Abstract 2749: Age Is An Independent Risk Factor For Early Morning Surge In Untreated Hypertensives.
Background: 24-h ambulatory blood pressure monitoring(ABPM) is superior to official or home-monitored blood pressure(BP) values in assessing the circadian rhythm of BP. Recently, the early morning surge(EMS) has been reported to be associated with cardiovascular events. The aim of this study is to investigate the relationship between the parameters of 24-h ABPM and conventional cardiovascular risk factors.
Method: Untreated 346 patients (mean age: 48 ± 12yrs, M:F=175:171) diagnosed as essential hypertension without any other cardiovascular risk factors such as diabetes, dyslipidemia and nephropathy were enrolled. EMS was defined as early morning systolic BP minus the lowest night systolic BP. We compared the 24-h ABPM parameters in 2 groups divided by age of 60.
Results: 1. EMS (18.1 ± 14.4 vs. 24.0 ± 14.1mmHg, p=0.002), 24-h mean BP (105.3 ± 10.9 vs.102.1 ± 8.5 mmHg, p=0.044), 24-h mean pulse pressure(PP) (51.7 ± 9.9 vs. 57.5 ± 10.6 mmHg, p=0.001), day-time mean BP (108.7 ± 11.2 vs. 104.5 ± 9.2 mmHg, p=0.005), day-time mean PP (52.9 ± 10.4 vs. 58.2 ± 10.9 mmHg, p<0.001), and night-time mean PP (49.7 ± 11.0 vs. 53.9 ± 14.6 mmHg, p<0.001) were significantly increased in elderly subjects than young. 2. The degree of dipping (9.6 ± 7.7 vs. 7.2 ± 9.5%, p=0.002) was decreased in elderly subjects than young. 3. Age was an independent risk factor for highest quartile of EMS (>28 mmHg) after adjusting gender difference and body mass index (odds ratio: 1.043[95% confidence interval: 1.018 –1.068], p=0.001).
Conclusion: Age is an independent risk factor for EMS in untreated hypertensives. The BP control of the early morning period is more important in elderly patients to prevent cardiovascular events.