High parathyroid hormone levels are associated with poor balance in older persons: A cross-sectional study.

OBJECTIVES: A high level of parathyroid hormone (PTH) was recently identified as a risk factor for falling. As balance instability is one of the major risk factors for falls, we aimed to investigate whether high PTH concentrations are associated with poor balance in older persons.

STUDY DESIGN: Cross-sectional study with 127 community-dwelling older adults (75% female), aged 65-96 years, at the Falls and Fracture Clinic, Western Health-Sunshine Hospital, Melbourne, Australia. Patients with clinical conditions that could affect balance (e.g. Meniere's disease), denosumab users, and those with advanced kidney failure were excluded.

MAIN OUTCOME MEASURES: We assessed dynamic balance by timed "up and go" (TUG)and four-square step tests, and by gait parameters; and static balance by posturography on a force platform. Blood tests provided values of PTH, vitamin D, calcium, albumin, and creatinine. Standard questionnaires were applied to assess clinical condition, medications and nutritional status, and to screen for depression.

RESULTS: For dynamic balance, elevated PTH concentrations resulted in increased time to complete the TUG test (β = 0.13; 95%CI: 0.01-0.26), indicating worse performance. For static balance, increased PTH was associated with increased instability in the center of pressure while standing with eyes closed on a hard surface (β = 0.38; 95%CI: 0.03-0.73). Both models were controlled for vitamin D, renal function, nutritional and depressive status, age, sex, and number of medications.

CONCLUSION: Increasing concentrations of PTH in this population of older persons had an independent negative association with both static and dynamic balance, which could place them at risk of falls. However, longitudinal studies are still required.