What is the difference between basal insulin and bolus insulin?

Basal insulin refers to the insulin required to control your blood sugar in the absence of food intake. A cer- tain amount of insulin is always necessary to keep the blood sugar in the normal range, even in the absence of eating for prolonged periods. Without  any insulin in the body, the starch, fat, and  protein in the body will break down with severe health  consequences, as occurs in people with type 1 diabetes. The amount of insulin that the body requires in the absence of food intake is known as the basal requirement and it is pro- vided  by  the  one  or  two  injections  of  long-acting insulin that most patients give themselves each day. If a person is using an insulin pump, then it is covered by the  basal setting  on  the  pump.  Modern  insulin pumps  offer several basal settings  in  each 24-hour period, as the basal insulin production  in a  healthy individual varies over the  course of  the  day, being higher in the 2-to 3-hour period before arising in the morning, for example.

Bolus insulin refers to the insulin required to remove the energy derived from a meal from the bloodstream and into the tissues, to replenish energy stores. This is typically provided by the short-acting insulin injec- tion given just prior to eating or by the bolus setting for patients on an insulin pump. Recently developed and marketed forms of insulin very closely match the pattern of insulin production from the pancreas itself in  response to food. In this way, they are able to

prevent the blood sugar from rising excessively after a meal,  while also preventing  the  occurrence of  low blood sugar after the glucose from the meal has been cleared from the bloodstream. The latest insulin pumps offer different rates and patterns in which this bolus is given, in order to more effectively deal with rapidly or  more  slowly absorbed types of  foods.  mental insulin are given to mimic this as closely as possible.

Of course, once it has been delivered to the body, the insulin  cannot  distinguish  between basal and  meal- derived glucose and so different types of insulin prepa- ration  will overlap with  each  other  in  their  action. Distinguishing  between the  two  requires specialized knowledge and is beyond the scope of this book.