Anti-osteoporotic medication and scleroderma

Abstract

Scleroderma (systemic sclerosis) represents a challenging condition, usually requiring a multi-disciplinary team due to multi-organ involvement; it is mostly considered an autoimmune disease; the signature of the malady is the extensive fibrosis at the level of skin and multiple organs, associating endothelial/vessel damage and anomalies of immune response. We point out a few aspects concerning scleroderma-related osteoporosis. This is a literature review. Patients might associate low bone mineral density (the underling mechanisms are not entirely understood), thus an increased risk of fractures; so early recognition and treatment is mandatory for a better outcome. Some data showed that particularly vertebral fractures are prone to the condition. Almost half of individuals with the malady have osteoporosis (female prevalence, especially post-menopausal) and one third of them have an osteoporotic fracture. Older age and associated vitamin D deficiency increases the risk of fracture. Vitamin D has pleomorphic distribution, also targeting the immune modulation, cytokines puzzle, and the muscle-bone crosstalk in scleroderma. Hypovitaminosis D might be expected in these patients, while general D-supplementation has controversial benefits effects. Chronic inflammatory rheumatic conditions might benefit from the TBS use as fracture risk indicator through micro-architecture evaluation. It seems that patients with systemic sclerosis and malnutrition have lower TBS; high Dkk-1 serum levels (Dickkopf-1) is correlated with reduced TBS and advanced disease; TBS is correlated to the extent of microvascular complications; exposure to glucocorticoids (certain high-dose regimes) supplementary lowers TBS. Gastrointestinal complications are presented in 90% of patients with systemic sclerosis, involving fibrosis at any level which is a poor prognostic factor; malabsorption of nutrients and weight loss correlates with reduced bone formation while esophageal and gastric anomalies contraindicate the use of oral bisphosphonates for osteoporosis. Other abnormal elements of skeleton frame include: premature ovarian failure, serotonin system anomalies, chronic inflammation, potential side effects of immunosuppressant drugs. In patients with systemic sclerosis, the choices of medication targeting osteoporosis are limited; the use of intravenous bisphosphonates remains first line option (if renal function is adequate); the consideration of skin and esophageal anomalies is mandatory in the management of osteoporosis. Overall, the landscape of bone domain in systemic sclerosis is multi-leveled and some areas are still waiting for clear answers.