White-coat hypertension is defined as high blood pressure (BP) on clinical assessment but normal BP elsewhere or on ambulatory measurement. Autonomic dysfunction may be one of the mechanisms causing white-coat hypertension. Slowed heart rate recovery and excessive BP response during exercise test are associated with autonomic dysfunction. The purpose of this study was to determine the association between white-coat hypertension and abnormal autonomic nervous system response.

We assessed 295 patients stratified into three groups via 24hr ambulatory BP monitoring, following 2017 ACC/AHA guidelines: normal BP group, white-coat hypertension group, and a hypertension group. We analyzed medical history, blood test, echocardiography, 24hr ambulatory BP monitoring, and exercise test data.

There was no difference in basement characteristics and echocardiography among the groups. Blunted heart rate recovery of each group showed a significant difference. Control group had 0% blunted heart rate recovery, but 33.3% in white coat group and 27.6% in true hypertension group (P < 0.001). Also, in the control group, 4.5% showed excessive BP response, but 31.5% in the white coat hypertension group and 29.3% in the true hypertension group (P < 0.001). Excessive BP response during the exercise test or blunted heart rate recovery, which is an indicator of autonomic nervous system abnormality, was more common in the hypertensive group and white-coat hypertension group than in the normal BP group.

These results confirmed that white-coat hypertension has an autonomic nervous system risk. Therefore, white-coat hypertension can be a future cardiovascular risk factor.