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Comment: the corticotropin-releasing hormone stimulation test in white coat hypertension
Isao Tabeta1, Hajime Ueshiba, Takamasa Ichijo
1First Department of Internal Medicine, Toho University School of Medicine, Ota-ku, Tokyo 143-0015, Japan.
Insights
Patients with white coat hypertension show heightened adrenocorticotropic hormone (ACTH) and cortisol responses to corticotropin-releasing hormone (CRH), suggesting stress-induced hypothalamic-pituitary-adrenal axis hypersensitivity.
Area of Science:
- Endocrinology
- Cardiovascular Physiology
- Stress Response
Background:
- White coat hypertension (WCH) is characterized by elevated clinic blood pressure but normal ambulatory blood pressure.
- The hypothalamic-pituitary-adrenal (HPA) axis plays a crucial role in the body's stress response.
- Previous research has not fully elucidated the HPA axis activity in WCH patients.
Purpose of the Study:
- To investigate the adrenocorticotropic hormone (ACTH) and cortisol responses to corticotropin-releasing hormone (CRH) stimulation in patients with WCH.
- To determine if WCH is associated with altered HPA axis reactivity to stress.
Main Methods:
- Eleven patients with WCH and eleven age- and sex-matched normal subjects underwent CRH stimulation tests.
- Blood pressure, heart rate, ACTH, and cortisol levels were measured at baseline and at timed intervals post-CRH administration.
- WCH was defined by a significant difference between clinic and ambulatory blood pressure measurements.
Main Results:
- Patients with WCH exhibited significantly higher systolic and diastolic clinic blood pressures compared to controls.
- Basal ACTH and cortisol levels did not differ between WCH patients and controls.
- CRH stimulation resulted in significantly greater ACTH and cortisol elevations in WCH patients compared to controls.
Conclusions:
- White coat hypertension is associated with an exaggerated ACTH and cortisol response to CRH.
- This hypersensitivity of the HPA axis to stressors may be a contributing factor in the pathophysiology of WCH.
- Further research is warranted to explore the long-term implications of this finding.
Abstract:
This study was undertaken to clarify the status of the ACTH and cortisol responses to CRH in patients with white coat hypertension. White coat hypertension was defined as a difference between clinic blood pressure and ambulatory blood pressure of at least 20 mm Hg for systolic blood pressure and/or 10 mm Hg for diastolic blood pressure. CRH stimulation tests were performed between 1400 and 1700 h in 11 patients with white coat hypertension (4 males and 7 females) and 11 normal subjects (4 males and 7 females). Blood pressure and heart rate were measured 15 min before, at time zero, and 15, 30, 60, and 120 min after initiation of the CRH stimulation tests. In white coat hypertension, both the mean systolic blood pressure (162 +/- 15 mm Hg) and diastolic blood pressure (97 +/- 10 mm Hg) were higher than in controls (P < 0.01) on 3 occasions. The mean ambulatory blood pressure for the 24-h period of the test did not differ between patients with white coat hypertension and normal subjects. Basal levels of ACTH and cortisol did not differ between patients with white coat hypertension and control subjects. However, challenge with CRH elevated ACTH (30 min) and cortisol (30, 60, and 120 min) to levels higher than those in controls, with the net increase in both ACTH and cortisol being higher than that in controls over the study period (P < 0.01). These significant responses suggest that white coat hypertension is associated with hypothalamic-pituitary-adrenal hypersensitivity to stressors.