By Daniel M. Keller, PhD
PARIS—Convincing evidence that white coat (WC) hypertension carries an equivalent long-term risk for cardiovascular events to essential hypertension was presented at the European Society of Hypertension meeting, suggesting that part of the reason may be the metabolic risk profile associated with it compared with normotensive patients.
Among 566 patients whom Asbjörn Hoegholm, MD, of the Department of Internal Medicine, Naestved University Hospital, Denmark, screened previously with office and ambulatory blood pressure (BP), 412 participated in a follow-up examination 10 years later. Results showed that 70.5% of those previously categorized as WC hypertensives now had essential hypertension (ie, >135/90 mm Hg) versus 43.0% of previously noromotensive patients.
Compared with normotensive persons, WC hypertensives “have an unfavorable metabolic profile. They have a little lower HDL [high-density lipoprotein], a little higher VLDL [very-low-density lipoprotein], a little higher triglycerides, C-reactive protein is marginally higher…[and their] uric acid is higher,” he said. Most of the metabolic parameters of WC hypertensives were similar to those with essential hypertension.
The finding is important because clinicians have often assumed that WC hypertension is a benign condition that did not need treatment. In reality, these patients comprise “20% of the newly diagnosed hypertensives; maybe they believe they could just live on the usual way,” said Dr Hoegholm, “but now it seems that they do get ill.”
Physicians should carefully follow these patients’ BP on a yearly basis, as well as support patients’ efforts at lifestyle changes, he said.
White coat hypertension may be result of a fear reaction and elevated sympathetic response, Dr Hoegholm speculated. Results of a psychological profile questionnaire showed that significantly more WC hypertensives and essential hypertensives felt discomfort visiting a physician or a hospital compared with normotensives.
Franz Messerli, MD, Associate Head of the Hypertension Section at the Oschner Clinic Foundation and Clinical Professor of Medicine at Tulane University Medical School, New Orleans, La, commented that when WCH patients are followed for several years “their survival is just about as bad as patients who do have established hypertension.” He agreed that patients with WC hypertension patients were not treated because clinicians assumed it was a benign condition. “It turns out this isn’t necessarily so,” he noted, but the dilemma remains about whether to start WC hypertension patients on antihypertensive therapy or not. “Given this [finding], we should probably become much more aggressive in looking at these patients.”
Since WC hypertension appears during office BP measurement and should be followed based on this finding, it would seem that ambulatory monitoring still has a role, although Drs Messerli and Hoegholm disagreed about this point. “In the context of [diagnosing] white coat hypertension, ambulatory blood pressure measurement is not of great prognostic significance,” said Dr Messerli said. In contrast, Dr Hoegholm noted that morbidity correlates much more closely with ambulatory BP than with office BP.