Nutrition Intervention to Promote Immune Recovery From Sleep Restriction

Physical and psychological stress on Warfighters during training and operational missions can suppress immune responsiveness. Skin wound models can be used to detect changes in immune function. Investigators have recently demonstrated that relatively modest sleep disruption degrades immune response at the site of the disrupted skin barrier and delays the initial restoration of the skin barrier. Provision of additional protein and a multi-nutrient beverage during and after sleep restriction seems to mitigate decrements in local immune function, without producing detectable effects on initial restoration of the skin barrier. However, the prior work used a parallel-group study design and inter-subject variability may have made it more difficult to detect significant differences in skin barrier restoration between participants receiving the nutrition intervention versus those receiving the placebo. Therefore, the purpose of the proposed cross-over study is to test the efficacy of a multi-nutrient beverage and additional protein (1.5 g protein per kg body weight versus 0.9 g protein per kg body weight) on immune function and the initial restoration of the skin barrier consequent to an operational stressor (i.e., 72-h sleep restriction). The effect of sleep restriction on a friend-foe marksmanship task, flow state, and measures of cognitive and neuromotor performance, will be investigated as a sub-study (Appendix A). Additionally, the effects of sleep restriction on appetite physiology, eating behaviors and intestinal permeability will be tested. Research will be conducted in a laboratory environment using male and female Soldiers from the human research participant detachment (NSRDEC), or Soldiers or civilians at NSRDEC and/or USARIEM. Participants in the study described herein (n = 20) will be exposed, in a single-blind, cross-over design to a \~72 hour normal sleep control phase, and to 2 periods of \~72 hours of sleep restriction (monitored in laboratory with \~2-h sleep per night) during which time eight blisters will be induced via suction on participant's forearm and the top layer of blisters will be removed to reveal the dermal layer of skin. In the normal sleep trial, participants will consume \~0.9 g protein per kg body weight per day and a placebo beverage during (3 days). In the first sleep restriction trial, participants will consume \~0.9 g protein per kg body weight per day and a placebo beverage during (3 days) and after (5 days) sleep restriction; and, in the second sleep restriction trial (after at least two weeks wash-out) participants will instead consume \~1.5 g protein per kg body weight and a multi-nutrient beverage (arginine: 20 g·d-1, glutamine: 30 g·d-1, zinc sulfate: 24 mg·d-1, vitamin C: 400 mg·d-1, vitamin D3: 800 IU·d-1 and omega-3 fatty acids: 1 g·d-1). Outcome measures include immune function (e.g., circulating markers of inflammation, cytokines at the blister site, and secretory immunoglobin A), skin barrier restoration time (by transepidermal water loss), subjective appetite ratings, appetite-mediating hormone concentrations, food preferences and cravings, gut microbiota composition, and intestinal permeability. Findings from this study will determine if a nutritional intervention attenuates the loss of immune responsiveness to a military relevant stressor (i.e., sleep restriction), and will determine the effects of acute sleep restriction on appetite, gut microbiota composition, and intestinal permeability.