Bone Health in Parkinson’s Disease

Abstract

Parkinson’s disease (PD) is a chronic neurodegenerative disease characterized by tremor at rest, bradykinesia, rigidity, and loss of postural reflexes. Patients can also exhibit a plethora of non-motor symptoms, such as autonomic dysfunction, sleep disturbances, and neuropsychiatric comorbidities. In the last years, a growing body of evidence has revealed that PD patients have relevant abnormalities in bone health. A substantial number of studies have shown that PD is associated with an increased risk of fractures, with low bone mineral density and with decreased vitamin D levels in serum. Osteoporosis in PD may be understood as a multifactorial process triggered by several causes, such as immobility or low sunlight exposure. However, several lines of evidence suggest that the presence of PD is associated with osteoporosis, fractures, and vitamin D abnormalities since the early stages of the disease and even before the onset of the motor symptoms. In the clinical setting, it must be kept in mind that fractures in PD patients may have deleterious consequences and even increase their functional impairment. In this regard, the availability of treatment guidelines based on clinical trials is an unmet need. This review summarizes the available studies from the last 26 years that have assessed bone health in PD regarding four major issues: (1) risk and specific features of fractures, (2) bone mineral density, (3) the vitamin D status, and (4) treatment options. In addition to the available literature, we endeavor to provide with insights into future developments in this area.