Relation between Blood Pressure Variability within a Single Visit and Stroke

Blood pressure variability (BPV) has been identified as an important risk factor for cardiovascular events. The white coat effect (WCE), which is measured as the first systolic blood pressure (SBP) measurement minus the mean of the second and third measurements, is a BPV indicator within a single visit. In total, 2,972 participants who had three measurements of BP within a single visit were included. The participants were divided into three groups based on their WCE percentiles: Group 1 (WCE2.5-97.5, 2.5–97.5th percentiles of WCE), Group 2 (WCE2.5, 0–2.4th percentiles of WCE), and Group 3 (WCE97.5, 97.6–100th percentiles of WCE). A multiple logistic regression model was used to analyze the relationship between WCE and stroke after adjusting for cardiovascular disease risk factors. Compared with the WCE2.5-97.5 group, the OR for stroke in the WCE2.5 group was 2.78 (95% CI: 1.22, 6.36, <a:math xmlns:a="http://www.w3.org/1998/Math/MathML" id="M1"> <a:mi>p</a:mi> <a:mo>=</a:mo> <a:mn>0.015</a:mn> </a:math> ). After adjusting for cardiovascular factors, OR increased to 3.12 (95% CI: 1.22, 7.96, <c:math xmlns:c="http://www.w3.org/1998/Math/MathML" id="M2"> <c:mi>p</c:mi> <c:mo>=</c:mo> <c:mn>0.017</c:mn> </c:math> ). The OR of WCE for stroke was 0.93 (95%CI: 0.87, 0.99, <e:math xmlns:e="http://www.w3.org/1998/Math/MathML" id="M3"> <e:mi>p</e:mi> <e:mo>=</e:mo> <e:mn>0.036</e:mn> </e:math> ). BPV within a single visit is associated with stroke. The value and direction of the change may be important as well.