Study: Weight loss key to manage asthma in obese adults

In a prospective, controlled, parallel-group study, Smita Pakhale, MD, Department of Medicine, The Ottawa Hospital and University of Ottawa, and colleagues, followed 22 obese participants with asthma aged 18 to 75 years with a BMI ≥ 32.5 kg/m₂ and airway hyper-responsiveness (AHR) (provocative concentration of methacholine causing a 20% fall in FEV₁ [PC20] < 16 mg/mL).

Of the 22 participants, 16 followed a behavioral weight-reduction program for three months, and six served as control subjects. The primary outcome was change in AHR over three months. Secondary outcomes included changes in lung function, asthma control, and quality of life.

Upon joining the study, participant mean ± SD age was 44 ± 9 years, 95% were women, and mean BMI was 45.7 ± 9.2 kg/m₂. After three months, mean weight loss was 16.5 ± 9.9 kg in the intervention group, and the control group had a mean weight gain of 0.6 ± 2.6 kg. In the intervention group, significant improvements were seen in PC20 (P=.009), FEV₁ (P=.009), FVC (P=.010), asthma control (P< .001), and asthma quality of life (P=.003), but these parameters remained unchanged in the control group. Physical activity levels also increased significantly in the intervention group but not in the control group, according to the authors.

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“These findings support the need to actively pursue healthy weight-loss measures in this population,” the authors wrote.

“Weight gain and obesity have been associated with many chronic conditions such as asthma,” said John Santilli a partner with consulting firm Access Market Intelligence, in Trumbull, Conn. “Studies have shown that an obese person has a better chance of developing asthma and is less likely to respond well to medications. Weight loss is becoming the prevailing strategy to manage asthma.”

Asthma is a serious and widespread disease affecting 300 million individuals worldwide. In the U.S., about 25 million people have asthma - one out of every 12 people, according to the American Asthma Foundation. The cost of asthma to society in the U.S. is more than $50 billion per year in healthcare expenses, missed school and workdays, and early death, according to the Foundation.

The study is the first of its kind to rely on appropriate physiologic tests as diagnostic criteria for asthma, found normalization or improvements in AHR, asthma control, and quality of life.

According to the Centers for Disease Control and Prevention, obesity affects about one-third (33.8%) of adults in the U.S. and nearly one out of five (17%) children have childhood obesity. Over the past decade, national medical expenditures for obesity have risen to approximately $147 billion per year.