The association of antihypertensives with postural blood pressure and falls among seniors residing in the community: a case control study

BACKGROUND: A drop in postural blood pressure(BP) may contribute to falls, while antihypertensives have been considered to induce postural drop or orthostatic hypotension (OH) and falls among older people. However, this relationship between antihypertensives, postural BP and the risk of falls has never been evaluated in a single study.

OBJECTIVE: To examine the association of postural BP changes and BP therapy with the risk of falls among community-dwelling older people in a case-control manner.

METHOD: Cases(n=202) included participants aged ≥65years with two falls or one injurious fall while controls(n=156) included participants ≥65years with no falls in the preceding 12months. Antihypertensives usage and medical history were recorded. Supine blood pressure measurements were obtained at 10minutes' rest and at 1,2 and 3 minutes after standing. Orthostatic hypotension was defined as a reduction in BP of 20mmHg/10mmHg within 3 minutes of standing.

RESULTS: Individual antihypertensive classes were not associated with falls. Minimal standing systolic BP(SBP) was significantly lower among fallers [128(±27.3)vs.135.7(±24.7)mmHg;p=0.01], but fallers were not more likely to fulfil the diagnostic criteria for OH. Diuretics were associated with OH and α-blockers were associated with minimal standing SBP. The use of ≥2 antihypertensives was significantly associated with recurrent and injurious falls [OR,1.97;CI,1.2-3.1], which was not attenuated by adjustment for either OH or minimal standing SBP, but was no longer significant after adjustment for age and number of comorbidities [OR, 1.6; CI, 0.95-2.6].

DISCUSSION: Minimal standing SBP or a lower SBP at 2 or 3 minutes standing was associated with falls rather than OH using consensus definition, while the association between ≥2 antihypertensives and falls was attenuated by age and comorbidities but not by OH or minimal standing SBP, challenging previous assumptions that antihypertensives are associated with OH related falls. Future studies should now seek to link these findings prospectively with falls in order to guide decision-making for BP lowering therapy among older patients. This article is protected by copyright. All rights reserved.