Inter-Arm Blood Pressure Difference Among Nigerian Primary Care Patients— the Need for Dual Arm Blood Pressure Measurement

Background: For many decades, hypertension guidelines have recommended dual-arm blood pressure measurement. However, the practice is poor in Nigerian primary care and its significance largely unidentified. Hence, the need to determine the significance of detecting inter-arm blood pressure difference among primary care patients in our local population. This study was done to determine the point prevalence of inter-arm blood pressure difference and its relationship with hypertension and diabetes mellitus. Methods: A cross-sectional study was conducted among 214 respondents at the general outpatient clinic of a tertiary hospital in Nigeria. Demographic characteristics and anthropometric indices were obtained. Blood pressure readings were obtained through sequentially repeated measurements in respondents’ arms. Results: One hundred and eighty-six respondents had complete data given a completion rate of 86.9%. Systolic blood pressure was higher on the right and left arm in 102 (54.8%) and 56 (30.1%) of the respondents respectively. Diastolic blood pressure was higher on the right and left arm in 73 (39.2%) and 63 (33.9%) of the respondents respectively. The overall prevalence of significant systolic inter-arm difference (≥ 10 mmHg) and diastolic inter-arm difference (≥ 10 mmHg) were 24.2% and 18.8% respectively. Significant systolic inter-arm difference (p=0.033) and diastolic inter-arm difference (p=0.01) were significantly more among respondents with hypertension and/or diabetes mellitus. Conclusion: The blood pressure readings in both arms were different among majority of the respondents, being higher on the right arm in more of them. The prevalence of significant inter-arm difference was high in the unselected primary care patients studied especially among patients with hypertension and/or diabetes mellitus. Blood pressure measurement in both arms should become a routine practice during initial patients’ visits in primary care.