Which disease is associated with hypertrophy of accessory muscles?

Hypertrophy of accessory muscles is typically associated with chronic obstructive pulmonary disease (COPD) due to the respiratory demands created by this condition. In COPD, which includes emphysema and chronic bronchitis, patients often experience airflow limitation and increased work of breathing. As a compensatory mechanism, they may recruit accessory muscles such as the sternocleidomastoid and scalene muscles to assist with respiration. Over time, the repeated use of these muscles can lead to hypertrophy, making them larger and potentially more prominent.

In contrast, while asthma can also involve accessory muscle use during severe exacerbations, it does not typically lead to the sustained hypertrophy seen in chronic conditions like COPD. Pneumonia often results in acute respiratory distress rather than chronic muscle hypertrophy, and bronchitis is a component of COPD; therefore, while it has similar characteristics, it does not distinctly highlight accessory muscle hypertrophy to the extent observed in COPD. Thus, COPD is the condition most closely associated with this physiological change, making it the correct answer in this context.