Explaining gender differences in the white coat effect

Objectives: To discern whether gender was a unique predictor of the white coat effect (WCE) in a population of normotensives and patients diagnosed with hypertension. Methods: Participants (n=252) underwent a doctor's office visit to have their blood pressure measured. Multiple blood pressure readings were taken by both a research assistant and by the attending physician. In addition, measures of anxiety variables were collected during the visit. Participants then underwent a 36-h ambulatory blood pressure monitoring. Results: Gender was a significant predictor of the systolic WCE, but, as expected, the effect size was small and was no longer significant when age and BMI were included in the regression model. State anxiety emerged as a significant independent predictor of systolic WCE; however, when household income was included in the model it became the only significant independent predictor (β=0.203, P<0.05), in addition to gender, age, and Bmi. Conclusion: This study suggests that the association between gender and the systolic WCE is small, and likely accounted for by other variables including age, BMI, state anxiety, and household income. Thus, gender may be of limited use in helping identify patients who may be more likely to have WCE or white coat hypertension. Gender differences in this area should be interpreted with great caution.