Insulin resistance is a major precursor to the development of type-2 diabetes. Obesity is the primary cause of insulin resistance in both male and female patients, but a lesser known symptom of insulin resistance is the presence of acanthosis nigricans, a darkening and thickening of the skin around the neck and axilla. In female patients, abnormal menstrual cycles may also signal the possibility of insulin resistance.
Tricia Santos Cavaiola, MD
Division of Endocrinology, Diabetes, and Metabolism: University of California San Diego