The association between sleep quality and cognitive function in patients with non-functioning pituitary adenoma

Cortisol and growth hormone are important for sleep regulation and cognition. Sleep is critical for cognitive functioning and memory consolidation. Patients with pituitary disease experience hormonal dysregulation, impaired sleep quality, and cognitive dysfunction. We wished to examine the relationship between objective sleep and cognitive functioning in patients with pituitary adenomas.

Ten patients with non-functioning pituitary adenomas (NFPA) and ten healthy controls were assessed using a crossover design. Each participant was administered standardised neuropsychological tests (Wechsler logical memory test (LMT) and finger tapping task (FTT)) assessing declarative and procedural memory performance after a period of sleep and after an equivalent period of wakefulness. Objective sleep data were elicited, and the Pittsburgh Sleep Diary captured self-reported sleep data.

Controls performed better than patients with NFPA on retention on the LMT (P = 0.027). Objective measures of sleep quality revealed no between-group differences, whereas controls reported better subjective sleep quality (P = 0.016) and being more alert when awake (P = 0.015) than patients. Generally, sleep was not related to cognition in either group.

Patients demonstrated poorer performance on declarative memory tasks, but not poorer sleep. Interventions for memory rehabilitation may assist their capacity to complete other important daily activities.