Dynamic Cerebral Autoregulation following the Acute Consumption of Soft‐drinks in Healthy Adults

Abstract

Chronic consumption of high-fructose corn syrup (HFCS) and artificially sweetened beverages (ASB) are associated with an increased risk of stroke. An attenuation in dynamic cerebral autoregulation (dCA), a measure cerebral vascular function during changes in arterial blood pressure, may indicate cerebral vascular dysfunction. Thus, understanding the acute effects that HFCS and ASB consumption has on dCA may help understand the increased risk of stroke associated with the chronic consumption of these beverages. Purpose We tested the hypothesis that dynamic cerebral autoregulation (dCA) is attenuated following the acute consumption of HFCS and ASB soft-drinks compared to Water. Methods Twelve healthy adults (age: 23±2 y, 4 females) completed three randomized, double-blind trials. Participants drank 500 mL of Water, HFCS (Mountain Dew) or ASB (Diet Mountain Dew). We continuously measured blood pressure (MAP), mean middle cerebral artery blood velocity (MCAv), and end-tidal CO2 tension (PETCO2). Cerebral vascular conductance (CVC) was calculated as mean MCAv/MAP. Twenty minutes after experimental beverage consumption participants completed a 5 minute seated baseline, followed by an oscillatory blood pressure challenge. The oscillatory blood pressure challenge consisted of squat-to-stand intervals at two different frequencies (0.10 Hz and 0.05 Hz) for 5 minutes each separated by 5 minutes of seated rest. dCA was assessed in the MCA using transfer function analysis. Coherence, gain and phase are reported in in predefined frequency domains: low frequency (LF; 0.07-0.2 Hz) and very low frequency (VLF; 0.01-0.07 Hz) for the 0.10 Hz and 0.05 Hz, respectively. Values are reported as mean±SD. Results At baseline, MCAv (HFCS: 53.7±11.5 and ASB: 52.2±10.3 vs. Water: 61.4±10.8 cm/s; p<0.01) and MCA CVC (HFCS: 0.6±0.2 and ASB: 0.5±0.1 vs. Water: 0.7±1 cm/s/mmHg; p<0.02) were lower following HFCS and ASB vs. Water. During the 0.10 Hz squat-to-stand, there were no differences between beverages for coherenceLF (p=0.30) or phaseLF (p=0.68). GainLF was lower following ASB (0.81±0.21 cm/s/mmHg) compared to Water (0.95±0.27 cm/s/mmHg; p=0.01) but there was no difference in gainLF between HFCS (0.92±0.23 cm/s/mmHg) and Water (p=0.53). During the 0.05 Hz squat-to-stand, there were no differences between beverages for coherenceVLF (p=0.83) or gainVLF (p=0.28). PhaseVLF was higher following ASB (45.4±8.5 degrees) compared to Water (39.8±8 degrees; p=0.06) but there was no difference in phaseVLF between HFCS (43.8±10.3 degrees) and Water (p=0.31). Conclusions Our data indicate that acute consumption of an ASB did not consistently alter dCA in both frequency bands. Additionally, dCA was not altered following a HFCS soft-drink. However, future research is warranted to determine the effects of chronic consumption of HFCS and ASB soft-drinks on cerebral vascular function and the increased the risk of stroke.