Association of an abnormal blood glucose level and morning blood pressure surge in elderly subjects with hypertension

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 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.