Age is an Independent Risk Factor for the Early Morning Blood Pressure Surge in Patients Never-Treated for Hypertension

Background and objectives: The early morning blood pressure surge (EMBPS) has been reported to be associated with cardiovascular events. The aim of this study was to investigate the relationship between 24-hour ambulatory BP monitoring (ABPM) parameters and conventional cardiovascular risk factors.

Subjects and methods: Patients (n=346) never-treated for essential hypertension with no other cardiovascular risk factors, such as diabetes, dyslipidemia, and nephropathy were enrolled. The EMBPS was defined as the early morning systolic BP minus the lowest night systolic BP. We compared the 24-hour ABPM parameters in two groups divided by age (<60 and >/=60 years) and examined the association between the 24-hour ABPM parameters and cardiovascular risk factor.

Results: The EMBPS (18+/-14 vs. 24+/-14 mmHg, p=0.002), 24-hour mean blood pressure {MBP; 102+/-9 vs. 105+/-11 mmHg, p=0.044}, and 24-hour mean pulse pressure (PP; 52+/-10 vs. 58+/-11 mmHg, p<0.001) were significantly increased in the elderly subjects compared to the younger subjects. The degree of decrease was less in the elderly subjects (10+/-8 vs. 7+/-10%, p=0.002). Based on multivariate analysis, age was an independent risk factor for the highest quartile of EMBPS (>28 mmHg) after adjusting for gender differences, body mass index, and various 24-hour ABPM parameters (odds ratio, 1.051; 95% confidence interval, 1.028-1.075; p<0.001).

Conclusion: Age is an independent risk factor for EMBPS in patients with never-treated hypertension. BP control in the early morning period is more important in elderly patients so as to prevent cardiovascular events.