Editing Intensive insulin therapy (section)

==General description==
A working pancreas continually secretes small amounts of insulin into the blood to maintain normal glucose levels, which would otherwise rise from glucose release by the liver, especially during the early morning [[dawn phenomenon]].  This insulin is referred to as ''basal insulin secretion'', and constitutes almost half<ref>{{cite journal | vauthors = Davidson PC, Hebblewhite HR, Steed RD, Bode BW | title = Analysis of guidelines for basal-bolus insulin dosing: basal insulin, correction factor, and carbohydrate-to-insulin ratio | journal = Endocrine Practice | volume = 14 | issue = 9 | pages = 1095–1101 | date = December 2008 | pmid = 19158048 | doi = 10.4158/EP.14.9.1095 | s2cid = 39503937 }}</ref> the insulin produced by the normal pancreas.

Bolus insulin is produced during the digestion of meals. Insulin levels rise immediately as we begin to eat, remaining higher than the basal rate for 1 to 4 hours. This meal-associated (''prandial'') insulin production is roughly proportional to the amount of carbohydrate in the meal.

Intensive or flexible therapy involves supplying a continual supply of insulin to serve as the ''basal insulin'', supplying meal insulin in doses proportional to nutritional load of the meals, and supplying extra insulin when needed to correct high glucose levels. These three components of the insulin regimen are commonly referred to as basal insulin, bolus insulin, and high glucose correction insulin.

===Two common regimens: pens, injection ports, and pumps===
One method of intensive insulinotherapy is based on multiple daily injections (sometimes referred to in medical literature as ''MDI''). Meal insulin is supplied by injection of rapid-acting insulin before each meal in an amount proportional to the meal. Basal insulin is provided as a once or twice daily injection of dose of a long-acting insulin.

In an MDI regimen, long-acting insulins are preferred for basal use. An older insulin used for this purpose is ultralente, and beef ultralente in particular was considered for decades to be the gold standard of basal insulin.  Long-acting [[insulin analog]]s such as [[insulin glargine]] (brand name ''Lantus'', made by [[Sanofi-Aventis]]) and [[insulin detemir]] (brand name ''Levemir'', made by [[Novo Nordisk]]) are also used, with insulin glargine used more than insulin detemir.{{citation needed|date=October 2012}}  Rapid-acting insulin analogs such as [[Insulin lispro|lispro]] (brand name ''Humalog'', made by [[Eli Lilly and Company]]) and [[Insulin aspart|aspart]] (brand name ''Novolog''/''Novorapid'', made by Novo Nordisk and ''Apidra'' made by Sanofi Aventis) are preferred by many clinicians over older regular insulin for meal coverage and high correction. Many people on MDI regimens carry [[insulin pen]]s to inject their rapid-acting insulins instead of traditional [[syringe]]s.  Some people on an MDI regimen also use [[injection port]]s such as the [[injection port#I-Port|I-port]] to minimize the number of daily skin punctures.

The other method of intensive/flexible insulin therapy is an [[insulin pump]]. It is a small mechanical device about the size of a deck of cards. It contains a syringe-like reservoir with about three days' insulin supply. This is connected by thin, disposable, plastic tubing to a needle-like [[cannula]] inserted into the patient's skin and held in place by an adhesive patch. The infusion tubing and cannula must be removed and replaced every few days.

An insulin pump can be programmed to infuse a steady amount of rapid-acting insulin under the skin. This steady infusion is termed the basal rate and is designed to supply the background insulin needs. Each time the patient eats, he or she must press a button on the pump to deliver a specified dose of insulin to cover that meal. Extra insulin is also given the same way to correct a high glucose reading. Although current pumps can include a glucose sensor, they cannot automatically respond to meals or to rising or falling glucose levels.

Both MDI and pumping can achieve similarly excellent glycemic control. Some people prefer injections because they are less expensive than pumps and do not require the wearing of a continually attached device.  However, the clinical literature is very clear that patients whose basal insulin requirements tend not to vary throughout the day or do not require dosage precision smaller than 0.5 IU, are much less likely to realize much significant advantage of pump therapy.  Another perceived advantage of pumps is the freedom from syringes and injections, however, infusion sets still require less frequent injections to guide infusion sets into the subcutaneous tissue.

Intensive/flexible insulin therapy requires frequent blood glucose checking. To achieve the best balance of blood sugar with either intensive/flexible method, a patient must check his or her glucose level with a meter [[blood glucose monitoring|monitoring of blood glucose]] several times a day. This allows optimization of the basal insulin and meal coverage as well as correction of high glucose episodes.