Is acanthosis nigricans a good marker for diabetes or is it just a marker for that ur obese? They say this is the result of insulin resistance...but the mechanism is largely unkown. They just associate it with diabetes and fatness. I'm actually developing this in my armpits and groin and neck, a slight darkening around my skin. I bought a glucose monitor and i have never had a glucose reading above 105 mg/dL. And I take readings after meals immediately, and 2 hours after. I take my fasting glucose in the morning which is usually 95mg/dL. I just sit in this 95-105 area. In fact I exercised so much the other day and fasted and my glucose was 85 after exercising: so that means my receptors are working right? can someone shed some light