So far this month I've mentioned three places where diabetics can have more sugar.
More sugar in your blood (high blood sugar); more sugar attached to the proteins in your blood (high A1c); more sugar in your pee.
But those are not the only places where you can have more sugar. Diabetics' hair has been known since the 1960s to have different levels of sugar and trace minerals. In this article, 46 diabetics(27 of them type 1) and 50 nondiabetics got a haircut. The hair was analyzed for the presence of fructosamine (a product of fructose- a type of sugar- plus either ammonia or protein- I think). There was fructosamine in all of the hair samples; there was roughly twice as much fructosamine in the hair of the diabetics. The diabetics with higher A1cs tended to have higher levels of fructosamine in their hair.
Other studies with online abstracts or results:
Comparing type 1 diabetic women, women with gestational diabetes, and normal women.
Comparing correlations in hair to A1c, fructosamine over different lengths of time
A study of 41 type 2 diabetics comparing hair fructosamine to fructosamine values at the time and over the course of the year
Analyzing hair has been suggested as useful in finding average blood sugar in diabetics, but also in seeing differences in blood sugar over a long period of time, since a single hair may have been growing for over a year and may provide a record of blood sugar over a longer period of time than an A1c. This would be useful for many reasons, including assessing risk of complications, letting your doctor know if it's really true that it's just in the last two weeks your blood sugar's been wonky, and figuring out if diabetes in a pregnant woman is merely gestational diabetes.
But the idea must have been forgotten by the medical community. I have never met a person whose hair was used for a test like this, and I have seen no articles on the topic published in the last ten years. Too bad. I think I might prefer a haircut to a blood draw- wouldn't you?