Asthma Linked to Obesity

Scientists have already linked numerous health problems to the obesity from which one-third of Americans suffer, and Harvard Medical School instructor Dr. Carlos A. Camargo Jr. might have found another complication to add to the list: statistical evidence suggests a link between obesity and adult-onset asthma.

At this week's American Lung Association Conference in Chicago, Camargo presented a study of 89,061 women, aged 27 to 44, that indicated obese women were three times as likely to develop asthma.

While anecdotal evidence has long suggested a connection between being overweight and suffering from asthma, Camargo and his colleagues are the first to separate causation from correlation. Tracking a group of nurses from 1991 to 1995, he found that overweight women were considerably more likely to develop adult asthma.

Camargo said he was careful to establish that these women were free from asthma at the start of the study and became seriously asthmatic while under observation.

The correlation between obesity and asthma was strong both in women who were smokers and non smokers. Additionally, Camargo said, the women who developed asthma came from all socioeconomic classes, discounting a link between obesity, asthma and income level.

Because cases of asthma jumped 61 percent from 1982 to 1994, Camargo's study could have important implications.

The research is "a recognition that adult asthma is more complicated and more heterogeneous" than researchers had previously thought, Camargo said.

Researchers in the field have speculated that obesity serves as a marker of a sedentary lifestyle. Obese people tend to spend more time indoors, breathing in harmful air pollutants that are recycled in air circulation systems.

Researchers are also investigating the tendency of obese people to have constricted airways, possibly increasing susceptibility to invasion by asthma-triggering pollutants.

At the conference, a group of British doctors also presented a study with similar findings.

Camargo's study has not yet been published in a peer-reviewed academic journal, the medical community's stamp of approval for research.