Fatness and Fluctuating Body Weight: Effect on Central Vasculature.

Abstract

Weight Cycling (WC) is a prevalent behavior associated with adverse cardiovascular (CV) health. However, a 2010 review on the effects of WC and blood pressure (BP) determined that there was not enough evidence to draw definitive conclusions. Central BP is the principal predictor of CV risk compared to peripheral BP. The influence that WC may have specifically on central BP is unknown. Cross-sectional observation of self-reported history of WC on measures of CV health was undertaken. Seventy-five women completed a Weight and Lifestyle Inventory questionnaire, which is considered a reliable index of WC (r = 0.87, p < 0.001). Measures of visceral fat, BP, arterial stiffness, and VO₂peak were taken. Regression equations were used to assess primary predictors of these outcomes. Seventy-five middle aged (39 ± 11 years), obese (32 ± 7 kg/m²), and relatively unfit (24 ± 8 ml·kg^-1 min^-1) women completed the study. Visceral fat was the strongest predictor of brachial systolic blood pressure (SBP; r² = 0.283), brachial diastolic blood pressure (DBP; r² = 0.176), central SBP (r² = 0.375), and augmentation index (AIx; r² = 0.535, all p < 0.001). VO₂peak was the strongest predictor of central DBP (r² = 0.062, p = 0.036) and augmentation pressure (AP; r² = 0.491, p < 0.001). Weight cycling index was associated with visceral fat (r = 0.521, p < 0.001). Visceral fat was a mediator between WC and central SBP (confidence interval [CI] = 0.0053-0.0602), AP (CI = 0.0507-0.4915), AIx (CI = 0.0025-0.0699), and carotid-femoral pulse wave velocity (CI = 0.0115-0.1227; all p < 0.05). WC may increase visceral fat accumulation, which was associated with increased central SBP and measures of arterial stiffness.