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The effect of pharmacokinetically guided acute intravenous testosterone administration on electrocardiographic and
C M White1, M J Ferraro-Borgida, N M Moyna
1Nuclear Cardiology and Exercise Physiology Laboratory, Hartford Hospital Division of Cardiology, CT 06102-5037, USA.
Insights
Intravenous testosterone did not significantly alter blood pressure or electrocardiogram (ECG) variables in older men, even at superphysiologic concentrations. This study investigated the cardiovascular effects of testosterone infusions in men.
Area of Science:
- Cardiovascular Physiology
- Endocrinology
Background:
- Previous research indicates intravenous testosterone dilates coronary arteries and improves exercise capacity.
- However, the specific hemodynamic and electrocardiographic (ECG) effects of testosterone infusions remain largely unknown.
Purpose of the Study:
- To determine the hemodynamic and ECG effects of intravenous testosterone administration.
- To compare these effects at both physiologic and superphysiologic serum concentrations.
Main Methods:
- A randomized, placebo-controlled trial involving 20 older men (mean age 70.6 years).
- Participants received individualized testosterone infusions (bolus and continuous) to achieve 2x (physiologic) or 6x (superphysiologic) baseline serum testosterone levels, or a placebo.
- Blood pressure and 12-lead ECGs were recorded before and during infusions.
Main Results:
- The testosterone regimens successfully increased serum testosterone concentrations as intended (physiologic: 2.39x; superphysiologic: 6.22x).
- No significant changes in systolic or diastolic blood pressure were observed across the groups.
- Key ECG intervals (PR, QRS, QT, QTc, RR) remained unchanged compared to baseline and between treatment groups.
Conclusions:
- Intravenous testosterone administration, at doses achieving both physiologic and superphysiologic serum concentrations, does not significantly impact blood pressure or ECG variables in older men.
- These findings suggest a lack of acute cardiovascular electrical or pressure effects from intravenous testosterone in this population.
Abstract:
Previous studies have demonstrated that intravenous testosterone can dilate coronary arteries and increase exercise treadmill time, but the electrocardiographic and hemodynamic effects are unknown. This trial determined the hemodynamic and electrocardiographic effects of dosing intravenous testosterone to achieve a physiologic and a superphysiologic serum testosterone concentration. Twenty men (70.6 +/- 6.2 years) had individualized testosterone bolus and continuous infusions designed to increase the serum testosterone concentration by two (physiologic) and six times baseline (superphysiologic). The men were studied on three occasions when they were randomly allocated to received a placebo, physiologic testosterone regimen, or superphysiologic testosterone regimen. Blood pressures and 12-lead electrocardiograms (ECGs) were taken preinfusion and 28 minutes after initiating the infusion on each visit. The blood pressure (systolic and diastolic) and ECG variables (PR, QRS, QT, QTc, and RR intervals) preinfusion and during the infusion were compared, and the delta changes in the variables were compared between groups. The physiologic testosterone regimen increased the serum testosterone concentration by 2.39 +/- 0.48 times the preinfusion concentration, while the superphysiologic regimen increased it by 6.22 +/- 0.99 times. No significant changes occurred in the blood pressure or ECG variables in any group versus preinfusion values or between the three groups. Exogenously administered intravenous testosterone does not significantly affect the blood pressure or ECG variables when given to achieve physiologic or superphysiologic concentrations.