We’re learning as we go with this new flu.
We already know how it attacks young children and pregnant women. But a study released today of the first 16 weeks of the H1N1 swine flu now shows a new, highly vulnerable population: People who are very overweight.
A study by the California Pandemic Working Group that appears in today’s Journal of the American Medical Association compiled numbers from the California department of Public Health and 61 of the state’s local health departments between April 23 and Aug. 11.
The research studied 1,088 people who were hospitalized or died from the swine flu in California between those dates. Of those for whom body mass index (BMI) information was available, more than 50% were obese and about 25% were morbidly obese. That’s way out of proportion to our normal population – in society, only 4% to 5% of us are morbidly obese.
Why is this so?
Experts aren’t yet sure, and the Centers for Disease Control want even more study. But some believe that carrying the extra weight makes a person more vulnerable to breathing problems or respiratory complications. The most common causes of death in the California patients were viral pneumonia and acute respiratory distress syndrome.
And of course, we already know that obesity makes us much more vulnerable to other underlying conditions – lung disease, heart disease, diabetes – that can make it harder for us to fight off this virulent flu.
"It makes intuitive sense," Dr. Thomas R. Frieden, director of the Centers for Disease Control and Prevention, told the Los Angeles Times. He noted that obese people have a higher risk of many diseases and thus a lower life expectancy. "It should be added as one of the underlying conditions."
An excerpt from the LA Times story:
“There are many possible explanations.
“Some of them are physiological. The lungs of obese patients are compressed because the abdomen presses up on the diaphragm. In addition, the chest wall is heavier, so it's more difficult for the lungs to stay inflated.
“Both of those factors make it difficult for blood and oxygen to travel throughout the lungs and fight off infection, said Dr. Lena Napolitano, chief of acute-care surgery at the University of Michigan Health System. She recently published a report in the CDC's Morbidity and Mortality Weekly Report on 10 swine flu patients admitted to the intensive care unit there; of the 10, nine were obese, including seven who were morbidly obese.
“The compromised immune system of obese people probably also plays a role, said Dr. David Heber, director of the Risk Factor Obesity Program at UCLA's David Geffen School of Medicine. Scientists believe that people who are obese have a baseline level of inflammation that diminishes the body's ability to fight diseases.’
OK. You know whether you are overweight. But do you know if you are considered obese or morbidly obese? Do you know your BMI?
There are easy online calculators to help you figure it out. The CDC has two: one for adults, and another for children and teens. Both are on this page:
In general, a BMI below 18.5 is considered underweight; between 18.5 and 24.9 is considered normal weight; between 25 and 29.9 is considered overweight, over 30 is considered obese, and over 40 is considered morbidly obese. Here’s a page of explanation about BMI and your results:
What can you do? In addition to following all the normal recommendations for resisting a flu virus, such as washing your hands often, be sure to get the H1N1 flu vaccine as soon as you can. If you have an underlying condition or are pregnant, you are among the high-risk groups who can be vaccinated now. And if you get the flu, stay home. Take care of yourself. Realize that your risk is higher than that of a normal-weight person, and act on that. If you get to the doctor quickly, you can be prescribed an anti-viral medicine such as Tamiflu, which will help with your symptoms. And If you start to have breathing difficulties or a horrible cough, get to the doctor. If it’s at night, get to the ER. This flu is not something we should be casual about.