Prevalence and factors associated with ambulatory blood pressure phenotypes in a semi-urban Nigerian population

Office blood pressure (BP) measurement alone may underestimate the true burden of abnormal BP regulation, particularly in sub-Saharan Africa, where ambulatory blood pressure monitoring (ABPM) remains underutilised. This study characterised the distribution and sociodemographic factors of ABPM-derived hypertension phenotypes in a semi-urban Nigerian population. This community-based cross-sectional study enrolled 348 adults in Ido-Ekiti, Nigeria, who underwent 24-hour ABPM alongside standardised office BP measurement. Phenotypes (white-coat, masked, sustained hypertension, and true normotension) and circadian abnormalities (nocturnal and morning hypertension) were classified using 2024 European Society of Hypertension thresholds. Associations with sociodemographic and lifestyle factors were assessed using chi-square tests and multivariable logistic regression. Sustained hypertension was present in 36.9% of participants, white-coat hypertension in 17.8%, masked hypertension in 5.0%, and true normotension in 40.3%. Nocturnal hypertension (56.8%) and morning hypertension (40.6%) were highly prevalent. Age showed the strongest and most consistent gradient across nearly all phenotypes (all P < 0.001), with sustained and nocturnal hypertension rising sharply and true normotension declining with advancing age. Female participants had significantly higher morning hypertension (46.4% vs. 33.3%, P = 0.013) and lower true normotension (29.6% vs. 41.0%, P = 0.025) than males. Monthly income showed phenotype-specific, non-uniform associations with sustained, morning, nocturnal hypertension, and true normotension, while showing no association with white-coat hypertension. ABPM revealed a substantial burden of abnormal BP patterns, particularly sustained, nocturnal and morning hypertension, with pronounced age-related variation. These findings support wider ABPM adoption in African clinical practice, while socioeconomic and behavioural associations should be regarded as hypothesis-generating rather than causal.