Introduction The purpose of the study was to compare lung function tests in patients with occupational interstitial lung disease (silicosis) and patients with airways diseases (COPD, asthma) by spiroergometry examination and spirometry, and to find diferences between groups.

Methods From 2005 to 2016, one hundred and fifty-five patients underwent spiroergometry and lung function testing. The sample of patients was male (143) and female (12) who were or have been exposed to hazardous work with exposure to solid fibrogenic aerosol. From the sample we exclude 6 patients with hypersensitive pneumonitis. Patients sample we split into 3 groups: the first is represented by patients with silicosis (50), where we included patients with simple and complicated silicosis; the second group represents patients with airways disease (chronic obstructive pulmonary disease, asthma and chronic bronchitis – 52) and the last group consists of a comparative sample of patients without pulmonary or respiratory disease (47). Spiroergometry was performed by a bicycle spiroergometer with gas analysis (O2 and CO2). The test was done by ramp-type load. The termination of the examination depended on the patient‘s abilities.

Results Oxygen consuption (VO2 – Lt/min.) at rest, at anaerobic threshold (AT) and at maximal load (MAX.) show no statistical significant diferences (Rest: 1.gr. 0,37 vs 2.gr. 0,35 vs 3.gr. 0,36; AT: 1.gr. 1,12 vs 2.gr. 1,25 vs 3.gr. 1,24; MAX: 1.gr. 1,66 vs 2.gr. 1,88 vs 3.gr. 2,0). We found only statistical diference (p=0,044) between groups in oxygen consumption per kilogram of weight (VO2/kg – ml/kg/min.) at maximal load (1.gr. 19,23 vs 2.gr. 22,07 vs 3.gr. 23,35). Exhaled carbon dioxide (VCO2—Lt/min.) show statistical significant values (p=0,018) between groups at maximum load (1.gr. 1,82 vs 2.gr. 2,1 vs 3.gr. 2,33). There were statistical significant differences at respiratory parameters (BR-breath reserve, VD/VT ratio).

Discussion Parameters VO2/kg-max and VCO2-max can be very valuable and useful for diagnosis and prognosis of the patient. Benini (2017) suggests that patients with significantly reduced oxygen consumption per kilogram of weight have an increased risk of death and overall impaired exercise tolerance. Also abnormal ventilation response during an exercise test is associated with worse survival.