Relationship Between White-Coat Effect and Blood Pressure Variability in Essential Hypertension

Background To investigate the incidence of white-coat effect (WCE) and to analyze the relationship between WCE and blood pressure (BP) variability in essential hypertension (EH). Methods A total of 410 patients with grade 1 and 2 EH voluntarily participated in this study. BP was self-measured at home for 1 week. Based on home and office BP, the untreated subjects were divided into white-coat hypertension (WCH, n = 38) and sustained hypertension (SHT, n = 66). The treated subjects were grouped into sustained controlled hypertension (SCH, n = 131), white-coat uncontrolled hypertension (WCUH, n = 95), masked uncontrolled hypertension (MUCH, n = 16), and sustained uncontrolled hypertension (SUCH, n = 64). A subgroup analysis was performed in the treatment hypertensives whose diagnosis based on BP inside and outside the clinic. Results WCH and WCUH patients accounted for 36.5% (95% confidence interval [CI] 27.2%–45.8%) and 31.0% (95% CI 25.8%–36.2%), respectively, in this population while only accounted for 21.7% (95% CI 14.5%–28.9%) in hypertensives whose diagnosis based on office BP and out-of-office BP, which was significantly lower than that based on office BP alone (34.5%). The WCE, that was, the difference between office and home BP, in the WCH patients was significantly higher than SHT patients (P < 0.05), and stronger in the WUCH group compared with SCH and SUCH groups (P < 0.05). Home systolic BP variability exhibited decreasing trends in the WCH and WUCH patients compared with SHT and SUCH patients. Conclusions The incidences of WCH and WUCH are high in grade 1 and 2 hypertensive patients. However, the incidence of WUCH decreases in treated patients diagnosed with office and out-of-office BP. Relative to other patients, WCH and WUCH patients exhibit stronger WCE and a decreasing trend of BP variability.