Leptin moderates the relationship between sleep quality and memory function: A population-based study

Area of Science:

• Neuroscience
• Sleep Science
• Metabolic Health

Background:

• Sleep is vital for memory encoding, consolidation, storage, and retrieval.
• Leptin, an appetite-regulating hormone, influences neuroplasticity and memory processes, particularly in the hippocampus.
• Existing research suggests a connection between sleep, memory, and leptin, necessitating further investigation into their interplay.

Purpose of the Study:

• To investigate the relationship between subjective sleep quality, memory complaints, and leptin levels.
• To explore the mediating and moderating roles of leptin in the association between sleep quality and memory function.

Main Methods:

• Analysis of data from 881 participants in the São Paulo Epidemiologic Sleep Study (EPISONO) 2007.
• Assessment of subjective sleep quality using the Pittsburgh Sleep Quality Index.
• Evaluation of memory function with the Prospective and Retrospective Memory Questionnaire, alongside measurements of body mass index and plasma leptin levels.

Main Results:

• Poor sleep quality was associated with increased memory complaints.
• Individuals with more memory complaints exhibited higher leptin levels, but leptin levels were not directly associated with sleep quality.
• Leptin did not act as a mediator but moderated the relationship, enhancing the positive effect of sleep quality on memory.

Conclusions:

• Sleep quality directly impacts memory function.
• Leptin plays a moderating role, amplifying the beneficial effects of sleep on memory, highlighting the complex interaction between sleep, memory, and metabolic factors.