Frailty and rate of fractures in patients initiating antihypertensive medications: a cohort study in primary care

Abstract BackgroundTreatment for hypertension improves cardiovascular outcomes. Frailty is common in people treated for hypertension, and associated with increases in adverse drug effects, potentially including falls resulting in fractures. We aimed to determine the association between baseline frailty and fractures in patients initiated on antihypertensive treatment. MethodsWe conducted a retrospective cohort study using United Kingdom primary care data, including new-users of first-line antihypertensives aged 65 years or over. We reported degree of frailty (fit, mild, moderate, severe) at antihypertensive initiation using the Electronic Frailty Index. We examined the association of frailty with fractures using multivariable Poisson regression, and assessed for interaction between antihypertensive class and frailty. Results49634 (43%) people initiated on first-line antihypertensives were mildly or more frail. Over 4.1 years mean follow-up, 6567 (5.8%) experienced a fracture, with 3832 (58%) of these fractures occurring in frail people. Among those with severe frailty doubling of fracture risk was observed after antihypertensive initiation, compared with fit people [adjusted rate ratio 2.26 (95% CI 1.93-2.65)]. This pattern was replicated for hip and arm fractures, and strongest for spine fractures. The association between different types of antihypertensives and fractures varied by frailty (P=0.004), with a lower rate in moderately frail users of renin-angiotensin blockers compared with calcium-channel blockers (RR 0.81 95% CI 0.71-0.94) ConclusionsFrailty is common among people initiating first-line antihypertensive treatment, and was associated with an increased fracture rate. Awareness of this is important to encourage clinicians to consider risk of falls and fractures when treating hypertension.