What is insulin? What are some types? What is it used for?
Insulin is a peptide hormone produced by beta cells of the pancreatic islets; it is considered to be the main anabolic hormone of the body. It regulates the metabolism of carbohydrates, fats and protein by promoting the absorption of glucose from the blood into liver, fat and skeletal muscle cells. There are five types of insulin currently available for clinical use; these include Insulin Glargine, Insulin Detemir, Insulin Glulisine, Insulin Lispro and Insulin Aspart among others.
Key functions of insulin
Insulin is a hormone that is produced by beta cells in the pancreas. Its main function is to regulate how much glucose (sugar) can enter cells for energy and storage. Without enough insulin, it can be very dangerous for your body. If you have diabetes and are not properly managing it through diet and exercise or taking medication to help manage your blood sugar levels, insulin injections may be required. Types of insulin: There are two types of insulin available: rapid-acting and long-acting. The type used depends on when blood sugar levels rise—the timing will vary based on each individual's needs.
Structure of insulin
Understanding how insulin works involves a basic understanding of how it is constructed. Insulin is made up of two subunits: an alpha-subunit and a beta-subunit. The alpha-subunit contains 21 amino acids, while the beta-subunit contains 30 amino acids. The two subunits are joined by 2 disulfide bonds and when these bonds break, as in diabetes mellitus, less insulin is produced by pancreatic beta cells. To maintain normal blood glucose levels when there is decreased secretion of insulin from pancreatic cells due to disease or inadequate production in type 1 diabetes mellitus, exogenous sources may be necessary via injection or ingestion. Injections usually take place once or twice daily.
Uses of Insulin
There are two primary uses for insulin: treating diabetes and lowering blood glucose after a meal. When people with diabetes do not take in enough carbohydrates from their diet or if they have problems absorbing food (such as those who suffer from Celiac disease), they may need to take insulin or certain other drugs to help them get glucose into their cells. Insulin is also used to bring down extremely high blood glucose levels in type 2 diabetics who have developed severe hyperglycemia due to a rapid loss of large amounts of weight through dieting or fasting. These situations may require hospitalization until insulin can be dosed appropriately at home; otherwise, it would take too long and could be dangerous.
Types of insulin
There are a number of different types of insulin available. The type you’ll use depends on your condition and whether you have type 1 or type 2 diabetes.
1. Rapid acting insulin
2. Short acting insulin
3. Intermediate acting insulin
4. Mixed insulin
5. Long acting insulin
Rapid acting insulin
If you take insulin to treat diabetes it’s important to know that some insulins are faster acting than others. These short-acting insulins should be taken right before or right after a meal (as soon as possible after), while long-acting and basal insulins can be taken at any time during your daily routine. There is also a group of ultra-fast acting insulins on the market; these will work in 15 minutes or less. However, they’re expensive and are typically only recommended for people with type 1 diabetes who experience extremely quick rises in blood sugar levels. To learn more about types of insulin click here.
Short acting insulin
Short-acting insulin (also known as fast-acting insulin) is a type of insulin that starts to work within 15 minutes after injection. The effects last up to 4 hours after injection. Short-acting insulin is used in people with diabetes mellitus who have problems in maintaining blood sugar levels at normal levels throughout the day. This type of insulin works well when you eat meals that are high in carbohydrates and low in fat.
Intermediate acting insulin
After injection, intermediate-acting insulin begins to work within 30 minutes and its effects last for around 4–12 hours. Examples include: NPH (Neutral Protamine Hagedorn) or isophane. This type of insulin is usually taken two or three times daily and works well in those with a regular eating schedule. Since it acts at a slower rate than long-acting insulin, patients are more likely to experience low blood sugar levels if they miss a meal. Examples include: NPH (Neutral Protamine Hagedorn) or isophane. This type of insulin is usually taken two or three times daily and works well in those with a regular eating schedule.
Mixed insulin
(B50 + NPH): Insulin is used with a long-acting basal insulin to provide around-the-clock blood glucose control. Long-acting insulins include detemir (Levemir), glargine (Lantus) and degludec (Tresiba). Mixed insulin can also be used to cover meals in people with both type 1 and type 2 diabetes or those who cannot self-administer regular insulin injections. Mixing NPH with detemir or glargine provides better meal coverage than using NPH alone. Mixed insulins are available as premixed combinations of R and B insulins or in vials that require mixing before use.
Long acting insulin
This is available in a variety of forms and must be administered by injection. There are two main kinds: Lantus (basal insulin) and Levemir (prandial insulin). Basal insulins provide background insulin levels throughout a 24-hour period. Prandial insulins are used to regulate blood sugar after meals. Long acting insulins begin working in 30-60 minutes, peak in 4-10 hours and last up to 20 hours. The dosage can be decreased after several months as your body becomes more adept at using insulin and needs less support. People with type 1 diabetes usually take one dose every day; people with type 2 diabetes often use one dose every morning plus prandial doses as needed.
Side effects of insulin
Because insulin is also a growth hormone it can cause weight gain. Over time high levels of insulin may lead to increased risk for type 2 diabetes and heart disease. Using insulin in ways other than how it was prescribed (ex. injecting more than prescribed amount) could lead to major health complications. The most serious concern associated with using extra doses is that an overdose could result in low blood sugar leading to coma or death.
