Description

The goal of this proposal is to explore the feasibility of, and potential for, dietary supplementation with branched chain amino acids (BCAAs) to effect sleep quality and cognitive function in Veterans. The BCAAs (Leucine, Isoleucine, and Valine) cannot be synthesized endogenously (i.e., they must be obtained through the diet) and are the precursors to >50% of de novo glutamate and GABA synthesis in the brain, which are the primary excitatory and inhibitory neurotransmitters, respectively. Preclinical evidence strongly suggests that dietary BCAA supplementation restores normal sleep-wake patterns and cognitive function following TBI through a restoration in the global cortical excitation:inhibition ratio. BCAA supplementation has been studied extensively in healthy humans and in a variety of disease states, including following TBI, but not yet in Veterans in the chronic phase of recovery from TBI. BCAAs are a commercially available dietary supplement and very well tolerated with minimal side-effects.

Subjects will be randomized in a double-blind fashion through the VA Research Pharmacy to one of three groups: 1) BCAA; 60 g/day in two 30 g doses, 2) rice protein; 60 g/day in two 30 g doses, and 3) placebo; 60 g microcrystalline cellulose in two 30 g doses. BCAA and placebo will be prepared by the VA Research Pharmacy and dispensed in a blinded fashion to Veterans after demonstrating informed consent. Following a ~4-week period of baseline, Veterans will be instructed to consume study product after waking and ~6 hours later, on an empty stomach for a period of up to 21-days. Self-report questionnaires assessing sleep quality, cognitive function, trauma-related symptom severity, and other measures of mental and physical well-being will be administered before and after the experimental period. Wrist actigraphy will be continuously collected over the baseline and the experimental period. Cognitive function will be assessed before and after the experimental period using an established battery of neuropsychological tests (i.e., selected tests from WAIS, D-KEFS, HVLT, COWAT, among others. Pressure pain testing will be conducted before and after the experimental period.