Relationship between obstructive sleep apnea and diurnal leptin rhythms

Area of Science:

• Endocrinology
• Sleep Medicine
• Metabolic Research

Background:

• Obstructive sleep apnea (OSA) is a prevalent condition associated with metabolic disturbances.
• Leptin, a hormone regulating satiety and body weight, has been implicated in OSA.
• Previous studies suggest a link between OSA and leptin levels, but the dynamics of this relationship require further investigation.

Purpose of the Study:

• To evaluate the relationship between obstructive sleep apnea and serum leptin levels.
• To assess the association of the overnight change in leptin levels with the severity of sleep apnea.

Main Methods:

• Cross-sectional analysis of data from a prospective cohort study.
• Inclusion of 138 participants from the Cleveland Family Study with varying apnea-hypopnea index (AHI) values.
• Measurement of serum leptin levels in the evening and morning.

Main Results:

• Serum leptin levels in the evening and morning were positively correlated with AHI, but this association was attenuated after adjusting for body mass index.
• The evening/morning leptin ratio was independently associated with AHI, irrespective of age, sex, race, body mass index, and waist-hip ratio.
• A higher AHI (>15) was associated with a significant increase in the leptin ratio, indicating a stronger relationship than other sleep parameters.

Conclusions:

• Findings suggest that obstructive sleep apnea may suppress morning leptin secretion.
• Alternatively, elevated evening leptin levels in individuals with OSA might contribute to the pathogenesis of the condition.
• The overnight dynamic of leptin secretion is a significant factor related to OSA severity.