Diabetes Due to Secretion of an Abnormal Insulin

Abstract
A 51-year-old, nonobese man with diabetes mellitus had marked hyperinsulinemia (70 to 120 μU per milliliter; 502 to 860 pmol per liter) and fasting hyperglycemia (140 to 170 mg per 100 ml; 7.8 to 9.4 mmol per liter). Plasma proinsulin, glucagon, growth hormone, and cortisol levels were normal; insulin antibodies and insulin-receptor antibodies were not detected. The patient showed relatively normal insulin sensitivity, and insulin receptors on circulating monocytes were within the normal range.