Cerebral vascular function following the acute consumption of caffeinated artificially- and sugar sweetened soft drinks in healthy adults

Figures

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  Figure 1. Experimental study visits timeline (A) where the experimental drinks were randomized and the order of cerebral vascular function tests was randomized and counterbalanced. The example tracings of mean arterial pressure (blue), middle cerebral artery blood velocity (green), end-tidal carbon dioxide (red), and posterior cerebral artery blood velocity (magenta) for squat-to-stand at 0.10 Hz (B), squat-to-stand at 0.05 Hz (C), and cerebral vascular reactivity to hypercapnia (D) tests. ASB, artificially-sweetened beverage; SSB, sugar-sweetened beverage.

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  Figure 2. Seated baseline values 20 min after consuming each experimental beverage for middle cerebral artery blood velocity (A), middle cerebral artery vascular conductance (B), posterior cerebral artery blood velocity (C), and posterior cerebral artery vascular conductance (D). Data are reported as mean ± standard deviation. Mixed effects models were used to compare data between conditions. If a mixed effects model revealed a significant effect, a post-hoc Holm-Sidak multiple comparisons test was used to determine where differences existed. n = 12, four females unless otherwise noted. Missing data occurred due to the loss of signal and/or inability to obtain a quality signal while maintaining the same depth and/or gain with the transcranial Doppler signal. WDifferent from Water (P < 0.050); SDifferent between soft drinks (P < 0.050); ASB, artificially-sweetened beverage; SSB, sugar-sweetened beverage.

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  Figure 3. Dynamic cerebral autoregulation mean (bars) ± standard deviation and individual (circles) responses of the middle cerebral artery for gain (A), phase (B), and coherence (C) for both squat-to-stand frequencies (0.10 Hz and 0.05 Hz). Mixed effects models were used to compare data between conditions. If a mixed effects model revealed a significant effect, a post-hoc Holm-Sidak multiple comparisons test was used to determine where differences existed. Values are presented as the 5 min mean (bars) ± standard deviation and individual responses (circles). n = 12, four females unless otherwise noted. Missing data occurred due to exclusion due to noise during transfer function analysis. ASB, artificially-sweetened beverage; SSB, sugar-sweetened beverage.

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  Figure 4. Mean arterial pressure (A), PETCO2 (B), middle cerebral artery blood velocity (C), middle cerebral artery conductance (D), posterior cerebral artery blood velocity (E), and posterior cerebral artery conductance (F) obtained during each 5 min squat-to-stand frequency (0.10 Hz and 0.05 Hz). Mixed effects models were used to compare data between conditions. If a mixed effects model revealed a significant effect, a post-hoc Holm-Sidak multiple comparisons test was used to determine where differences existed. Values are presented as the 5 min mean (bars) ± standard deviation and individual responses (circles). n = 12, four females unless otherwise noted. Missing data occurred due to the loss of signal and/or inability to obtain a quality signal while maintaining the same depth and/or gain with the transcranial Doppler signal. WDifferent from Water (P < 0.050); ASB, artificially-sweetened beverage; SSB, sugar-sweetened beverage.

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  Figure 5. Left middle cerebral artery (A) and right posterior cerebral artery (B) reactivity to hypercapnia. Mixed effects models were used to compare data between conditions. If a mixed effects model revealed a significant effect, a post-hoc Holm-Sidak multiple comparisons test was used to determine where differences existed. Data are presented as mean (bars) ± standard deviation and individual (circles) responses. n = 12, four females unless otherwise noted. Missing data occurred due to the loss of signal and/or inability to obtain a quality signal while maintaining the same depth and/or gain with the transcranial Doppler signal. WDifferent from Water (P < 0.050); ASB, artificially-sweetened beverage; SSB, sugar-sweetened beverage.

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  Figure 6. Mean arterial pressure (A), PETCO2 (B), middle cerebral artery blood velocity (C), middle cerebral artery conductance (D), posterior cerebral artery blood velocity (E; n = 10, three females for water, n = 11, n = 4 for ASB, and n = 10, two females for SSB), and posterior cerebral artery conductance (F; n = 10, three females for water, n = 11, four females for ASB, and n = 10, two females for SSB) obtained from each stage of the cerebral vascular reactivity to hypercapnia test. Mixed effects models were used to compare data between conditions. If a mixed effects model revealed a significant effect, a post-hoc Holm-Sidak multiple comparisons test was used to determine where differences existed. Data are presented as mean ± standard deviation. n = 12, four females unless otherwise noted. Missing data occurred due to the loss of signal and/or inability to obtain a quality signal while maintaining the same depth and/or gain with the transcranial Doppler signal. BDifferent from baseline (P < 0.050); WDifferent from water (P < 0.050); SDifferent between soft drinks (p < 0.050); all B = all three beverages are different (P < 0.050) from baseline; all W = both the SSB and ASB are…