Vitamin T

1 in 4 men with type 2 diabetes has low testosterone levels, and insulin sensitivity usually increases in med with low testosterone levels. However, high testosterone levels in women (especially from PCOS) usually causes insulin resistance, and very high testosterone levels (about male normal range) also causes insulin resistance. 

Testosterone significantly affects insulin sensitivity, but not linearly.

Today marks five years since my first injection of testosterone. The five year mark is significant in an artificial sort of way because it's recommended that transmen get bottom surgery by then because of concerns about endometrial and ovarian cancers (more endometrial). In one of life's little ironies, transgender people are at increased risk of reproductive organ cancers (so, for that matter, are some types of intersexed people).