Btw, what is basal and bolus?
Jenny Ruhl explains basal insulin here:
"To understand what happens as your blood sugar deteriorates from normal to pre-diabetes, and finally, to full-fledged diabetes you first need to understand how blood sugar control works in a normal body. The most important factor here is the role played by special cells called
beta cells. These tiny cells are scattered through an organ called the
pancreas which is located just under your stomach. The job of the beta cell is to produce insulin, store it, and release it into the blood stream at appropriate times.
You can learn how blood sugar fluctuates during the day in people with normal blood sugar, those with mildly diabetic blood sugars, and those with full fledged Type 2 Diabetes on this page:
Blood Sugar Throughout the Day.
Healthy beta-cells are continually making insulin, storing it within the cell in little granules you can see in the illustration above. This insulin is released into the blood stream in two different fashions. Some of it is secreted into the blood continually. This is called basal insulin."
Injecting basal insulin can help lower fasting and pre-prandial bg, but does not help with post prandial (after meals) bg. For that we need a bolus.
I am by no means expert in the use of insulin, but my understanding is that people with an inadequate supply of insulin can inject some (called a bolus) before eating. They have to decide how many grams of carbohydrate they are going to eat and how much insulin they will need to cope with that. Different insulins are faster or slower acting and that has to be taken into account. If the insulin hits before the food, a hypo / serious fall in bg may ensue which can even be dangerous. If it arrives too late, the person has a spike of bg / become hyper. Hence Dr Bernstein's Law of Small Numbers. He reckons that it is almost impossible to get this calculation right all the time, so the best thing to do is keep carb intake low and insulin injections small. In this way, when there is a mismatch, the damage is not too great.
In my case, I suffer from delayed stomach emptying / gastoparesis. This is one of the known complications due to prolonged raised bg. Unfortunately this is completely unpredictable, so that after some meals my bg may not rise at all for several hours, and after others much more quickly. This would make it impossible to match insulin dose to food intake.