Poor vascular function and reduced nitric oxide (NO)-bioavailability have been recognized to be involved in aging and Alzheimer's Disease (AD). A non-pharmacological treatment that is gaining clinical interest in the context of vascular function is dietary inorganic nitrate (NO3-) supplementation which increases NO-bioavailability through the NO3- -nitrite (NO2-) - NO pathway. This treatment has been demonstrated to improve vascular function in several clinical populations, but no study has investigated the effects in individuals with AD. Therefore, changes in plasma NO(3)(- )and NO2- and vascular responsiveness (hyperemic response to single-passive leg movement (Delta PLM)) were measured in individuals with AD (n = 10, 76 +/- 9 years), healthy elderly (OLD, n = 10, 75 +/- 6 years), and young individuals (YN, n = 10, 25 +/- 4 years) before (T0) and hourly for 4 h (T1, T2, T3, and T4) after ingestion of either NO3--rich beetroot juice (BR) or a placebo (PLA). No changes in NO3- and NO2- , nor Delta PLM were detected in any group following PLA intake. Plasma NO3- and NO2- increased significantly in all three groups at T1 (p < 0.001) and remained elevated for the rest of the trial. The same trend was found in Delta PLM, which significantly increased in all three groups over the time (p < 0.001). However, AD exhibited significantly lower Delta PLM values at any time point compared to YN (p < 0.001) and OLD (p < 0.001). These data suggest that AD-individuals included in this study were able to reduce NO3- to NO2- and to increase NO-mediated vascular responsiveness as non-AD-individuals. Other mechanisms, beyond NO-bioavailability, may be involved in vascular dysfunction in patients with AD. This research suggests that an acute administration of inorganic nitrate is not enough to revert chronically adapted vascular properties and completely restore vascular responsiveness in AD.
Increasing nitric oxide availability via ingestion of nitrate-rich beetroot juice improves vascular responsiveness in individuals with Alzheimer's Disease / Pedrinolla, A.; Dorelli, G.; Porcelli, S.; Burleigh, M.; Mendo, M.; Martignon, C.; Fonte, C.; Dalle Carbonare, L. G.; Easton, C.; Muti, E.; Schena, F.; Venturelli, M.. - In: NITRIC OXIDE. - ISSN 1089-8611. - 156:(2025), pp. 50-56. [10.1016/j.niox.2025.03.001]
Increasing nitric oxide availability via ingestion of nitrate-rich beetroot juice improves vascular responsiveness in individuals with Alzheimer's Disease
Pedrinolla A.
;Dalle Carbonare L. G.;Schena F.;Venturelli M.
2025-01-01
Abstract
Poor vascular function and reduced nitric oxide (NO)-bioavailability have been recognized to be involved in aging and Alzheimer's Disease (AD). A non-pharmacological treatment that is gaining clinical interest in the context of vascular function is dietary inorganic nitrate (NO3-) supplementation which increases NO-bioavailability through the NO3- -nitrite (NO2-) - NO pathway. This treatment has been demonstrated to improve vascular function in several clinical populations, but no study has investigated the effects in individuals with AD. Therefore, changes in plasma NO(3)(- )and NO2- and vascular responsiveness (hyperemic response to single-passive leg movement (Delta PLM)) were measured in individuals with AD (n = 10, 76 +/- 9 years), healthy elderly (OLD, n = 10, 75 +/- 6 years), and young individuals (YN, n = 10, 25 +/- 4 years) before (T0) and hourly for 4 h (T1, T2, T3, and T4) after ingestion of either NO3--rich beetroot juice (BR) or a placebo (PLA). No changes in NO3- and NO2- , nor Delta PLM were detected in any group following PLA intake. Plasma NO3- and NO2- increased significantly in all three groups at T1 (p < 0.001) and remained elevated for the rest of the trial. The same trend was found in Delta PLM, which significantly increased in all three groups over the time (p < 0.001). However, AD exhibited significantly lower Delta PLM values at any time point compared to YN (p < 0.001) and OLD (p < 0.001). These data suggest that AD-individuals included in this study were able to reduce NO3- to NO2- and to increase NO-mediated vascular responsiveness as non-AD-individuals. Other mechanisms, beyond NO-bioavailability, may be involved in vascular dysfunction in patients with AD. This research suggests that an acute administration of inorganic nitrate is not enough to revert chronically adapted vascular properties and completely restore vascular responsiveness in AD.I documenti in IRIS sono protetti da copyright e tutti i diritti sono riservati, salvo diversa indicazione
