Obesity and Sleep Apnea Syndrome

Have you ever wondered why patients with Obstructive Sleep Apnea (OSA) may also be overweight?  OSA is present in approximately 40% of obese individuals and about 70% of OSA patients are obese.  Could it because their sleep is fragmented frequently at night due to upper airway collapse causing the brain to ‘arouse’ to breath thus causing daytime sleepiness?  Maybe?  Or are there other mechanisms behind this?

Frequent sleep fragmentation due to OSA as well as sleep restriction disturbs many processes in the body.   In particular, levels of our hunger hormone (ghrelin) increases.   Increased ghrelin levels will stimulate appetite.  In addition, levels of leptin (a protein produced in fat cells) decrease.  The primary function of leptin is to send a signal to the brain when you are full.    Since leptin levels are low, the brain will not get the signal that you are full.  This will cause you to eat more.  These 2 processes working against each other will lead to obesity.

The good news is that effective treatment with Positive Airway Pressure (PAP) will normalize these levels.