Not a diagnosis, but personal anecdote. 52 and work outdoors in Las Vegas then ride technical for fun. Insulin resistance has been misdiagnosed for twenty years by my doctors as fatty liver disease. The fasting blood tests look at glucose and diabetes, not my super high levels of insulin from a diet of carbs to feed my love of caffeine and hard work. Getting it squared not by the usual fad diet (ketos) but studying Dr. Bikman, a scientist at BYU.
Also, arm pump and leg cramping? Quinine in diet tonic water helps even more than handfuls of tums which spike insulin.