Diabetes and obesity are significant risk factors for morning hypertension: From Ibaraki Hypertension Assessment Trial (I-HAT)

Aims: Although morning hypertension (HT) has been identified as a major cardiovascular risk, susceptible populations remain unknown. This study aimed to clarify the relationship between morning HT and diabetes or obesity in a large-scale population. Main methods: Clinic blood pressure (BP) and BP upon awakening were recorded in 2554 outpatients with HT who attended 101 clinics or hospitals for two weeks. Mean clinic and awakening BP > 140/90 and > 135/85 mm Hg, respectively, were considered as HT. The patients were classified according to values for clinic and home BP, into normal BP, white coat HT, masked HT, and sustained HT. Key findings: Morning BP (mm Hg) significantly and progressively elevated in the order of normal glucose tolerance, impaired glucose tolerance and diabetes (134.1 +/- 12.2, 135.4 +/- 13.1 and 137.5 +/- 11.5; p < 0.0001). The incidence of morning HT significantly increased and progressively in the same order (53.4%, 55.6%, 66.4%, p < 0.0001). Morning BP was significantly higher among obese patients with diabetes than among non-obese and non-diabetic patients (138.8 +/- 10.5, 133.1 +/- 11.9, p < 0.0001). In addition, the incidence of morning HT was significantly higher in obese diabetic patients than in non-obese and non-diabetic patients (73.0% vs. 49.9%, p < 0.0001). Significance: Diabetic or obese patients frequently have morning HT. (C) 2014 Elsevier Inc. All rights reserved.