Diurnal rhythm of blood pressure among Nigerians with hypertension using 24-hour ambulatory blood pressure monitoring

Abstract

Introduction: hypertension is the most common cardiac disease in Nigeria. There are very limited studies in Nigeria on the use of 24-hour ambulatory blood pressure monitoring (24-h ABPM) for evaluation of hypertensive patients. Twenty four-hour ABPM, unlike office blood pressure (OBP), can assess diurnal variation using parameters like awake blood pressure (BP), asleep (nocturnal) BP, mean 24-hour BP and dipping pattern. This can help in assessment of increased cardiovascular risk and management of hypertensive patients. We purposed to assess the diurnal rhythm of BP among Nigerians with hypertension.

Methods: this was a prospective cross-sectional study. Consecutive 77 hypertensive subjects were studied using Schiller MT-300 for 24-h ABPM.

Results: out of the 77 patients reviewed, 39 (50.6%) were females. The mean age was 50.9 years (SD 13.5). The mean awake systolic and diastolic BP were 135.6mmHg (SD 15.0) and 83.2mmHg (SD 10.0) respectively; mean asleep systolic and diastolic BP were 127.6mmHg (SD 17.9) and 76.2mmHg (SD 12.2) respectively; and mean 24-h systolic and diastolic BP were 133.6mmHg (SD 15.3) and 81.4mmHg (SD 10.2) respectively. Awake BP was elevated in 59.7% of study subjects. Elevated awake systolic BP and awake diastolic BP were present in 50.6% and 41.6% of the study population. Nocturnal (asleep) BP was elevated in 79.2%. Non-dipping pattern was the most prevalent pattern at 55.8%, followed by dipping (24.7%), reverse dipping (15.6%) and extreme dipping (3.9%).

Conclusion: a high proportion had nocturnal hypertension (79.2%) and non-dipping pattern was the most prevalent pattern (55.8%). Mean awake systolic BP, mean asleep systolic and diastolic BP and mean 24-h systolic and diastolic BP were elevated. The use of 24-h ABPM will enhance assessment of increased cardiovascular risk and management of Nigerians with hypertension.