February 22, 2021
2 min read
One author reports he received speaker honoraria and conference support from Bayer, Besins Healthcare and Lilly; research support from Bayer, Lawley Pharmaceuticals and Lilly; and participated in advisory roles for Besins Healthcare, Ferring, Lawley Pharmaceuticals and Lilly. The other authors report no relevant financial disclosures.
A supervised center-based exercise training program, not testosterone therapy, improved vascular function among middle-aged men with central adiposity, according to research published in Hypertension.
“The global increase in testosterone use has been very large, particularly among middle-aged and older men who might see it as a restorative hormone to increase energy and vitality,” Daniel J. Green, PhD, Winthrop Professor and cardiovascular exercise physiology researcher in the School of Human Sciences at The University of Western Australia in Perth, said in a press release. “However, previous studies are mixed as to whether replacement testosterone is beneficial or not, or whether it provides additional benefit over and above the effects of an exercise program.”
For this 12-week randomized controlled trial, researchers enrolled 80 men aged 50 to 70 years with waist girth of at least 95 cm, no prior CVD and low to normal testosterone at baseline of 6 nmol/L to 14 nmol/L. Participants were randomly assigned to transdermal testosterone therapy (AndroForte 5, Lawley Pharmaceuticals) or placebo and supervised center-based exercise or no exercise to determine whether the addition of testosterone therapy to exercise improved vascular function.
Hormone therapy vs. exercise
In the testosterone therapy cohort, 62% of participants had testosterone increase to levels greater than 14 nmol/L (P = .003). The placebo arm experienced no change.
According to the researchers, supervised center-based exercise increased flow-mediated dilation among the exercise cohort (P = .033); however, testosterone did not affect flow-mediated dilation, nor was it additive to exercise (P for all > .05).
Researchers observed no significant effects on glyceryl trinitrate responses among patients in the testosterone-alone and exercise-alone cohorts (P for all > .05).
Exercise training increased baseline diameter (P = .004), and compared with the testosterone therapy-alone group, change in baseline diameter was larger in both exercise groups (P for exercise plus placebo = .004; P for exercise plus testosterone = .037).
Within the placebo groups, participants who underwent exercised training experienced larger change in baseline diameter compared with those who did not exercise (P = .045).
Researchers reported that change in flow-mediated dilation was larger in both exercise groups compared with the testosterone therapy-alone group (P for exercise plus placebo = .004; P for exercise plus testosterone = .001).
Flow-mediated dilation percentage increased in the exercise-only cohort compared with the testosterone therapy-only cohort (P = .011).
According to the study, vascular smooth muscle sensitivity to nitric oxide was not modified by exercise, testosterone or their combination.
Caution needed when prescribing testosterone
“Our findings indicate that 12 weeks of exercise training was more effective than testosterone for improving vascular endothelial function (FMD%),” Lauren C. Chasland, PhD candidate in the School of Human Sciences at The University of Western Australia, and colleagues wrote. “The administration of testosterone, at therapeutic doses, did not impact FMD%, nor was it additive to exercise. This effect of exercise on FMD% was not accompanied by a main effect of exercise on glyceryl trinitrate, indicating that the FMD benefit was indeed endothelium mediated. While we conclude that exercise improves vascular function in middle-to-older aged men with low-normal testosterone levels, caution should be applied when prescribing testosterone if the primary aim is improvement in artery function and health.”