The association between morning hypertension and metabolic syndrome in hypertensive patients

Morning hypertension (MHT) and metabolic syndrome (MS) have been reported as important risk factors for stroke and cardiovascular events. We investigated the prevalence of MHT and MS among hypertensive patients in our outpatient clinic from June to August, 2005. We studied 181 hypertensive patients (91 men and 90 women) in our outpatient clinic using home-use electronic sphygmomanometers. Seventy-nine of these 181 patients (43.6%) demonstrated MHT, defined as systolic blood pressure (SBP) > or = 135 mmHg in the morning. Only 48.1% of the patients demonstrated normal SBP both at the clinic and in the morning at home, whereas 72.9% of the patients demonstrated normal diastolic blood pressure (DBP) under the same conditions. Sixty-one patients (33.7%) had MS, and 34 patients had both MHT and MS. Twenty-seven of the 102 patients (26.5%) without MHT had MS. The frequency of MS was significantly higher among those with MHT than those without MHT (p = 0.019). Multiple logistic regression analysis including smoking, alcohol consumption, sex, and age as confounding factors showed significant association between MHT and MS (odds ratio: 1.99; 95% confidence interval: 1.04-3.80; p = 0.039). In conclusion, although 1 year has passed since the JSH 2004 guidelines, 43.6% of our patients still showed MHT, and there was a significantly higher prevalence of MS among those with MHT. Our results suggest the need for a more vigorous intervention for controlling BP.