Lung Function Impairment Linked to Metabolic Syndrome in Both Sexes

Laurie Barclay, MD

March 17, 2009

To earn CME related to this news article, click here.

March 17, 2009 — There is a positive independent relationship between lung function impairment and metabolic syndrome in both sexes, primarily related to abdominal obesity, according to the results of a cross-sectional, population-based study reported in the March issue of the American Journal of Respiratory and Critical Care Medicine.

"Increased risk for cardiovascular morbidity and mortality has been related to both lung function impairment and metabolic syndrome," write Nathalie Leone, MD, from INSERM U700, Université Denis Diderot, Paris VII, France, and colleagues. "Data on the relationship between lung function and metabolic syndrome are sparse."

The goal of this study was to assess the risk for lung function impairment based on components of the metabolic syndrome. The study sample consisted of 121,965 men and women evaluated between 1999 and 2006 at the Paris Investigations Préventives et Cliniques Center.

Lung function impairment was defined as forced expiratory volume in 1 second (FEV1) or forced vital capacity (FVC), at lower limit of normal, and the metabolic syndrome was defined by criteria from the American Heart Association and the National Heart, Lung, and Blood Institute. Differential associations between lung function impairment and specific components of metabolic syndrome were assessed with a logistic regression model and principal component analysis.

Independently of age, sex, smoking status, alcohol consumption, educational level, body mass index, leisure-time physical activity, and cardiovascular disease history, lung function impairment was associated with metabolic syndrome (prevalence, 15.0%). For FEV1, odds ratio (OR) was 1.28 (95% confidence interval [CI], 1.20 - 1.37), and for FVC, OR was 1.41 (95% CI, 1.31 - 1.51).

Factor analysis revealed 3 factors predictive of impaired lung function: "lipids" (low high-density lipoprotein [HDL] cholesterol levels, high triglyceride levels), "glucose-blood pressure" (high fasting glycemia, high blood pressure), and "abdominal obesity" (large waist circumference). Although all 3 factors were inversely related to lung function, abdominal obesity was the strongest predictor of lung function impairment (OR, 1.94 [95% CI, 1.80 - 2.09] and OR, 2.11 [95% CI, 1.95 - 2.29] for FEV1 and FVC, respectively). Findings were similar among women and men.

"We found a positive independent relationship between lung function impairment and metabolic syndrome in both sexes, predominantly due to abdominal obesity," the study authors write. "Further studies are required to clarify the underlying mechanisms."

In an accompanying editorial, Paul Enright, MD, from the University of Arizona in Tucson, suggests 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," Dr. Enright writes. "Waist size is easier to measure, using a cloth tape at the umbilicus while the patient relaxes their stomach muscles, than other indices of obesity such as waist/hip ratio or abdominal height."

The Caisse Nationale d'Assurance Maladie and the Caisse Primaire d'Assurance Maladie de Paris supported this study. The study authors and Dr. Enright have disclosed no relevant financial relationships.

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


Comments on Medscape are moderated and should be professional in tone and on topic. You must declare any conflicts of interest related to your comments and responses. Please see our Commenting Guide for further information. We reserve the right to remove posts at our sole discretion.