Complex sentence: The likelihood of developing COPD increases with age and the total smoke exposure, and almost all lifelong smokers will develop COPD, provided that smoking-related, extrapulmonary diseases (cardiovascular, diabetes, cancer) do not claim their lives beforehand.
Split into simpler sentences: The likelihood of developing COPD increases with age and the total smoke exposure. Almost all lifelong smokers will develop COPD, provided that smoking-related, extrapulmonary diseases (cardiovascular, diabetes, cancer) do not claim their lives beforehand.