Investigating a clinically informed sleep disturbance threshold for physical and mental health among Gulf War Illness veterans

Abstract

Study Objectives This study (a) assessed sleep quality and health in Gulf War veterans (GWV) meeting the Gulf War Illness (GWI) criteria and (b) compared health associations for both those meeting a “clinically disturbed sleep” threshold, and those below, as determined by the Pittsburgh Sleep Quality Index (PSQI) cut-off for military populations (>10) on measures of physical, mental, and cognitive health. Methods Participant data consisted of questionnaires and assessments completed prior to group assignment in a clinical trial. The sample consisted of 147 GWV, where 81.0% were males, and the median age was 53.4 years. Results The mean (SD) PSQI global score was 12.34 (4.00) with 61% of the sample qualifying as clinically disturbed sleepers according to the cut-off (global PSQI > 10). GWI veterans with PSQI scores >10 did not differ from others in age (p = 0.20), sex (p = 0.19), or years of education (p = 0.87), but showed worse GW related symptomology on the Gulf War Kansas questionnaire (p < .01), and poorer mental health on the Veterans Rand-36 (p < .01). Conclusions Disturbed sleep was associated with measures of pain, fatigue, and cognitive health. Our results suggest that a previously determined clinical threshold for clinically disturbed sleep is useful when examining the health status of the study population. Given that Gulf War Illness is associated with elevated PSQI scores and a high frequency of disturbed sleep, cut-offs determining sleep health should be sensitive to population exposures and health history to improve interpretability.