Aerobic Exercise Offsets Endothelial Dysfunction Induced by Repetitive Consumption of Sugar‐Sweetened Beverages in Young Healthy Males

Abstract

Consumption of a single, sugar‐sweetened beverage (SSB) impairs vascular endothelial function. However, no study to date has examined if these observations persist without confounding increases in blood [glucose] and [insulin]. Additionally, regular aerobic exercise improves endothelium‐dependent vasodilation although it remains unknown if these beneficial‐effects continue with frequent consumption of SSBs. Therefore, the purpose of this study was two‐fold; first, we studied the effects of repetitive SSB consumption (75g glucose/SSB, 3 SSBs/day) for one week in young males (Glu, n=13, 23±4yrs, 23.5±3.4kg/m2). Then, in a separate cohort of young males, we investigated if moderate‐intensity aerobic exercise (45min at 60–65% age‐predicted maximal heart rate on a recumbent cycle ergometer) on five separate days offset the hypothesized decrease in vascular endothelial function while completing the above protocol (Glu+Ex, n=11, 21±3yrs, 23.8±2.4kg/m2). Endothelium‐dependent vasodilation of the brachial artery was assessed before and after subjects completed their respective protocol using the flow‐mediated dilation (FMD) technique. Here, brachial artery blood velocity and diameter were continuously measured via Doppler ultrasound at baseline as well as following five minutes of forearm occlusion. FMD was calculated as the change (%) in peak post‐occlusion diameter (DPeak) relative to baseline (DBase): (DPeak−DBase)/DBase×100. Shear rate (SR) area the curve (SRAUC) was calculated as 4×Velocity/Diameter integrated over time from post‐occlusion to DPeak using the trapezoid rule: ∑[1/2((xi+1)−xi)((yi+1)−yi)+((xi+1)−xi)(yi−z)], where x is time, y is SR, and z is basal SR. At baseline, fasting [glucose] (p=0.15), [insulin] (p=0.25), %FMD (p=0.48), absolute FMD (p=0.66), and SRAUC (p=0.82) were similar between groups. Following one week of repetitive SSB consumption, fasting [glucose] (Glu: 94±6 to 92±6mg/dL, Glu+Ex: 89±8 to 87±6mg/dL) and [insulin] (Glu: 11.3±6.2 to 11.8±8.9μU/mL, Glu+Ex: 8.7±2.9 to 9.4±3.2 μU/mL) were changed (both group‐by‐times p=0.74). %FMD was reduced in Glu (6.1±2.2 to 5.1±1.3%) and increased in Glu+Ex (6.6±2.2 to 7.8±2.4%, p<0.05 for both). SRAUC increased to a similar extent in both Glu (17,715±8,275 to 22,922±4,808 A.U.) and Glu+Ex (18,216±4,516 to 21,666±5,392 A.U., main effect of time p<0.05). When %FMD was adjusted for SRAUC, attenuation was observed in Glu (0.41±0.18 to 0.23±0.08%/sec*103, p<0.05) but not Glu+Ex (0.38±0.14 to 0.38±0.13%/sec*103, p=0.88). Despite no change in fasting [glucose] or [insulin], repeated consumption of SSBs impairs conduit artery vascular endothelial function. Additionally, subjects whom engaged in regular moderate‐intensity aerobic exercise did not demonstrate the same SSB‐induced endothelial dysfunction. Collectively, these data suggest aerobic exercise may offset the deleterious effects of repetitive SSB consumption.Support or Funding InformationAmerican Diabetes Association 1‐16‐1CTA‐015.