Probably NOT a good idea to assume that because I am reading a book about a medical condition, that I am reading it because I have or think I might have that medical condition.
At around 23%/loc 2000 or thereabouts, Becker discusses "tight" vs. "normal" control of blood sugar. She covers the 1993 Diabetes Control and Complications trial, T1D, 1441 participants, "relatively young". She summarizes this as "showed beyond a doubt that people with tight control of their BG levels had significantly fewer microvascular complications". She expends a single sentence on a Japanese study of 110 T2D people. Then 1998's UK Prospective Diabetes Study, T2D, microvascular complication rates decreased, and lowering blood pressure "to 144/82" also reduced both micro and macro complication rates.
Then a followup of participants in the DCCT (the 1993 T1D above) study called EDIC (Epidemiology of Diabetes Interventions) showed the "normal" group how to do with the "tight" group did and the A1c's of the two groups converged HOWEVER the earlier tight group had lower micro and lower macro BUT CV complications didn't appear because everyone was still too young.
And then, "if that doesn't convince you", general summary that since then blah blah blah.
But it's of course all bullshit, because (a) micro- and macro- effects are still a proxy for what we really care about and (b) how you get there matters (did you do it with diet and exercise, yay, but if you took a stack of drugs, the side effects overwhelm the benefits).
For the most part, this DOES NOT MATTER, because Becker's book is focused on people who have just learned they have diabetes, and she is quite relentless in her focus on diet/exercise/lifestyle modifications, at least in the first quarter of the book. But it is worrisome. I'm reading the 3rd edition, dated 2015. This section should have been brought further up to date.
This is actually sort of a chronic issue with this book -- she wrote it during the early years of the consumer internet (that would be the mid 90s, for anyone who is wondering), and so a lot of her resource information is getting more and more dated. She's trying to bring it current, but that section is weak.