Individuals with higher body mass index (BMI) values generally have a larger waist-to-hip ratio (WHR), but the reverse is not necessarily true. Thus, centralized obesity may not be captured by high BMI values. WHR may offer a more effective measure for assessing obesity-related hypertension risk than BMI. Nighttime blood pressure dipping, defined as a 10-20% reduction in blood pressure during nighttime sleep from daytime values, may have prognostic value for both normotensive and hypertensive individuals as a lack of dipping has been associated with structural and function cardiovascular changes, such as left-ventricular hypertrophy (LVH), in addition to target organ damage. Given that a greater incidence of non-dipping status has been observed in overweight and obese populations, the goal of the present study was to evaluate the predictive ability of WHR on nighttime blood pressure dipping, relative to BMI.
A total of 226 healthy, college-aged women participated in a 24-hour ambulatory monitoring session, with blood pressure readings taken every 20 minutes during the day and every 30 minutes during nighttime sleep.
Multivariate regression models revealed that BMI and WHR were both significant predictors of systolic blood pressure (SBP) and diastolic blood pressure (DBP) dipping. However, WHR explained a greater proportion of variance in DBP dipping (10%), relative to BMI (3%).
WHR - a simple and non-invasive measure of body composition - is a useful technique for evaluating risk of a non-dipping profile.
© 2012 Canadian Cardiovascular Society. Published by Elsevier Inc. All rights reserved.