ABSTRACT
As early as the 1930s, Sir Harold Percival Himsworth and colleagues described the existence of a type of diabetes caused not by a lack of insulin but rather insensitivity to insulin.
By performing two oral glucose tolerance tests (OGTTs) in the same individuals, one with, and one without a concomitant injection of insulin, Himsworth observed that subjects with insulin insensitivity were unable to lower their glucose levels after insulin injection, compared to insulin-sensitive subjects. He noted that this type of diabetes was more common, but not conned to elderly subjects and may be preceded by obesity.1 Himsworth also found that weight loss not only removed the symptoms of diabetes but also restored the glucose-tolerance response to almost normal.2 The condition Himsworth described is now known as insulin resistance, dened as an impaired ability of insulin to suppress hepatic glucose output and to promote peripheral glucose disposal into tissues.
