کد مقاله | کد نشریه | سال انتشار | مقاله انگلیسی | نسخه تمام متن |
---|---|---|---|---|
5514293 | 1541599 | 2016 | 9 صفحه PDF | دانلود رایگان |
- Plasma and salivary [thiocyanate] was higher in cigarette smokers than non-smokers.
- Dietary NO3â metabolism was compromised in smokers compared to non-smokers.
- Blood pressure was lower after NO3â supplementation in non-smokers but not smokers.
- Smoking blunts some of the vascular benefits of NO3â supplementation.
Dietary supplementation with inorganic nitrate (NO3â) has been reported to improve cardiovascular health indices in healthy adults. Cigarette smoking increases circulating thiocyanate (SCNâ), which has been suggested to competitively inhibit salivary nitrate (NO3â) uptake, a rate-limiting step in dietary NO3â metabolism. Therefore, this study tested the hypothesis that dietary NO3â supplementation would be less effective at increasing the circulating plasma nitrite concentration ([NO2â]) and lowering blood pressure in smokers (S) compared to non-smokers (NS). Nine healthy smokers and eight healthy non-smoking controls reported to the laboratory at baseline (CON) and following six day supplementation periods with 140 mL dayâ1 NO3â-rich (8.4 mmol NO3â dayâ1; NIT) and NO3â-depleted (0.08 mmol NO3â dayâ1; PLA) beetroot juice in a cross-over experiment. Plasma and salivary [SCNâ] were elevated in smokers compared to non-smokers in all experimental conditions (P < 0.05). Plasma and salivary [NO3â] and [NO2â] were elevated in the NIT condition compared to CON and PLA conditions in smokers and non-smokers (P < 0.05). However, the change in salivary [NO3â] (S: 3.5 ± 2.1 vs. NS: 7.5 ± 4.4 mM), plasma [NO3â] (S: 484 ± 198 vs. NS: 802 ± 199 μM) and plasma [NO2â] (S: 218 ± 128 vs. NS: 559 ± 419 nM) between the CON and NIT conditions was lower in the smokers compared to the non-smokers (P < 0.05). Salivary [NO2â] increased above CON to a similar extent with NIT in smokers and non-smokers (P > 0.05). Systolic blood pressure was lowered compared to PLA with NIT in non-smokers (P < 0.05), but not smokers (P > 0.05). These findings suggest that dietary NO3â metabolism is compromised in smokers leading to an attenuated blood pressure reduction compared to non-smokers after NO3â supplementation. These observations may provide novel insights into the cardiovascular risks associated with cigarette smoking and suggest that this population may be less likely to benefit from improved cardiovascular health if they increase dietary NO3â intake.
Journal: Nitric Oxide - Volume 61, 30 December 2016, Pages 29-37