Diagnosing hypertension in primary care: a retrospective cohort study to investigate the importance of night-time blood pressure assessment

Background Ambulatory blood-pressure monitoring (ABPM) has become less frequent in primary care since the COVID-19 pandemic,with home blood-pressure monitoring (HBPM) of ten the preferred alternative;however, HBPM cannot measure night-time blood pressure (BP), and patients whose night-time BP does not dip, or rises (reverse dipping), have poorer cardiovascular outcomes. Aim To investigate the importance of measuring night-time BP when assessing individuals for hypertension. Design and setting Retrospective cohort study of two patient populations - namely, hospital patients admitted to four UK acutehospitals located in Oxfordshire, and participants of the BP in different ethnic groups (BP-Eth) study, who were recruited from 28 UK general practices in the West Midlands. Method Using BP data collected for the two cohorts,three systolic BP phenotypes (dipper, non-dipper, and reverse dipper) were studied. Results Among the hospital cohort, 48.9% (n = 10 610/21 716) patients were' reverse dippers',with an average day-night systolic BP difference of +8.0 mmHg. Among the community (BP-Eth) cohort, 10.8%( n = 63/585) of patients were reverse dippers, with an average day-night systolic BP difference of +8.5 mmHg. Non-dipper and reverse-dipper phenotypes both had lower day time systolic BP and higher night-time systolic BP than the dipper phenotype. Average daytime systolic BP was lowest in the reverse-dipping phenotype (this was 6.5 mmHg and 6.8 mmHg lower than for the dipper phenotypein the hospital and community cohorts, respectively), there by placing them at risk of undiagnosed, or masked, hypertension. Conclusion Not measuring night-time BP puts reverse dippers (those with a BP rise at night-time) at risk of failure to diagnose hypertension.As a result of this study,it is recommended that GPs should offer ABPM to all patients aged >= 60 years as a minimum when assessing for hypertension.

Automated summary

The study emphasizes the importance of measuring night-time blood pressure when assessing individuals for hypertension. It found that not measuring night-time blood pressure puts reverse dippers (those with a rise in blood pressure at night) at risk of failure to diagnose hypertension. Therefore, it is recommended that general practitioners offer ambulatory blood-pressure monitoring (ABPM) to all patients aged >= 60 years as a minimum when assessing for hypertension.