For obese men, a dramatic weight loss can be an effective way to improve moderate to severe sleep apnea, scientists at Karolinska Institutet in Sweden report. Those with severe sleep apnea when the study began benefited most from weight loss.
But at least one expert questions the long-term benefits of the process.
"Our findings suggest that weight loss may be an effective treatment strategy for sleep apnea in obese men," says Kari Johansson, one of the researchers involved in the study.
Sleep apnea -- the temporary cessation of breathing during sleep -- is a relatively common but under-diagnosed disease. Five or more such events per hour are considered a disease. Untreated, sleep apnea is associated with an increased risk of traffic accidents, as well as stroke and heart disease, for example.
Moderate and severe sleep apnea also increases the risk of premature death. It has long been known that people who are overweight or obese are more likely to develop the disease, and that men are more affected than women.
More than 18 million American adults have sleep apnea, according to the National Sleep Foundation, with the aliment occurring in all age groups and both sexes. It also seems to run in some families, suggesting a possible genetic basis.
In a randomized study published in the British Medical Journal, researchers examined if weight-loss can help to cure moderate and severe sleep apnea. The study included 63 obese men (BMI between 30 and 40) aged between 30 and 65.
The study participants had moderate to severe sleep apnea as measured by the AHI (apnea-hypopnea) index. They also had symptom alleviation treatment through CPAP -- continuous positive airway pressure -- which produces more normal breathing patterns during sleep. The men were randomly assigned to two groups, one of which underwent an intense weight-loss program the other served as a control group, for a period of nine weeks.
The results of the study show that the weight loss group lost 19 kilos (about 40 pounds) on average after nine weeks and reduced the number of apnea events by more than half. None of the treated patients had severe sleep apnea, half had only mild sleep apnea and one in six could be declared healthy. The researchers also noted that the effect of the weight loss program was greatest in patients with severe sleep apnea.
To achieve significant weight loss, the treatment group were put on a very low calorie diet (VLCD), which gave them an initial energy input of 554 calories per day for seven weeks followed by a two-week period's successive increase up to 1,500 calories per day at week nine. The control group maintained their normal dietary habits during the nine-week study period, but was afterwards offered a VLCD program.
After the VLCD period, the participants were also invited to take part in a behavioral change program to help them maintain their weight loss.
"We often use VLCD in the form of a low calorie powder as part of the treatment of obese patients with a serious comorbidity, such as sleep apnea," says Johansson. "The powder is mixed with water and replaces every meal of the day, which gives a rapid loss of weight. It's also a good way of boosting the patients' motivation."
Dr. Barbara Phillips, a board member of the National Sleep Foundation and a sleep apnea expert at the University of Kentucky, calls this a "short-term, drastic approach." Phillips told ConsumerAffairs.com that people who are overweight and suffer from sleep apnea "need to change the way that they eat and the way that they move" for weight loss to have any long-term effect on the ailment.
The study's approach, said Dr. Phillips, is "very exciting. Would I recommend it to my patients? Probably not."
The researchers acknowledge that the VLCD diet is not a general solution to weight problems, but something mainly to be used in the first phase of a long-term treatment program. To keep the weight off, patients need to work hard to improve their dietary and exercise habits, usually with the aid of a long-term behavior modification program. Drugs can also be used in the post-weight loss phase to further improve weight loss maintenance.
Dr. Nancy Collop, an associate professor of medicine at Johns Hopkins University and a former president of the American Board of Sleep Medicine, says that if a person gains weight or becomes obese, he is more likely to develop sleep apnea. But, in an interview with The New York Times, she noted, "There is some debate in the medical community over which comes first, the apnea or the obesity."
Dr. Collop says there is one theory that if you develop sleep apnea, it may change your metabolism or it may make you less active, leading to eventual weight gain. But she adds "we can't answer that question fully until we have more of an understanding of the natural history of the disease."
The current study was funded in part by Cambridge Manufacturing Company Limited, which markets the Cambridge Diet, the low-calorie powder used in the study. Researchers say the company had no influence on the study, the analyses or the collation of the results.
SOURCE: consumersaffairs
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