Poster Presentation ESA-SRB-ANZBMS 2024 in conjunction with ENSA

Markers of blood pressure variability and their association with incident hip fracture: a secondary analysis of the Cardiovascular Health Study (#381)

Alexander J. Rodriguez 1 , Petra Buzkova 2 , Kenneth J. Mukamal 3 , Zhao Chen 4 , Howard A. Fink 5
  1. Bone and Muscle Research Group, School of Clinical Sciences at Monash Health, Monash University, Melbourne, Victoria, Australia
  2. Department of Biostatistics, School of Public Health, University of Washington, Seattle, WA, USA
  3. Department of Medicine, Beth Israel Deaconess Medical Center, Harvard University, Boston, Massachusetts, USA
  4. Department of Epidemiology & Biostatistics, School of Public Health, University of Arizona, Tucson, Arizona, USA
  5. Geriatric Research Education and Clinical Center, VA Health Care System, University of Minnesota, Minneapolis, MN, USA

Background: Blood pressure (BP), autonomic function and atherosclerosis have all been associated with incident hip fractures in the Cardiovascular Health Study (CHS). These entities may independently and/or concomitantly affect blood pressure variability (BPV). However, few studies have directly investigated the association of BPV with hip fracture.

 

Methods: Individuals who attended the 1994-95 visit and had BP measurements at >4 of the 6 visits between 1989/90 and 1994-95 were included. Measures of systolic (SBP), diastolic (DBP) and pulse pressure (PP) was estimated as: between-visit mean, between-visit slope (linear trajectory over time) and between-visit standard deviation (SD) of the observed residuals (departure from the linear trajectory). Incident hip fractures were recorded until 2015. Multivariable Cox models (95% confidence intervals, CI) estimated the association of BPV with hip fracture. Analyses were conducted in individuals not taking anti-hypertensive agents (aHTN), and then in all individuals.

 

Results: Among 1820 individuals not taking aHTN [60% women; age 76±5 years; 52% current/past smokers], 292 incident hip fractures (222 women, 70 men) occurred over 12±6 years mean follow-up. One SD increase (3.12mmHg) in DBP residual was associated with an 8.9% increased risk (1.00-1.18) in men only. Among 3931 individuals taking aHTN [59% women; age 77±5years; 52% current/past smokers] 554 incident hip fractures (406 women, 148 men) occurred over a mean 11±6 years. One SD increase in PP residual (4.64mmHg) was associated with a 2.3% (1.00-1.04) increased risk in the total cohort. In men, a one SD increase in SBP residual (5.39mmHg) was associated with a 5.5% increased risk (1.02-1.09).

 

Interpretation: We observed several statistically significant, but small magnitude associations between BPV and incident hip fracture risk, predominantly in men. However, findings may have been attributable to chance, and their clinical utility is uncertain. BPV may offer increased insight into the contribution of BP control on bone health.