Patients with Parkinson's disease, with or without osteoporosis more likely to experience hip fractures

Tae lim Kim et al conducted a nationwide database study on the risk of fractures and the impact of osteoporosis on patients with Parkinson's disease (PD) compared to controls. They found that patients with PD, with or without osteoporosis, are more likely to experience fractures, especially hip fractures. There seems to be no interaction between PD and osteoporosis in regard to the occurrence of fractures, and therefore no effect modification by osteoporosis.

Although there are many reasons why patients with PD have a greater risk of fracture, greater fall risk and decreased bone mineral density are the most frequently reported causes. PD is the most common movement disorder, and falls have been identified as a common complication in people with PD. Osteoporosis and osteopenia are also prevalent confounding factors, with an occurrence rate of up to 91% in female patients with PD. Reduced mobility, malnutrition, reduced sunlight exposure time resulting in 25-(OH) D deficiencies, and endocrine factors, such as hyperhomocysteinemia, vitamin B12, and folic acid deficiencies, are the leading risk factors for osteoporosis in patients with PD.

With a unique registration program for PD and other rare diseases, the Korean National Health Insurance Service (NHIS) database provides reliable data for investigating all patients with PD. The database includes almost the entire population of one country and is sufficient for evaluating many confounding factors simultaneously. Therefore, the authors conducted a population-based study using this database to investigate the relative risk of overall fracture and hip fracture in patients with PD compared to the general population over 10 years from diagnosis, with adjustment for confounding factors.

Using a nationwide database in South Korea, the authors identified incident patients with PD and selected four age- and sex-matched controls. They checked the occurrence rates of overall and hip fractures and plotted Kaplan–Meier curves and a Cox proportional hazards model to determine risk. They also conducted stratified analyses according to the presence or absence of osteoporosis.

The observations of the study were:

• 9126 patients (3637 men, 39.85%; 5489 women, 60.15%) with PD and 35,601 controls (14,049 men, 39.46%; 21,552 women, 60.54%).

• Patients with PD had a greater probability of fractures throughout the study period in Kaplan–Meier curves, and an increased risk of overall (aHR 1.35, 95% CI 1.297–1.405) and hip (aHR 1.814, 95% CI 1.66–1.983) fractures in a Cox proportional hazards model.

• In the stratified analysis, the increased risk of overall fracture (aHR 1.333, 95% CI 1.273–1.396 and aHR 1.412, 95% CI 1.301–1.532, respectively) and hip fracture (aHR 1.773, 95% CI 1.604–1.96 and aHR 2.008, 95% CI 1.657–2.434, respectively) due to PD was similar between patients with and without osteoporosis.

The authors concluded that - Patients with PD were more likely to experience fractures than the general population throughout the course of the disease. The risk of fractures was higher in patients with PD than in controls, and it was twice as high for hip fractures, even after adjusting for other confounders. In addition, patients with PD showed a similarly increased risk of fractures, regardless of coexisting osteoporosis. It seems that there might be no interaction between PD and osteoporosis in the occurrence of a fracture. The results will help clarify the risk of fractures due to PD and control modifiable risk factors to prevent them.

Further reading:

Fracture risk and impact of osteoporosis in patients with Parkinson's disease: a nationwide database study Tae lim Kim, Seong Jun Byun et al Journal of Bone and Mineral Metabolism (2022) 40:602–612 https://doi.org/10.1007/s00774-022-01322-w