Integrating a gender dimension into osteoporosis and fracture risk research

Abstract

Background: Sex (referring to the strict biological sense) and gender (referring to the sociocultural dimension) are major determinants of health and disease. Objective: This review examines similarities and differences between the sexes in the prevalence of osteoporosis and fractures, bone- and fall-related risk factors for incident fractures, and the possibilities of fracture prevention, as well as gender differences in the perception of osteoporosis. Methods: We reviewed recent English-language publications on sex and gender differences in the context of osteoporosis and fracture risk. We refer to several reviews that provide extensive reference lists on the topics discussed. Results: The incidence of fractures is higher in boys than in girls. The burden of fractures in adults increases with age, and it starts earlier and is higher in adult women than in adult men. With life expectancy increasing, the annual number of fractures is likely to increase substantially. Fractures in adults contribute to increased mortality (more in men than in women), increased morbidity (equal in men and women), and high costs (greater for women than for men). Adult men experience fewer fractures than women do. Men build larger bones with better microarchitecture while they are growing and thereafter have less increase in bone remodeling. Furthermore, they develop bone loss at a later age. Compared with their female counterparts, fewer older men are hypogonadic, and life expectancy is shorter for men than for women. There are multiple reasons for the differences in the incidences of fractures between men and women, related to the many factors associated with both bone and falls that influence fracture risk from the molecular and cellular level to the organ level. Sex hormones play a central and essential role in the physiology of bone by direct and indirect mechanisms (eg, by interfering with the growth hormone and insulin-like growth factor-1 axis). Case-finding strategies to identify patients at highest risk for fractures, including bone densitometry and clinical risk factors, are much better documented at the population level in women than in men. Drug therapies that reduce the risk of a broad spectrum of fractures, even in the short term, are more clearly demonstrated in randomized controlled studies in women than in men. Drug therapy is more widely available for women with osteoporosis, but it is rarely given to men with osteoporosis. Differences in the perception of osteoporosis between men and women are even less well documented. Conclusions: In general, osteoporosis is underdiagnosed and undertreated in women but even more so in men, and is related to limits in the patient's and the physician's awareness at all clinical stages, from case finding to compliance with and persistence of therapy. Furthermore, the lay perception of a healthy lifestyle, the level of social isolation, networking within the health care system, and opportunities for screening appear to contribute to gender differences in participating in osteoporosis prevention and therapy. These aspects of health care deserve further attention and research.