Diabetes type 2 – five food swaps to lower your blood sugar
A Review of the Current Diabetes Treatment Landscape
Lower Blood Sugar Prevents Diabetes
New insulin and oral insulin
What advances can we expect in the development of new insulin in the coming years?
Over the last 20 years, we have gone through a stage of producing purer and purer insulins with patterns of absorption varying from the very quick-acting to the very long-acting formulations. In recent times biosynthetic human insulins have replaced the animal insulins for most people. We go into more detail about human insulins before, but basically, they are manufactured by interfering with the genetic codes of bacteria and yeasts and inserting material that ‘instructs’ the organisms to produce insulin. By inserting the genetic material coding for human insulin, scientists can get the organisms to produce human insulin. They can equally well get them to make any insulin with a known structure; indeed, they can even get them to make ‘new’ insulins with ‘invented’ structures – we are now in the era of ‘designer’ insulins! There is virtually unlimited capability to modify the natural insulin and see if we can improve on this: by analogy to other areas, we expect to be able to develop a whole new range of insulins with new properties that should be able to make therapy better.
We are already beginning to see the benefits from this remarkable advance in scientific manufacturing. Trials have shown that one of these insulins is absorbed much more quickly than any of the existing fast-acting insulins, is very good for covering meals and can be given immediately before the meal rather than 15–30 minutes beforehand. Two such insulins have now been released for general use, Humalog from Lilly and Novorapid from NovoNordisk. We are also looking for variations in the structure of the insulin, which will ‘target’ the insulin more directly to the liver, the major organ responsible for glucose production in the body. Normally insulin is produced by the pancreas and goes directly to the liver but, unfortunately, in insulin-treated people, the injected insulin reaches the liver only after it has been through all the other tissues in the body. It should be possible to modify the structure in such a way that it can be targeted at the liver and in that way, perhaps, it may turn out to be a more effective and easier way of controlling blood glucose levels.
I have heard that it is possible to get away from insulin injections either by using nasal insulin sprays or some form of insulin that is active when taken by mouth. Are these claims true and are we going to be able to get away from insulin injections in the future?
There is no doubt that a small proportion of any insulin delivered via the nose is absorbed through the membranes into the bloodstream and can lower the blood glucose. Unfortunately, only a small percentage of that which is put into the nose is ever absorbed and it is, therefore, an inefficient and expensive way of administering insulin. Because the absorption is erratic, the blood glucose is not very stable. Experiments have been done with insulin suppositories showing that they too can lower the blood glucose without the need for injections but, again, the absorption is only incomplete and the response erratic.
Regarding oral insulins, it is possible to prevent the stomach from digesting the insulin by incorporating it into a fat (lipid) droplet (liposome), which enables it to be absorbed from the gut without being broken down by the digestive juices. Unfortunately again, the absorption is erratic, the whole lipid droplet with the insulin is absorbed, and there is no way of knowing when the insulin will be released from the droplet and become active.
Inhale Therapeutic Systems Inc. is developing an insulin inhaler (using compressed air), that delivers an insulin powder deep into the lungs, where it is absorbed into the bloodstream, (a pulmonary drug delivery system). These new forms of insulin are taking a long time to come onto the market and we just have to wait and see how successful they will be. NovoNordisk and Aradigm Corporation is beginning further trials of their insulin inhaler. This is an electronic inhaler that releases a blister pack of liquid insulin deep into the lungs. Generex Biotechnology Corporation is developing an oral insulin spray administered by a device that looks like a small asthma inhaler. A pressurised container holding liquid insulin administers the drug into the mouth, and this is quickly absorbed through the cheeks into the blood-stream.
Oral insulin crystals are being used in capsule form in the Diabetes Prevention Trial in the US, but, although they are thought to be effective against the antibodies that destroy the insulin-producing cells, they cannot control diabetes after onset.
All these developments are exciting but there are various issues to be aware of when considering the effectiveness of inhaled and oral insulin:
• People must be confident of receiving an accurate dose of the insulin.
• Inhalers often use very large doses of insulin.
• We do not yet know the potential side effects of such large doses.
• The inhalers being developed so far do not totally eliminate the need for insulin injections.
• The devices need to be portable, compact and competitively priced.
We await the publication of the clinical trials with great interest. Diabetes UK is likely to keep people informed by articles in Balance, or on their website.
New technology
Will there be any benefits to people with diabetes from the computer and microelectronic revolution?
You will have already seen some of the benefits in the blood glucose monitoring devices currently available, and all the modern insulin pumps rely heavily on microchips to control the rate of infusion. We have microcomputer programs that help store and analyse home blood glucose monitoring records. It should be possible soon to simulate the blood glucose response to different insulin injections and in this way produce means of exploring the effect of different types and doses of insulin, and stimulating the body’s response. We are also using computers as a way of teaching people about diabetes and its management, as well as a way of testing people about their knowledge of diabetes. There is now a multimedia interactive CD ROM containing a great deal of excellent educational material but, as it is expensive at present, it is only suitable for diabetes clinic or practice use. Microcomputers are being used to help record and analyse information from the diabetes clinic as well as to help to plan and organize monitoring of diabetes care and to write letters. It is quite likely that this will lead to an improvement in the efficiency of the organization of diabetes clinics, as it has done to the organizing, for example, of airline tickets and flights. There are early experiments going on in the use of so-called ‘expert systems’ to transfer the expert knowledge and reasoning of specialists to general practitioners in order to facilitate their management of people with diabetes within general practice, without the need for them to attend hospital diabetes clinics so often.
It is not unreasonable to expect that the microelectronic revolution will produce a lot of benefits over the next 10 years.
Our local diabetes unit has just run a successful Christmas Fair to raise a lot of money for a mass spectrometer. What good is this going to do for diabetes research?
A mass spectrometer is a complicated machine, which can be used to measure minute amounts of very similar substances present in the bloodstream or in other body constituents. It is often used to measure the amounts of naturally occurring stable ‘isotopes’, which can be administered to people with diabetes to investigate their body’s metabolism in great detail. In the past, this type of study could be done only by injecting radioactive isotopes, which could then be followed in the body as they were metabolized. As their name implies, radioisotopes produce radiation, which can have harmful effects on cells in the body. As we know, even the smallest amount of radiation is best avoided: mass spectrometry allows even more detailed research into metabolism than radioisotopes with none of the risk. Your local researchers are lucky to have this facility
