Prevalence of Circadian Blood Pressure Patterns and Factors Associated with Non-Dipping among Black Patients with Untreated and Treated Hypertension: A Cross-Sectional Study

Objective: To determine the prevalence of circadian BP patterns and to assess factors associated with the non-dipping pattern in untreated and treated hypertensive patients, studied separately. Methods: Clinical data and ABPM were obtained from 52 untreated and 168 treated hypertensive patients referred for ABPM to Monkole Hospital in Kinshasa. Twenty-four ABPM was performed using an oscillometric device. Non-dipping pattern encompasses non-dipping (nocturnal systolic BP dip less than 10% of daytime systolic BP) and reverse dipping (mean night SBP higher than the day SBP). Results: the prevalence of non-dipping pattern was 75% (63.5% non-dipping and 11.5% reverse dipping) and 70% (60.1% non-dipping and 10.1% reverse dipping) in untreated and treated hypertensive patients, respectively. Advanced age (adjusted OR 1.80; 95%CI 1.96 - 3.38; p = 0.015), female sex (adjusted OR 2.28; 95%CI 1.19 - 4.36; p = 0.013), diabetes (adjusted OR 5.06; 95%CI 1.38 - 6.95; p = 0.014), reduced kidney function (adjusted OR 3.10; 95%CI 1.50 - 6.43; p = 0.018), inflammation (adjusted OR 2.65; 95%CI 1.76 - 6.48; p = 0.031), LVH (adjusted OR 4.45; 95%CI 1.78 - 7.67; p = 0.024) and antihypertensive therapy (adjusted OR 0.19; 95%CI 0.12 - 0.64; p = 0.018) emerged as the main independent factors significantly associated with the non-dipping pattern in the study population. Conclusion: the non-dipping pattern was a common finding in studied patients and associated with traditional and emerging risk factors suggesting that this abnormal pattern could be a marker of high cardiovascular risk.