An increased BMI or obesity are both important risk factors for obstructive sleep apnea (OSA) and weight loss can decrease the apnea severity or in some instances even lead to the resolution of OSA in some patients. Excessive body fat has the ability to narrow the upper airway, making it more prone to collapsing and resulting in the block of airflow. Factors such as BMI, neck circumference, and the size of the retroglossal space are considered to be primary determinants of OSA in obese individuals.
While obesity is a known cause of OSA, it may also be a result of the disorder. For example, a person who experiences daytime sleepiness may be less active and therefore at greater risk for weight gain. Physicians will demonstrate the importance of an active weight loss plan, as many patients may believe that treatment of OSA with CPAP alone will lead to weight loss. Although CPAP can improve quality of sleep for those with OSA, patients may not increase activity levels and caloric expenditure beyond energy intake. A portion of OSA patients are obese when diagnosed, meaning that weight management may be difficult for this group and patients must take an active role in weight loss plans and use improved daytime alertness to their advantage to shift the balance of energy intake and energy expenditure.
References:
Redenius R; Murphy C; O’Neill E; Hamwi MA; Zallek SN. Does CPAP lead to change in
BMI? Retrieved from: J Clin Sleep Med 2008;4(3):205-209.
