How to manage osteoporosis in iatrogenic Cushing’s syndrome?

According to the recommendations of the American College of Rheumatology (ACR) from 2010, the glucocorticoid dose and the duration of therapy should be reduced to a minimum, which is clinically effective in specific diseases, such as rheumatoid arthritis, asthma or others. The glucocorticoid dose reduction and shortening therapy duration minimizes the risk of fractures. Similar to the general recommendations for osteoporosis treatment, lifestyle modifications, consisting of regular physical activity including exercises with own body weight, fall prevention, smoking cessation, limiting alcohol, compensation of calcium deficiency to a total intake of 1200–1500 mg/day and control of vitamin D3 alteration of 25-hydroxyvitamin D3 concentration are also very important. A recommended preventive dose of vitamin D3 is 800–1000 IU per day. Monitoring patient’s height and Bone Mineral Density (BMD) is also essential in glucocorticoid therapy. The ACR recommends radiological or morphometric assessment of the spine in patients receiving 5 mg or more of prednisolone daily. Before starting treatment, the assessment of global fracture risk based on the presence of other known coexisting risk factors beyond steroids, such as low BMI, parental hip fracture, current smoking, consumption of more than 3 units of alcohol a day and a significant decrease in BMD should also be considered.

American College of Rheumatology recommendations distinguish two groups of patients: Premenopausal women and men less than 50 years of age and postmenopausal women and men over 50 years of age. In the former group as there are no adequate studies and guidelines, individual approach is recommended. For patients with osteoporotic fractures receiving ≥5 mg prednisolone or equivalent for more than a month, it is recommended to start treatment with bisphosphonates of proven effectiveness in glucocorticoid-induced osteoporosis, such as alendronate or risedronate, and if steroid dose is ≥7.5 mg, zoledronic acid should also be considered. If treatment with glucocorticoids is continued for a period of 3 months then, regardless of the dose, the patient should receive one of four treatment options: alendronate, risedronate, zoledronate or teriparatide.

The patients in the second group of the ACR recommendations should be divided into three subgroups, depending on the established global fracture risk, calculated on the basis of well proven algorithms, such as FRAX (low, medium or high fracture risk). Among patients with low or medium fracture risk, it is recommended to start therapy with alendronate, risedronate or zoledronate, if steroid administration exceeds 3 months and daily dose is ≥7.5 mg of prednisolone or equivalent. In patients with an average risk of fracture, it is advisable to administer alendronate and risedronate if steroid daily dose is <7.5 mg of prednisolone or equivalent and the patient has been treated for ≥3 months. Patients with high fracture risk should receive one out of the following three drugs: alendronate, risedronate or zoledronate, if they use steroids in a dose of <5 mg/day, even for <1 month, and when they receive >5 mg glucocorticoids per day, teriparatide should be considered.