787 OSA Risk is Associated with Number of White Matter Hyperintensities, But History of Mild TBI is Not: A LIMBIC-CENC Study

Introduction Individuals with a history of mild traumatic brain injury (mTBI) have higher risk levels for obstructive sleep apnea (OSA). However, no studies have examined the association between OSA and white matter hyperintensities (WMHs) in this group. The purpose of this study is to explore the relationship between OSA risk, mTBI, and WMHs in a military cohort with a history of combat deployment. Methods Secondary analyses were conducted from a large clinical database of a multi-center, longitudinal study of current and former military personnel. Participants were included who had complete STOPBANG (sleep apnea risk) data and MRI. Univariable and multivariable regressions were conducted, including age, race, gender, education, hypertension, diabetes, history of mTBI, and STOPBANG score in the models. Results The final sample (N=1017) included participants with (n=823) and without (n=194) a history of mTBI. The sample was predominantly male (87%) with a median age of 38 (IQR; 32–48). WMHs were reported in 37% of the sample. Univariate analyses revealed that increasing age, female sex, hypertension, diabetes, and higher sleep apnea risk score were each positively associated with higher number of WMHs, while a history of lifetime mTBI exposure was not associated. Multivariable analyses revealed that of these factors, only age remained associated with WMH presence. When restricting the sample to the 37% with WMHs, OSA risk and female sex were each associated with higher number of WMHs (p Conclusion Consistent with the literature in non-brain injured populations, age was the strongest predictor of WMH presence and number. In those with identified WMHs, OSA risk was a significant predictor of WMH number, while history of mTBI was not. Thus, in persons with mTBI, presence of WMHs may be linked to sleep comorbidities, providing potential treatment targets. Limitations include assessment of OSA rather than established diagnosis. Support (if any) Defense and Veterans Brain Injury Center (HT0014-19-C-004), DOD(W81XWH-13-2-0095), VA(I01 CX001135). The views expressed in this abstract are those of the authors and do not necessarily represent the official policy or position of the Defense Health Agency, Department of Defense, or any other U.S. government agency. For more information, please contact dha.TBICoEinfo@mail.mil. UNCLASSIFIED