Osteoporosis is defined by the World Health Organization

(WHO) as a systemic skeletal disease that is characterised by low bone mass and microarchitectural deterioration of bone tissue, with a consequent increase in bone fragility and susceptibility to fracture which usually involves the wrist, spine, hip, ribs, pelvis or humerus. In 1994, the WHO proposed a stratified definition of osteoporosis,1 which was updated in 2008,2 that encompassed the concepts of both low bone mass and fracture. According to this classification, there are four general categories: normal, low bone mass (osteopenia), osteoporosis and severe osteoporosis. Currently, a diagnosis of osteoporosis is established based on evidence of (i) a fragility fracture or (ii) low bone mineral density (BMD) measured with central dual-energy X-ray absorptiometry (DXA). In its recently published guideline