Background: We previously reported that morning blood pressure (BP) surge (MBPS) was an independent risk factor for stroke. We evaluated the determinants of MBPS in hypertensive patients.
Methods: We analyzed 24-h ambulatory BP monitoring (ABPM) records in 458 hypertensive patients (mean: 72.2 +/- 8.5 years). The MBPS was calculated as the mean systolic BP (SBP) over 2 h after waking minus mean SBP during the hour of sleep that included the lowest nighttime BP. The cutoff value for identifying the top decile (the MBPS group) was defined as > or =55 mm Hg.
Results: The MBPS was associated with age, fasting plasma glucose, and 24-h SBP, and they were independent and significant determinants of MBPS in multivariate analysis (age, P = 0.01; fasting plasma glucose, P < 0.01; 24-h SBP, P = 0.04) after adjustment for confounding factors of gender, body mass index (BMI), and smoking status. The subjects in the MBPS group (n = 45) were older in age (76.4 years vs. 71.8 years, P < 0.01) and had higher fasting plasma glucose (97.6 mg/dl vs. 91.4 mg/dl, P = 0.04) than those in the non-MBPS group. In logistic regression analysis, the MBPS group was associated with older age (10 years older: odds ratio (OR) 1.85, 95% confidence interval (CI) 1.26-2.72, P < 0.01) and higher fasting plasma glucose (10-mg/dl increase: OR 1.16, 95% CI 1.01-1.33, P = 0.03).
Conclusion: In addition to older age and higher mean 24-h SBP, higher fasting plasma glucose was associated with MBPS.