Obesity as a Risk Factor for Swine Flu

indigo girl · Jul 10, 2009

Obese May Be Biggest Losers as Swine Flu, Fat Epidemic Collide

http://www.bloomberg.com/apps/news?pid=20601202&sid=a0DakJmBpgrc

Doctors tracking the pandemic say they see a pattern in hospital reports from Glasgow to Melbourne and from Santiago to New York. People infected with the bug who have a body mass index greater than 40, deemed morbidly obese, suffer respiratory complications that are harder to treat and can be fatal.
With the new virus on a collision course with the obesity epidemic, the World Health Organization says it’s gathering statistics to confirm and understand this development. Drugmaker Roche Holding AG is combing through studies to determine whether heavier people should get bigger doses of its Tamiflu antiviral.
“Morbid obesity is one of the most common findings turning up in severely ill patients,” said Nikki Shindo, who is leading the investigation of swine flu patients at the WHO in Geneva. “It’s a huge problem.”
So far, the evidence is anecdotal. No global or national data have been reported.
No deaths or severely ill patients have been recorded from among the 2,146 laboratory-confirmed cases in Japan, said Yasuyuki Abe, a health ministry spokesman in Tokyo. Only 1.6 percent of adults in Japan are obese, according to the WHO.
“We were surprised by the frequency of obesity among the severe cases that we’ve been tracking,” Anne Schuchat, director of the CDC’s National Center for Immunization and Respiratory Diseases, told reporters on May 19. “If there truly is an increased risk of severe complications on obese patients, it would be important to take steps to attend to that.”
Scientists don’t yet know whether extremely overweight people get sicker because of associated conditions like heart disease and asthma, or whether the excess fat itself makes them more vulnerable. Both may be to blame.
Fat cells secrete chemicals that cause chronic, low-level inflammation that can hamper the body’s immune response and narrow the airways, says Tim Armstrong, a doctor working in the WHO’s chronic diseases department in Geneva.
What’s more, “excess fatty tissue compresses the chest, and the fatty infiltration of the chest wall causes an increase in the pulmonary blood volume,” Armstrong said. Being obese “is associated with a shallower breathing pattern. That all compounds to make it difficult to draw sufficient breath.”
The morbidly obese are also more likely to experience insulin resistance, a condition that makes it harder for doctors to lower the level of sugar in the blood of critically ill patients, said Greet Van den Berghe, head of acute medical sciences at Belgium’s Catholic University of Leuven.

(hat tip Avian Flu Diary)