Type II diabetes mellitus is associated with decreased measures of lung function in a clinical setting

Type II diabetes mellitus has been associated with reduced forced expiratory volume in first second (FEV(1)) and forced vital capacity (FVC). We investigated if this relationship is maintained in a clinical setting, independent of respiratory infections and heart failure.

Pulmonary function tests and discharge summaries of 639 adults 18-80 years of age, of different races/ethnicities, seen at an urban hospital during a two years period were reviewed. After selection of patients based on inclusion/exclusion criteria, 286 patients were included in our analysis. Using multivariable linear regression we examined cross-sectional differences of FEV(1) and FVC between patients with and without diabetes, adjusting for age, sex, race/ethnicity, BMI, smoking and respiratory symptoms.

Patients with diabetes were older (63 ± 1 vs. 56 ± 1), more likely to be African-Americans (30% vs. 25%) and Hispanics (40% vs. 31%), have respiratory symptoms (79% vs. 68%), and a higher BMI (34.2 ± 1.0 vs. 30.1 ± 0.6), compared to patients without diabetes. The distribution of women and smoking among the two groups were similar. The mean unadjusted percent predicted values of FEV(1) and FVC in patients with diabetes were lower than in those without diabetes, and remained significantly reduced after adjustment (77.3 ± 0.5 vs. 82.0 ± 0.3, p < 0.01 for FEV(1) and 73.8 ± 0.6 vs. 82.8 ± 0.3, p < 0.01 for FVC, respectively).

In a clinical setting, patients with diabetes have decreased lung function compared to their non-diabetic counterparts, independent of respiratory infections and heart failure.