|Year : 2019 | Volume
| Issue : 4 | Page : 131-136
The study of prevalence and determinants of white-coat hypertension in medical personnel: A prospective study
Himanshu Gupta1, Sanjay Mehrotra2, Ayushi Gupta3
1 Department of Cardiology, Government Medical College, Kozhikode, Kerala; Department of Medicine, King George Medical College, Lucknow, Uttar Pradesh, India
2 Department of Medicine, King George Medical College, Lucknow, Uttar Pradesh, India
3 Department of Anesthesia, Government Medical College, Kozhikode, Kerala, India
|Date of Submission||13-Jun-2019|
|Date of Decision||10-Aug-2019|
|Date of Acceptance||24-Sep-2019|
|Date of Web Publication||11-Dec-2019|
Dr. Himanshu Gupta
Flat 1B, Sreerosh Apartments, Golf Link Road, Chevayur, Kozhikode - 673 017, Kerala
Source of Support: None, Conflict of Interest: None
Context: White-coat hypertension (WCH) has variable prevalence with prognostic significance, and ambulatory blood pressure monitoring (ABPM) is a reliable method for its identification. Assessment of WCH is necessary to prevent overtreatment. Aims: The objective was to study the prevalence and determinants of WCH in medical personnel. Settings and Design: A cross-sectional observational study was performed on young medical students. Duration was 23 months. Subjects and Methods: A total of 354 medical students were screened for hypertension, and those who were found hypertensive were then subjected to ABPM using CONTEC-06C monitor. Baseline characteristics were compared between white-coat hypertensive and true hypertensive groups. Hamilton Anxiety Rating Scale was used for anxiety assessment. Patients with target organ damage were excluded from the study. Statistical Analysis: Continuous groups were compared by independent Student's t-test, whereas categorical groups were compared using Chi-square test. P < 0.05 was considered as statistically significant. Results: Among 50 hypertensive patients on ABPM, the prevalence WCH was 66% and true hypertension was 34%. Mild anxiety (Hamilton anxiety rating score (HRS) <18) was found to be significantly high (54.5%) among WCH group, while severe anxiety (HRS 25–30) was associated with true hypertensive group (41.2%). A significantly high reverse dipping is found in hypertensive group patients as compared to WCH group (9.1% vs. 23.5%; P = 0.03). Overall, nondippers were found to be in highest percentage in the study. Conclusions: WCH is high in young population, especially among medical professionals. The prevalence of WCH is 66% which is significantly high as compared to the literature available. Reverse dipping on ABPM is strongly associated with true hypertension.
Keywords: Ambulatory blood pressure monitoring, nocturnal dipping, target organ damage, white-coat hypertension
|How to cite this article:|
Gupta H, Mehrotra S, Gupta A. The study of prevalence and determinants of white-coat hypertension in medical personnel: A prospective study. Heart India 2019;7:131-6
|How to cite this URL:|
Gupta H, Mehrotra S, Gupta A. The study of prevalence and determinants of white-coat hypertension in medical personnel: A prospective study. Heart India [serial online] 2019 [cited 2020 Jul 10];7:131-6. Available from: http://www.heartindia.net/text.asp?2019/7/4/131/272661
| Introduction|| |
White-coat hypertension (WCH), which is also known as white-coat syndrome, is said to be present if a person has an elevated blood pressure (BP) in clinical settings, but normal BP when recorded out of medical setup. It is said to be due to the anxiety experienced by a patient during a clinic visit. It is diagnosed when average daytime ambulatory BP is below 135/85 mmHg in a true hypertensive patient with conventional BP ≥140/90 mmHg. Other measures of normal BP on ambulatory blood pressure monitoring (ABPM) are <130/80 mm Hg for full 24-h BP and <120/70 mm Hg for nighttime BP.
About 10%–50% of patients with Stage I hypertension (140–159/90–99 mmHg) have WCH. Studies have shown that the risk of future cardiovascular disease events is less in patients with WCH than true hypertensives.,,
In general, individuals with WCH have lower morbidity than patients with sustained hypertension but high morbidity than the clinically normotensive.
ABPM is a reliable method for the detection of WCH and for the prediction of target organ damage (TOD). Using ABPM, BP can be monitored during sleep, and it helps to identify whether the patient is a dipper or nondipper, that is, whether or not BP falls at night compared to daytime values. The nighttime fall is normal and desirable. Absence of a nighttime dip is associated with poor health outcomes, including increased mortality in various studies. In addition, nocturnal hypertension is associated with TOD , and is a much better indicator than the daytime BP reading.
Identification of these patients with WCH, which are otherwise at low risk of cardiovascular events, is utmost important to prevent overtreatment. Hence, aims and objectives of our study are to study the prevalence and determinants of WCH in medical personnel.
| Subjects and Methods|| |
It is a cross-sectional observational study in which we screened 354 medical students including undergraduate, postgraduate students, and nursing staff for hypertension clinically by well-calibrated hand-held mercury sphygmomanometer with calibration between 0 and 300 after taking their written consent. All the medical patients were unaware of their hypertensive status and were not on any antihypertensive medications.
European Heart Society international validation protocols for BP measuring instrument in adults were used for calibration.
Duration of the whole study was about 23 months with the period extending from June 2011 to May 2013 conducted in our college campus. Individuals with two separate readings, each ≥140/90 mmHg (JNC-7 Stage 1) taken on two separate visits, were considered as hypertensives. We took 50 such hypertensive patients and subjected them to ABPM after excluding TOD from the study. CONTEC 06-C fully automated ABPM which was factory validated according to Advancement of medical instrumentation (AAMI) and British Hypertension Society protocols were used for ambulatory monitoring. Device used in this study is usually accurate to within 5 mmHg of readings taken with a mercury sphygmomanometer. A correlation of the device measurements and mercury sphygmomanometer used in the study was done before the study with r value of 0.97 and 0.94 in systolic BP (SBP) and diastolic BP (DBP), respectively. BP cuff size we use in our study was of standard adult size (25–35 cm arm circumference, bladder size –13.1 × 23.5).
NICE guidelines for the use and assessment of ABPM results were followed in this study. Individuals with 24-h average BP >130/80, daytime average BP >135/85, and nighttime average BP >120/75 mmHg were considered to be hypertensive on the basis of ABPM results [Table 1].
Accordingly, patients were then classified into two groups: true hypertensives and white-coat hypertensives. Prevalence studied and comparison of various determinants such as age, sex, body mass index, day and night systolic and DBP, smoking history, heart rate, and psychometric scoring based on Hamilton Anxiety Rating Score (HRS, a 14-questionnaire system to analyze anxiety levels) were done between these two groups. All the individuals were screened for TOD with the help of relevant history and various biochemical and radiological investigations.
History of smoking, alcohol, and drugs which can cause hypertension as well as family history of hypertension which can confound the results was taken and those with a positive history and TOD were excluded from the study [Flow chart 1].
TOD workup protocols used in the study were as follows:
- Kidney – Urine protein creatinine ratio of >0.2 in adults was considered abnormal
- Eyes – Keith–Wagner–Barker Grading for hypertensive changes during fundus examinations was used
- Heart – Sokolow–Lyon Criteria (SV1 + RV6 >35 mm) for left ventricular hypertrophy in electrocardiograph was used
- Central nervous system - ruled out on the basis of history of transient ischemic attacks, stroke, and visual blindness.
Continuous data were summarized as mean ± standard deviation while discrete (categorical) data in number and percent. Continuous groups were compared by independent Student's t-test, while categorical groups were compared by Chi-square test. A two-sided (α = 2) P < 0.05 was considered statistically significant. All analysis was performed on SPSS (PSAW, Windows version 18.0, IBM) software.
| Results|| |
The prevalence of hypertension on clinical BP monitoring was found to be 14.1% in overall cohort. Of 50 hypertensive patients on ABPM, there were 33 WCH and 17 true hypertensive patients with prevalence being 66% and 34%, respectively.
The mean age of WCH group was slightly higher than hypertensive group. In both groups, the frequency (%) of males was higher than females with higher being in WCH group (84.8%) as compared to hypertensive group (64.7%). Overall, males were found to be more consistently associated with WCH.
Anthropometric measurements such as weight, height, waist circumference, and body mass index (BMI) were not found to be associated to WCH. The Hamilton Anxiety Rating Scale (HAM-A) score of hypertensive group was found to be significantly different and higher (19.6%) as compared to WCH group (17.5 ± 7 vs. 21.8 ± 5; P = 0.039).
Both the groups had addiction (alcohol/smoking) (χ2 = 1.41, P = 0.235) and family history of hypertension (χ2 = 2.23, P = 0.328) but did not differ statistically [Table 2].
Mild anxiety (HRS <18) was found to be significantly high (54.5%) among white-coat hypertensive patients, while severe anxiety (HRS 25–30) was found to be associated with true hypertensive patients (41.2%) [Table 3].
On comparing the mean ABPM parameters of two groups, daytime average, nighttime average, and 24-h average systolic and DBP as well as daytime, nighttime systolic and diastolic load values as measured by ABPM were found to be significantly low in white-coat hypertensive group as compared to true hypertensive group [Table 4].
|Table 4: Ambulatory blood pressure monitoring parameters (mean±standard deviation) of two groups|
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Twenty-four hour average pulse rate (PR) and pulse pressure were 6.5% and 9.6% higher in hypertensive group, respectively, as compared to the WCH group but not significantly.
Comparison of dipper proportion of the two groups, the Chi-square test revealed significantly high reverse dippers in hypertensive group as compared to WCH group (9.1% vs. 23.5%; P = 0.03). Overall, nondippers were found to be in highest percentage in this study [Table 5].
| Discussion|| |
The study has been performed in a large cohort of a young healthy population of medical personnel's of King George Medical University, Lucknow (UP, India).
The prevalence of WCH in medical patients enrolled in our study was found to be 66% which appears to be maximum in contrast to various previous studies.
Indian guidelines of hypertension-3 found a prevalence of 20%–25%, while Pickering et al. reported the prevalence of 21% of all hypertensive patients with female dominance. Other studies have suggested a prevalence of between 12% and 54%, being more common in the elderly.
The proper definition of WCH was given by Mancia et al. and found the prevalence of 60% among previously normotensive patients.
Abir-Khalil et al. found that the prevalence of WCH can range from 18% to 60%. They showed that the intensity of white-coat effect (WCE) is greater in patients with WCH than it is in those with sustained hypertension. The difference between clinic BP and mean daytime ambulatory BP was used to quantify the WCE; patients were considered as having WCE if this difference was ≥5 mmHg.
Determinants of white-coat hypertension
Dolan et al. stated that there was a higher prevalence of WCH among nonsmokers, female gender, and patients with lower clinic SBP, and logistic regression analysis of their study showed that age, gender, and smoking history were independent predictors of WCH. Similar findings were seen in studies by Ecaterina Usurel et al. and Verdecchia et al.,
These studies were in contrast to our study, in which we did not find any statistically significant association of WCH with age, smoking history, or female gender although males were found to be more consistently associated with WCH as compared to females. Various studies found that the prevalence of WCH is higher in the elderly age group which was in contrast to our study which suggests that young population has more WCH.
Mary MacDonald et al. concluded that stress was the most important predictor of white-coat response in females, while depression was a weak predictor for men with higher depression scores predicting sustained hypertension. Type-A personality scale(Minnesota multiphasic personality inventory-2 type A scale) and von zerssen mood scale for the assessment of stress levels were used in their study.
We did not study the level of stress and depression as separate factors, but we use the Hamilton Anxiety Rating Score for the assessment of anxiety levels in the patients and found that mild anxiety (HRS <18) was significantly high (54.5%) among white-coat hypertensive patients, and severe anxiety (HRS 25–30) was associated with true hypertensive patients (41.2%).
Abir-Khalil et al. found a strong association of BMI with WCH; but in our study, we did not get any such association of BMI or any anthropometric parameters with WCH.
Youngkeun Ahn found that pulse pressure was positively correlated with WCE. In our study, 24-h average pulse pressure and PR both not differed between the two groups.
Comparison of dipping status
Murielle Bochud et al. found the association between white-coat effect and blunted dipping of nocturnal BP. The Syst-Eur study found that cardiovascular risk is higher in older white-coat hypertensive nondippers independent of the average 24-h BP.,
Dipping analysis in our study reveals a high percentage (46%) of nondippers that indicate the strong association of blunted dipping with raised BP levels and anxiety. Reverse dippers were found to be strongly associated with true hypertension.
Target organ damage association
HARVEST study shows that young stage I hypertensive patients with ambulatory BP in the “normal” range has less target-organ involvement than patients with high ambulatory BP. However, in comparison with normotensive patients, white-coat hypertensive patients seem to be at greater risk. Verdecchia et al. and Staessen et al. stated that patients with WCH are at a lower risk from target organ involvement than patients with sustained hypertension.
We excluded the patients with TOD since it is associated with true hypertension.
| Conclusions|| |
The study concluded that WCH is significantly higher in young population, especially among medical professionals contributed by high stress and anxiety levels at their workplace as measured by HAM-A. The prevalence of WCH is significantly higher (66%) as compared to the literature available. The prevalence of true hypertension was found to be 34%. Reverse dipping on ABPM is strongly associated with true hypertension.
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Conflicts of interest
There are no conflicts of interest.
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[Table 1], [Table 2], [Table 3], [Table 4], [Table 5]