Pulmonary function in insulin-dependent diabetes mellitus with limited joint mobility

Patients with insulin dependent diabetes mellitus (IDDM) and limited joint mobility (LJM) were studied to determine if altered respiratory mechanics were another manifestation of a generalized disturbance in collagen metabolism. Lung volumes and maximal expiratory flow volume curves were measured in 23 patients with IDDM. Patients were divided into 2 groups: (1) 11 without LJM, and (2) 12 with severe LJM. The groups were matched for age, sex, and glycemic control but not for duration of IDDM. In patients with severe LJM, forced vital capacity (FVC) and forced expiratory volume in one second (FEV1) were significantly decreased (p less than 0.05). Total lung capacity (TLC), thoracic gas volume (TGV) at functional residual capacity (FRC) and residual volume (RV) were also significantly lower (p less than 0.05) in the severe LJM group. There was no evidence of air-flow obstruction in either group. Our results demonstrate an association between severe LJM and a significant decrease in lung volumes. This could be due to decreased lung compliance or restriction of chest wall expansion.