@article {9004, title = {Cardiovascular autonomic nervous system function and hip fracture risk: the Cardiovascular Health Study.}, journal = {Arch Osteoporos}, volume = {16}, year = {2021}, month = {2021 10 31}, pages = {163}, abstract = {

Among 1299 older adults with 24-h Holter monitoring data at baseline, followed for approximately 15~years, 190 incident hip fractures occurred. Increased heart rate variability was independently associated with reduced risk of hip fracture among female participants.

PURPOSE: Autonomic nervous system function modulates bone remodeling in rodent osteoporosis models. We tested whether cardiovascular autonomic function is associated with hip fracture risk in humans.

METHODS: Participants were 1299 subjects from the Cardiovascular Health Study (mean age 72.8~years). Eight heart rate variability (HRV) measures (time and frequency domains, detrended fluctuation analysis variables, and heart rate turbulence) were derived from 24-h Holter monitor scans in sinus rhythm. Median follow-up for incident hip fracture was 14.7~years [IQR 9.1, 20.2]. Cox proportional hazards models were used to calculate hazard ratios (95\% confidence intervals, CI).

RESULTS: There were 144 hip fractures among 714 women (1.31 [1.06, 1.61] per 100-person years) and 46 among 585 men (0.62 [0.43, 0.90] per 100 person-years). From among HRV variables examined, a one standard deviation (SD) higher variation between normal heart beats over 24~h (the SD of NN intervals [SDNN]) was associated with a multivariable-adjusted lower hip fracture risk (HR [Formula: see text] 0.80; 95\% CI 0.65-0.99; p = 0.04) in women. The adjusted association between very low frequency power, and hip fracture was borderline statistically significant in women (HR [Formula: see text] 0.82; 95\% CI, 0.66-1.00; p = 0.06). When the 8 HRV variables were considered conjointly and adjusted for each other{\textquoteright}s association with hip fracture risk, a 1 SD higher SDNN value was significantly associated with reduced hip fracture risk in women (HR 0.74; 95\% CI, 0.50-0.99; p = 0.05). No HRV variables were associated with hip fracture in men.

CONCLUSIONS: In older women, increased heart rate variation is associated with hip fracture risk.

}, keywords = {Aged, Autonomic Nervous System, Female, Heart Rate, Hip Fractures, Humans, Osteoporosis, Proportional Hazards Models}, issn = {1862-3514}, doi = {10.1007/s11657-021-01028-y}, author = {Stein, Phyllis K and B{\r u}zkov{\'a}, Petra and Fink, Howard A and Robbins, John A and Mukamal, Kenneth J and Cauley, Jane A and Carbone, Laura and Elam, Rachel and McMillan, David W and Valderrabano, Rodrigo and Barzilay, Joshua I} }