0363 Insomnia with Short Sleep Duration Is Associated with Increased Catecholamine Secretion in Young Adults

Abstract Introduction Prior studies have shown insomnia to be associated with increased sympatho-adrenal-medullary (SAM) axis activity, as indexed by higher 24-hour urinary catecholamine secretion. These studies also showed that the activity of both axis of the stress system in those with insomnia is positively related to the degree of polysomnography (PSG)-measured sleep disturbance, ascertained by four consecutive nights. However, these pathophysiologic findings have not been replicated in population-based samples. Methods We studied 270 young adults (median 25y, 53% female, 24% racial/ethnic minority) from the Penn State Child Cohort who underwent a 9-hour PSG recording, clinical history, self-report scales and provided a urine sample upon awakening from the PSG to assay for 8-hour release of catecholamines (i.e., epinephrine, norepinephrine, and dopamine). Insomnia symptoms were defined as difficulties initiating or maintaining sleep, insomnia diagnosis or complaint, and/or sleep medication use. PSG-measured short sleep duration was defined by the median total sleep time of the sample (i.e., < 7-h), and identified normal sleep duration (NSD), short sleep duration (SSD), insomnia with normal sleep duration (INSD) and insomnia with short sleep duration (ISSD). A multivariate general linear model tested mean differences in catecholamine levels across the four groups while adjusting for sex, race/ethnicity, age, waist circumference, sleep apnea, cardiometabolic disorders, medication and substance use. Results Compared to NSD (18.8±1.5) and INSD (20.9±1.1), ISSD showed significantly higher total epinephrine/norepinephrine levels (24.0±1.1; p=0.007 and p=0.046, respectively). This association was primarily driven by higher norepinephrine levels in ISSD (3.1±0.3) compared to NSD (2.2±0.5; p=0.018). Neither INSD (p=0.260) nor SSD (21.4±1.7; p=0.255) showed significantly elevated levels compared to NSD. There were no significant differences in dopamine levels across groups [e.g., NSD (238.1±10.8) vs. ISSD (241.6±7.6); p =0.809]. Conclusion ISSD, but not INSD, is associated with higher morning norepinephrine levels, suggesting hyperactivity of the SAM axis of the stress system and increased risk for cardiovascular and psychiatric disorders. Support (if any) NIH (R01HL136587, R01MH118308, UL1TR00127)