Psychosocial stress and neuroendocrine biomarker concentrations among women living with or without HIV

Validity of mental and physical stress models

Different stress models are employed to enhance our understanding of the underlying mechanisms and explore potential interventions. However, the utility of these models remains a critical concern, as their validities may be limited by the complexity of stress processes. Literature review revealed that both mental and physical stress models possess reasonable construct and criterion validities, respectively reflected in psychometrically assessed stress ratings and in activation of the sympathoadrenal system and the hypothalamic-pituitary-adrenal axis. The findings are less robust, though, in the pharmacological perturbations' domain, including such agents as adenosine or dobutamine. Likewise, stress models' convergent- and discriminant validity vary depending on the stressors' nature. Stress models share similarities, but also have important differences regarding their validities. Specific traits defined by the nature of the stressor stimulus should be taken into consideration when selecting stress models. Doing so can personalize prevention and treatment of stress-related antecedents, its acute processing, and chronic sequelae. Further work is warranted to refine stress models' validity and customize them so they commensurate diverse populations and circumstances.

A 4-session written emotional disclosure intervention lowers 6-month sympathoadrenal urinary output in persons living with HIV

OBJECTIVE

We previously reported that a brief guided written emotional disclosure (WED) intervention resulted in significant reductions in post-traumatic stress disorder (PTSD) symptomology in women, but not men, living with HIV. Levels of 24-hour urinary output of epinephrine (E) and norepinephrine (NE) are shown to be elevated in persons diagnosed with PTSD. The current study tested whether there was an effect for the 4-week WED intervention on 6-month change in urinary E and NE output amongst persons living with HIV.

METHOD

Fourteen women and 11 men living with HIV randomized to four 30-min expressive writing sessions of either trauma writing or daily events writing in the parent trial were included based upon collection of urine specimens at baseline, 1-, and 6-months after the intervention. Total volume (µg) and concentration (µg/ml) of urinary E and NE were derived from the specimens as study outcomes.

RESULTS

Four repeated measures analyses of covariance (ANCOVA) were performed to evaluate study outcomes using trauma- versus daily-writing as the between-subject factors and collection time point as the within-subject factor, controlling for age and sex. A group x time interaction was observed wherein the trauma writing treatment group showed a significantly greater decrease in total urinary output, F(2, 46) = 4.03, p = .03, and concentration, F(2, 46) = 4.74, p = .01 of epinepherine. Post-hoc analyses revealed the interaction effect for the total, F(2, 22) = 4.82, p = .03, and concentration, F(2, 22) = 7.57, p = .005, of urinary E output over 6-months was significant for women. Interactions were not observed in urinary NE output.

CONCLUSIONS

Significant reductions in the total output and concentration of urinary E were found up to 6-months following initiation of a 4-session guided written emotional disclosure intervention. Profiles of sympathoadrenal activity and response to expressive writing differ between men and women living with HIV. Futher research is need to characterize the putative pathways linking sympathoadrenal response to upstream neurobiological function and downstream inflammatory-immune status in women living with HIV and PTSD.

Dehydroepiandrosterone in fibrotic interstitial lung disease: a translational study

BACKGROUND

Dehydroepiandrosterone (DHEA) is a precursor sex hormone with antifibrotic properties. The aims of this study were to investigate antifibrotic mechanisms of DHEA, and to determine the relationship between DHEA-sulfate (DHEAS) plasma levels, disease severity and survival in patients with fibrotic interstitial lung diseases (ILDs).

METHODS

Human precision cut lung slices (PCLS) and normal human lung fibroblasts were treated with DHEA and/or transforming growth factor (TGF)-β1 before analysis of pro-fibrotic genes and signal proteins. Cell proliferation, cytotoxicity, cell cycle and glucose-6-phosphate dehydrogenase (G6PD) activity were assessed. DHEAS plasma levels were correlated with pulmonary function, the composite physiologic index (CPI), and time to death or lung transplantation in a derivation cohort of 31 men with idiopathic pulmonary fibrosis (IPF) and in an independent validation cohort of 238 men and women with fibrotic ILDs.

RESULTS

DHEA decreased the expression of pro-fibrotic markers in-vitro and ex-vivo. There was no cytotoxic effect for the applied concentrations, but DHEA interfered in proliferation by modulating the cell cycle through reduction of G6PD activity. In men with IPF (derivation cohort) DHEAS plasma levels in the lowest quartile were associated with poor lung function and higher CPI (adjusted OR 1.15 [95% CI 1.03-1.38], p = 0.04), which was confirmed in the fibrotic ILD validation cohort (adjusted OR 1.03 [95% CI 1.00-1.06], p = 0.01). In both cohorts the risk of early mortality was higher in patients with low DHEAS levels, after accounting for potential confounding by age in men with IPF (HR 3.84, 95% CI 1.25-11.7, p = 0.02), and for age, sex, IPF diagnosis and prednisone treatment in men and women with fibrotic ILDs (HR 3.17, 95% CI 1.35-7.44, p = 0.008).

CONCLUSIONS

DHEA reduces lung fibrosis and cell proliferation by inducing cell cycle arrest and inhibition of G6PD activity. The association between low DHEAS levels and disease severity suggests a potential prognostic and therapeutic role of DHEAS in fibrotic ILD.