NEW YORK (Reuters Health) – New research suggests that metabolic syndrome, primarily the abdominal obesity component, is associated with lung function impairment. Moreover, the degree of obesity need not be severe to increase the risk.

The findings showed that “mild abdominal adiposity, even with a normal body mass index, is associated with lower forced vital capacity (FVC),” lead author Dr. Nathalie Leone, from Universite Denis Diderot, Paris, said in a statement.

“The association,” Dr. Leone explained, “may result from the mechanical effects of truncal obesity and/or the metabolic effects of adipose tissue. Abdominal obesity may mechanically affect the diaphragm and chest wall compliance with decreased lung volumes.”

The findings come from a cross-sectional study of 121,965 men and women seen at the Paris Investigations Preventives et Cliniques Center from 1999 to 2006. Lung function impairment was defined as a forced expiratory volume in 1 second (FEV1) or forced vital capacity (FVC) below the lower limit of normal.

After adjusting for age, gender, smoking status, alcohol use, educational level, body mass index, leisure-time activity, and cardiovascular disease history, metabolic syndrome was still linked to lung function impairment, according to the report in the American Journal of Respiratory and Critical Care Medicine for March.

In addition to abdominal obesity, other metabolic syndrome components tied to lung dysfunction were abnormalities in lipid levels and in glucose/blood pressure. Still, abdominal obesity showed the strongest association, raising the risk of abnormal FEV1 and FVC by 1.94- and 2.11-fold, respectively.

In a related editorial, Dr. Paul Enright, from The University of Arizona, Tucson, writes that “there is now enough evidence to recommend that waist circumference always be measured before spirometry tests. Abdominal obesity could then be highlighted on the printed report so that the physician interpreting the report could take the effect of obesity into account.”

Reference:
Am J Respir Crit Care Med 2009;179:432-433,509-516.