Do you know what it was prior to going primal?
The bottom line is aside from what the carb cure's all crew have posted here, the reality is low carb is the solution for many with insulin resistance issues. I am one of them and fasting went from 140 to normal on low carb. That kind of story is seen countless times on diabetes forums etc. So while I guess it's possible given that everyone's body reacts differently to diet, I find it pretty unlikely that low carb is the culprit here.
Request an A1C test if they haven't already done that.