Obesity & Sleep Apnea

Jan. 13, 2016

Did you know obesity is an important risk factor for OSA and weight loss can reduce apnea severity and even lead to resolution in some patients?

Even though obesity usually is not the cause of sleep apnea, it makes the severity of sleep apnea greater. There are different factors that may cause sleep apnea to be more severe in the heavier population such as: increases in neck circumference and fat deposit around the upper airway, increase in upper airway collapsibility and reduction in lung volume (which leads to a loss of caudal traction on the upper airway and an increase in pharyngeal collapsibility).  Obesity and OSA form a vicious cycle where each results in worsening of the other. Obstructive sleep apnea in turn could worsen obesity because of sleep deprivation, daytime somnolence, and disrupted metabolism. It also could increase appetite and caloric intake by changes in hormones such as ghrelin, leptin and orexin.

Let’s look at a few more facts:

• 10% change in body weight is associated with a parallel change of approximately 30% in the apnea-hypopnea index (AHI), which is the major index of sleep apnea severity.
• The chance of that an obese male has sleep apnea is 2-3fold of a female because of the fat distribution in men. Male predominantly have central fat deposition pattern around the neck, trunk and abdominal viscera compare with women.
• Increases in visceral fat with age may also account for an increase in sleep apnea occurrence in middle-aged and older men and in postmenopausal women.

Effective CPAP therapy may lead to weight loss by a few mechanisms such as increased physical activity and increased responsiveness to Leptin.

Talk to your clinical specialist at CanSleep to find out your AHI and if it has changed over the years with aging and gain/loss weight.

By Bahareh Ezzati (BSc, CPhT, RRT)