Summary
Background: Depression and anxiety are the most prevalent diseases that contribute to global disability, especially if they are not early recognised and properly treated. They occur as part of many chronic diseases, often remain unrecognised at an early stage, and significantly contribute to the progression of the underlying disease reducing the quality of life in these patients. Numerous studies have shown that anxiety / depression and dyspnea are the leading symptoms in patients with COPD that are associated with high morbidity and mortality. The aim of this study was to determine the relationship between the degree of depression, anxiety and stress, using DASS- 21 scale, and changes in locomotor parameters in smokers who are prone to develop COPD.
Subjects and methods: The study included 164 patients, smokers and non-smokers, who underwent spirometry, 6-minute walk test and bicycle ergometer. They were all measured for body weight, height, waist circumference, pulse, blood pressure and each patient completed DASS-21, CAT and IPAQ questionnaire.
Results: The results of the IPAQ questionnaire indicated a statistically significant difference in the physical activity of smokers and non-smokers. A statistically significant was found between DASS-21 and patients physical activity (p=0.0001), 6-minute walk test (r=-0.186, p=0.017), VO2 max (r=-0.220, p=0.005) and weekly calorie consumption (r=-0.222, p=0.004).
Conclusion: According to the results of the study, an increased degree of anxiety, depression and stress is an important factor influencing changes in locomotor parameters in smokers who are prone to develop COPD.

Relevance
The study confirms that stress, poor well-being and impaired mental health, such as depression and anxiety, can negatively affect the incidence of chronic lung disease. Furthermore, other studies show that depressed people may have lower levels of physical activity and, because of the above, are additionally exposed to the risk of developing this disease. The article indicates the importance of mental health in the prevention and treatment of chronic lung diseases.