Diabetes is a chronic disease that occurs when the Pancreas is no longer able to make insulin, or when the body cannot make good use of the insulin it produces.
What is insulin ?
Insulin is a hormone made by the pancreas that helps glucose in your blood enter cells in your muscle, fat, and liver, where it’s used for energy. Glucose comes from the food you eat. The liver also makes glucose in times of need, such as when you’re fasting. When blood glucose, also called blood sugar, levels rise after you eat, your pancreas releases insulin into the blood. Insulin then lowers blood glucose to keep it in the normal range.
Insulin secretion is the only hormone in the pancreas that has the ability to lower blood glucose levels. If not, the blood sugar will rise. Hormone is secreted into the blood by the endocrine organs and presented in target organs to work by binding with receptive protein.
The insulin receptor is present in the cell membrane, and insulin is secreted from the beta cell. It is combined with the receptor to draw out glucose from the muscle into cells in a glucose metabolism which promotes fat synthesis. In other words, insulin only changes the state of cells to use glucose. It does not directly digest glucose.
This is where most people misunderstand the process.
Degradation of glucose is "glucose metabolism". Glucose is metabolized before the blood sugar level falls. However, if an abnormality occurs in the insulin receptor in the cell membrane, insulin can not bind to the receptor. Then glucose can not enter the cell. As a result, there is no raw material glucose to be used in glucose metabolism, and the blood glucose level increases due to no metabolism. If for some reason the blood sugar level is high, the amount of glucose that binds to the protein in the blood increases. Since glucose has "aldehyde group“ which will bind to the amino acid group of lysine. In other words, active oxygen is generated from the protein bound to the sugar which causes arteriosclerosis, cataracts, diabetic cardiomyopathy or diabetic nephropathy.
What is insulin resistance ?
Insulin resistance is when cells in your muscles, fat, and liver don’t respond well to insulin and can’t easily take up glucose from your blood. As a result, your pancreas makes more insulin to help glucose enter your cells. As long as your pancreas can make enough insulin to overcome your cells’ weak response to insulin, your blood glucose levels will stay in the healthy range.
Types of Diabetes
There are Three main types of Diabetes –
- Type 1
- Type 2
1. Type 1 Diabetes
Around 10% of all people with diabetes have type 1 diabetes. Type 1 diabetes is caused by an autoimmune reaction where the body’s defense system attacks the cells that produce insulin. As a result, the body produces very little or no insulin. The exact causes of this are not yet known, but are linked to a combination of genetic and environmental conditions.
Type 1 diabetes can affect people at any age, but usually develops in children or young adults. People with type 1 diabetes need daily injections of insulin to control their blood glucose levels. If people with type 1 diabetes do not have access to insulin, they will die.
The risk factors for type 1 diabetes are still being researched. However, having a family member with type 1 diabetes slightly increases the risk of developing the disease. Environmental factors and exposure to some viral infections have also been linked to the risk of developing type 1 diabetes.
Symptoms of Type 1 Diabetes
The most common symptoms of type 1 diabetes include :
- Abnormal thirst and dry mouth
- Sudden weight loss
- Frequent urination
- Lack of energy, tiredness
- Constant hunger
- Blurred vision
Diagnosing type 1 diabetes can be difficult so additional tests may be required to confirm a diagnosis.
Prevention of type 1 Diabetes
No effective and safe intervention currently exists to prevent type 1 diabetes despite a large number of clinical trials aimed at halting the on-going autoimmune destruction of pancreatic beta cells. However, there is some evidence that overweight and a high growth rate in children are weak risk factors, indicating that a healthy lifestyle that avoids both over-eating and a sedentary lifestyle is recommended for high-risk groups such as the siblings of children with type 1 diabetes. However, this is just one of a number of factors that have also been implicated. These include not being breast-fed, being the first-born, being born by caesarean section and having an older or obese mother.
Although a ‘cure’ for type 1 diabetes is being actively sought, preventing or delaying it in those known to be at risk or, in those already diagnosed, slowing down the auto-immune destruction of beta cells and protecting those cells that are still active are likely to be more achievable goals in the foreseeable future. Neither has been convincingly achieved as yet. However, several studies are underway using interventions such as oral insulin in people known to have markers of islet autoimmunity, trialling drugs already used, for example in psoriasis, to prolong beta cell life and the use of peptide immunotherapies to ‘retrain’ killer T cells, the lymphocytes that are closely involved in the underlying mechanism of type 1 diabetes.
2. Type 2 Diabetes
Type 2 diabetes is more common in adults and accounts for around 90% of all diabetes cases. When you have type 2 diabetes, your body does not make good use of the insulin that it produces. The cornerstone of type 2 diabetes treatment is healthy lifestyle, including increased physical activity and healthy diet. However, over time most people with type 2 diabetes will require oral drugs and/or insulin to keep their blood glucose levels under control.
- Type 2 diabetes is the most common type of diabetes, accounting for around 90% of all diabetes cases.
- It is generally characterized by insulin resistance, where the body does not fully respond to insulin. Because insulin cannot work properly, blood glucose levels keep rising, releasing more insulin. For some people with type 2 diabetes this can eventually exhaust the pancreas, resulting in the body producing less and less insulin, causing even higher blood sugar levels (hyperglycaemia).
- Type 2 diabetes is most commonly diagnosed in older adults, but is increasingly seen in children, adolescents and younger adults due to rising levels of obesity, physical inactivity and poor diet.
- The cornerstone of type 2 diabetes management is a healthy diet, increased physical activity and maintaining a healthy body weight. Oral medication and insulin are also frequently prescribed to help control blood glucose levels.
Symptoms of type 2 Diabetes
The symptoms of type 2 diabetes are similar to those of type 1 diabetes and include :
- Excessive thirst and dry mouth
- Frequent urination
- Lack of energy, tiredness
- Slow healing wounds
- Recurrent infections in the skin
- Blurred vision
- Tingling or numbness in hands and feet.
These symptoms can be mild or absent and so people with type 2 diabetes may live several years with the condition before being diagnosed.
The most commonly used oral medications for type 2 diabetes include :
- Metformin : reduces insulin resistance and allows the body to use its own insulin more effectively. It is regarded as the first-line treatment for type 2 diabetes in most guidelines around the world.
- Sulfonylureas : stimulate the pancreas to increase insulin production. Sulfonylureas include gliclazide, glipizide, glimepiride, tolbutamide and glibenclamide.
Prevention of type 2 Diabetes
There are a number of factors that influence the development of type 2 diabetes. The most influential are lifestyle behaviours commonly associated with urbanisation. Research indicates that a majority of cases, up to 80% according to some studies, of type 2 diabetes could be prevented through healthy diet and regular physical activity. A healthy diet includes reducing the amount of calories if you are overweight, replacing saturated fats (eg. cream, cheese, butter) with unsaturated fats (eg. avocado, nuts, olive and vegetable oils), eating dietary fibre (eg. fruit, vegetables, whole grains), and avoiding tobacco use, excessive alcohol and added sugar.
Regular physical activity is essential to help keep blood glucose levels under control. It is most effective when it includes a combination of both aerobic (eg. jogging, swimming, cycling) exercise and resistance training, as well as reducing the amount of time spent being inactive.
3. Gestational diabetes (GDM)
Gestational diabetes (GDM) is a type of diabetes that consists of high blood glucose during pregnancy and is associated with complications to both mother and child. GDM usually disappears after pregnancy but women affected and their children are at increased risk of developing type 2 diabetes later in life.
People with diabetes have an increased risk of developing a number of serious health problems. Consistently high blood glucose levels can lead to serious diseases affecting the heart and blood vessels, eyes, kidneys, nerves and teeth. In addition, people with diabetes also have a higher risk of developing infections. In almost all high-income countries, diabetes is a leading cause of cardiovascular disease, blindness, kidney failure, and lower limb amputation.
Maintaining blood glucose levels, blood pressure, and cholesterol at or close to normal can help delay or prevent diabetes complications. Therefore people with diabetes need regular monitoring.
Cardiovascular disease : affects the heart and blood vessels and may cause fatal complications such as coronary artery disease (leading to heart attack) and stroke. Cardiovascular disease is the most common cause of death in people with diabetes. High blood pressure, high cholesterol, high blood glucose and other risk factors contribute to increasing the risk of cardiovascular complications.
Kidney disease (diabetic nephropathy) : caused by damage to small blood vessels in the kidneys leading to the kidneys becoming less efficient or to fail altogether. Kidney disease is much more common in people with diabetes than in those without diabetes. Maintaining near normal levels of blood glucose and blood pressure can greatly reduce the risk of kidney disease.
Nerve disease (diabetic neuropathy) : diabetes can cause damage to the nerves throughout the body when blood glucose and blood pressure are too high. This can lead to problems with digestion, erectile dysfunction, and many other functions. Among the most commonly affected areas are the extremities, in particular the feet. Nerve damage in these areas is called peripheral neuropathy, and can lead to pain, tingling, and loss of feeling. Loss of feeling is particularly important because it can allow injuries to go unnoticed, leading to serious infections and possible amputations. People with diabetes carry a risk of amputation that may be more than 25 times greater than that of people without diabetes. However, with comprehensive management, a large proportion of amputations related to diabetes can be prevented. Even when amputation takes place, the remaining leg and the person’s life can be saved by good follow-up care from a multidisciplinary foot team. People with diabetes should regularly examine their feet.
Eye disease (diabetic retinopathy) : most people with diabetes will develop some form of eye disease (retinopathy) causing reduced vision or blindness. Consistently high levels of blood glucose, together with high blood pressure and high cholesterol, are the main causes of retinopathy. It can be managed through regular eye checks and keeping glucose and lipid levels at or close to normal.
Pregnancy complications : Women with any type of diabetes during pregnancy risk a number of complications if they do not carefully monitor and manage their condition. To prevent possible organ damage to the fetus, women with type 1 diabetes or type 2 diabetes should achieve target glucose levels before conception. All women with diabetes during pregnancy, type 1, type 2 or gestational should strive for target blood glucose levels throughout to minimize complications. High blood glucose during pregnancy can lead to the foetus putting on excess weight. This can lead to problems in delivery, trauma to the child and mother, and a sudden drop in blood glucose for the child after birth. Children who are exposed for a long time to high blood glucose in the womb are at higher risk of developing diabetes in the future.
Oral complications : People with diabetes have an increased risk of inflammation of the gums (periodontitis) if blood glucose is not properly managed. Periodontitis is a major cause of tooth loss and is associated with an increased risk of cardiovascular disease (CVD). Regular oral check-ups should be established to ensure early diagnosis, particularly among people with previously undiagnosed diabetes and prompt management of any oral complications in people with diabetes. Annual visits are recommended for symptoms of gum disease such as bleeding when brushing teeth or swollen gums.