OBJECTIVE

The aim of this study was to assess the determinants of home morning and evening blood pressure (BP) differences in general population.

METHODS

We studied a representative sample of the general Finnish adult population with 1919 study subjects, aged 41-74 years. Study subjects underwent a clinical interview, clinical examination and home BP measurement (28 measurements performed twice in the morning and in the evening during 7 consecutive days).

RESULTS

In untreated hypertensive subjects, systolic home BP was lower in the morning than in the evening while no difference was detected for diastolic home BP (137.7/85.1 vs 141.5/85.2 mmHg, p < 0.001/0.64). In treated hypertensive subjects, the difference between systolic morning and evening BP was smaller (136.2 vs 137.1 mmHg, p = 0.023) and diastolic morning BP was even higher than evening BP (83.3 vs 82.1 mmHg, p < 0.001). In the univariate analysis, higher home BP and higher body mass index were associated with relatively higher morning BP compared with evening BP. In addition, men, excessive alcohol users, subjects with cardiovascular disease, sleep apnea and subjects using antihypertensive medication had relatively higher morning BP compared with evening BP. In the multivariate analysis, male gender, excessive alcohol consumption, cardiovascular disease, sleep apnea and use of antihypertensive medication were independent determinants of elevated morning BP compared with evening BP.

CONCLUSION

Knowledge of the underlying causes affecting morning and evening home BP difference in patients facilitates physicians to make rational antihypertensive medication and lifestyle adjustments, such as examining probable sleep disorder, and give alcohol and cardiovascular disease prevention counseling.