Urine & Blood Testing for Glucose

When I was discharged in 1954 mum was given a Ames Clinitest Urine Testing Kit which was first developed in 1945. This kit was used from when I was diagnosed until the mid-80s. It was basically a small chemistry set, quite compact containing a test tube, a dropper, & a bottle of Reagent tablets together with a colour chart, used to analyse your results. I was very fortunate, as in some areas they still used Benedict's solution first developed in 1908. Which was boiled together with urine & water in a test tube over a Bunsen burner, then compared with a chart.

Clinitest Urine Testing Kit. Photo from the Science History Institute's Digital Collections. No known copyright.

The Clinitest reagent tablets were corrosive and were highly sensitive to moisture from air or water. Warning on the packages insert stated "Moisture may cause a chemical reaction and the glass bottle could explode". Worrying, but throughout the many years of use this never happened to me. This test was carried out using the 5-drop method. But first you had to empty your bladder & then wait until your urine could be collected for testing. This was to try to get the best reading possible. Once collected using the dropper - 5 drops of urine & 10 of water were added to the test tube.

The bottle of reagent tablets was carefully opened & 1 tablet taken out. The cap was then replaced tightly so the tablets would not spoil. This tablet was dropped into the test tube & the reaction was watched as the mixture began to boil. When this boiling had subsided & 15 extra seconds added. You'd shake the tube & compare the result with the chart. Ideally it would be green ¼% sugar. Blue meant Negative 0% sugar. Orange meant 2% sugar in urine. If the colours changed rapidly whilst boiling the colour would end up a greeny / tan colour this would indicate over 2% sugar. Another test using the 2-drop method could be carried out. Using the same test but with only 2 drops of urine. This gave a higher range reading up to 5%!

Mine, often would be around 2%. I did go through a stage where I didn't test regularly at all. When I was due to see my consultant Dr Bolton at the hospital. I would make up the results using different coloured pens adding the odd 2% in & even put tea stains on the pages! I can remember now him peering over has half frame glasses & me thinking "He knows" as he said "Who been a naughty boy, eh!" as my hospital urine test had caught me out!

Today the National Institute for Health & Care Excellence (NICE) recommend the range for adults is between 4 & 7 mmoL/L (72 & 126 mg/dl) before meals & between 5 & 9 mmoL/L (90 & 162 mg/dl) after meals.

A blue or negative Clinitest result could be anywhere up to 10.5 mmoL/L (180.0 mg/dl) or 3.1%. I recently found a paper from University of Gondar that a Clinitest type reading of 2% sugar in urine was equivalent to 111 mmoL/L (2000 mg/dl) or 12%. Unthinkable nowadays. But I have survived with minimal complications.

When in the mid-80s Diastix & Ketostix came out, Urine testing for glucose & ketones became much easier. (Personally, I had never been advised to check for ketones.)  You just put the strip in your urine stream & compared with the chart. So I replaced Clinitest with Diastix, though better it was still only telling you if you were high & couldn't tell you how low you were plus the results were always in the past. But this was about to change.

Blood glucose testing had only been available in hospitals using bulky professional equipment & a syringe to extract your blood. In 1965, Ames developed the Dextrostix - the first blood glucose test strip only for use in hospitals & surgeries. They needed a large blood sample & strips had to be washed off. In 1970s a meter was developed by Ames to read these sticks, but they were not accurate. In late 1980s smaller meters were used such as BM Reflolux II using the existing visually read BM Stixs. More things changed in hospitals with the testing of glycated haemoglobin (HbA1c) in the blood which gave an average level of blood glucose control over the past 2 to 3 months.

The advent of the self-monitoring of blood glucose (SMBG) at home was a gamechanger. This for the first time told you what your levels were at that exact time that you tested. The first meter I had in 1992 was a BM Reflolux S, it had a 20-test memory & came in a navy leather case. Blood glucose tests using BM test strips took 2 minutes for the result to appear.

Since then, I have used various meters some of which I still have. The major improvements for me were meters which had built in calculators, that offered insulin bolus advice for carbs input. Some my meters tested not only for blood glucose but also ketones. This enables an instant blood ketone reading as opposed to the Ketostix Urine test strip which only told you what your levels had been in the past & finally, meters that connected to an Insulin pump.

A selection of blood glucose test meters I have used.

A selection of finger pricking devices that I have used.

Hypos (hypoglycaemia) are the scourge of diabetics.  My current go to are jelly babies.  Each one is worth 5g Cho.

When I was a child. I remember waking up in the morning, my face & pillow sticky with sugar because Mum had been spoon feeding me sugar in water during the night because I'd had a hypo. I had woken the house up screaming & shouting but, in the morning had no memories of the event.

Another memory early in the morning around 3am, is becoming aware of sitting on the worktop in the kitchen surrounded by empty chocolate wrappers & my wife asking if I was okay. Greta had been woken up by banging kitchen cupboard doors! Chocolate was my go to for hypos but nowadays not recommended as the fat content can slow absorption.

Now I am normally aware of any oncoming hypos but am helped by alarms going off on my phone or a wonderful device on by nightstand its called a M5 Stack monitor.  It's a DIY programmable device which I have by my beside. This works with my current DIY setup, getting it readings via wifi from Nightscout.

My M5 Stack showing my blood glucose readings updated 3 minutes ago.