Patterns of nocturnal dipping in patients undergoing ambulatory blood pressure monitoring in BPKIHS, Dharan: A Cross Sectional Study

Abstract

BACKGROUND Ambulatory blood pressure monitoring (ABPM) provides important information about circadian blood pressure variation. Normally, blood pressure declines by 10–20% during sleep (nocturnal dipping). Abnormal patterns such as non-dipping, extreme dipping, and reverse dipping are associated with increased cardiovascular risk. Data regarding nocturnal dipping patterns in the Nepalese population are limited.

AIMS To evaluate the prevalence of nocturnal dipping patterns and their association with cardiovascular risk factors among patients undergoing ABPM.

METHODS This observational cross-sectional study was conducted in the Department of Cardiology at B. P. Koirala Institute of Health Sciences (BPKIHS), Dharan. A total of 66 patients aged ≥18 years undergoing ABPM were included. Twenty-four-hour ABPM was performed using a validated oscillometric device. Patients were categorized into normal dipper, non-dipper, extreme dipper, and reverse dipper based on the percentage decline in nighttime systolic blood pressure. Demographic variables and cardiovascular risk factors were recorded. Statistical analysis was performed using descriptive statistics and chi-square test.

RESULTS Among 66 patients in the study, reverse dipping was the most common pattern observed in 26 patients (39.4%), followed by non-dipping in 24 patients (36.4%), normal dipping in 13 patients (19.7%), and extreme dipping in 3 patients (4.5%). In this study reverse dipping was more frequently observed in the 41–49 and 50–59 year age groups, although the association between age groups and dipping pattern was not statistically significant (p = 0.216). Similarly, there was no significant association  between dipping patterns and cardiovascular risk factors including diabetes mellitus (p = 0.39), hypertension (p = 0.36), and smoking (p = 0.24).

CONCLUSION Reverse dipping and non-dipping patterns were highly prevalent among patients undergoing ABPM in this study. However, no statistically significant association was found between dipping patterns and age groups or major cardiovascular risk factors in this study.