Lung Dysfunction in Diabetes

• COPD, chronic obstructive pulmonary disease
• EBC, exhaled breath condensate
• INH, inhaled insulin
• PEF, peak expiratory flow
• PFT, pulmonary function test
• SC, subcutaneous insulin

Clear decrements in lung function have been reported in patients with diabetes over the past 2 decades, and many reports have suggested plausible pathophysiological mechanisms. However, at the present time, there are no reports of functional limitations of activities of daily living ascribable to pulmonary disease in patients with diabetes. Accordingly, this review is directed toward a description of the nature of reported lung dysfunction in diabetes, with an emphasis on the emerging potential clinical implications of such dysfunction.

More than a quarter-century ago, Schuyler et al. (1) investigated lung function in 11 young (21–28 years old) patients with type 1 diabetes and age-matched normal control subjects. This classic study was the first to report measurements of nearly all the available tests of lung function, including lung elasticity, capacity to transfer carbon monoxide (CO, a surrogate for oxygen transfer capacity), absolute thoracic gas volumes, airflow resistance, and maximal forced spirometric pulmonary function tests (PFTs). As their subjects were lifelong nonsmokers without allergies or lung disease, their finding that lung elastic recoil was decreased in these young patients with diabetes was interpreted to reflect effects of diabetes on lung elastic proteins. This was the first suggestion in the literature that the lung may be a target organ of diabetes. Because the elastic structure of the lung supports the intrathoracic airways and helps to maintain their patency, the authors suggested that patients with diabetes were at risk for developing chronic airflow obstruction. While small changes in lung elastic recoil do not have direct clinical implications, subsequent development of chronic airflow obstruction could incur significant disability due to mechanical dysfunction of the lungs and airways.

Schernthaner et al. (2) could not confirm the findings of Schuyler et al. in patients with type 1 diabetes. However Sandler et al. (3) did find decreased lung …