Epidemiology of osteoporosis in the United States of America.

Abstract

Consensus definition: Osteoporosis is a metabolic bone disease characterized by low bone mass and microarchitectural deterioration of bone tissue, leading to enhanced bone fragility and a consequent increase in fracture risk [1]. From an epiderniological perspective, osteoporosis traditionally has been studied in terms of fracture incidence and fracture prevalence. However, the above definition is based upon 'fracture risk' and a more practical definition of osteoporosis has evolved which is based upon its major (known) risk factor reduced bone mass, or density [2]. This definition becomes useful because it includes those individuals who are at high risk but have not yet fractured. By this consensus definition, there are an estimated 26 million women in the United States alone who are affected with osteoporosis [3]. Despite the utility of the 'bone mass' definition, it is important to understand that bone density is a single risk factor, measured at a single point in time. Other major risk factors are not incorporated into the World Health Organization definition, including age, life expectancy, bone loss and bone tumover, and many others. Thus the consensus definition does not serve as an adequate clinical definition of osteoporosis and should not be used as the sole basis for clinical decision making.