Experience of Hypoxic Conditioning in Rehabilitation Programs for Patients with Chronic Occupational Lung Diseases: a Pilot Study

INTRODUCTION. Chronic occupational lung diseases (COLD) represent a serious medical and social problem associated with a high degree of comorbidity and systemic disorders, including cardiometabolic changes, pronounced oxidative stress, chronic inflammation, autonomous and immune dysregulation, and leading to disability and reduced quality of life. Hypoxic conditioning (HC), in particular, intermittent hypoxic-hyperoxic exposures (IHHE), which can improve adaptation mechanisms and reduce inflammatory processes, is a promising method of rehabilitation of patients with COLD, along with basic medication and physiotherapy. AIM. To evaluate the efficacy and safety of IHHE application in the programs of complex rehabilitation of patients with COLD. MATERIALS AND METHODS. A single-center blind randomized placebo-controlled study with participation of 60 patients (32 men, age 58,2 ± 14,1 years, desiase’s duration 15,9 ± 2,8 years) with COLD (occupational bronchial asthma — 59.3 %), occupational chronic bronchitis — 18.5 %, occupational chronic obstructive pulmonary disease — 11.1 %) and occupational exogenous allergic alveolitis — 11.1 %), divided into two groups was conducted: the main group received 12 sessions of IHHE in 3 weeks, control group — placebo procedures. Both groups underwent standard medical and physiotherapeutic rehabilitation. Clinical, functional and laboratory parameters before and after the rehabilitation course were evaluated. RESULTS AND DISCUSSION. In the IHHE group there was a significant improvement of hypoxic resistance (according to Stange’s and Gench’s tests, hypoxic test), reduction of broncho-obstructive manifestations, improvement of external respiratory function indices and reduction of blood pressure. There was also an increase in exercise tolerance according to the six-minute walk test (6MWT) (an increase of 11.9 ± 8.6 % from baseline), a decrease in the severity of dyspnea and subjective assessments of exercise severity according to the Borg scale. In the control group, the positive dynamics in the indicators of hypoxic tolerance, broncho-obstruction, and 6MWT tolerance were significantly less pronounced. The results of the study confirm that IHHE procedures can serve as a significant addition to the standard rehabilitation of patients with COLD, contributing to the improvement of clinical and functional parameters, correction of comorbid disorders. CONCLUSION. IHHE is a safe and effective method to be added to standard rehabilitation of patients with COLD, leading to more pronounced improvements of hypoxic resistance, exercise tolerance, reduction of broncho-obstruction and normalization of blood pressure.