“…Although well investigated, the effects of sleep deprivation on cortisol, a hypothalamic–pituitary–adrenal (HPA) axis marker, and C-reactive protein (CRP), an inflammatory marker, remain inconsistent: some studies report no change in cortisol ( Vgontzas et al, 2004 ; Frey et al, 2007 ; van Leeuwen et al, 2009 ; Pejovic et al, 2013 ; Honma et al, 2020 ) or CRP ( Faraut et al, 2011 ; Irwin et al, 2016 ; Choshen-Hillel et al, 2021 ), while others report decreases in cortisol ( Åkerstedt et al, 1980 ) or CRP ( Frey et al, 2007 ; Baek et al, 2020 ), or increases in cortisol ( Leproult et al, 1997 ; Wright et al, 2015 ; Baek et al, 2020 ; Choshen-Hillel et al, 2021 ; Lamon et al, 2021 ) or CRP ( Meier-Ewert et al, 2004 ; van Leeuwen et al, 2009 ). Similarly, studies have found that both acute and prolonged stress increase cortisol ( Jönsson et al, 2010 ; Allen et al, 2014 ) and CRP ( Eraly et al, 2014 ; Kennedy et al, 2014 ), although other studies reported no change in CRP ( La Fratta et al, 2018 ; Szabo et al, 2020 ).…”