Sugar Matters
June 13, 2008

There’s an insulin for everybody

Okay folks, we are continuing our slow walk through the world of insulin. This week we have a brief intro to the types of insulin, important information because your doctor will likely pick one for you based on how it works. Some people need insulin that lasts a longer time, some need a short acting insulin, many people need both because that is how our body works.{{more}} When your doctor starts you on insulin be sure to ask how long it takes to work and how long it lasts. These are critical points to know in order to stay safe, and this is as important as keeping your blood sugars controlled.

There are different ways of categorizing insulins, but a useful way is to look at them based on the “how long, how fast” profile:

  • Very fast acting insulins -examples include Lispro, Apidra and Aspart insulins. These are some of the newer agents having come into wide use pretty much within the last 10 years or so. They are, as described, very fast acting, meaning that they start working to bring your blood sugars down within the first 15 minutes of taking them, and usually have their most powerful effect by about 1 hour after taking them. The effect lasts about 2-3 hours in most people when injected right under the skin. Now because these insulins act so quickly, they should only be taken right when you are about to eat or when your blood sugars are very high and need to come down.
  • Fast Acting insulins-Regular insulin, which is one of the most commonly used insulins, falls into this group. It starts working within 1 hour of injecting and lasts about 4-6 hours in most people.
  • Intermediate acting insulins-Another of the most common insulins, NPH, belongs in this group with it starting to work at about 2 hours after injecting and lasting 8-10 hours.
  • Long acting insulins-We have a number of candidates here including Lente, Ultralente, Lantus(Glargine), and Levemir(Detemir). Lente and Ultralente have been around for a while but the last few years have seen the rise of new kids Lantus and Levemir. The advantages of the newer agents is that they are supposedly “peakless”, meaning that they will not cause a big drop in your sugars after taking them but instead will gradually bring sugar down and keep them somewhat level over a long period(usually 18-24 hours). Now please know this important point – these insulins do not usually take care of increases in blood sugar that happen after eating. This is a very big point that patients and doctors misunderstand, and they assume you can start one of these 24-hour insulins and have magically lovely blood sugars all day. It is not quite that simple I am afraid. I know, burst your bubble there…
  • And, of course, we have mixed insulins that include some Intermediate acting and shorter acting insulins in one medication, for example 70/30 insulin which has some NPH and some Regular in it. This makes dosing more convenient but may not work for everyone.

That’s the short and sweet version, but there are many nuances your doctor will know in order to prescribe the right insulin for you. Remember, ask questions!

Anita Ramsetty, MD
endodocs@endocrinehelp.com
Medical Director Endocrine Care Group
www.endocrinehelp.com
Tel: 843-798-4227