Bariatric Surgery and Sleep Apnea
Bariatric surgery includes procedures designed to reduce oral intake, and thus help patients reduce weight. These are the “gastroplasties” or “banding” you may have heard about on health programs. These procedures are designed to make your stomach smaller. People will end up taking smaller meals and in doing so lose weight.
The success rates with bariatric surgery are usually quite good, as long as the patient is motivated to follow all the directions afterwards. Unfortunately, you can “cheat” the beneficial effects of a smaller stomach by loading it with high calorie intake (such as juices, ice cream, gravies, creamy soups). Most of the relapses in weight occur when patients who initially had good success end up finding new ways to get around the smaller stomach. Surgeons and follow up staff will try to work with patients to avoid this relapse.
Post-Bariatric Surgery and Sleep Apnea
Studies have been done looking at the effects of bariatric surgery on sleep apnea. Most of the people on a waitlist for bariatric surgery who get tested for sleep apnea end up testing positive for sleep apnea (80% positive scores vs 20% negative for sleep apnea). If someone you know is on a waitlist for bariatric surgery and they have not been tested for OSA, it is a good idea to find out if they have it. Problems can arise in surgery, and having the diagnosis of OSA in advance can be beneficial.
One year after surgery, the average body mass index (BMI – a determinant of healthy weight) has dropped from 51 (normal range 21-25), down to 32. For the average 5 foot 8 inch person, that is a loss of close to 120 pounds. That is a success!
Studies have been done to show the effects of bariatric surgery on the severity of sleep apnea. Patients on waitlist for bariatric surgery will have a severe sleep apnea, obstructing 47 times per hour on average (normal range 0-5 events per hour). One year after successful surgery, their obstructive index has dropped from 47 events per hour to about 24 events per hour on average. That has dropped them from severe to moderate sleep apnea; however, sleep apnea is still present. Those using CPAP before surgery will require less pressure after weight loss, as there is less restriction of the airway.
It is possible for someone to lose enough weight to eliminate the need for CPAP therapy, however this is not the norm. Once bariatric surgery and weight loss is completed, a repeat sleep study should be completed to assess severity and CPAP necessity.
Lettieri CJ; et al. Persistence of obstructive sleep apnea after surgical weight loss. J Clin Sleep Med 2008;4(4):333-338.
Khan A; et al. Assessment of obstructive sleep apnea in adults undergoing bariatric surgery in the Longitudinal Assessment of Bariatric Surgery-2 (LABS-2) study. J Clin Sleep Med 2013;9(1):21-29.