OBSTRUCTIVE SLEEP APNEA AND LONG-TERM FOLLOW UP
In our practice, we developed a sense that all problems resolve after weight loss surgery. I bet if you polled the nurses, the nurse practitioners, office staff, physician assistants and the doctors at Western Bariatric Institute, you would find that through the experience of thousands of patient having undergone weight loss surgery, our clinical staff has come to believe that most health problems fade away and disappear.
This is not hubris; it is just the impression one gets from seeing people in follow up who gradually reduce the number of medications they are on and show up years later looking like an entirely new, and healthier, person. It is very common for people to have been on eight or twelve medications plus CPAP machines for their obstructive sleep apnea, only to return a year or two or three later not only looking like an entirely different person, but also having stopped all their medications and their CPAP.
This impression may be accurate for many people. However, there is some concern among the sleep specialists that obstructive sleep apnea may be a bit more complex disease than we have imagined. In the world of medically supervised weight loss and in bariatric surgery, we tend to view all diseases as being purely weight-related or obesity-related. But that of course is not entirely true.
Around 25% of people with obstructive sleep apnea are not obese. Their risk factors may be more of an anatomic one, having to do with the shape of their mouth and jaw and pharynx. So if a normal weight person has obstructive sleep apnea and then goes on to gain weight, you can imagine that the sleep apnea becomes more severe. Once the weight is lost through bariatric surgery or medically supervised weight loss, the structure of the face and throat has not really changed, so it stands to reason that some degree of obstructive sleep apnea would continue.
As weight loss doctors, we have not taken a highly sophisticated approach to the long-term follow up of obstructive sleep apnea. We probably thought that if the patient reported they were sleeping better and feeling better, and they had lost weight, then what would be the reason for more studies of their sleep?
Well, although there is not much long-term data out there on this question, it may be the case that people with obstructive sleep apnea do need long-term follow up and many of them do need ongoing CPAP. Most of the people who lost weight and kept it off do not need the same level of CPAP. For example, they do not need the pressure settings to be as high as 15 or 18 cm, but rather they can use CPAP more comfortably at 7 or 8 cm. But the big reason to continue with CPAP and to continue visiting the sleep doctors is that independent data shows that untreated sleep apnea carries its own risks of mortality and contributes to other health problems including hypertension and daytime sleepiness.
We see such dramatic resolution of patient’s health conditions like high blood pressure, diabetes and high cholesterol that we naturally lump in obstructive sleep apnea in the same categories and expect its complete and total resolution after weight loss surgery. The truth is probably a bit more complicated. Patients with obstructive sleep apnea undergo weight loss surgery, lose weight and markedly improve or resolve their sleep apnea, but many patients will benefit from ongoing CPAP at lower pressures to avoid the long-term risks and adverse effects of untreated obstructive sleep apnea.
One future study we may undertake at Western Bariatric Institute will be a long-term observation of obstructive sleep apnea over the course of ten years and beyond after their weight loss surgery. This would provide really meaningful data on the need for ongoing sleep studies and titration of CPAP.