For years, I knew that I took one unit of Humalog for every 15 carbs I ate. What else does that mean? There was some information missing – some important mathematical detail in fact. The blanks were filled in (as were many others) when I read Dr. Richard Bernstein’s The Diabetes Solution a few years ago.
How many of you know that each carb means a five-point increase in blood sugar? I did not until I read Dr. Bernstein’s book. Why did I not know that?
There is a disclaimer on that number though. Your basal right must be set correctly. If your basal rate (long-acting insulin) is too high, your basal insulin will be covering some of your food. If your basal rate is too low, your bolus (rapid/intermediate-acting) insulin will be covering some of your basal requirements.
So, I tested the theory. I take a very low dose of long acting insulin. I regularly test my basal amounts to verify my long acting accuracy so I was all set there. I also know when my long acting insulin peaks which is important for verifying carb to insulin ratios.
The other things to consider are:
· Perform this test when blood sugar is in the 80-110 range to avoid the possibility of rebound effects or highs influencing the results and to avoid creating a difficult high during the test.
· Ensure there is no rapid acting or intermediate insulin in the system.
The test as I do it:
· Eat an easily digestible food. I used Ritz Crackers.
· Eat an exactly defined number of carbs using the caloric information.
· Watch what your blood sugar does. I tested crackers for about an hour at 15-minute intervals.
· Subtract the difference between the end-result of your blood sugar and the starting point.
Example Part One: Blood sugar was 80 at start of test. Final blood sugar was 120. Blood sugar increased 40 points.
· Take the blood sugar increase and divide it by the total number of carbs eaten. This is the points per carb your blood sugar increases.
Example Part Two: Blood sugar increased 40 points. Ate eight carbs. Blood sugar is affected 5 points for every carb eaten.
This is particularly useful information for treating lows. For example, if your blood sugar increases five points for every carbohydrate eaten and you need to raise your blood sugar 30 points that means you need to eat six carbs to return to target. Knowing this might help prevent you from overeating while treating low blood sugar.
Doris J. Dickson