The assessment of pulmonary diffusing capacity in diabetes mellitus with regard to microalbuminuria.

OBJECTIVE: The current study was conducted to determine whether or not the lung is one of the target organs in the development of vascular complications in diabetic patients. We also investigated the relationship between pulmonary diffusing capacity and microalbuminuria.
MATERIALS AND METHODS: A total of 68 patients with type 2 diabetes and 44 with type 1 diabetes (male/female [M/F] n=19/49 and 15/29; age: 52.4+/-8.8 and 32.5+/-11 years;) and 80 healthy controls (M/F=22/58; age=40.1+/-12.4 years) were recruited for the study. All of the participants were evaluated with simple spirometric tests and a simple breath carbon monoxide (CO) diffusion test. CO lung diffusion capacity (DLCO) and the ratio of DLCO value to the alveolar volume (VA) were used to assess alveolar membrane permeability (DLCO/VA). Urinary albumin excretion (UAE) per day of the participants was also evaluated.
RESULTS: DLCO, DLCO% and DLCO/VA% values were significantly lower in diabetics than in the control group (p=0.006; p=0.039; p=0.003, respectively). UAE was inversely correlated with DLCO, DLCO/VA, DLCO/VA% and DLCO% (p=0.050; p=<0.001; p=0.001; p=0.004, respectively).
CONCLUSION: This study demonstrated that alveolar gas exchange capacity is significantly decreased in diabetic patients. Microalbuminuria may be one of the predictors of this decline.