Impaired breathing in obese tied to big waist

NEW YORK, Feb 17 (Reuters) Morbidly obese men tend to have more breathing difficulties than morbidly obese women, partly because they have much larger waistlines, a new study suggests.

Dr. Gerald S Zavorsky from McGill University Health Center, Montreal, and colleagues examined the effect of the so-called ''waist-to-hip ratio'' on breathing in 25 morbidly obese adults scheduled for bariatric (stomach) surgery.

As the name implies, the waist-to-hip ratio is a calculation of a person's waist circumference divided by their hip circumference. People with a high ratio have an ''apple-shaped body,'' whereas people with a low ratio have a ''pear-shaped body.'' The investigators noticed that the men who were morbidly obese, defined as a body mass index (BMI) greater or equal to 40, had a larger waist-to-hip ratio compared with the morbidly obese women. ''This shows that men tend to have more of an apple shape and women more of a pear shape,'' Zavorsky noted in comments to Reuters Health.

Men also tended to have poorer ''pulmonary gas exchange'' compared with women. Because of the larger waistlines in men, ''the oxygenation of their blood is lower and the impairment of oxygen transfer is higher,'' Zavorsky explained.

''What this means,'' he said, ''is that those who are apple shaped may have a more difficult time breathing due to a large waist circumference pressing the lungs.'' Due to their higher waist-to-hip ratio, the complication rate of bariatric surgery may be higher in men compared to women, a hypothesis that Zavorsky and his team plans to further explore.

REUTERS BDP HS0907