Diabetes is a chronic disease taking our world by storm. There is an estimated 1.2 million Australians diagnosed with diabetes. Of this 1.2 million, most are diagnosed with preventable type 2 diabetes. How much trouble are we really in? What can we do to change course, off this bleak path?
Diabetes comes in 3 varieties; type 2, type 1 and gestational. They all have one thing in common- high blood glucose levels (BGL). What is different between the 3 types, is how they progress, why they occur and how they are treated.
Type 2 Diabetes
Despite largely being preventable, type 2 diabetes dominates the diabetes scene. It is often the result of unhealthy eating and physical inactivity. This lifestyle results in high BGL, which puts pressure on the pancreas to create insulin. This hormone encourages cells to take up glucose, and therefore, promotes a lower BGL. After a while, cells get tired of responding to the high concentrations of insulin. Insulin is constantly shouting, ‘TAKE UP GLUCOSE!!’. Eventually, the cells say ‘Hey, I’m tired of having you shout at me all the time. Let’s turn down the volume down a bit’. Consequently, the cells receive weaker and weaker insulin signals despite more and more insulin being produced. This is how insulin resistance occurs and BGL climbs. With time, the pancreas gets tired of producing insulin and gives up, which only exacerbates the condition. A balanced diet and regular exercise can prevent type 2 diabetes from occurring, and can slow down its progression. Furthermore, maintaining a healthy weight helps reduce insulin resistance as fat mass is associated with the disease. Type 2 diabetes historically presents in adults, a grand finale to a lifetime of unhealthy choices. Alarmingly, recent cases of type 2 diabetes have presented in childhood. This is a testament to the severity of our unhealthy lifestyle and should be a wakeup call for society.
Type 1 Diabetes
Unlike type 2, type 1 diabetes is an auto-immune condition. The insulin producing cells of the pancreases (Beta cells) are destroyed by our own immune system. This means that insulin is not produced. Consequently, cells don’t receive the ‘take up glucose’ message. Hence, high BGL persists. Type 1 diabetes generally onsets in childhood, and cannot be combated with lifestyle changes, unlike type 2. Type 1 diabetes represents 10% of all diabetes cases (diabetesaustralia.com).
Gestational diabetes occurs during pregnancy due to hormonal changes. Between 5 and 10% of all pregnant women develop gestational diabetes. Some risk factors include; being over 25 years of age, overweight, having a family history of diabetes and being of Aboriginal/Torres Strait Islander or Asian descent. Usually, gestational diabetes subsided with the end of the gestation period, but not always. Around 37% of women with gestational diabetes, will develop type 2 later in life. Gestational diabetes can affect the unborn child’s risk of overweight and diabetes later in life. For this reason, it is a public health concern.
Diabetes and The Kidneys
In healthy people, glucose should not present in the urine, we have sophisticated structures at the kidney that prevent it. In diabetes, circulating glucose can reach such extreme heights that glucose forces its way into the urine. Once in the urine, glucose exerts an osmotic pressure that draws water into it, from the blood. What results is increased urine production and decreased water in the blood. If this extra water loss is not replaced, the sufferer is at risk of dehydration. This is why diabetes often experience extreme thirst.
Diabetes and The Eyes
Behind the eye ball there is a very fragile structure known as the retina. It is crucial to normal vision. High circulating glucose damages this structure and can cause blindness. Diabetes is the leading cause of blindness in the developed world.
Diabetes and The Blood Vessels
High circulating blood glucose damages blood vessel walls. Glucose within the blood can bind to proteins of the vessel wall, and disrupt their function. This leads to a hardening of the wall, that increases blood pressure. Furthermore, damaging effects of glucose at the capillary means that perfusion of oxygen and nutrients to the tissue is inhibited. This has a wide spread negative affect on the body.
Diabetes and The Nerves
High circulating glucose is also damaging to the neurons that make up our nervous system. This has a whole body affect that leads to a variety of complications. Sufferers may experience numbness and tingling at their extremities. In severe cases, ulcerations to the extremities go unnoticed (especially those that are not visibly obvious e.g. foot). The wound therefore goes un-treated. Damage to the blood vessels means that necessary nutrients and oxygen cannot be delivered to the wound. It therefore, cannot heal. In severe cases, if the wound is left untreated, part of the tissue will die, and need to be amputated.
Diabetes and Oxidative Stress
High glucose in the blood results in glucose forcing itself on to proteins throughout the body. These protein-glucose adducts are known as advanced glycation end products (AGEs). These AGEs promote the production of reactive species, contributing to oxidative stress that has wide spread inflammatory affects in the body.
Diabetes and The Liver
‘Take up glucose’ is not the only phrase insulin can shout. It also sends messages to cells that favour the storage of fatty acids as TAG. In the case of diabetes, all of insulins signals are dulled, not just those pertaining to glucose. This means that the storage of fat is, also, inhibited. This results in fat cells releasing their fatty acids into circulation. Hence, sufferers have high circulating fat (as well as glucose). These fatty acids then pass through the liver where they are stored. Under normal circumstances, the liver would never store fat, but the sheer magnitude of its concentration forces the body to look for alternate storage forms e.g. the liver. This results in fat accumulation at the liver that promotes inflammation and decreases liver function. Since the liver is so important to whole body health, the affects are wide spread.
Drugs and Treatment
The main line of defence for type 2 diabetes is lifestyle change. Exercise helps the cells take up glucose, without the need for insulin. So, this is a great way for sufferers to lower their blood glucose, and hopefully restore some normality.
By consuming a diet that is lower in fat and refined carbohydrates, type 2 patients can begin to reverse insulin resistance. To achieve this, the patent needs to be consuming whole grain carbohydrates and plenty of vegetables. The fibre in this diet helps reduce blood glucose spikes and reduces pressure on the pancreas.
Medication is considered when lifestyle changes fail to improve the condition. The most common is Metformin, which aims to lower BGL. These medications treat the symptoms but do not cure the problem. So, they should always be accompanied by lifestyle changes. Interestingly, metformin is currently being tested as a life extension tool! However, the research is still in its’ early days.
The treatment of type 1 diabetes is very different. Since the issue is lack of insulin production (not insulin insensitivity), insulin is administered as treatment. This can be through injection or through the insulin pump. It is important that type 1 diabetes sufferers time their treatment and dosage in accordance with carbohydrate consumption in order to avoid a hypoglycaemic fit. In very late stage type 2 diabetes, treatment with insulin can be considered. When the pancreas is so tired that it secretes no insulin, by providing insulin, it is possible to stimulate the few cells that are still responsive to the hormone.
Diabetes has a tight grip on our population. Looking into the future, diabetes will continue to be a major burden on public health if we do not make serious changes to our lifestyles.