Shahrul Kamaruzzaman

Sir— We appreciated Dr MacMahon and colleagues’ letter commenting on our paper and the accompanying editorial [1]. We agree that there is no strong evidence on the effects on falls of withdrawing antihypertensive medication in people with postural symptoms or in those with asymptomatic orthostatic hypotension (OH). We did not conclude that OH alone should be a criterion for withdrawing antihypertensive treatment. Data from the British Women’s Heart & Health Study have shown that falls are more strongly associated with co-morbidity than with polypharmacy [2, 3]. We did show that OH was twice as prevalent in women with undiagnosed and uncontrolled high blood pressure. On the basis of the findings presented in our paper, we concluded that ‘uncontrolled hypertension, use of three or more antihypertensives and multiple co-morbidities are predictors of OH in older women. Detection or monitoring of OH in these groups may prevent women from suffering its adverse consequences’.

Objective: to determine the prevalence of orthostatic hypotension (OH) and associations with medication use in community-dwelling older women. Design: cross-sectional analysis using data from the British Women’s Heart and Health Study. Setting: general practices in 23 towns in the UK. Participants: 3,775 women aged 60–80 years from 1999 to 2001. Main outcome measure: orthostatic hypotension—drop of ≥20 mmHg in systolic and/or a drop of ≥10 mmHg in diastolic blood pressure on standing. Results: prevalence of OH was 28% (95% confidence interval [CI] 26.6, 29.4), which increased with age and hypertension. Regardless of treatment status or diagnosed hypertension, raised blood pressure was strongly associated with OH (P < 0.001). OH was strongly associated with number of antihypertensives taken (none vs three or more: odds ratio [OR] 2.24, 95% CI 1.47–3.40, P < 0.001); the association was slightly attenuated after allowing for age and co-morbidities (OR 1.99; 95% CI 1.30, 3.05; P = 0.003). Women with multiple co-morbidities had markedly increased odds of OH independent of age, number and type of medications taken (none vs four or more diagnoses: OR 2.28, 95% CI 1.58–3.30, P = 0.005). Conclusion: uncontrolled hypertension, use of three or more antihypertensives and multiple co-morbidities are predictors of OH in older women. Detection or monitoring of OH in these groups may prevent women from suffering its adverse consequences.