with a marker of low-grade inflammation (i.e., C-Reactive Protein; CRP). Reasoning that greater day-to-day cortisol variability could reflect a dysregulation of the HPA axis, we hypothesized that it would predict higher levels of CRP, above and beyond inter-individual differences in cortisol levels. Methods: A 10-year longitudinal study of 130 older adults examined diurnal cortisol secretion on three different days across each of the 6 waves of data collection and levels of CRP during the last 3 waves. Indicators of mean cortisol levels, short-term cortisol variability, and long-term cortisol variability were analyzed. Results: Hierarchical linear modeling showed significant main effects, linking baseline mean cortisol levels, T-ratio = 2.25, p = .03, and long-term cortisol variability, T-ratio = 2.63, p = .01, with higher CRP values six to ten years after study entry. In addition, a two-way interaction demonstrated that short-term variability in cortisol were associated with higher levels of CRP among individuals who secreted relatively high, T-ratio = 2.68, p = .01, but not low, T-ratio = -1.09, p = .28, baseline levels of cortisol. Finally, a three-way interaction, T-ratio = 2.24, p = .03, suggested that the effect of long-term cortisol variability on CPR became stronger over time among participants who secreted high average levels of cortisol, whereas it became weaker among their counterparts who secreted low average levels of cortisol. Conclusion: Variability in cortisol secretion across days forecasts low-grade inflammation, and this association is paramount among older adults who secrete high levels of diurnal cortisol