Older men who have higher levels of sex hormones tend to have a lower biological age, according to a new study presented at the 2019 Endocrine Society annual meeting. The study was conducted at the University of Western Australia‘s medical school in Perth.
It is well known that not all of people age at a similar rate and despite having the same chronological age they look different. This is because their chronological age may be different from the biological age. Biological age refers to how old our cells really are and therefore, determineς our real age. Subsequently, slower biological aging is a measure of a person’s ability to remain healthier and live longer.
One way to measure biological age is the length of telomeres, which are DNA-protein complexes located at the end of chromosomes that shorten with age, leading to cellular dysfunction. Past research shows that stress, smoking, obesity, lack of exercise and poor diet can also shorten telomeres.
Sex hormones on the other hand are substances of youth which however, decline beyond doubt while we are getting older. The researchers wanted to see if sex hormones such as testosterone and its active metabolite, estradiol, may reflect or possibly determine biological youth.
To this regard they have studied data from 2.913 men aged 70 to 89 years who lived in the community. The investigators measured telomeres in DNA from white blood cells using a molecular biology method called quantitative polymerase chain reaction. They also measured sex hormones as testosterone and estradiol taken from blood samples.
Interestingly, it was found that the higher the estradiol level, the longer the telomeres were likely to be, indicating lower biological age. In men estradiol occurs after peripheral conversion of testosterone. Although no cause effects could be inferred from this kind of studies, it could be interesting to see if the administration of testosterone, which is then converted to estradiol, could have also a favorable effect on biological age by modulating the length of telomeres. This could open new avenues for the use of testosterone in older men with low testosterone levels.