**4. Aromatase inhibitors (AIs)-induced bone loss**

The majority of adverse reactions to aromatase inhibitors (AIs) affect the musculoskeletal system and can be divided into three groups [21]:

1.Metabolic bone disease, which increases the risk of fractures;


All of these adverse outcomes begin to manifest after varying amounts of time have passed since the start of treatment with AIs. Although the precise pathophysiology is not fully understood, the pathogenetic pathways endorsed to explain these

disorders are primarily related to the estrogen deficiency caused by a prolonged AIs treatment [21].
