Babcock MC, DuBose LE, Witten TL, et al. - According to this cross-sectional study, healthy middle-aged and older (MA/O) men with low testosterone appear to have more age-associated endothelial dysfunction, which may be related to increased oxidative stress and inflammation. Such findings imply that low testosterone levels may contribute to accelerated vascular ageing in men.

• Participants in the study were 58 healthy, non-smoking men categorized as young (N = 20; age: 29 ± 4 years, testosterone: 500 ± 58 ng/dL), MA/O with higher testosterone (N = 20; age: 60 ± 6 years, testosterone: 512 ± 115 ng/dL), and MA/O lower testosterone (N = 18; age 59 ± 8 years, testosterone: 269 ± 48 ng/dL).

• Brachial artery flow-mediated dilation (FMD _BA) was lower in MA/O during saline compared with young, regardless of testosterone status.

• FMD _BA was decreased in MA/O lower testosterone compared with MA/O higher testosterone, regardless of symptoms.

• Vitamin C enhanced FMD _BA in MA/O lower testosterone but had no impact in young or MA/O higher testosterone.

• FMD _BA was found to be related to serum testosterone, IL-6, and C-reactive protein.