Higher fasting brain glucose is associated with lower gray matter volume in healthy adults.

Cystic fibrosis–related diabetes (CFRD) is a highly prevalent comorbidity of cystic fibrosis (CF) affecting up to half of adults with CF and increasing morbidity and mortality.[,] CFRD is characterized by progressive insulin insufficiency caused primarily by damage to the pancreas, leading to fluctuating glucose excursions. As hyperglycemia in CF has been linked to adverse clinical outcomes, a key priority in CFRD is to identify strategies for optimizing glycemia.[] Factors recognized to exacerbate hyperglycemia in CFRD include infection, inflammation, corticosteroid use, and nutritional interventions, but others may exist.[,] Current management of CFRD primarily relies on insulin therapy, with nutritional management and exercise also recommended.[] However, sleep is not currently emphasized as a modifiable behavioral target in CFRD care, despite growing evidence linking poor sleep with adverse glycemic outcomes in other forms of diabetes.[,] Sleep disturbance is a well-recognized but underappreciated complication of CF and may be particularly relevant in individuals with CFRD.[,] In the general population, sleep is essential for cognitive performance, emotional regulation, and overall well-being, but also plays a central role in metabolic regulation.[–] Sleep is a fundamental regulator of metabolism by synchronizing neuroendocrine signaling, insulin sensitivity, and appetite control.[,] In the general population, insufficient and disrupted sleep are associated with impaired glucose tolerance, increased insulin resistance, and greater glycemic variability, whereas adequate and quality sleep are linked to improved glycemic control.[–] It is therefore plausible that poor sleep may contribute to dysglycemia in CFRD. Persons with CF (PwCF) often report poor sleep due to nocturnal cough, dyspnea, gastroesophageal reflux, abdominal pain, anxiety, and the burden of nighttime treatments (e.g., airway clearance and medications).[,,] In adolescents with CF, shorter and fragmented sleep has been associated with higher glucose levels and reduced insulin sensitivity.[] These preliminary findings suggest that sleep may be a modifiable behavior in achieving and maintaining normoglycemia in adults with CFRD.