White Coat Hypertension by Giuseppe Mancia Guido Grassi Gianfranco Parati & Alberto Zanchetti

Author:Giuseppe Mancia, Guido Grassi, Gianfranco Parati & Alberto Zanchetti
Language: eng
Format: epub
Publisher: Springer International Publishing, Cham

Normotensive group

Hypertensive group

(n = 178)

All subjects

(n = 1,280)

White-coat HT

(N = 238)

Ambulatory HT

(N = 1,042)

Systolic BP (mmHg)

+1.8 (9.7)

+13.9 (15)

+19.7 (13)

+12.6 (15)*

Diastolic BP (mmHg)

+0.1 (7.3)

+5.7 (9)

+12.5 (8)

+4.2 (9)*

Mean BP (mmHg)

+0.7 (7.0)

+8.4 (9)

+14.9 (7)

+6.9 (9)*

*P < 0.01 vs white coat hypertension

Modified from Verdecchia et al. [32] by permission

A further analysis of the Hypertension and Ambulatory Recording Venetia Study (HARVEST) and PIUMA collaboration study, in 1,564 subjects with stage I hypertension, not yet receiving antihypertensive treatment, showed that WCH is most frequent among women, nonsmokers, and subjects with low clinic BP and smaller LV mass. In multivariate logistic regression analyses, lower values of office diastolic BP, female gender, and nonsmoking status were the sole independent predictors of WCH. In the subjects with adequate echocardiographic tracings, a smaller value of left ventricular mass was a further independent predictor of WCH [5].

Evidence has also been provided that metabolic alterations may predict development of white-coat and sustained hypertension in the long term. In the frame of a population-based longitudinal study in elderly men (enrolled at age 50), individuals who after a 20-year follow-up period were diagnosed as having white-coat or sustained hypertension showed significantly higher BP levels, heart rate, and impaired glucose tolerance compared to normotensive controls. Remarkably, compared to sustained hypertensive subjects, those with white-coat hypertension showed a lower body mass index and more favorable lipid profile. By the end of the prospective follow-up (when participants had reached the age of 70), compared to normotensive subjects, both white-coat and sustained hypertensive subjects showed a significant impairment in insulin sensitivity, higher glucose and insulin levels, and an increased heart rate, without significant differences in left ventricular mass and prevalence of microalbuminuria. This study could thus consistently identify the presence of metabolic abnormalities and elevated heart rate as predictors of incident white-coat hypertension [33].

Also the potential role of indices of endothelial dysfunction has been studied. While some reports have shown a reduced endothelial function (assessed as variation in the diameter of the brachial artery produced by flow-mediated dilation) in subjects with white-coat hypertension (which has been shown to be similar to that of subjects with sustained hypertension) compared to healthy controls [34], other studies, however, have found no significant differences in indices of endothelial function among sustained hypertensives, white-coat hypertensives, and normotensive controls [35].

Overall, the data provided by different studies have indicated that in untreated subjects with essential hypertension, the probability of having WCH increases in subjects with mild hypertension (i.e., office systolic BP 140–159 mmHg or diastolic BP 90–99 mmHg), subjects with female gender, subjects with nonsmoking status, subjects with hypertension of recent onset, subjects with a limited number of BP measurements in the office, and subjects without evidence of target organ damage (i.e., a small left ventricular mass on echocardiography) [5, 6].

However, given the heterogeneity of the populations studied and the different study designs implemented, it is hard to outline a consistent cluster of clinical predictors specific enough for identifying WCH. Further studies are thus required to better understand the determinants and mechanisms underlying WCE and WCH.

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