Intraindividual Cortisol Variability and Psychological Functioning in Caregivers of Hematopoietic Stem Cell Transplant Patients

Abstract

Objective Caregiving for allogenic hematopoietic stem cell transplant patients (Allo-HSCT) carries a significant psychological burden yet it remains unclear whether Allo-HSCT caregivers demonstrate disruptions to stress systems, such as hypothalamic pituitary adrenal axis. Greater intraindividual cortisol variability (ICV) has been observed in psychiatric disorders; however, there is a knowledge gap evaluating ICV in caregivers. We predicted greater ICV would be related to poorer mental health in Allo-HSCT caregivers. Methods Allo-HSCT caregivers (n=140) collected saliva for 3 consecutive days at 4 time points/day. Psychological variables included sleep quality and a summary composite score of overall mental health. Results Regression analyses demonstrated that greater ICV was significantly related to poorer overall mental health (β = .25; p = .009), while poorer sleep did not reach significance (β = .16; p = .069). No significant relationships emerged for the cortisol area under the curve, diurnal decline or awakening response. Conclusions Results extend prior work examining ICV as a unique marker that is possibly more sensitive than other widely applied measures of HPA-axis dysregulation to a distressed population of caregivers.

Latent virus reactivation in astronauts on the international space station

“…5) is similar to dysregulation associated with psychosocial challenges such as chronic caregiving stress, 23, 24 early trauma, 25 and breast cancer. 26 Herein with longitudinal sampling during the course of extended space flight, there were indications of disruption in cortisol levels reflected by a higher diurnal level at mid-day.…”

Sleep Inconsistency and Markers of Inflammation

“…Evidence suggests sleep inconsistency may provide unique information beyond that of average sleep (5). The importance of sleep inconsistency highlighted by previous studies mirrors a broader trend in medical research recognizing that the presence of individual-level variation in behavior and cognitive functioning may reflect impaired physiologic systems and brain processes (6)(7)(8)(9). Likewise, sleep inconsistency may represent an underlying collection of dysfunction in biological systems involved in sleep-wake regulation, dysfunction that may be missed by only examining average sleep.…”

Intraindividual variability in cortisol: Approaches, illustrations, and recommendations

“…Cortisol has both levels of IIV – structured, slope cIIV and unstructured, net cIIV – and the iSD of all measurements does not discriminate between these two levels. One way to isolate net cIIV is to remove variance due to the diurnal slope (i.e., detrend within day) by regressing cortisol levels on time of day and taking the iSD of the residuals (Marceau et al, 2013; Sannes et al, 2016; Wang, Hamaker, & Bergeman, 2012). When applied within each day (i.e., detrending by clock time), the iSD of the residuals reflects net cIIV and excludes slope cIIV.…”

“…cIIV is a promising direction for research; indeed, that research has already yielded interesting results (Marceau et al, 2013; Peeters et al, 2004; Sannes et al, 2016). In the present paper, the substantive result for the law students suggests that people higher in neuroticism had less variable slopes.…”

“…Outpatients with major depressive disorder had a lower autocorrelation between cortisol observations (indicating higher cIIV) than did healthy controls (Peeters, Nicholson, & Berkhof, 2004). After fitting models predicting cortisol from time of day, the standard deviation of the residuals was higher (indicating higher cIIV) among caregivers who had poorer psychological health and among adopted children whose adoptive mothers engaged in more overreactive parenting (Marceau et al, 2013; Sannes, Mikulich-Gilbertson, Natvig, & Laudenslager, 2016). Similarly, depressed patients had higher residual error around the circadian rhythm, compared with controls and PTSD patients (Yehuda et al, 1996).…”