Also, t levels don't seem to clearly correlate with decreased or increased lifespans. And as your last link points out, lower levels of t (ie hypogonadism) are correlated with increased risk of CVD mortality.
Yes, you're right about that. The paper says that:
"Our meta-analysis shows that patients with CVD have, on average, lower testosterone level than healthy controls."
However, the paper also says that:
"Taken together, these results suggest that low testosterone may be considered as a marker of poor general health status, negatively affecting prognosis, rather than a specific CV risk factor (11, 84–86, 95). Low testosterone level has also been associated with an increased mortality in patients affected by non-CVD..."
In fact, since there is a tradeoff between health and reproductive ability, we might expect the development of health problems in previously healthy males to cause testosterone levels to drop, as a means of offsetting some of the negative effects of said health problem. This could account for why lower levels of testosterone are correlated with increased CVD mortality.
However,
Whether male eunuchs actually live longer is controversial to say the least.
is a statement which I emphatically disagree with.
In my view there is reasonable evidence for a trade-off between health and reproduction between species, but not within species. Am I wrong on this?
On eunuch lifespan, you are basically relying on three studies, each of which are historical, ie the Mental Health studies in the mid 20th century and the historical Korean eunuch study. I think there are big problems in interpreting these studies. For example, it's not like the eunuch lifespans in either sample is as long as men in wealthy countries, which makes things like infections and generally risky beha...
Imagine you had the following at your disposal:
Imagine that your goal were to slow or prevent biological aging...
Thanks for your input.
Update
I thank everyone for their input and apologize for how long it has taken me to post an update.
I met with Aubrey de Grey and he recommended using the anonymized patient data to look for novel uses for already-prescribed drugs. He also suggested I do a comparison of existing longitudinal studies (e.g. Framingham) and the equivalent data elements from our data warehouse. I asked him that if he runs into any researchers with promising theories or methods but for a massive human dataset to test them on, to send them my way.
My original question was a bit to broad in retrospect: I should have focused more on how to best leverage the capabilities my project already has in place rather than a more general "what should I do with myself" kind of appeal. On the other hand, at the time I might have been less confident about the project's success than I am now. Though the conversation immediately went off into prospective experiments rather than analyzing existing data, there were some great ideas there that may yet become practical to implement.
At any rate, a lot of this has been overcome by events. In the last six months I realized that before we even get to the bifurcation point between longevity and other research areas, there are a crapload of technical, logistical, and organizational problems to solve. I no longer have any doubt that these real problems are worth solving, my team is well positioned to solve many of them, and the solutions will significantly accelerate research in many areas including longevity. We have institutional support, we have a credible revenue stream, and no shortage of promising directions to pursue. The limiting factor now is people-hours. So, we are recruiting.
Thanks again to everyone for their feedback.