Background
Medications used to treat hypertension may affect fracture risk. This study investigated fracture risk for users of angiotensin converting enzyme inhibitors (ACEI) or angiotensin II receptor blockers (ARB).
Methods
Participants (899 men, 574 women, age≥50yr) were from the Geelong Osteoporosis Study. Medication use was self-reported and incident fractures were ascertained using radiological reports. Bone mineral density (BMD) was measured at the femoral neck. Participants were divided into four groups: 1) non-users without hypertension, 2) non-users with hypertension, 3) ACEI users and 4) ARB users. Dosage was calculated using the defined daily dose (DDD) criteria. Participants were followed from date of visit to first fracture, death or 31 December 2016, whichever occurred first. Cox proportional hazards models were used for analyses.
Results
At least one incident fracture was sustained by 156 men and 135 women over a median(IQR) of 11.5(6.2-13.2) and 10.9(6.3-11.6) years of follow-up, respectively.
For men, in unadjusted analyses, compared to non-users without hypertension, all three other groups had higher risk of fracture (Hazard Ratio (HR)(95%CI): 1.54(1.00-2.37), p=0.049; 1.90(1.18-3.05), p=0.008; 2.15(1.26-3.66), p=0.005, for non-users with hypertension, ACEI and ARB users respectively). Following adjustment for age, prior fracture and BMD, these associations became non-significant. A dose effect for ARB use was observed; men using lower doses (DDD≤1.0) had a higher risk of fracture than non-users without hypertension, in both unadjusted (2.66(1.34-5.29), p=0.005) and adjusted (2.03(1.01-4.10), p=0.047) analyses.
For women, unadjusted analyses showed a higher risk for ACEI users compared to non-users without hypertension (1.74(1.07-2.83), p=0.025). This was explained after adjustment for age, alcohol consumption, prior fracture and BMD (1.28(0.74-2.22), p=0.375). No other differences were observed.
Conclusion
ACEI or ARB use was not associated with increased risk of incident fracture in women. However, in men, lower dose ARB use was associated with an increased risk of fracture.