Serum parathyroid hormone levels predict falls in older adults with diabetes mellitus

To examine the association between serum parathyroid hormone (PTH) levels and incident falls in older adults with diabetes mellitus.

Longitudinal analysis of incident falls over 1 year in a substudy of participants with diabetes mellitus in the Health, Aging and Body Composition Study.

Pittsburgh, Pennsylvania, and Memphis, Tennessee.

Well-functioning, community-dwelling black and white adults aged 70 to 79 with diabetes mellitus (N=472).

Measured baseline serum PTH. Self-report of falls over the subsequent 12 months. Baseline physical performance and self-reported demographic, behavioral, and health status measures including kidney function, chronic conditions, and medication use.

One-third (30.3%) of participants reported falling over 1 year of follow-up. Mean baseline serum PTH was 53.5+/-30.0 pg/mL in nonfallers and 62.6+/-46.2 pg/mL in fallers (P=.01). For every 1 standard deviation (36 pg/mL) increment in baseline serum PTH, there was approximately a 30% greater likelihood of reporting a fall in the subsequent year, after adjusting for age, sex, race, field center, alcohol consumption, body mass index, physical activity, and winter or spring season (adjusted odds ratio (aOR)=1.30, 95% confidence interval (CI)=1.06-1.59). Further adjustment for kidney function, chronic conditions, medication and supplement use, and physical performance attenuated the association slightly (aOR=1.26, 95% CI=1.01-1.58). A trend remained after additional adjustment for reported falls in the previous year.

Higher serum PTH was associated with incident falls in older, well-functioning men and women with diabetes mellitus. Further investigation aimed at understanding the underlying mechanism for the association between serum PTH and falls is needed.