Sleep improvement for metabolic health: A feasibility trial of a digital sleep treatment in people with insomnia and non-diabetic hyperglycaemia

Insomnia may play a causal role in type 2 diabetes (T2D). Addressing insomnia through cognitive behavioural therapy (CBTi) in people with non-diabetic hyperglycaemia could potentially reduce the risk of progression to T2D. To inform a future randomised trial, we performed a feasibility study of digital CBT (dCBTi) in individuals at increased risk of T2D. Participants were identified from ten primary care practices in the UK and given access to dCBTi. Outcomes were evaluated at baseline (week-0) and post-treatment (week-11). Primary feasibility outcomes were ability to recruit and treatment engagement. We also quantified within-group mean change (95%CI) in insomnia severity (Insomnia Severity Index), health-related quality of life (EQ-5D-3L), depression (Center for Epidemiologic Studies Depression Scale), chronotype (reduced Morningness-Eveningness Questionnaire), sleep (7-day actigraphy and diary), continuous glucose monitoring (7-days) and fasting blood metabolites (insulin, lipids, glucose, and C-reactive protein). The recruitment target was 20. Of 242 people completing screening, 36 were eligible, and 24 were enrolled (age 65.5±12.4 years, 70.8% female). Twenty-three (96%) completed post-intervention assessments. Treatment engagement was excellent (83.3% completed ≥4 sessions). The intervention was associated with a large reduction in insomnia severity [−4.7(95%CI:−6.2 to −3.2), d =−1.4] and medium reduction in depressive symptoms [−2.7(95%CI:−5.1 to −0.2), d =−0.5]. Sleep diary parameters tended to show greater improvement following intervention relative to actigraphy. There was evidence of a reduction in serum lactate, glycerol and triglycerides but no clear change in glucose or insulin. Results suggest a full trial is likely feasible and that people with NDH find the intervention acceptable and beneficial.