Circadian cortisol and fatigue severity in relapsing-remitting multiple sclerosis

TY - JOUR

T1 - Circadian cortisol and fatigue severity in relapsing-remitting multiple sclerosis

AU - Powell, Daniel J. H.

AU - Moss-Morris, Rona

AU - Liossi, Christina

AU - Schlotz, Wolff

N1 - Acknowledgments The preparation of this manuscript was supported by an Economic and Social Research Council PhD studentship (Ref: ES/1026266/1) awarded to Daniel Powell, and the funding for the study was provided by the Psychology Unit at the University of Southampton. We acknowledge Dr Matthew Jones who programmed the handheld EMA software, and Ms Chelsea Lane who assisted with London-based introductory sessions. We also thank Dr Victoria Williams, Ms Carrie Day, and Ms Lesley Kempson for their support with participant recruitment.

PY - 2015/6

Y1 - 2015/6

N2 - Cortisol is a key regulator of the immune system, energy metabolism, and stress, yet its relevance to fatigue experienced by people with relapsing-remitting multiple sclerosis (RRMS) remains uncertain. We examined cortisol secretory activity in RRMS and its association with fatigue severity between-individuals and within-individuals (day-to-day) using a case-control ecological momentary assessment design. Whilst undergoing usual daily routines, 38 people with RRMS and 38 healthy control participants provided saliva samples at strategic time-points over 4 consecutive weekdays to measure the cortisol awakening response (CAR; 0, 30 ,and 45 min after awakening) and the diurnal cortisol slope (DCS; 6 quasi-random samples provided between 1000h and 2000h). Recalled fatigue was measured at baseline, and daily fatigue was measured as the mean average of momentary fatigue ratings provided alongside each DCS sample. Multilevel modelling found CAR output was greater in RRMS than controls, and recalled fatigue in RRMS was associated with both lower waking cortisol level and larger awakening response. Day-to-day, the CAR was not associated with same-day fatigue levels in RRMS. Cortisol appears to have a role in fatigue experienced in RRMS, but whether it is a causal factor remains unclear.

AB - Cortisol is a key regulator of the immune system, energy metabolism, and stress, yet its relevance to fatigue experienced by people with relapsing-remitting multiple sclerosis (RRMS) remains uncertain. We examined cortisol secretory activity in RRMS and its association with fatigue severity between-individuals and within-individuals (day-to-day) using a case-control ecological momentary assessment design. Whilst undergoing usual daily routines, 38 people with RRMS and 38 healthy control participants provided saliva samples at strategic time-points over 4 consecutive weekdays to measure the cortisol awakening response (CAR; 0, 30 ,and 45 min after awakening) and the diurnal cortisol slope (DCS; 6 quasi-random samples provided between 1000h and 2000h). Recalled fatigue was measured at baseline, and daily fatigue was measured as the mean average of momentary fatigue ratings provided alongside each DCS sample. Multilevel modelling found CAR output was greater in RRMS than controls, and recalled fatigue in RRMS was associated with both lower waking cortisol level and larger awakening response. Day-to-day, the CAR was not associated with same-day fatigue levels in RRMS. Cortisol appears to have a role in fatigue experienced in RRMS, but whether it is a causal factor remains unclear.

KW - Multiple sclerosis

KW - Fatigue

KW - Cortisol

KW - Hypothalamic-Pituitary-Adrenal Axis

U2 - 10.1016/j.psyneuen.2015.03.010

DO - 10.1016/j.psyneuen.2015.03.010

M3 - Article

VL - 56

SP - 120

EP - 131

JO - Psychoneuroendocrinology

JF - Psychoneuroendocrinology

SN - 0306-4530

ER -