Two types of diabetes: Different strokes for different folks (continued)
The two types of diabetes
Last week’s article discussed the discovery that there are two different kinds of diabetes and the differences between them: in type 1, later called juvenile diabetes, the patients are relatively young – children, adolescents, young adults; the onset of symptoms is sudden and acute; weight loss is striking; and, without insulin, death follows rapidly after the onset of symptoms. Before the advent of insulin, most type 1 diabetics did not live longer than a year after the onset of symptoms. In type 2, later called adult-onset diabetes, patients are older – middle aged and older; the onset of symptoms is slow and gradual; patients are usually overweight or obese; and they can control the sugar in their urine with a low carbohydrate diet.
Two types of diabetes, two different causes
With the advent of insulin, it was assumed that an insufficiency of insulin was responsible for both juvenile and adult-onset diabetes. Therefore, the commonly prescribed treatment for adult-onset or type 2 diabetes was daily injections of animal insulin, just as it was for juvenile or type 1 diabetes.
It was not until the 1930s that anyone questioned this protocol. In 1936 a medical pioneer named H. P. Himsworth was the first to propose that type 1 and type 2 diabetes have different causes. He came to this conclusion because of his clinical observations and the clinical observations of other doctors of the different responses to insulin by the two types of diabetics. In type 1 diabetics, he observed, a slight excess of insulin very quickly resulted in a hypoglycemic (low blood sugar) attack. Whereas in type 2 diabetics a large excess of insulin was tolerated without a hypoglycemic attack developing. In type 1 diabetics an increase in dietary carbohydrates accompanied by insulin did not result in an increase of sugar in the urine or a rise in fasting blood sugar levels. Whereas in type 2 diabetics an increase in dietary carbohydrates did result in an increase of sugar in the urine and a rise in fasting blood sugar levels despite the accompaniment of insulin. In type 1 diabetics the rate at which injected insulin came into action was normal. In type 2 diabetics the rate was much slower. In summary, in type 1 diabetes there was impairment in the secretion of insulin, but no impairment in response to it. In type 2 diabetes there was no impairment in secretion of insulin, but impairment in response to it. Himsworth concluded that type 1 diabetes is due to a lack of insulin while type 2 diabetes is due, not to a lack of insulin, but to an insensitivity or resistance to insulin.
Two different causes, two different treatments
Therefore, the treatment of type 2 diabetics with injections of insulin was not correcting their problem but actually exacerbating it. Since the causes of type 1 and type 2 diabetes are different, their treatments have to be different.
Himsworth was right, but his theory was largely ignored. There was no change in the clinical treatment of type 2 diabetes until the 1950s. What finally led to a change? Another theory, that was wrong, and a Nobel prize. This will be the subject of next week’s article.
Mary Lou Williams, M. Ed., is a lecturer and writer in the field of nutrition;. She welcomes inquiries. She can be reached at 267-6480.