Piling on extra pounds speeds up the decline of lung function in older adults, a new study suggests.
While lung function decreases naturally as people age, researchers linked moderate or significant weight gain to an even sharper decline.
The study included 3 700 people in Europe and Australia who were recruited between the ages of 20 and 44, and followed for 20 years.
Whether they started out with healthy weight or were overweight or obese, people who gained weight during the study period all had accelerated lung function decline, the investigators found.
Varied population sample
The study also found that losing weight slowed lung function decline in obese people, and that people who maintained a low weight throughout adulthood had a much slower decrease in lung function.
The study was published in the journal Thorax.
"Although previous research has shown that weight gain is linked to lung function decline, ours is the first study to analyse such a varied population sample over a longer period of time," said study leader Judith Garcia Aymerich. She's head of the non-communicable diseases and environment program at Barcelona Institute for Global Health (ISGlobal), in Spain.
Most previous studies followed participants for no more than 10 years and focused on adults up to 50 years old, according to the researchers.
The study authors said there are two possible explanations for the link between heavier weight and reduced lung function.
Effects can be reversed
First, large amounts of fat in the abdomen and chest can limit the space lungs have to expand when people inhale. Second, fat produces inflammatory chemicals that can damage lungs and reduce the diameter of airways.
Maintaining good lung function during adulthood is crucial in preventing chronic respiratory diseases, according to the study authors.
"Given the epidemic levels of overweight and obesity that we are currently seeing, it is fundamental to understand the effects of weight changes on lung function," Garcia Aymerich said in an institute news release.
"The good news is that the negative pulmonary health effects of excess weight and obesity can be reversed through weight loss. Therefore, public health policies that promote healthy lifestyles can be the key to achieving good pulmonary health," she added.
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