Relevance to Home Blood Pressure Monitoring Protocol of Blood Pressure Measurements Taken Before First-Morning Micturition and in the Afternoon

Background

The importance of measuring blood pressure before morning micturition and in theafternoon, while working, is yet to be established in relation to the accuracy ofhome blood pressure monitoring (HBPM). Objective: To compare two HBPM protocols,considering 24-hour ambulatory blood pressure monitoring (wakefulness ABPM) asgold-standard and measurements taken before morning micturition (BM) and in theafternoon (AM), for the best diagnosis of systemic arterial hypertension (SAH),and their association with prognostic markers.

Methods

After undergoing 24-hour wakefulness ABPM, 158 participants (84 women) wererandomized for 3- or 5-day HBPM. Two variations of the 3-day protocol wereconsidered: with measurements taken before morning micturition and in theafternoon (BM+AM); and with post-morning-micturition and evening measurements(PM+EM). All patients underwent echocardiography (for left ventricular hypertrophy- LVH) and urinary albumin measurement (for microalbuminuria - MAU).

Result

Kappa statistic for the diagnosis of SAH between wakefulness-ABPM and standard3-day HBPM, 3-day HBPM (BM+AM) and (PM+EM), and 5-day HBPM were 0.660, 0.638,0.348 and 0.387, respectively. The values of sensitivity of (BM+AM) versus (PM+EM)were 82.6% × 71%, respectively, and of specificity, 84.8% × 74%, respectively. Thepositive and negative predictive values were 69.1% × 40% and 92.2% × 91.2%,respectively. The comparisons of intraclass correlations for the diagnosis of LVHand MAU between (BM+AM) and (PM+EM) were 0.782 × 0.474 and 0.511 × 0.276,respectively.

Conclusions

The 3 day-HBPM protocol including measurements taken before morning micturitionand during work in the afternoon showed the best agreement with SAH diagnosis andthe best association with prognostic markers.