REPRODUCIBILITY AND PREDICTIVE VALUE OF WHITE COAT HYPERTENSION IN YOUNG TO MIDDLE AGE SUBJECTS

Abstract

Objective: The reproducibility and the prognostic value of white-coat hypertension (WCH) is still debated. The aim of the study was to investigate the reproducibility of WCH assessed twice within 3 months and its predictive capacity for development of hypertension needing antihypertensive treatment (HT) in young-to-middle-age subjects screened for stage 1 hypertension. Design and method: We investigated 1096, 18-to-45-year old subjects from the HARVEST. Office BP and 24hour BP were measured at baseline and after 3 months. On the basis of BPs measured after 3 months, 132 participants were classified as normotensive, 159 as WCH, 195 as masked hypertensive and 610 as sustained hypertensive. The reproducibility of WCH, office hypertension, and ambulatory hypertension was evaluated with Kappa statistics. The predictive capacity of WCH defined with a single assessment or with double assessment was tested in multivariate Cox models (N = 1054). Results: Baseline WCH was confirmed at 3-month assessment in only 33.3% of participants, whereas 31.6% became normotensive, 8.8% masked hypertensive and 26.3% sustained hypertensive. Reproducibility evaluated with weighted Kappa was fair (0.27, 95%CI 0.20 - 0.37) for WCH, poor (0.14, 95%CI 0.09 - 0.19) for office Hypertension (BP> = 140/90 mmHg), and moderate (0.47, 95%CI 0.41 - 0.53) for ambulatory Hypertension (24hBP> = 130/80 mmHg). During 17.4 years of follow-up, 80.5% of participants developed HT. WCH assessed either at baseline (p = 0.86) or after 3 months (p = 0.16) was not a significant predictor of future HT. However, participants who had WCH both at baseline and after 3 months (N = 76) had an increased risk of HT compared to the normotensives (Hazard ratio, 1.50, 95%CI 1.06 - 2.13, p = 0.022). HRs were 1.35 (95%CI 1.02 - 1.80, p = 0.037) in participants with masked hypertension and 1.52 (95%CI 1.19 - 1.95, p < 0.001) in those with sustained hypertension. Conclusions: These results show that in young-to-middle-age individuals, WCH was confirmed in only one third of people at repeat assessment. This was mainly due to a poor reproducibility of office hypertension. WCH diagnosed with two but not with one BP assessment showed an increased risk of future HT. Our data indicate that people with WCH at first assessment should undergo a second set of ambulatory and office BP measurements before clinical decisions are made.