CPAP use after weight-loss surgery

Obstructive sleep apnea (OSA) and obesity are related. Weight loss can improve OSA, sometimes enough to eliminate it altogether. However, if OSA is severe, weight loss alone is often not enough to cure OSA.

Most patients who undergo weight loss surgery have OSA, and most use CPAP prior to weight loss surgery. Unfortunately, most patients discontinue their CPAP use after weight loss surgery. This study assessed long-term CPAP use in 21 patients who had undergone gastric banding. Results showed that body-mass index significantly increased by 6.8 in those patients who did not use their CPAP after weight loss surgery. And BMI dropped by 1.8 in those patients that were adherent to CPAP therapy after weight loss surgery.

Another important point is that OSA persisted in almost all of the patients who underwent the surgery, despite the substantial weight loss (average 121 pounds lost). And, after 7.2 years of follow up, the majority of patients had gained back some weight (22 pounds).

So the data in this study suggest that CPAP adherence for the long term may help with weight loss maintenance. Remember this is a small study though. Other confounding factors could contribute to reasons why some patients chose to keep using CPAP. For instance, some may have continued only because using CPAP made them sleep better or have more energy. And that increased energy could have helped them keep exercising, which may help maintain weight. Or those that kept using CPAP may have adhered better to diet restrictions.

In the end, follow up with the sleep medicine specialist is important after weight loss surgery. In that way, post-operative OSA severity can be assessed after the first year. Then, the patient and sleep medicine physician can discuss the pros and cons of continuing CPAP therapy if necessary.

Weight loss and obstructive sleep apnea

Most people I see already know that obstructive sleep apnea (OSA) is related, at least in part, to elevated weight. Many of my patients start coming to my clinic for help after their OSA symptoms have worsened. Almost all of them report weight gain that occurred as the OSA symptoms worsened. Part of my treatment options, at least for mild to moderate OSA is weight reduction. Easier said than done, however. And if my patient has severe OSA, weight loss alone may not be enough to eliminate their OSA.

This study confirms what I said above. It showed that even moderate weight loss, if maintained, can eliminate mild OSA. The key here is maintaining the weight loss. Many of my patients are able to temporarily drop weight, only to regain it again.

CPAP and weight

Elevated weight contributes to obstructive sleep apnea (OSA). Some studies even suggest that OSA can contribute to elevated weight. Many of my patients know this and hope that they may lose weight by treating their OSA. This study is part of a larger one that examined the effect of CPAP therapy on neurocognitive functioning in patients with OSA. CPAP usage was monitored by the CPAP device - so the researchers knew if the patient was actually using CPAP enough. The researchers randomly assigned participants to either real CPAP or sham (fake) CPAP. The results showed that participants on real CPAP gained weight over six months, whereas those on the sham CPAP lost weight over the same time period. And interestingly, weight gain was greater the more the participant used the real CPAP per night. This effect was not seen in those on the sham CPAP. Finally, the results were independent of age, gender, race, OSA severity, and sleepiness.

Keep in mind that we are talking about small changes in weight - The real CPAP users, on average, gained less than one pound at the six month mark. And the sham CPAP users, on average, lost about 1.5 pounds during the same six months. The study authors do not know the reason for the weight increase in real CPAP users. They postulated that perhaps people with OSA burn more calories when they sleep due to the effects of stopping breathing - and that treating the OSA with real CPAP can mitigate that effect. I'm not sure I buy that argument. More studies will certainly be needed.

Bottom line - CPAP therapy is not a weight loss treatment - if it were, compliance would be much better and I would have a line of people outside my office wanting to get CPAP. But adherence to CPAP therapy is low and CPAP won't make people lose weight. Weight loss is achieved only with dietary change and exercise.

Weight loss in obese type 2 diabetics with obstructive sleep apnea

Obesity, type 2 diabetes, and obstructive sleep apnea (OSA) occur together commonly. Weight reduction has been shown to improve both blood sugar control and OSA severity. There is a study that looked at intensive lifestyle intervention (ILI) versus usual diabetic support (DS) in OSA severity. After one year, the ILI group had greater weight reductions and less severe OSA than the DS group. The researchers then looked at the results after 3 more years, as reported in this paper.

So after the first year, the intensive lifestyle intervention was provided on an individual basis and included one on-site visit per month. There was a second contact by telephone, regular mail, or email. At each session, participants were weighed, self-monitoring records reviewed, and a new lesson presented. The usual diabetes support group had three annual sessions, with each one focusing on diet, physical activity, and social support. Information on behavioral strategies was not presented and participants were not weighed, like in the ILI group.

Results showed that at year 4, >5 times as many participants in the ILI group had total remission of their OSA. The prevalence of severe OSA among ILI group was half that of the diabetes support group. OSA remission occurred in those with mild to moderate OSA at baseline. But in those with severe OSA at baseline, none achieved remission and few changed to mild severity. And in both groups, a similar prportion had a worsening of OSA severity at year 4. Some had mild OSA at baseline and then severe OSA at year 4! A limitation of this study is that almost 38% of participants dropped out by year 4, primarily due to not wanting to repeat PSG.

So what does all this mean? That if you have severe OSA, weight reduction alone is unlikely to get rid of the OSA. However, weight reduction alone may eliminate OSA that is mild to moderate.

Overnight diet claims to lose weight in your sleep

This article is about a new diet book. Ordinarily, I don't post about diet books. This one caught my attention because of it's claim that weight loss is related to sleep. Beware, I am only giving my opinion here about the article. I haven't read the book.

The diet plan consists of 6 days of high protein meals followed by 1 day of liquid meal. Specifics are not given. The book author claims that you will lose two pounds the first night while you sleep. The author also says that you need to get enough sleep, 8 hours, because lack of sleep is what makes you hungry.

If you read the article, there is some criticism about the rapid weight loss. I agree with the statement that the 2 pounds of overnight weight loss is almost entirely water. Basically, this diet is low carb. Of course you will lose weight - but it's mostly water in the beginning. Also, sleep deprivation is not why we get hungry. It's more complicated than that.

Weight loss pill helps reduce obstructive sleep apnea severity

Obstructive sleep apnea (OSA) usually gets worse with weight gain, and better with weight loss. A new, combination medication, Phentermine + Topiramate, has been shown to help in weight reduction. This study evaluated the safety and efficacy of Phentermine + Topiramate compared to placebo for treatment of obese patients with moderate to severe OSA that were unwilling or unable to use CPAP. Both groups received a standardized weight reduction counseling program and the study lasted for 28 weeks.

The results showed that the Phentermine + Topiramate treatment showed significant improvements in sleep apnea severity, subjective sleep quality, weight loss, and systolic blood pressure when compared to placebo. Of note, the placebo group also had a reduction in OSA severity and weight reduction, just not as much as the treatment arm. There were no serious adverse events reported, except one case of kidney stones in a patient who already had a history of them. Topiramate typically causes fatigue, but this was not present, probably due to the stimulating effects of the Phentermine.

Phentermine is an appetite suppressant, and was once used in the combination weight loss medication Fen-Phen. The Fen part, or fenfluramine, was taken off the market because it was associated with heart valve damage. Topiramate is an anti-seizure medication, but has been shown to reduce weight through an unknown mechanism. It's not clear from this study if the combination of the two would be better than Phentermine alone. Also, this study was for 7 months, but what would happen when the medications were discontinued? Or would this have to be a life-long treatment?

Weight loss may improve sleep quality

This article discusses research showing that modest weight loss (about 15 pounds) may improve self-reported sleep quality by 20%. I've seen this happen in my clinic, and the results can be impressive. Researchers think that belly fat may be responsible for sleep disruption, and losing the belly fat may be what helps improve sleep.

Obstructive sleep apnea did not statistically improve with weight loss surgery

Interesting study showing that weight loss from weight loss surgery did not significantly improve obstructive sleep apnea (OSA) severity compared to those on a standard weight loss program. The surgery patients lost more weight and had a greater reduction in OSA severity. But statistically, it was not different. I am not so sure about these results. It seems like the study was underpowered to show a significant effect. My experience is that weight reduction can reduce OSA significantly. I agree that these patients should not assume their OSA is improved just because they have lost weight. It is better to have a repeat sleep study to see if they still have OSA.

Weight Loss Improves Metabolic Parameters and Sleep Disordered Breathing in Children

This article describes findings from a study presented at the American Thoracic Society about how weight loss can improve metabolic markers and sleep disordered breathing in adolescents.