Abstract P007: Age and Gender Differences in Response to Repeat Blood Pressure Measurement After Brief Rest Period

Abstract

Background: Office-based blood pressure (BP) measurement is a snapshot of a patient’s ambulatory BP, and is subject to variations which may influence management. The objective of this study is to assess the effect of age and gender on repeat BP measurement after a brief rest period in an outpatient cardiology clinic. Methods: Patient charts reviewed in University-based cardiology clinic identified 170 encounters which contained BP re-measurement data due to elevated initial BP of > 130/80 mmHg. BP was measured initially by a nurse, with the patient in a sitting position and the arm resting at the level of the heart. If BP was > 130/80 mmHg, it was repeated by physician after resting the patient for 15 minutes. There were: 86 males (51%); 84 females (49%); 113 (66%) elderly patients ≥ 60 years; 57 (34%) younger patients < 60 years. Results: Allowing 15 minutes of rest resulted in decrease in the systolic BP (SBP) from 153 ± 27 mmHg to 145 ± 27 mmHg (P = 0.003), and decrease in the diastolic BP (DBP) from 87 ± 16 mmHg to 83 ± 15 mmHg (P = 0.04) in the whole patient cohort. The decrease in SBP was 8 mmHg in both males and females (P = NS); while the decrease in DBP was 5 mmHg in males and 2 mmHg in females (P = 0.04). The decrease in SBP was 11 mmHg in the elderly patients compared to 2 mmHg in the younger patients (P = 0.02), while the decrease in DBP was 3 mmHg in the elderly patients compared with 4 mmHg in the younger patients (P = NS). Conclusion: Hypertension is a challenging public health problem. JNC guidelines recommend that prior to BP measurement, persons should be seated quietly for at least 5 minutes in a chair, with feet on the floor, and arm supported at heart level. This resulted in a significant decrease in BP in our patients. In this study we found that, after a brief rest period, males and females decrease SBP to the same extent; males drop DBP greater than females; patients ≥ 60 years of age drop SBP greater than patients < 60 years of age. With a high reported prevalence rates of White-coat hypertension in the elderly, between 15% and 25%, this is a clinically significant observation that reinforces that physicians should remeasure the blood pressure, especially the subset of males and the elderly, in whom a bigger decrement may be detected in blood pressure measurement after a brief rest period.