Low serum adiponectin levels predict an increased future risk for developing asthma in middle-aged women, particularly among smokers, according to a new study.
"Adiposity is known to be related to asthma. Although a causal link between adiponectin (a protein produced by adipose tissue) and asthma has been demonstrated in mice, the evidence in humans has been conflicting," said lead author Akshay Sood, MD, MPH, associate professor in the Division of Pulmonary and Critical Care Medicine at the University of New Mexico Health Sciences Center School of Medicine.
"In an earlier cross-sectional study, we found an association between low serum adiponectin levels and prevalent asthma among women, but the direction of this association is not known," Dr. Sood continued. "In the current study, we examined the longitudinal association between asthma and adiponectin and found that low serum adiponectin concentrations, independent of obesity, predicted a higher risk for developing asthma."
The findings were published online ahead of print publication in the American Thoracic Society's American Journal of Respiratory and Critical Care Medicine.
The researchers analyzed data on 1,450 women, including 1,011 pre-menopausal women, from the 10, 15, and 20 year examinations of the Coronary Artery Risk Development in Young Adults (CARDIA) study.
Being in the lowest tertile of serum adiponectin concentrations (<7 mg/L) at year 15 was a significant predictor of a higher risk of incident asthma at year 20, particularly among current smokers. Low serum adiponectin concentrations were a more important predictor of risk for incident asthma than body mass index. Having asthma at year 10 did not predict serum adiponectin concentrations at year 15.
The study had several limitations, including the use of self-report for asthma diagnoses and the possibility that using only CARDIA patients who had serum adiponectin measured may have introduced selection bias.
"Our results show that low serum adiponectin levels in middle-aged women are associated with an elevated risk of developing asthma in the future," concluded Dr. Sood. "This suggests that raising systemic adiponectin concentrations could potentially be useful as an asthma prevention measure in women, particularly those that smoke."