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Sunday, 23 March 2014

Sweet Tea and Diabetic Wee

Thirty eight years ago, aged eleven, I was discharged after a week in hospital. I was sent home with a glass syringe, a plastic tub and a bottle of surgical spirit to store the syringe, five reusable needles (a year's supply), a couple of bottles of insulin and a chemistry set.

I had been diagnosed with juvenile onset diabetes, later called insulin dependent diabetes and now known as type 1 diabetes. Simply put, my body had ceased to make any insulin and so I could no longer control my blood sugar. The treatment was to inject insulin refined from the pancreases of cows. The chemistry set was so that I could determine whether I was injecting the right amount of insulin. It contained a test tube, an eye dropper and a bottle of tablets containing caustic soda and copper sulphate. Five drops of urine, ten drops of water, then drop a tablet in the tube and wait 30 seconds while it fizzed and turned the liquid a colour between blue (no sugar: good) and bright orange (2% sugar: bad). The value was recorded in a notebook to show the consultant at the six monthly appointments. Although it is almost forty years ago, I remember my book was littered with 1% and 2% readings.

Just think about this: regularly, 2% of my urine was sugar. If a teaspoon holds about 4g of sugar, and a mug of tea is about 200ml, a mug of tea with a teaspoon of sugar is about 2% sugar. On a regular basis, my urine was as sweet as your tea*. (Diabetes mellitus comes from the Greek word diabetes meaning siphon - to pass through - and the Latin word mellitus meaning honeyed or sweet, in other words sweet urine.)

To get that sweet, empirical measurements show that on average my blood sugar would have to be about 12 mmol/l and this is about double the recommended level for a diabetic. The urine tests gave results up to 2%, so when I got the bright orange result it mean that the concentration of sugar in my urine was 2% or more. Since the test didn't show a value higher than 2% I have no way of knowing how high my urine sugar really got. (In fact, I now know that I could have repeated the test with two drops of urine rather than five, and this could have measured up to 5% of sugar.) I was also prescribed urine dipsticks to test for ketones. Ketonuria occurs when the body breaks down amino acids to get energy rather than glucose, and in a diabetic this can occur when blood sugar is over 15 mmol/l (due to too little insulin). From memory, I occasionally detected ketones, so my blood sugar was likely to be three times or more the recommended level.

The problem with urine testing is that it is hours after the fact. My bladder could have several hours of urine (eight, for the early morning pee) and hence my blood sugar could be high for all of this time. Worse, four decades ago, there was not the concept of taking an adjustment dose of insulin to correct a bad result. Re-usable needles meant that injecting was an unbearable pain, and blunt needles (and the impure animal insulin) affected the injection sites (scarring and fat loss) so it was always best to have as few injections as possible. For the first ten years I had two injections a day: one before breakfast and another before dinner. Consequently, without an adjustment dose, a high urine test could mean a high blood sugar for at least half a day. Controlling blood sugar in the 70s and 80s was not easy.

These days diabetics have finger prick blood testing monitors, so we can instantaneously test blood sugar, we also have insulin pens that can accurately deliver small adjustment doses of insulin and (the most significant innovation) we have sharp needles. Controlling blood sugar, though easier, is still not easy because injected insulin does not act immediately, and (depending on the type of insulin) it may continue to affect blood sugar for a couple of hours. Further, some foods are digested quicker than others and hence affect blood sugar in different ways. Managing diabetes is always a case of finding out what works and then sticking with it. Change is the worst word in a diabetic's life.

In my next blog I will describe the issues with the controlling diabetes using finger-prick blood glucose tests, and what could be done to improve the situation.

[*] This is all very approximate, but figure 1 in this paper suggests that 2% Clinitest represents between 2.5g and 4.5g (say about 3g) in 100ml of urine, which means my urine was as sweet as one and a half teaspoons of sugar in a mug of tea.

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