Levels of tissue kallikrein, a component of the kallikrein??”kinin system (KKS), are elevated in people with Type 2 diabetes, Australian researchers have shown.

Interestingly, this relationship was unaffected by statin therapy, indicating that the KKS is not involved in the beneficial effects of statins on endothelial function.

David Campbell (St Vincent’s Institute of Medical Research, Fitzroy, Victoria) and co-workers tested the hypothesis that diabetes increases the activity of the KKS, a system with a broad spectrum of actions including inflammation and organ protection.

They obtained blood from 71 patients scheduled for coronary artery bypass (CABG) surgery, 16 of whom had diabetes. CABG patients were chosen because they routinely have arterial cannulae inserted before surgery, which allows rapid blood collection with minimal kallikrein activation.

Writing in the journal Diabetologia, Campbell et al report that circulating levels of tissue kallikrein were 62% higher in diabetic versus nondiabetic patients. Diabetic patients also had increased tissue kallikrein immunoreactivity in atrial myocytes and increased tissue kallikrein messenger RNA levels in atrial tissue.

By contrast, there were no differences in blood levels of angiotensin, bradykinin, and kallidin peptides, or in plasma levels of plasma kallikrein or kallistatin between diabetic and nondiabetic individuals.

Separate analyses showed that treatment with statins, aspirin, calcium antagonists, beta-blockers, or long-acting nitrates had no effect on circulating levels of any of the KKS components. However, statin therapy was associated with decreased plasma aldosterone levels, which the authors suggest may be due to an effect of statins on cholesterol supply for steroid-hormone synthesis.

Campbell et al say that the mechanism underlying the increase in tissue kallikrein in diabetes is uncertain, but it may be caused by hyperinsulinemia.

Noting that tissue kallikrein plays an essential role in protecting the heart from ischemic injury, they conclude: “[T]issue kallikrein may play a greater role in cardioprotection in Type 2 diabetic than in nondiabetic patients and may also contribute to the benefits that Type 2 diabetic patients derive from angiotensin-converting enzyme inhibitor and other therapies inhibiting kinin metabolism.”

They add: “Our findings do not support the idea that the KKS plays a role in the impaired endothelial function of Type 2 diabetes or in mediating the improvement of endothelial function by statin therapy in nondiabetic and diabetic patients.”

MedWire (www.medwire-news.md) is an independent clinical news service provided by Current Medicine Group, a trading division of Springer Healthcare Limited. © Springer Healthcare Ltd; 2010

Free abstract

Medical treatments for diabetes has changed over the last 50 years. While diet is a primary means of treatment, medications to increase insulin production, lower glucose the liver releases, deal with insulin resistance, decrease absorption of carbs in the intestines and actually slow down digestion in the stomach are also used. Naturally, if needed, insulin injections can be used, if needed.

Not all patients can tolerate these medications, which can be a problem. At this point, not a lot can be done other than falling back on diet and insulin injections. There is hope, however.

Before I get to that, let me talk a bit about the diabetic diet. A chief concern is carbohydrates. Carbs can be turned into glucose very quickly in the body; they are, after all, instant fuel. However, controlling sugar levels in the blood is of paramount importance.

While a diet high in whole grains, fruits and vegetables is recommended, care has to be taken as to which you eat. Carrots contain a lot of sugar, as do many fruits. You’ll need to keep track of your carb allowance and follow portion control to make sure it’s accurate.

People with this condition used to be required to strictly follow a low fat diet, as well. Now, however, that has changed. Some fats are allowed, but they should be limited to healthy choices.

Due to our “on the go” culture, many people end up buying convenience foods rather than cooking, and that is a problem for people trying to watch carb intake. Most of them are highly processed and contain a lot more than what is safe. Reading nutrition labels is extremely important in choosing these products.

Now, about herbs. Diabetics have to be particularly careful when choosing supplements. Some of them will counteract medications, some will raise sugar levels and some may drop them dangerously low. Never start a new supplement without discussing it with your doctor and pharmacist to be sure it will be safe.

Of those that lower sugar levels, one might actually become an accepted treatment in the relatively near future. Cinnamon bark has gone through three extensive double blind, placebo controlled clinical trials. The results indicate that the bark lowers blood sugar. It may take a while for them to decide on dosage issues, etc. but it looks good.

Many people think the Glycemic Index (GI) and Glycemic Load (GL) are one in the same, but the food ratings on each list are actually very different. Looking at a GI food list would lead you to eat M&M candies and avoid foods such as carrots, while a GL food list would have you eat the carrots and skip the chocolate candies. Its important for people with type 1 or type 2 diabetes, to understand the difference between GI and GL, and how they actually go hand in hand.

Glycemic Index Calculation:

Glycemic Index ranks carbohydrate foods on a scale from 0 to 100 in relation to how they affect your blood sugar levels. The lower the number the smaller the fluctuations are in your blood sugar and insulin levels. Foods with a GI of 70 or higher are considered “high” foods, foods with a GI of 55 to 70 are “moderate,” and foods with a GI 55 or below are considered “low.”

Facts About Glycemic Index:

Glycemic Index does not take food serving size or proportion into consideration. When foods are measured, or indexed, scientists take the index from the amount of food that would have 50 grams of carbohydrate. This is where foods such as carrots and watermelon come in. Carrots are considered a “high” food, yet an individual would have to eat a whopping pound and a half of them to match the amount of food that puts carrots in the “high” category.

GI is also very sensitive and easy to manipulate. Little things such as the ripeness of your produce, the doneness of your pasta, or what foods you combine, affect the GI of a food.

Glycemic Load Calculation:

Glycemic Load is the amount of carbohydrate in a food multiplied by that food’s GI, with the serving size taken into account. The GL for a single serving of a food can be calculated:

• as the quantity (in grams) of its carbohydrate content
• multiplied by its GI and
• that total divided by 100

Take a 100g slice of watermelon for example. It would have a GI of 72 and a carbohydrate content of 5g, which makes the calculation… 72 x 5 divided by 100 = 3.6. So the GL is 3.6.

As with the Glycemic Load, the lower the Glycemic Load, the lower the spike in your blood sugar levels. Aim to eat mostly low-GL foods, which have a value of 10 or less. Foods considered moderate-GL have a value range of 11 to 19. Any food with a value of 20 or higher is considered a high-GL food, which can cause large spikes in your blood sugar and insulin levels.

While both watermelon and carrots are considered “high” on the GI index, they are considered low on the GL index. Common sense tells you that produce is good for you based on its nutritional value but looking at the GI and GL, it can be hard to tell. It is important for you to understand the serving size was not a factor in calculating the GI.

Remember that not all carbohydrate foods are created equal, and each food can have a different reaction in your body. It is a great benefit to your health that you regulate your blood sugar levels by eating foods with a low GI and GL index, and to understand how the indexes were calculated.