Age Comparisons of Exercising Muscle O2 Supply in Healthy Adults: Effects of Esmolol Infusion

Status

Completed

Phases

Early Phase 1

Study type

Interventional

Source

ClinicalTrials.gov

Registry ID

NCT04181606

Enrollment

Registered

2019-11-29

Start date

2022-02-02

Completion date

2023-04-25

Last updated

2025-05-13

For informational purposes only — not medical advice. Sourced from public registries and may not reflect the latest updates. Terms

Conditions

Aging

Keywords

Esmolol hydrochloride, Exercise

Brief summary

Detailed description

This study will test the central hypothesis that postmenopausal women will demonstrate increased oxygen extraction in active leg muscle during leg cycling exercise while receiving an infusion of Esmolol, a fast-acting β1 selective antagonist, when compared to premenopausal women. β1 selective antagonists (or β1 blockers) are used to lower heart rate and improve O2 supply-to-demand balance in patients with coronary artery disease. By using esmolol to attenuate the central sympathetic response to exercise (increased heart rate and cardiac output) we can examine peripheral mechanisms of O2 delivery. The current project will evaluate how older postmenopausal women adjust active muscle O2 supply to an acute reduction in systemic O2 delivery during large muscle dynamic exercise when compared to younger premenopausal women.

Interventions

DRUGEsmolol infusion

The Esmolol loading dose will be 0.5 mg/kg fat free mass/min administered over the first 3 minutes, followed by a maintenance dose of 0.25 mg/kg fat free mass/min for the remainder of the protocol (maximum of 60 minutes).

DRUGSaline infusion

Saline will be rate/volume matched to the calculated esmolol dose.

OTHERPre exercise baseline

Subject rests quietly while drug infusion begins (3 min loading dose followed by 10 min of maintenance dose) until heart rate and blood pressure stabilize.

OTHERIsometric handgrip exercise

The subject will grip at 40% of their maximum and maintain that grip for 90 seconds. Once at rest and once during heavy intensity cycling.

OTHERSemi-recumbent cycling

Subjects will pedal for 2-4 minutes at a very light intensity (20W), followed immediately by 5 minutes at a moderate intensity (at a workload intended to elicit 85% of the oxygen consumption observed at the lactate threshold), and 5 minutes of cycling at a heavy intensity (at a workload estimated to elicit oxygen consumption half way between those observed at the lactate threshold and respiratory compensation point). Subjects will then continue cycling at the heavy intensity for 90 seconds while performing isometric handgrip exercise.

Study design

Allocation

RANDOMIZED

Intervention model

CROSSOVER

Primary purpose

BASIC_SCIENCE

Masking

TRIPLE (Subject, Investigator, Outcomes Assessor)

Masking description

The participants, investigators, and data analysts (outcomes assessors) will be blinded to the treatment (drug) order. The care providers (research nurse and physician) will be aware of the treatment order for safety reasons i.e., they will be assessing heart rate, blood pressure and symptoms before, during, and after the infusion.

Eligibility

Sex/Gender

FEMALE

Age

18 Years to 75 Years

Healthy volunteers

Yes

Inclusion criteria

3.1 Inclusion Criteria 1. Capable of giving informed consent 2. Premenopausal women ages 18-35 years OR post-menopausal women ages 55-70 years 3. Satisfactory medical history and physical exam, as determined by a Clinical Research Center (CRC) clinician 4. Not currently taking medications affecting heart rate or contractility 5. Fluent in written and spoken English 3.2

Exclusion criteria

Participants who will not be studied are those who: 1. Are less than 19 years of age or more than 70 years of age 2. Are pregnant or lactating 3. Are prisoners or institutionalized individuals or unable to consent 4. Diagnosed renal failure (Creatinine \>2.0 mg/dl) 5. Diagnosed liver disease (ALT and aspartate aminotransferase {AST} 2 times normal) 6. Diagnosed Reynaud's disease 7. Have uncontrolled diabetes 8. Have uncontrolled hypertension 9. Have a left ventricular ejection fraction \< 40% 10. Have a recent history of unstable angina or myocardial infarction (\<6 months), unstable angina, or use of nitrate medications within past 2 weeks 10\. Severe lung disease (i.e., on supplemental oxygen or frequently use rescue inhalers) 11. Diagnosed bleeding or clotting disorder or recent blood transfusion 12. Have asthma, history of thyroid issues or hyperkalemia 13. Known use of recreational drugs 14. Methylphenidate use

Design outcomes

Primary

Measure	Time frame	Description
Tissue Saturation Index (TSI) - Active Leg Muscle	Last 60 seconds of Rest, Moderate exercise, and Heavy Exercise.	The primary outcome variable is the change in skeletal muscle oxygenation (∆TSI%) in the active leg muscle from baseline during recumbent cycling using near-infrared spectroscopy. TSI% represent the percentage of oxygenated hemoglobin relative to total hemoglobin in the tissue beneath the NIRS probe. Lower values represent a greater reduction in tissue oxygenation from baseline (greater oxygen extraction and/or reduced oxygen delivery). TSI% = oxy\[heme\] / total\[heme\] x 100

Secondary

Measure	Time frame	Description
Heart Rate	Last 60 seconds of Rest, Moderate exercise, and Heavy Exercise.	Heart rate recorded via EKG
Cardiac Output	Last 60 seconds of Rest, Moderate exercise, and Heavy Exercise.	Cardiac Output recorded using bioimpedance cardiography
Diastolic Blood Pressure	At rest and 3 minutes into moderate exercise and heavy exercise.	Diastolic Blood Pressure recorded via an automatic sphygmomanometer (SunTech Tango)
Mean Arterial Pressure	At rest and 3 minutes into moderate exercise and heavy exercise.	Mean Arterial Pressure recorded via an automatic sphygmomanometer (SunTech Tango)
Systemic Vascular Conductance	Last 60 seconds of Rest, Moderate exercise, and Heavy Exercise.	Systemic Vascular Conductance recorded using bioimpedance cardiography
Tissue Saturation Index - Inactive Forearm Muscle	Last 60 seconds of Rest, Moderate exercise, and Heavy Exercise.	The change in skeletal muscle oxygenation (∆TSI%) in the inactive forearm from baseline during recumbent cycling using near-infrared spectroscopy. TSI% represent the percentage of oxygenated hemoglobin relative to total hemoglobin in the tissue beneath the NIRS probe. Lower values represent a greater reduction in tissue oxygenation from baseline (greater oxygen extraction and/or reduced oxygen delivery). TSI% = oxy\[heme\] / total\[heme\] x 100
Systolic Blood Pressure	At rest and 3 minutes into moderate exercise and heavy exercise.	Systolic Blood Pressure recorded via an automatic sphygmomanometer (SunTech Tango)
∆HHb - Inactive Forearm	Last 60 seconds of Moderate and Heavy Exercise	Change in deoxygenated hemoglobin (∆HHb) in the inactive forearm muscle from baseline during recumbent cycling exercise using near-infrared spectroscopy (NIRS) relative to the Total Labile Signal. ∆HHb is an index of oxygen extraction obtained using NIRS. The total labile signal is defined as the difference between the highest observed HHb value during 5 minutes of limb occlusion at 250 mmHg and the lowest observed HHb value observed during reperfusion following removal of the occlusion. Greater ∆HHb values indicate greater oxygen extraction in the tissue under the NIRS probe.
Stroke Volume	Last 60 seconds of Rest, Moderate exercise, and Heavy Exercise.	Stroke Volume recorded using bioimpedance cardiography

Countries

United States

Participant flow

Recruitment details

37 Participants were screened for eligibility between February 2, 2022 and April 25, 2023 at the Clinical Research Center in University Park, Pennsylvania (PA). Of these, 30 were considered enrolled.

Pre-assignment details

30 participants were considered enrolled and 27 participants were randomized. The 3 participants who were not randomized dropped out of the study prior to the infusion visit.

Participants by arm

Arm	Count
Esmolol, Then Saline Participants first received esmolol hydrochloride via intravenous infusion. Dosage/Frequency: 0.5 mg/(kg Fat Free Mass·min) for 3 min followed by a maintenance infusion of 0.25 mg/(kg Fat Free Mass·min) for remainder of trial, up to a maximum of 1 hour. After a washout period of 45 mins, they then received saline via intravenous infusion (volume/rate matched to the calculated dose of esmolol).	13
Saline, Then Esmolol Participants first received saline via intravenous infusion (volume/rate matched to the calculated dose of esmolol). After a washout period of 45 mins, they then received esmolol hydrochloride via intravenous infusion. Dosage/Frequency: 0.5 mg/(kg Fat Free Mass·min) for 3 min followed by a maintenance infusion of 0.25 mg/(kg Fat Free Mass·min) for remainder of trial, up to a maximum of 1 hour.	14
Total	27

Baseline characteristics

Characteristic	Esmolol, Then Saline	Saline, Then Esmolol	Total
Age, Categorical <=18 years	0 Participants	0 Participants	0 Participants
Age, Categorical >=65 years	1 Participants	2 Participants	3 Participants
Age, Categorical Between 18 and 65 years	12 Participants	12 Participants	24 Participants
Age, Continuous	45.0 Years STANDARD_DEVIATION 18.2	44.1 Years STANDARD_DEVIATION 18.2	44.6 Years STANDARD_DEVIATION 18.2
Ethnicity (NIH/OMB) Hispanic or Latino	2 Participants	2 Participants	4 Participants
Ethnicity (NIH/OMB) Not Hispanic or Latino	11 Participants	12 Participants	23 Participants
Ethnicity (NIH/OMB) Unknown or Not Reported	0 Participants	0 Participants	0 Participants
Race (NIH/OMB) American Indian or Alaska Native	0 Participants	0 Participants	0 Participants
Race (NIH/OMB) Asian	0 Participants	1 Participants	1 Participants
Race (NIH/OMB) Black or African American	0 Participants	1 Participants	1 Participants
Race (NIH/OMB) More than one race	1 Participants	0 Participants	1 Participants
Race (NIH/OMB) Native Hawaiian or Other Pacific Islander	0 Participants	0 Participants	0 Participants
Race (NIH/OMB) Unknown or Not Reported	2 Participants	1 Participants	3 Participants
Race (NIH/OMB) White	10 Participants	11 Participants	21 Participants
Region of Enrollment United States	13 participants	14 participants	27 participants
Sex: Female, Male Female	13 Participants	14 Participants	27 Participants
Sex: Female, Male Male	0 Participants	0 Participants	0 Participants

Adverse events

Event type	EG000 affected / at risk	EG001 affected / at risk
deaths Total, all-cause mortality	0 / 27	0 / 27
other Total, other adverse events	0 / 27	0 / 27
serious Total, serious adverse events	0 / 27	0 / 27

Outcome results

Primary

Tissue Saturation Index (TSI) - Active Leg Muscle

The primary outcome variable is the change in skeletal muscle oxygenation (∆TSI%) in the active leg muscle from baseline during recumbent cycling using near-infrared spectroscopy. TSI% represent the percentage of oxygenated hemoglobin relative to total hemoglobin in the tissue beneath the NIRS probe. Lower values represent a greater reduction in tissue oxygenation from baseline (greater oxygen extraction and/or reduced oxygen delivery). TSI% = oxy\[heme\] / total\[heme\] x 100

Time frame: Last 60 seconds of Rest, Moderate exercise, and Heavy Exercise.

Population: 11 younger and 12 older at two different exercise intensities (Moderate and Heavy)

Arm	Measure	Group	Value (MEAN)	Dispersion
Esmolol Infusion	Tissue Saturation Index (TSI) - Active Leg Muscle	Younger - Moderate	-5.1 % Total Labile Signal	Standard Deviation 3.2
Esmolol Infusion	Tissue Saturation Index (TSI) - Active Leg Muscle	Younger - Heavy	-8.7 % Total Labile Signal	Standard Deviation 3.5
Esmolol Infusion	Tissue Saturation Index (TSI) - Active Leg Muscle	Older - Moderate	-1.5 % Total Labile Signal	Standard Deviation 0.9
Esmolol Infusion	Tissue Saturation Index (TSI) - Active Leg Muscle	Older - Heavy	-4.1 % Total Labile Signal	Standard Deviation 2.7
Saline Infusion	Tissue Saturation Index (TSI) - Active Leg Muscle	Older - Heavy	-2.8 % Total Labile Signal	Standard Deviation 3.2
Saline Infusion	Tissue Saturation Index (TSI) - Active Leg Muscle	Younger - Moderate	-3.1 % Total Labile Signal	Standard Deviation 2.4
Saline Infusion	Tissue Saturation Index (TSI) - Active Leg Muscle	Older - Moderate	-0.5 % Total Labile Signal	Standard Deviation 1.1
Saline Infusion	Tissue Saturation Index (TSI) - Active Leg Muscle	Younger - Heavy	-6.3 % Total Labile Signal	Standard Deviation 3.6

Secondary

Cardiac Output

Cardiac Output recorded using bioimpedance cardiography

Time frame: Last 60 seconds of Rest, Moderate exercise, and Heavy Exercise.

Population: 13 younger, 13 older

Arm	Measure	Group	Value (MEAN)	Dispersion
Esmolol Infusion	Cardiac Output	Younger - Rest	5.3 Liters/minute	Standard Deviation 0.9
Esmolol Infusion	Cardiac Output	Younger - Moderate Intensity	11.3 Liters/minute	Standard Deviation 2.2
Esmolol Infusion	Cardiac Output	Younger - Heavy Intensity	13.5 Liters/minute	Standard Deviation 2
Esmolol Infusion	Cardiac Output	Older - Rest	5.3 Liters/minute	Standard Deviation 0.8
Esmolol Infusion	Cardiac Output	Older - Moderate Intensity	10.1 Liters/minute	Standard Deviation 1.6
Esmolol Infusion	Cardiac Output	Older - Heavy Intensity	12.3 Liters/minute	Standard Deviation 1.7
Saline Infusion	Cardiac Output	Older - Moderate Intensity	11.0 Liters/minute	Standard Deviation 1.2
Saline Infusion	Cardiac Output	Younger - Rest	5.9 Liters/minute	Standard Deviation 0.7
Saline Infusion	Cardiac Output	Older - Rest	5.8 Liters/minute	Standard Deviation 0.6
Saline Infusion	Cardiac Output	Younger - Moderate Intensity	12.6 Liters/minute	Standard Deviation 1.9
Saline Infusion	Cardiac Output	Older - Heavy Intensity	14.1 Liters/minute	Standard Deviation 1.6
Saline Infusion	Cardiac Output	Younger - Heavy Intensity	15.9 Liters/minute	Standard Deviation 2.5

Secondary

Diastolic Blood Pressure

Diastolic Blood Pressure recorded via an automatic sphygmomanometer (SunTech Tango)

Time frame: At rest and 3 minutes into moderate exercise and heavy exercise.

Population: 13 younger, 13 older

Arm	Measure	Group	Value (MEAN)	Dispersion
Esmolol Infusion	Diastolic Blood Pressure	Younger - Rest	66 mmHg	Standard Deviation 8
Esmolol Infusion	Diastolic Blood Pressure	Younger - Moderate Intensity	64 mmHg	Standard Deviation 8
Esmolol Infusion	Diastolic Blood Pressure	Younger - Heavy Intensity	64 mmHg	Standard Deviation 8
Esmolol Infusion	Diastolic Blood Pressure	Older - Rest	69 mmHg	Standard Deviation 9
Esmolol Infusion	Diastolic Blood Pressure	Older - Moderate Intensity	68 mmHg	Standard Deviation 6
Esmolol Infusion	Diastolic Blood Pressure	Old - Heavy Intensity	69 mmHg	Standard Deviation 6
Saline Infusion	Diastolic Blood Pressure	Older - Moderate Intensity	68 mmHg	Standard Deviation 8
Saline Infusion	Diastolic Blood Pressure	Younger - Rest	63 mmHg	Standard Deviation 6
Saline Infusion	Diastolic Blood Pressure	Older - Rest	69 mmHg	Standard Deviation 8
Saline Infusion	Diastolic Blood Pressure	Younger - Moderate Intensity	59 mmHg	Standard Deviation 11
Saline Infusion	Diastolic Blood Pressure	Old - Heavy Intensity	68 mmHg	Standard Deviation 12
Saline Infusion	Diastolic Blood Pressure	Younger - Heavy Intensity	62 mmHg	Standard Deviation 12

Secondary

Heart Rate

Heart rate recorded via EKG

Time frame: Last 60 seconds of Rest, Moderate exercise, and Heavy Exercise.

Population: 13 Younger, 14 Older

Arm	Measure	Group	Value (MEAN)	Dispersion
Esmolol Infusion	Heart Rate	Younger - Rest	64.5 Beats/minute	Standard Deviation 8.7
Esmolol Infusion	Heart Rate	Younger - Moderate Intensity	106.3 Beats/minute	Standard Deviation 11.5
Esmolol Infusion	Heart Rate	Younger - Heavy Intensity	123.1 Beats/minute	Standard Deviation 11.8
Esmolol Infusion	Heart Rate	Older - Rest	60.5 Beats/minute	Standard Deviation 7.8
Esmolol Infusion	Heart Rate	Older - Moderate Intensity	89.9 Beats/minute	Standard Deviation 10.4
Esmolol Infusion	Heart Rate	Older - Heavy Intensity	105.5 Beats/minute	Standard Deviation 13.4
Saline Infusion	Heart Rate	Older - Moderate Intensity	97.6 Beats/minute	Standard Deviation 13
Saline Infusion	Heart Rate	Younger - Rest	70.0 Beats/minute	Standard Deviation 11.1
Saline Infusion	Heart Rate	Older - Rest	67.2 Beats/minute	Standard Deviation 11.7
Saline Infusion	Heart Rate	Younger - Moderate Intensity	115.4 Beats/minute	Standard Deviation 16.4
Saline Infusion	Heart Rate	Older - Heavy Intensity	118.5 Beats/minute	Standard Deviation 20.6
Saline Infusion	Heart Rate	Younger - Heavy Intensity	141.2 Beats/minute	Standard Deviation 18

Secondary

∆HHb - Inactive Forearm

Change in deoxygenated hemoglobin (∆HHb) in the inactive forearm muscle from baseline during recumbent cycling exercise using near-infrared spectroscopy (NIRS) relative to the Total Labile Signal. ∆HHb is an index of oxygen extraction obtained using NIRS. The total labile signal is defined as the difference between the highest observed HHb value during 5 minutes of limb occlusion at 250 mmHg and the lowest observed HHb value observed during reperfusion following removal of the occlusion. Greater ∆HHb values indicate greater oxygen extraction in the tissue under the NIRS probe.

Time frame: Last 60 seconds of Moderate and Heavy Exercise

Population: 9 younger, 12 older

Arm	Measure	Group	Value (MEAN)	Dispersion
Esmolol Infusion	∆HHb - Inactive Forearm	Younger - Moderate Exercise	8.6 % Total Labile Signal	Standard Deviation 5.7
Esmolol Infusion	∆HHb - Inactive Forearm	Younger - Heavy Exercise	13.5 % Total Labile Signal	Standard Deviation 10
Esmolol Infusion	∆HHb - Inactive Forearm	Older - Moderate Exercise	2.9 % Total Labile Signal	Standard Deviation 6.5
Esmolol Infusion	∆HHb - Inactive Forearm	Older - Heavy Exercise	4.1 % Total Labile Signal	Standard Deviation 9.1
Saline Infusion	∆HHb - Inactive Forearm	Older - Heavy Exercise	-2.6 % Total Labile Signal	Standard Deviation 10.4
Saline Infusion	∆HHb - Inactive Forearm	Younger - Moderate Exercise	5.0 % Total Labile Signal	Standard Deviation 4.1
Saline Infusion	∆HHb - Inactive Forearm	Older - Moderate Exercise	-3.4 % Total Labile Signal	Standard Deviation 6.1
Saline Infusion	∆HHb - Inactive Forearm	Younger - Heavy Exercise	5.9 % Total Labile Signal	Standard Deviation 7

Secondary

Mean Arterial Pressure

Mean Arterial Pressure recorded via an automatic sphygmomanometer (SunTech Tango)

Time frame: At rest and 3 minutes into moderate exercise and heavy exercise.

Population: 13 younger, 13 older

Arm	Measure	Group	Value (MEAN)	Dispersion
Esmolol Infusion	Mean Arterial Pressure	Younger - Rest	79 mmHg	Standard Deviation 7
Esmolol Infusion	Mean Arterial Pressure	Younger - Moderate Intensity	82 mmHg	Standard Deviation 7
Esmolol Infusion	Mean Arterial Pressure	Younger - Heavy Intensity	87 mmHg	Standard Deviation 7
Esmolol Infusion	Mean Arterial Pressure	Older - Rest	84 mmHg	Standard Deviation 11
Esmolol Infusion	Mean Arterial Pressure	Older - Moderate Intensity	87 mmHg	Standard Deviation 7
Esmolol Infusion	Mean Arterial Pressure	Old - Heavy Intensity	91 mmHg	Standard Deviation 8
Saline Infusion	Mean Arterial Pressure	Older - Moderate Intensity	94 mmHg	Standard Deviation 10
Saline Infusion	Mean Arterial Pressure	Younger - Rest	77 mmHg	Standard Deviation 6
Saline Infusion	Mean Arterial Pressure	Older - Rest	85 mmHg	Standard Deviation 8
Saline Infusion	Mean Arterial Pressure	Younger - Moderate Intensity	85 mmHg	Standard Deviation 10
Saline Infusion	Mean Arterial Pressure	Old - Heavy Intensity	103 mmHg	Standard Deviation 14
Saline Infusion	Mean Arterial Pressure	Younger - Heavy Intensity	93 mmHg	Standard Deviation 10

Secondary

Stroke Volume

Stroke Volume recorded using bioimpedance cardiography

Time frame: Last 60 seconds of Rest, Moderate exercise, and Heavy Exercise.

Population: 13 younger, 13 older

Arm	Measure	Group	Value (MEAN)	Dispersion
Esmolol Infusion	Stroke Volume	Younger - Moderate Intensity	107 mL/beat	Standard Deviation 20
Esmolol Infusion	Stroke Volume	Older - Rest	88 mL/beat	Standard Deviation 16
Esmolol Infusion	Stroke Volume	Younger - Rest	84 mL/beat	Standard Deviation 15
Esmolol Infusion	Stroke Volume	Older - Moderate Intensity	113 mL/beat	Standard Deviation 15
Esmolol Infusion	Stroke Volume	Younger - Heavy Intensity	110 mL/beat	Standard Deviation 18
Esmolol Infusion	Stroke Volume	Older - Heavy Intensity	117 mL/beat	Standard Deviation 14
Saline Infusion	Stroke Volume	Older - Heavy Intensity	119 mL/beat	Standard Deviation 16
Saline Infusion	Stroke Volume	Younger - Rest	86 mL/beat	Standard Deviation 13
Saline Infusion	Stroke Volume	Younger - Moderate Intensity	110 mL/beat	Standard Deviation 17
Saline Infusion	Stroke Volume	Younger - Heavy Intensity	114 mL/beat	Standard Deviation 19
Saline Infusion	Stroke Volume	Older - Rest	88 mL/beat	Standard Deviation 17
Saline Infusion	Stroke Volume	Older - Moderate Intensity	114 mL/beat	Standard Deviation 14

Secondary

Systemic Vascular Conductance

Systemic Vascular Conductance recorded using bioimpedance cardiography

Time frame: Last 60 seconds of Rest, Moderate exercise, and Heavy Exercise.

Population: 13 younger, 13 older

Arm	Measure	Group	Value (MEAN)	Dispersion
Esmolol Infusion	Systemic Vascular Conductance	Younger - Rest	70 mL/minute/mmHg	Standard Deviation 13
Esmolol Infusion	Systemic Vascular Conductance	Younger - Moderate Intensity	141 mL/minute/mmHg	Standard Deviation 27
Esmolol Infusion	Systemic Vascular Conductance	Younger - Heavy Intensity	159 mL/minute/mmHg	Standard Deviation 28
Esmolol Infusion	Systemic Vascular Conductance	Older - Rest	67 mL/minute/mmHg	Standard Deviation 8
Esmolol Infusion	Systemic Vascular Conductance	Older - Moderate Intensity	117 mL/minute/mmHg	Standard Deviation 14
Esmolol Infusion	Systemic Vascular Conductance	Older - Heavy Intensity	132 mL/minute/mmHg	Standard Deviation 15
Saline Infusion	Systemic Vascular Conductance	Older - Moderate Intensity	118 mL/minute/mmHg	Standard Deviation 8
Saline Infusion	Systemic Vascular Conductance	Younger - Rest	82 mL/minute/mmHg	Standard Deviation 9
Saline Infusion	Systemic Vascular Conductance	Older - Rest	72 mL/minute/mmHg	Standard Deviation 7
Saline Infusion	Systemic Vascular Conductance	Younger - Moderate Intensity	154 mL/minute/mmHg	Standard Deviation 32
Saline Infusion	Systemic Vascular Conductance	Older - Heavy Intensity	136 mL/minute/mmHg	Standard Deviation 14
Saline Infusion	Systemic Vascular Conductance	Younger - Heavy Intensity	179 mL/minute/mmHg	Standard Deviation 42

Secondary

Systolic Blood Pressure

Systolic Blood Pressure recorded via an automatic sphygmomanometer (SunTech Tango)

Time frame: At rest and 3 minutes into moderate exercise and heavy exercise.

Population: 13 younger, 13 older

Arm	Measure	Group	Value (MEAN)	Dispersion
Esmolol Infusion	Systolic Blood Pressure	Older - Rest	114 mmHg	Standard Deviation 16
Esmolol Infusion	Systolic Blood Pressure	Younger - Rest	105 mmHg	Standard Deviation 9
Esmolol Infusion	Systolic Blood Pressure	Younger - Moderate Intensity	119 mmHg	Standard Deviation 9
Esmolol Infusion	Systolic Blood Pressure	Younger - Heavy Intensity	134 mmHg	Standard Deviation 8
Esmolol Infusion	Systolic Blood Pressure	Older - Moderate Intensity	125 mmHg	Standard Deviation 12
Esmolol Infusion	Systolic Blood Pressure	Old - Heavy Intensity	137 mmHg	Standard Deviation 14
Saline Infusion	Systolic Blood Pressure	Older - Moderate Intensity	145 mmHg	Standard Deviation 14
Saline Infusion	Systolic Blood Pressure	Older - Rest	116 mmHg	Standard Deviation 11
Saline Infusion	Systolic Blood Pressure	Younger - Heavy Intensity	156 mmHg	Standard Deviation 13
Saline Infusion	Systolic Blood Pressure	Younger - Rest	104 mmHg	Standard Deviation 10
Saline Infusion	Systolic Blood Pressure	Old - Heavy Intensity	173 mmHg	Standard Deviation 24
Saline Infusion	Systolic Blood Pressure	Younger - Moderate Intensity	137 mmHg	Standard Deviation 14

Secondary

Tissue Saturation Index - Inactive Forearm Muscle

The change in skeletal muscle oxygenation (∆TSI%) in the inactive forearm from baseline during recumbent cycling using near-infrared spectroscopy. TSI% represent the percentage of oxygenated hemoglobin relative to total hemoglobin in the tissue beneath the NIRS probe. Lower values represent a greater reduction in tissue oxygenation from baseline (greater oxygen extraction and/or reduced oxygen delivery). TSI% = oxy\[heme\] / total\[heme\] x 100

Time frame: Last 60 seconds of Rest, Moderate exercise, and Heavy Exercise.

Population: 11 younger, 11 older

Arm	Measure	Group	Value (MEAN)	Dispersion
Esmolol Infusion	Tissue Saturation Index - Inactive Forearm Muscle	Younger - Moderate	-3.3 % Total Labile Signal	Standard Deviation 2.5
Esmolol Infusion	Tissue Saturation Index - Inactive Forearm Muscle	Younger - Heavy	-5.9 % Total Labile Signal	Standard Deviation 4.5
Esmolol Infusion	Tissue Saturation Index - Inactive Forearm Muscle	Older - Moderate	-0.1 % Total Labile Signal	Standard Deviation 2.3
Esmolol Infusion	Tissue Saturation Index - Inactive Forearm Muscle	Older - Heavy	-1.5 % Total Labile Signal	Standard Deviation 2.8
Saline Infusion	Tissue Saturation Index - Inactive Forearm Muscle	Older - Heavy	-0.4 % Total Labile Signal	Standard Deviation 2.5
Saline Infusion	Tissue Saturation Index - Inactive Forearm Muscle	Younger - Moderate	-1.3 % Total Labile Signal	Standard Deviation 1.6
Saline Infusion	Tissue Saturation Index - Inactive Forearm Muscle	Older - Moderate	-0.5 % Total Labile Signal	Standard Deviation 1.8
Saline Infusion	Tissue Saturation Index - Inactive Forearm Muscle	Younger - Heavy	-2.3 % Total Labile Signal	Standard Deviation 3.2

Source: ClinicalTrials.gov · Data processed: Feb 4, 2026

Age Comparisons of Exercising Muscle O2 Supply in Healthy Adults: Effects of Esmolol Infusion

Conditions

Keywords

Brief summary

Detailed description

Related papers

Interventions

Sponsors

Study design

Masking description

Eligibility

Inclusion criteria

Exclusion criteria

Design outcomes

Primary

Secondary

Countries

Participant flow

Recruitment details

Pre-assignment details

Participants by arm

Baseline characteristics

Adverse events

Outcome results

Tissue Saturation Index (TSI) - Active Leg Muscle

Cardiac Output

Diastolic Blood Pressure

Heart Rate

∆HHb - Inactive Forearm

Mean Arterial Pressure

Stroke Volume

Systemic Vascular Conductance

Systolic Blood Pressure

Tissue Saturation Index - Inactive Forearm Muscle