Are Metabolic Risk Factors and Target Organ Damage More Frequent in Masked Hypertension Than in White Coat Hypertension?

Patients with masked hypertension (MH) tend to have a higher risk than those with white-coat hypertension (WCH). Therefore, we evaluated the characteristics of MH and WCH in Korean patients receiving medical treatment for hypertension. We enrolled 1019 outpatients (56 +/- 10 y, 488 males) with diagnosed hypertension who had not changed oral anti-hypertensive medication for 6 months. Clinic blood pressure (CBP) was checked by a nurse and doctor twice per visit. Home BP (HBP) was checked every morning and evening for 1 week. In the MH patients, mean CBP was 130/80 mmHg, whereas HBP was 137/86 mmHg. In the WCH patients, mean CBP was 149/86 mmHg by physician and 143/85 mmHg by nurse and mean HBP was 124/75 mmHg. Age and gender did not differ between the groups. Waist and hip circumferences and the level of fasting glucose were higher in patients with MH than in patients with WCH (p = 0.008, 0.016, 0.009, respectively). Metabolic risk factors were more frequent in patients with WCH, MH, and uncontrolled hypertension than in patients with controlled hypertension. The incidence of metabolic risk factors, however, did not differ between patients with WCH and MH. Heart damage was more frequent in MH than in WCH (p = 0.03). The incidence of metabolic risk factors did not differ between patients with WCH and those with MH. Target organ damage was more closely related to MH than to WCH. Home BP measurement was a useful tool for discriminating WCH and MH in patients with hypertension.