Abstract

OBJECTIVES A high prevalence of hip and other fractures in elderly patients with Parkinson’s disease has been linked to reduced bone mass arising from a defect of renal synthesis of 1, 25-dihydroxyvitamin D (1, 25-[OH]₂D). Treatment with 1α-hydroxyvitamin D3 (1α(OH)D3; an active form of vitamin D) was evaluated for maintaining bone mass and reducing the incidence of hip and other non-vertebral fractures in patients with Parkinson’s disease.

METHODS In a double blind, randomised trial, 86 elderly patients with Parkinson’s disease (mean Hoehn and Yahr stage, 3; mean age 70.6 years) were randomised to receive either 1 μg 1α(OH)D₃ daily (treatment group, n=43) or a placebo (n=43) for 18 months. Bone mineral densities in the second metacarpals were determined by computed radiographic densitometry. Serum bone turnover indices were measured serially, and incidence of non-vertebral fractures was recorded.

RESULTS Bone mineral densities decreased 1.2% in the treatment group compared with 6.7% in the placebo group during 18 months (p<0.0001). At baseline in both groups, the serum concentration of 1, 25-[OH]₂D was reduced. Parathyroid hormone was abnormally increased in 15 patients (17%) and correlated negatively with serum 25-hydroxyvitamin D, indicating compensatory hyperparathyroidism. Eight patients sustained fractures (six at the hip and two at other sites) in the placebo group, and one hip fracture occurred among treated patients (odds ratio 9.8; p=0.0028).

CONCLUSION By increasing serum 1, 25-[OH]₂D concentrations, treatment with 1α(OH)D3 can reduce the risk of hip and other non-vertebral fractures in osteoporotic elderly patients with Parkinson’s disease by slowing the loss of bone mineral densities.