0600 The moderating effect of comorbid insomnia on the association of obstructive sleep apnea with mood, and with diabetes-related distress in adults with type 2 diabetes

Abstract

Abstract Introduction Previous findings showed that insomnia in persons with type 2 diabetes (T2D) may have a greater impact on mood disturbances than obstructive sleep apnea (OSA) and that insomnia contributed to the severity of diabetes-related distress. This study examined insomnia severity as a moderator of the association between OSA severity with mood, and with diabetes-related distress in adults with OSA and T2D. Methods This secondary analysis used pooled baseline data (N=240) from two independent randomized controlled trials that evaluating the efficacy of OSA and insomnia treatment in persons with T2D. OSA (apnea-hypopnea index [AHI] ≥ 5 events per hour) was determined by in-home ApneaLinkPlus®. Insomnia severity was measured by the Insomnia Severity Index, mood by the Profile of Mood States, and diabetes-related distress by the Problem Areas in Diabetes Scale. Possible moderator effect of insomnia severity was examined using hierarchical multiple linear regression analysis, controlling for demographic characteristics and restless leg syndrome (RLS). Results Participants were middle-aged (mean age ± SD [years] = 57.80 ± 10.17), White (65%), educated post high school (56.3%), evenly distributed by gender (49.6% female) and marital status (47.9%), with 34.3% reporting financial difficulty. Participants had poorly controlled diabetes (mean HbA1c ± SD [%] = 7.93 ± 1.62) and 15.5% reported symptoms of RLS. Insomnia severity had a moderating effect on the association between OSA severity and mood states (b = -.048, p = .017). Insomnia severity had no significant moderating effect on the relationship between OSA severity and diabetes-related distress (b = -.009, p = .458), but independently increased the level of diabetes-related distress (b =1.133, p < .001). Conclusion Insomnia severity moderated the association between OSA severity and mood states in adults with OSA and T2DM. Counterintuitively, as OSA severity increased, the level of mood disturbances decreased depending on insomnia severity. In addition, insomnia was independently associated with diabetes-related distress. These findings suggest that insomnia may be the primary underlying sleep disorder which is associated with psychological factors in persons with T2D. Findings need further investigation because psychological factors are known to be associated with worse glycemic control. Support (If Any) The NIH funded the parent studies (R01-DK0960281; K24-NR016685) and the CTSI grants (UL1-RR024153; UL1-TR000005)