June 18, 2021
Why does obesity cause hypertension in some individuals but not others? Consulting Editor Dr. Shawn Bender (University of Missouri) interviews authors Stephanie Watts and Greg Fink (both of Michigan State University), along with expert Andreas Beyer (Medical College of Wisconsin), about a new study by Watts et al. Fink and Watts have had a prolific research collaboration for over 20 years investigating the physiology and pharmacology of hypertension. In recent years they have focused on the genetically hypertensive-prone Dahl salt-sensitive rat, which becomes hypertensive on a high fat diet, and the vascular and perivascular mechanisms contributing to this form of hypertension. Zeroing in on endothelial function, basic hyper-reactivity, and perivascular adipose tissue (PVAT) in aortas of Dahl SS rats fed a high fat diet, the authors found vascular dysfunction was more prevalent in males vs. females. Watts and Fink want you to reconsider PVAT as a critically important part of the vasculature, not simply a secretor of anti-contractile substances. Why? Listen now.
Stephanie W. Watts, Emma S. Darios, G. Andres Contreras, Hannah Garver, Gregory D. Fink Male and Female High Fat Fed Dahl SS rats are largely protected from vascular dysfunctions: PVAT contributions reveal sex differences. Am J Physiol Heart Circ Physiol, published June 14, 2021. DOI: doi.org/10.1152/ajpheart.00131.2021
June 7, 2021
What is the impact of testosterone and exercise on fitness, body composition and strength in otherwise healthy middle-to-older aged men with mild testosterone deficiency? Associate Editor Jason Carter (Montana State University) interviews first author Lauren Chasland (University of Western Australia) and expert Megan Wenner (University of Delaware) about the new study by Chasland et al. Using a rigorous experimental approach which examined the effects of testosterone and exercise independently and in combination over a 12-week timeframe, Chasland and co-authors found that exercise alone was the primary driver of improved aerobic capacity. When assessing impact on body composition, the authors also saw greater decreases in total fat mass in the exercise-only group compared to the testosterone-only and testosterone + exercise groups. However, testosterone alone did increase leg lean mass, a result the authors think may have possible clinical translation for men unable to exercise due to disease or disability. Why did Chasland and collaborators choose a testosterone cream as their T-treatment modality? Did the exercise protocol—a circuit training routine combining cycling and resistance exercise—have an impact on the results? Listen as our experts unpack yet more evidence pointing to exercise as a potent treatment for sex hormone deficiency in aging adults.
Lauren C. Chasland, Bu B. Yeap, Andrew J. Maiorana, Yi X. Chan, Barbara A. Maslen, Brian R. Cooke, Lawrence Dembo, Louise H. Naylor, Daniel J. Green Testosterone and exercise: Effects on fitness, body composition and strength in middle-to-older aged men with low-normal serum testosterone levels Am J Physiol Heart Circ Physiol, published May 3, 2021. DOI: 10.1152/ajpheart.00010.2021