Will losing weight help?

The answer is yes! And the question, is invariably raised by patients at the sleep laboratory that are having a cpap implementation study after diagnosis of obstructive sleep apnoea.

It is a terrible cycle. We know that being overweight or obese increases the chances of having OSA and that losing weight can help but losing the weight is not always that easy when excessive levels of sleepiness are in play due to the OSA (hence the cycle).

It is always fantastic when a patient returns for a repeat diagnostic sleep study to see if their AHI has decreased after a significant weight loss. Some do it over time with diet and exercise and some undergo bariatric surgery.

A study on Polysomnography before and after weight loss in obese patients with severe osa demonstrated there was a decrease in the AHI with a decrease in BMI.

The subjects in this study all had laparoscopic adjustable gastric banding (LAGB) and prior to surgery all had severe OSA. Researchers also measured daytime sleepiness, the metabolic syndrome and quality of life (QOL) pre and post. Baseline BMI was 52.7kg/m(2).

The second PSG was conducted on average of 17.7+/-10 months after surgery and mean percentage of excess loss and weight loss were 50.1+/-15% and 44.9+/-22 kg (range 18-103 kg), respectively.

The AHI fell significantly from 61.6+/-34 to 13.4+/-13, improved sleep architecture was present with increased REM and stage 3 and 4 sleep. Daytime sleepiness, measured by Epworth Sleepiness Scale, also dropped from 13+/-7.0 to 3.8+/-3.0.

Weight can be a tricky subject to deal with but whenever faced with this question by a patient with a BMI in the overweight or obese category the answer is YES losing weight will help.

Jessica

nb: I have been asked to explain what AHI stands for. It is Apnoea Hypopnea Index that is used to assess the severity of OSA. The number of apnoeas and hypopneas per night are added up and divided by the hours of sleep. This gives a per hour score. Under 5 is normal, 5-15 is mild, 15-30 is moderate and over 30 is classified as severe.