Initial experience with 24-h ambulatory blood pressure monitoring in Nigerian patients with hypertension

Context: Ambulatory blood pressure monitoring (ABPM) is superior to office blood pressure (OBP) in predicting hypertension control/outcome. Despite the growing burden of hypertension in Africa, ABPM use remains rudimentary. Aims: To report our initial ABPM experience in Nigeria. Setting and Design: Ongoing prospective descriptive study, involving consecutive recruitment of consenting patients' ≥18 years, presenting at DOCS Heart Centre Enugu Nigeria. Methods: The study involved 78 hypertensive patients attending the clinic from May, 2013. OBP was taken in sitting position, using oscillometric BP device. Each patient was then monitored over 24 h with a Tonoport V (GE CS V6 71[21]), interpreted using GE CardiosoftTM ABPM software in accordance with British Medical Council guidelines. Statistical Analysis: Data were analyzed using EPI Info (version 3.3.5). Continuous variables were expressed as means ± standard deviation. Differences between group means were tested using two-tailed Student's t-test. Proportions were reported as percentages and compared between groups with Chi-square. Results: The study involved 78 adult hypertensive patients; mean age of the patients was 53 ± 13 years and body mass index 30.0 kg/m2, 53.8% were males. Control on OBP was 17.9%, on ABPM 24.4%. The mean 24-h BP was 144 ± 16/88 ± 10 mmHg; daytime BP, 146/90 ± 17/11 mmHg; night-time BP, 139/81 ± 17/9 mmHg; and waking BP 149/88 ± 20/14 mmHg. Borderline hypertension was seen in 4.5%, sustained hypertension in 36.4%, white coat hypertension in 13.6%, and nocturnal hypertension in 22.7%. The majority of patients had abnormal dipping pattern, with enormous BP load, 89.2% having a high load. Conclusion: BP control was better represented by ABPM more than OBP in the patients; showing that to optimize management, greater use of ABPM is a more pragmatic approach to mitigate the adverse outcomes among hypertensive patients.