The role of a crucial hormone called INSL3 (insulin-like peptide hormone) has been discovered, and it may help predict whether young men will develop diseases later in life. INSL3 is produced by the same testes cells that generate testosterone. But while testosterone levels fluctuate, INSL3 levels were found to remain consistent over time, and only drop slightly when men reach old age. That stability could make it a very reliable biomarker of age-reared morbidity compared to other biomarkers. The amount of INSL3 in blood samples were found to correlate with a variety of age-related issues, including diabetes, bone weakness, cardiovascular disease, and sexual dysfunction. The findings have been reported in Frontiers in Endocrinology.
While INSL3 levels stay consistent in a person, they vary from one individual to another. So, a young person who has a high INSL3 level, compared to average, will still have high levels of INSL3 when they are older. The same is true for people with low INSL3 levels; they will stay low from the time the person is young until old age. Men with low INSL3 levels are more likely to have age-related diseases.
This may also mean that INSL3 could be a way to predict or potentially, prevent age-related disease from occurring. Even if the disorders can't be stopped, if a person knows they are more likely to occur, more preventative measures can be taken.
"The holy grail of aging research is to reduce the fitness gap that appears as people age. Understanding why some people are more likely to develop disability and disease as they age is vital so that interventions can be found to ensure people not only live a long life but also a healthy life as they age. Our hormone discovery is an important step in understanding this, and will pave the way for not only helping people individually but also helping to ease the care crisis we face as a society," said study co-leader Professor Ravinder Anand-Ivell of the University of Nottingham.
In this study, the researchers assessed two blood samples, taken four years apart, from 3,000 men in the UK. This showed that INSL3 levels stayed mostly the same in a person over time. There was also a wide variation of INSL3 levels among the male population that was surveyed, which included young and basically healthy individuals; the differences were as much as ten-fold.
"Now we know the important role this hormone plays in predicting disease and how it varies amongst men, we are turning our attention to finding out what factors have the most influence on the level of INSL3 in the blood. Preliminary work suggests early life nutrition may play a role, but many other factors, such as genetics or exposure to some environmental endocrine disruptors, may play a part," added study co-leader Professor Richard Ivell of the Uinversity of Nottingham.
Sources: University of Nottingham, Frontiers in Endocrinology
