Bone mineral density and vitamin D status in Parkinson's disease patients

Bone loss is more common in Parkinson's disease (PD) than in the general population. Several factors may be involved in the development of bone loss, including malnutrition, immobilization, low body mass index, decreased muscle strength, vitamin D deficiency and medication use. This study investigates the prevalence of osteoporosis and possible risk factors associated with bone loss in early stage PD. In 186 PD patients (Hoehn and Yahr stage 1-2.5, mean age 64.1 years, 71 % men) bone mineral density (BMD) measurements were performed with DEXA. T- and Z-scores were calculated. Univariate linear regression analysis was performed to identify variables that contributed to BMD. 25-OH-vitamin D status of PD patients was compared with 802 controls (mean age 63.3 years, 50 % men) using linear regression analysis. Osteoporosis (11.8 %) and osteopenia (41.4 %) were common in PD patients. Mean Z-score for the hip was 0.24 (SD 0.93), and for the lumbar spine 0.72 (SD 1.91). Female gender, low weight, and low 25-OH-vitamin D were significantly correlated with BMD of the hip and lumbar spine. PD patients had lower 25(OH)D serum levels than controls (B = -10, p = 0.000). More than half of the patients with early stage PD had an abnormal BMD. Female gender, low weight, and low vitamin D concentration were associated with bone loss. Furthermore, vitamin D concentrations were reduced in PD patients. These results underscore the importance of proactive screening for bone loss and vitamin D deficiency, even in early stages of PD.