Correlates of non-dipping blood pressure in persons with and without hypertension

Abstract Background Blood pressure (BP) is known to follow a circadian rhythm with 10% to 15% lower values during the night than daytime. Non-dipping BP refers to the absence of BP dipping and has been associated with the development of target organ damage. The general goal of this study was to determine the correlates of non-dipping BP in persons with and without hypertension. Methods This was a cross-sectional study that recruited 98 participants at Chikankata Mission General Hospital. The outcome variable of the study was non-dipping BP, with sociodemographic and clinical explanatory variables. We used SPSS version 22 to describe and make inferences. Results The median (interquartile range (IQR)) age of participants was 42 years (34.7-52) and 54.1% (53/98) had hypertension while 45.9% (45/98) were normotensive. The proportion of females was slightly higher (59.2%, n=58) than that of males (40.2%, n=40), this being similar in hypertensives but equal in normotensives. The median (IQR) age of hypertensives was higher compared to the normotensives, 46 (40-56) vs. 35 (25-41) years. The prevalence of non-dipping BP was 38.8% overall and higher among those with hypertension (54.7%) compared to the normotensive group (20%). The factors associated with non-dipping BP in the multivariate analysis were age (adjusted odds ratios (AOR) of 1.15; 95% CI: 1.05 - 1.25), spot urine sodium (AOR of 1.16; 95% CI: 0.99 - 1.36), daytime systolic blood pressure (SBP) load (AOR of 1.28; 95% CI: 1.06 - 1.55), daytime diastolic blood pressure (DBP) load (AOR of 0.77; 95% CI: 0.65 - 0.92), and nighttime DBP load (AOR of 1.10; 95% CI: 1.02, 1.18). However, this was abrogated by hypertension status albeit among normotensives only age remained significantly associated with non-dipping BP, none of the factors remained significantly associated with non-dipping BP among persons with hypertension. Conclusion The prevalence of non-dipping BP was high, among hypertensives. This provides insights into the intricate links between BP patterns, sociodemographic and clinical characteristics but further underscores the need for mechanistic researches to further advance the understanding of mechanisms of associated characteristics.