Background and aim: The prevalence and associated risks of white-coat hypertension (WCH) are still a matter of debate. We aimed to assess differences in prevalence and associated conditions of WCH defined on the basis of the normality of all daytime, night-time, and 24-h blood pressure (BP), only daytime, or only 24-h BP.
Methods: We selected 115 708 patients (45 020 untreated and 70 688 treated) from the Spanish Ambulatory BP Monitoring Registry. WCH was estimated in patients with elevated office BP (≥140 and/or 90 mmHg) by using normal daytime (<135/85) BP, normal 24-h BP (<130/80), or normal daytime, night-time (<120/70) and 24-h BP. Demographic and clinical data (associated risk factors and organ damage) were compared among groups.
Results: Prevalence of WCH was 41.3, 35.2, and 26.1% in untreated, and 45.8, 38.9, and 27.2% in treated patients with elevated office BP, by using the criteria of daytime, 24-h, or all ambulatory periods. Compared with the normotensive group, WCH defined by normal daytime, night-time, and 24-h BP did not significantly differ in terms of other cardiovascular risk factors or organ damage. In contrast, patients from other groups (either only normal daytime BP or 24-h BP) had significantly more prevalence of diabetes, dyslipidaemia, microalbuminuria, left ventricular hypertrophy, reduced renal function, and previous history of cardiovascular disease.
Conclusion: Prevalence of WCH is dependent on definition criteria. Only diagnostic criteria which considers the normality of all ambulatory periods identifies patients with cardiovascular risk similar to normotensive patients. These results support using such criteria for a more accurate definition of WCH.