Introduction

Abstract

Osteoporosis is defined as a skeletal disorder characterized by compromised bone strength predisposing a person to an increased risk of fracture, bone strength reflecting the integration of bone density and bone quality [1]. Osteoporosis affects an estimated 75 million people in Europe, Japan and the USA [2]. Its prevalence increases with age, and it mainly affects postmenopausal women and older men. After accounting for age, the risk of fracture for postmenopausal women is about three times that for men, partly because women have a lower peak bone mass and partly because of hormonal changes that occur at the menopause. The lifetime risk of osteoporotic fracture in a 50-year-old woman is 40%, similar to that for coronary heart disease (Figure 1.1) [2].