Arterial stiffness responses to prolonged sitting combined with a high-glycemic-index meal: a double-blind, randomized crossover trial.

Regular exposure to uninterrupted prolonged sitting and the consumption of high-glycemic-index (HGI) meals is independently associated with increased cardiovascular disease risk. Sitting for as little as 1 h can impair the health of both peripheral and central arteries. However, it is currently unknown whether combined acute exposure to uninterrupted prolonged sitting and an HGI meal is more detrimental to global (peripheral and central) vascular health. The purpose of this study was to investigate the effect of prolonged sitting (3 h), following the consumption of an HGI or a low-glycemic-index (LGI) meal, on global pulse wave velocity (G-PWV). Eighteen healthy participants [70% female, mean (standard deviation, SD) age = 22.6 (3.1) yr, body mass index (BMI) = 25.5 (6.1) kg/m] sat for 3 h after consuming an HGI or LGI meal. G-PWV was assessed by incorporating three PWV measures (carotid-femoral, brachial-femoral, and femoral-ankle). The effects of time (PRE vs. POST) and condition (LGI vs. HGI) were analyzed using linear mixed models. Following prolonged sitting, G-PWV increased by 0.29 m/s (i.e., PRE vs. POST). However, the condition ( = 0.987) and time × condition ( = 0.954) effects were nonsignificant. The current findings support previous research showing an increase in arterial stiffness with prolonged sitting. However, in young and healthy adults, the arterial stiffness response was not worsened through HGI meal consumption. We used novel statistical techniques and study design characteristics to examine how the cardiovascular disruptions due to prolonged sitting are changed after the consumption of low- and high-glycemic-index meals. The current study indicates that changes in arterial stiffness due to prolonged sitting are not worsened in young, healthy adults after the consumption of a high-glycemic-index meal.