Osteoporosis and fracture risk are multifactorial in patients with inflammatory rheumatic diseases

Patients with inflammatory rheumatic and musculoskeletal diseases (iRMDs) such as rheumatoid arthritis, connective tissue diseases, vasculitides and spondyloarthropathies are at a higher risk of osteoporosis and fractures than are individuals without iRMDs. Research and management recommendations for osteoporosis in iRMDs often focus on glucocorticoids as the most relevant risk factor, but they largely ignore disease-related and general risk factors. However, the aetiopathogenesis of osteoporosis in iRMDs has many facets, including the negative effects on bone health of local and systemic inflammation owing to disease activity, other iRMD-specific risk factors such as disability or malnutrition (for example, malabsorption in systemic sclerosis), and general risk factors such as older age and hormonal loss resulting from menopause. Moreover, factors that can reduce fracture risk, such as physical activity, healthy nutrition, vitamin D supplementation and adequate treatment of inflammation, are variably present in patients with iRMDs. Evidence relating to general and iRMD-specific protective and risk factors for osteoporosis indicate that the established and very often used term 'glucocorticoid-induced osteoporosis' oversimplifies the complex inter-relationships encountered in patients with iRMDs. Osteoporosis in these patients should instead be described as 'multifactorial'. Consequently, a multimodal approach to the management of osteoporosis is required. This approach should include optimal control of disease activity, minimization of glucocorticoids, anti-osteoporotic drug treatment, advice on physical activity and nutrition, and prevention of falls, as well as the management of other risk and protective factors, thereby improving the bone health of these patients. In this Review, the authors argue that the risk of osteoporosis in patients with inflammatory rheumatic and musculoskeletal diseases (iRMDs) is multifactorial, with contributions from iRMD-specific factors, comorbidities, general risk factors and the effects of iRMD therapies such as glucocorticoids. Patients with inflammatory rheumatic and musculoskeletal diseases (iRMDs) are at a higher risk of osteoporosis and fractures than are those without iRMDs, the aetiopathogenesis of which is multifactorial.General risk factors (including age, female sex, menopause, previous fractures and genetic factors) and iRMD-specific factors (including inflammatory activity, disability and glucocorticoid therapy) might negatively affect bone health.iRMD activity and glucocorticoid therapy have inter-related negative effects on bone, as glucocorticoids reduce inflammatory activity and thereby mitigate the detrimental effects of inflammation on bone.To protect bone, it is recommended that patients with iRMDs achieve optimal disease control without glucocorticoids or with the lowest possible glucocorticoid dosage.Physicians and patients with iRMDs need to be aware of the plethora of positive and negative factors that influence bone health, and act together to optimize them.Most patients with iRMDs should undergo bone-health assessment according to current recommendations at iRMD diagnosis or commencement of glucocorticoid therapy, and at regular intervals, to inform decisions about bone-directed drug therapy.