Good Rule of Thumb

[Diabetesnet.com]

I have a question regarding your statement: “A good rule of thumb is that 1 gram of glucose raises the blood sugar 3, 4, or 5 points for body weights of 200 lb., 150 lb., and 100 lb., respectively. For example, a 5-gram glucose tablet raises the blood sugar about 20 points at 150 lbs.”

I weigh 140 so it would be 4 points per gram of glucose. My understanding is all carbs eventually turn to glucose. If that is true and something has 5 grams of carbs including 2 grams of sugar, do I multiple 4 points by 5(carbs) or 4 points by 2(sugar) to get the total points raised???

B

[John Walsh, PA, CDE]

You are correct. 5 grams of carb multiplied by 4 points (mg/dl) gives a 20 mg/dl rise in glucose. For those who use mmol, dividing 20 mg/dl by 18 mg/dl per mmol gives a 1.1 mmol rise.

For raising a low blood glucose, all carbs are counted because they all turn into glucose fairly quickly, EXCEPT for fiber which can be ignored. If a food has 12 grams of carb, but 2 grams of fiber, then 10 grams times 4 mg/dl (or 3 or 5 depending on weight) equals a 40 mg/dl (2.2 mmol) rise in glucose. If your insulin doses are set well and no active bolus insulin is still working, 10 grams should bring you up nicely from 60 mg/dl (3.3 mmol) to 100 or so (5.6 mmol).

Thanks for the question