Serum level of osteoprotegerin in patients with Parkinson’s disease: a preliminary study

Introduction:
Osteoprotegerin (OPG) has recently been suggested to be involved in the pathophysiology of Parkinson’s disease (PD).

Aim of the research:
To compare serum OPG levels in PD patients versus controls with mild headache or back pain (CG1) and acute ischaemic stroke (CG2) and evaluate the relationship between serum OPG level and 1) PD duration, 2) parathyroid hormone (PTH), vitamin D [25(OH)D], total calcium and 3) serum total cholesterol (TC), high-density lipoprotein cholesterol, low-density lipoprotein cholesterol and triglyceride levels.

Material and methods:
In the included 45 PD patients – 20 with initial PD (iPD) and 25 with advanced PD (aPD) and 50 controls (20 CG1, 30 CG2) – we measured serum OPG levels using a sandwich enzyme-linked immunosorbent assay and analysed data applying Student’s t, Mann-Whitney, c² tests, Pearson’s correlation and linear regression analysis.

Results:
OPG serum level was lower in iPD compared to CG2 subjects (p = 0.026). OPG level depended on the duration of PD (p < 0.01) and TC level (p < 0.03) in PD patients, on 25(OH)D level (p < 0.04) in CG1 and on TC (p < 0.05) and PTH (p < 0.01) levels in CG2.

Conclusions:
Our results indicate that serum OPG level increases with PD duration and is associated with serum TC level in PD and ischaemic stroke patients.