Sleep Time Irregularity Is Associated With Lower Vascular Function In Young Adults With Generalized Anxiety Disorder

Generalized anxiety disorder (GAD) and sleep dysfunction, two independent risk factors for CVD development, are commonly linked. It is currently unclear if sleep dysfunction, when observed in individuals with GAD, has a compounding effect on CVD risk evident by peripheral vascular dysfunction, a common precursor to CVD development. Purpose: The purpose of this study is to identify if lower sleep quality or regularity is associated with lower vascular function in young adults with GAD. Methods: Sleep data was objectively obtained from twenty-eight young, healthy adults (24 ± 4 yrs; 24 F / 4 M) with a prior diagnosis of GAD or symptoms of GAD (GAD7 score > 10) across 7 days via wrist-worn accelerometry. Participants completed 3 minutes of rhythmic handgrip exercise at 50% of their predetermined maximal voluntary contraction (MVC). Baseline and steady state (last minute of handgrip exercise) brachial artery (BA) diameter and shear rate was obtained via ultrasonography. Pearson product correlations were employed to determine relationships between sleep quality (total sleep time (TST), sleep efficiency (SE)), sleep regularity (7-day standard deviation (SD) of TST and SE values), and BA flow mediated dilation (FMD) normalized for BA shear rate values. Results: Total sleep time regularity was revealed to be significantly correlated (r = -0.45; p = 0.02) to BA dilation when normalized for BA shear rate. A median split (TST SD = 68 minutes) utilized to separate subjects into “Low TST” (n = 14; TST SD: 46 ± 11 minutes) and “High TST” (n = 14; TST SD: 89 ± 18 minutes) groups revealed that BA FMD was significantly lower (p < 0.01) in the “Low TST” group (2.5 ± 3.4%) when compared to the “High TST” group (6.2 ± 2.4%). No significant correlations between other sleep outcomes (TST, SE, or SE SD) and BA dilation were observed. Conclusion: This study revealed that sleep time irregularity in young adults with GAD was associated with lower vascular function potentially highlighting sleep regularity as a therapeutic target to reduce CVD risk in this population.