Presentation Title

Cardiovascular and Autonomic Responses to Acute Exposure to Mild Hypercapnic Conditions in Middle-Aged Adults

Advisor Information

Song-Young Park

Location

MBSC Omaha Room 304 - G

Presentation Type

Oral Presentation

Start Date

4-3-2022 2:00 PM

End Date

4-3-2022 3:15 PM

Abstract

Sedentary lifestyle in the US has significantly increased in recent decades, specifically, adults in modern workplaces have been known to be exposed to ~6 hours of uninterrupted prolonged sitting (PS) per day. PS has been shown to cause endothelial dysfunction, leading to an increased risk for cardiovascular disease such as peripheral arterial disease. Additionally, elevations in carbon dioxide (hypercapnia), commonly observed in workplaces such as offices, have been known to impair cardiovascular function. Interrupting PS with muscular contractions has been used to prevent the negative effects of PS. However, the underlying protective mechanism(s) of these muscular contractions during PS with hypercapnia in middle-aged adults is currently unknown. The purpose of this study was to examine the impacts of muscle contraction, specifically, activation of group III/IV muscle afferents via passive and active leg movement in middle-aged office workers during PS in a mild-hypercapnic environment. Healthy sedentary middle-aged adults (n=5, age: 45 ± 9) completed 3 visits in a mild-hypercapnic environment: control (CON) passive (PASS) and active (ACT) to determine how activating group III/IV muscle afferents during 2.5 hours of PS affect cardiovascular function. Following PS, popliteal shear rate increased in ACT (23.98%) compared to PASS (4.09%) and CON (11.44%). Popliteal artery flow-mediated dilation showed greater increase in ACT (3.33%) compared to PASS (1.44%) and CON (1.12%). This study provides novel insight towards the cardiovascular effects of PS with mild hypercapnia in sedentary middle-aged adults, and the roles of group III and IV muscle afferent activation in the preservation for vascular function.

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COinS
 
Mar 4th, 2:00 PM Mar 4th, 3:15 PM

Cardiovascular and Autonomic Responses to Acute Exposure to Mild Hypercapnic Conditions in Middle-Aged Adults

MBSC Omaha Room 304 - G

Sedentary lifestyle in the US has significantly increased in recent decades, specifically, adults in modern workplaces have been known to be exposed to ~6 hours of uninterrupted prolonged sitting (PS) per day. PS has been shown to cause endothelial dysfunction, leading to an increased risk for cardiovascular disease such as peripheral arterial disease. Additionally, elevations in carbon dioxide (hypercapnia), commonly observed in workplaces such as offices, have been known to impair cardiovascular function. Interrupting PS with muscular contractions has been used to prevent the negative effects of PS. However, the underlying protective mechanism(s) of these muscular contractions during PS with hypercapnia in middle-aged adults is currently unknown. The purpose of this study was to examine the impacts of muscle contraction, specifically, activation of group III/IV muscle afferents via passive and active leg movement in middle-aged office workers during PS in a mild-hypercapnic environment. Healthy sedentary middle-aged adults (n=5, age: 45 ± 9) completed 3 visits in a mild-hypercapnic environment: control (CON) passive (PASS) and active (ACT) to determine how activating group III/IV muscle afferents during 2.5 hours of PS affect cardiovascular function. Following PS, popliteal shear rate increased in ACT (23.98%) compared to PASS (4.09%) and CON (11.44%). Popliteal artery flow-mediated dilation showed greater increase in ACT (3.33%) compared to PASS (1.44%) and CON (1.12%). This study provides novel insight towards the cardiovascular effects of PS with mild hypercapnia in sedentary middle-aged adults, and the roles of group III and IV muscle afferent activation in the preservation for vascular function.