Achieved Blood Pressure And The Risk Of Osteoporotic Fracture

Objective: Optimal blood pressure (BP) target has been debated. Studies have linked intensive BP lowering with the risk of injurious fall or fracture. This study aimed to investigate the association between achieved BP level and the risk of osteoporotic fracture among hypertensive patients who are taking BP lowering treatment.Design and method: Adults aged 40 years or older who were free from cardiovascular disease and taking antihypertensive medication were extracted from the National Health Insurance Service-National Health Screening cohort. The exposure variable was the mean BP during the study duration. Osteoporotic fracture was the primary outcome variable, which included fractures of the femur neck, spine, distal radius and humerus. The association of achieved BP level and the risk of fracture was analyzed using restricted cubic spline and Cox proportional hazard models. Results: A total of 153,185 hypertensive patients who were under treatment were included in this analysis. Subjects who experienced fracture showed a higher risk of mortality than those who did not (hazard ratio [HR], 1.49; 95% confidence intervals (CI), 1.40 to 1.60; P < 0.001). While major cardiovascular events accounted for 41.7% of mortality in this study population, osteoporotic fracture explained 7.3% of future deaths from any cause. As shown in Figure, the risk of facture was inversely associated with achieved systolic BP after adjustment for age and sex. Every 10-mmHg lower systolic BP was associated with a 3.7% increase in the risk of fracture. Compared to achieved systolic BP of >140 mmHg, the adjusted risks with BP of 120–129 mmHg and <120 mmHg were 1.07 (95% CI, 1.02 to1.13; P = 0.005) and 1.10 (95% CI, 1.04 to1.18; P = 0.002), respectively. In the meantime, diastolic BP showed no significant relationship with fracture risk (HR, 0.99; 95% CI, 0.96 to 1.01; P = 0.240). Conclusions: We found that lower achieved BP was associated with increased risk of osteoporotic fracture. Clinicians should weigh the risk and benefit of BP lowering when treating hypertension medically. This study also suggests systolic rather than diastolic BP be considered the primary safety indicator.