Homocysteine-lowering therapy or antioxidant therapy for bone loss in Parkinson's disease

We investigated whether homocysteine (Hcy)-lowering therapy or an antioxidant prevented bone loss in Parkinson's disease (PD) patients taking levodopa. Forty-two PD patients with low bone mineral density (BMD) taking levodopa were randomly assigned to Hcy-lowering therapy (5 mg folate and 1500 μg vitamin B₁₂ daily), α-lipoic acid (α-LA) therapy (1200 mg daily), or control groups. Primary outcomes were BMD changes from baseline to 12 months. Secondary outcomes were changes in Hcy level, and C-telopeptide (CTX) levels at 12 months. Forty-one patients completed the study. Hcy-lowering therapy resulted in significantly greater BMD changes at the lumbar spine (4.4%), total femur (2.8%), and femur shaft (2.8%) than control (P = 0.005-0.023). BMD changes in the α-LA therapy group were similar to those of the control group, but changes at the trochanter (4.6%) were significantly greater in the α-LA therapy group than in the control group after adjustment for body mass index changes. Hcy concentrations decreased to 35.2% ± 13.4% in the Hcy-lowering therapy group, but increased in other groups. Serum CTX levels at 12 months tended to be lower in the Hcy-lowering group (0.442 ± 0.024 ng/mL) than control group (0.628 ± 0.039 ng/mL) (P = 0.159). This small trial suggests that Hcy-lowering therapy may prevent bone loss in PD patients taking levodopa.