Nasal versus Buccal Breathing and Non-Invasive Indices of Vascular Function in Healthy Young Adults: An Observational Crossover Study.
To compare the effects of nasal versus buccal breathing on non-invasive indices of vascular function under standardized resting conditions.
This observational crossover study included 45 young healthy Caucasian male volunteers (mean age 21.3 ± 2.3 years). Each participant completed two breathing protocols: nasal breathing (NB) and buccal breathing (BB), in randomized order, separated by a washout period. Vascular responses were assessed using several non-invasive methods: Digital Plethysmography (DP) and UltraSound Flow-Mediated Dilation (US-FMD). Pulse Propagation Time (PPT) and Reflection Index (RI) were derived from DP, while brachial artery diameter was measured with US-FMD at rest and following each breathing condition.
Nasal breathing significantly increased PPT (6.35% ± 1.51) and reduced RI (4.6% ± 1.25) compared with buccal breathing, indicating changes consistent with increased vascular relaxation (p < 0.05). Ultrasound assessment demonstrated a significant increase in brachial artery diameter (4.46% ± 0.05) during nasal breathing (p < 0.001), an effect absent during buccal breathing. These findings indicate that nasal breathing is associated with enhanced vasodilation and differences in non-invasive vascular indices compared with buccal breathing.
In healthy young adults, nasal and buccal breathing were associated with distinct patterns in non-invasive indices of vascular function. These findings highlight the physiological relevance of breathing route under resting conditions and warrant further investigation.
This observational crossover study included 45 young healthy Caucasian male volunteers (mean age 21.3 ± 2.3 years). Each participant completed two breathing protocols: nasal breathing (NB) and buccal breathing (BB), in randomized order, separated by a washout period. Vascular responses were assessed using several non-invasive methods: Digital Plethysmography (DP) and UltraSound Flow-Mediated Dilation (US-FMD). Pulse Propagation Time (PPT) and Reflection Index (RI) were derived from DP, while brachial artery diameter was measured with US-FMD at rest and following each breathing condition.
Nasal breathing significantly increased PPT (6.35% ± 1.51) and reduced RI (4.6% ± 1.25) compared with buccal breathing, indicating changes consistent with increased vascular relaxation (p < 0.05). Ultrasound assessment demonstrated a significant increase in brachial artery diameter (4.46% ± 0.05) during nasal breathing (p < 0.001), an effect absent during buccal breathing. These findings indicate that nasal breathing is associated with enhanced vasodilation and differences in non-invasive vascular indices compared with buccal breathing.
In healthy young adults, nasal and buccal breathing were associated with distinct patterns in non-invasive indices of vascular function. These findings highlight the physiological relevance of breathing route under resting conditions and warrant further investigation.