TY - JOUR

T1 - Effects of acute dietary nitrate supplementation on cold-induced vasodilation in healthy males

AU - Wickham, Kate Aiko

AU - Steele, S W

AU - Cheung, Stephen S

N1 - (Ekstern)

PY - 2021

Y1 - 2021

N2 - Purpose: Cold-induced vasodilation (CIVD) is a paradoxical rise in blood flow to the digits that occur during prolonged cold exposure. CIVD is thought to occur through active vasodilation and/or sympathetic withdrawal, where nitric oxide (NO) may play a key role in mediating these mechanisms. Beetroot juice (BRJ) is high in dietary nitrate (NO3−) which undergoes sequential reduction to nitrite (NO2−) and subsequently NO. Using a double-blind, randomized, crossover design, we examined the effect of acute BRJ supplementation on the CIVD response in 10 healthy males. Methods: Participants had a resting blood pressure measurement taken prior to ingesting 140 mL of nitrate-rich BRJ (13 mmol NO3−) or a NO3−-free placebo (PLA). After 2 h, participants immersed their hand in neutral water (~ 35 °C) for 10 min of baseline before cold water immersion (~ 8 °C) for 30 min. Laser-Doppler fluxmetry and skin temperature were measured continuously on the digits. Results: Compared to PLA (100 ± 3 mmHg), acute BRJ supplementation significantly reduced mean arterial pressure at -30 min (96 ± 2 mmHg; p = 0.007) and 0 min (94 ± 2 mmHg; p = 0.008). Acute BRJ supplementation had no effect on Laser-Doppler fluxmetry during CIVD (expressed as cutaneous vascular conductance) measured as area under the curve (BRJ: 843 ± 148 PU mmHg−1 s; PLA: 1086 ± 333 PU mmHg−1 s), amplitude (BRJ: 0.60 ± 0.12 PU mmHg−1; PLA: 0.69 ± 0.14 PU mmHg−1), and duration (BRJ: 895 ± 60 s; PLA: 894 ± 46 s). Conclusion: Acute BRJ supplementation does not augment the CIVD response in healthy males.

AB - Purpose: Cold-induced vasodilation (CIVD) is a paradoxical rise in blood flow to the digits that occur during prolonged cold exposure. CIVD is thought to occur through active vasodilation and/or sympathetic withdrawal, where nitric oxide (NO) may play a key role in mediating these mechanisms. Beetroot juice (BRJ) is high in dietary nitrate (NO3−) which undergoes sequential reduction to nitrite (NO2−) and subsequently NO. Using a double-blind, randomized, crossover design, we examined the effect of acute BRJ supplementation on the CIVD response in 10 healthy males. Methods: Participants had a resting blood pressure measurement taken prior to ingesting 140 mL of nitrate-rich BRJ (13 mmol NO3−) or a NO3−-free placebo (PLA). After 2 h, participants immersed their hand in neutral water (~ 35 °C) for 10 min of baseline before cold water immersion (~ 8 °C) for 30 min. Laser-Doppler fluxmetry and skin temperature were measured continuously on the digits. Results: Compared to PLA (100 ± 3 mmHg), acute BRJ supplementation significantly reduced mean arterial pressure at -30 min (96 ± 2 mmHg; p = 0.007) and 0 min (94 ± 2 mmHg; p = 0.008). Acute BRJ supplementation had no effect on Laser-Doppler fluxmetry during CIVD (expressed as cutaneous vascular conductance) measured as area under the curve (BRJ: 843 ± 148 PU mmHg−1 s; PLA: 1086 ± 333 PU mmHg−1 s), amplitude (BRJ: 0.60 ± 0.12 PU mmHg−1; PLA: 0.69 ± 0.14 PU mmHg−1), and duration (BRJ: 895 ± 60 s; PLA: 894 ± 46 s). Conclusion: Acute BRJ supplementation does not augment the CIVD response in healthy males.

KW - Beetroot juice

KW - CIVD

KW - Cold

KW - Cutaneous circulation

KW - Finger

KW - Skin blood flow

U2 - 10.1007/s00421-021-04621-8

DO - 10.1007/s00421-021-04621-8

M3 - Journal article

C2 - 33620545

AN - SCOPUS:85101695179

VL - 121

SP - 1431

EP - 1439

JO - European Journal of Applied Physiology

JF - European Journal of Applied Physiology

SN - 1439-6319

IS - 5

ER -