This 2014 UK human study found:
“Type 2 diabetes is characterized by disruption of stress-related processes across multiple biological systems and increased exposure to life stress.”
HOWEVER, the stress effects are not shown conclusively to be either a cause or consequence of type 2 diabetes. Correlation is not causation.
Looking around for clues as to what went wrong, I found this data sample of cortisol in a small table that comprised the total amount of information in the supplementary material:
“Geometric means, adjusted for education, marital status, BMI, smoking status, use of statins, and time of day.”
It takes a great imagination to think that the researchers improved the data measurements by averaging them after adjusting all of the six factors as well. Maybe the problem was elsewhere, maybe in the study design. Wherever the problems are, they seem to guarantee that the researchers will NEVER find cause and effect.
But maybe that’s the point?
There appear to be other agendas that make sure studies like these fail to make a contribution toward advancing science. The researchers inevitably use buzzwords such as “allostatic load” and cite the need for further studies (money). Everybody is okay with that, including the reviewer, and everybody keeps their safe jobs.
Such studies also have limiting effects on how we “do something” about real problems because the researchers won’t be permitted, in my view, to produce findings that aren’t politically correct.