The Relationship Between Actigraphy and Continuous Glucose Monitoring in Youth with Cystic Fibrosis

Science Center, Bent Corridor

Disrupted sleep is associated with insulin resistance and poor diabetes control in type 1 and type 2 diabetes. Cystic fibrosis (CF) youth demonstrate decreased sleep quality and worse glucose tolerance than healthy individuals, but the association between sleep and glycemia in CF is not well studied. We examined the association between actigraphy variables and glycemic status, measured by continuous glucose monitoring (CGM) and fasting estimates of insulin sensitivity, in youth with CF. CF youth and healthy controls (HC) wore an Actiwatch for 7 days concurrently with CGM and completed daily sleep and food logs. CF participants were classified by oral glucose tolerance testing (OGTT) standards. Two-sample independent t-tests tested the association between actigraphy and CGM outcomes in CF vs controls. Spearman’s correlation coefficients tested associations between actigraphy and CGM outcomes as well as insulin sensitivity (IS) estimates in the CF cohort. Significance was set at p<0.05. CF youth demonstrated greater sleep onset latency, wake after sleep onset (WASO), and lower sleep efficiency compared to HC. CF youth had higher average glucose, standard deviation, peak glucose, time over 140 and 200 mg/dL, and time under 60 mg/dL compared to HC. In the CF cohort, higher day minimum glucose correlated negatively with total sleep time and efficiency. No other correlations between CGM and actigraphy outcomes were noted in the overall CF cohort. There were not significant correlations between IS estimates and CF youth overall. CF youth had greater disrupted sleep than HC, reflected by greater onset latency, more WASO, and lower sleep efficiency. Associations between higher minimum sensor glucoses and decreased sleep time and efficiency were noted. CF youth with dysglycemia had IS correlated with greater sleep time and efficiency, shorter onset latency, and fewer WASO. Future studies may investigate the directionality and mechanisms behind the sleep and glycemia/IS relationship with CF.