Diabetes Mellitus (DM)

Diabetes Mellitus (DM)

Diabetes Mellitus (DM) is a lifelong condition which causes a person's blood sugar levels to become too high. The hormone insulin (produced by the pancreas) is responsible for controlling the amount of glucose in the blood. There are two main types of diabetes:

• Type 1 – where the pancreas does not produce any insulin;
• Type 2 – where the pancreas does not produce enough insulin or the body's cells do not react to insulin.

Another type of diabetes, known as gestational diabetes, occurs in some pregnant women and tends to disappear after birth.

Symptoms of diabetes

The symptoms of diabetes occur because the lack of insulin means glucose stays in the blood and is not used as fuel for energy. Your body tries to reduce blood glucose levels by getting rid of the excess glucose in your urine. Typical symptoms include:

• feeling very thirsty
• passing urine more often than usual, particularly at night
• feeling very tired
• weight loss and loss of muscle bulk.

It is very important for diabetes to be diagnosed as soon as possible, as it will get progressively worse if left untreated.

Causes of type 2 diabetes

Type 2 diabetes occurs when the body does not produce enough insulin to function properly, or the body's cells do not react to insulin. This means glucose stays in the blood and is not used as fuel for energy. Type 2 diabetes is often associated with obesity, and tends to be diagnosed in older people. It is far more common than type 1 diabetes.

Treating type 2 diabetes

As type 2 diabetes usually gets worse, you may eventually need medication (usually tablets), to keep your blood glucose at normal levels.

Complications of type 2 diabetes

Diabetes can cause serious long-term health problems. It is the most common cause of vision loss and blindness in people of working age. Everyone with diabetes aged 12 or over should be invited to have their eyes screened once a year for diabetic retinopathy. Diabetes is also responsible for most cases of kidney (renal) failure and lower limb amputation, other than accidents.

People with diabetes are up to five times more likely to have cardiovascular disease, such as a stroke, than those without diabetes.

Preventing type 2 diabetes

If you are at risk of type 2 diabetes, you may be able to prevent it developing by making lifestyle changes. These include:

• eating a healthy, balanced diet
• losing weight if you're overweight, and maintaining a healthy weight
• stopping smoking if you smoke
• drinking alcohol in moderation
• taking plenty of regular exercise.

Living with type 2 diabetes

If you already have type 2 diabetes, it may be possible to control your symptoms by making the above changes. This also minimises your risk of developing complications.

Causes

Type 2 diabetes occurs when the pancreas does not produce enough insulin to maintain a normal blood glucose level, or the body is unable to use the insulin that is produced (insulin resistance). The pancreas is a large gland behind the stomach, which produces the hormone insulin. Insulin moves glucose from your blood into your cells, where it is converted into energy. In type 2 diabetes, there are several reasons why the pancreas does not produce enough insulin.

Risk factors for type 2 diabetes

Four of the main risk factors for developing type 2 diabetes are:

• age – being over the age of 40 (over 25 for south Asian people)
• genetics – having a close relative with the condition, such as a parent, brother or sister
• weight – being overweight or obese
• ethnicity – being of south Asian, Chinese, African-Caribbean or black African origin, even if you were born in the UK or USA.

Age

Your risk of developing type 2 diabetes increases with age. This may be because people tend to gain weight and exercise less as they get older. Maintaining a healthy weight by eating a healthy, balanced diet and exercising regularly, are ways of preventing and managing diabetes.

White people over the age of 40 have an increased risk of developing the condition. People of south Asian, Chinese, African-Caribbean and black African descent have an increased risk of developing type 2 diabetes at a much earlier age. However, despite increasing age being a risk factor for type 2 diabetes, over recent years younger people from all ethnic groups have been developing the condition. It is also becoming more common for children (as young as seven years old in some cases), to develop type 2 diabetes.

Genetics

Genetics is one of the main risk factors for type 2 diabetes. Your risk of developing the condition is increased if you have a close relative such as a parent, brother or sister who has the condition. The closer the relative, the greater the risk. A child who has a parent with type 2 diabetes, has about a one in three chance of also developing the condition.

Being overweight or obese

You are more likely to develop type 2 diabetes if you are overweight or obese with a body mass index (BMI) of 30 or more. Fat around your tummy (abdomen) particularly increases your risk. This is because it releases chemicals that can upset the body's cardiovascular and metabolic systems. This increases your risk of developing a number of serious conditions, including coronary heart disease, stroke and some types of cancer.

Measuring your waist is a quick way of assessing your diabetes risk. This is a measure of abdominal obesity, which is a particularly high-risk form of obesity. Women have a higher risk of developing type 2 diabetes if their waist measures 80cm (31.5 inches) or more. Asian men with a waist size of 89cm (35 inches) or more have a higher risk, as do white or black men with a waist size of 94cm (37 inches) or more.

Exercising regularly and reducing your body weight by about 5% could reduce your risk of getting diabetes by more than 50%. 

Ethnicity

People of south Asian, Chinese, African-Caribbean and black African origin are more likely to develop type 2 diabetes. Type 2 diabetes is up to six times more common in south Asian communities than in the general UK and USA population, and it is three times more common among people of African and African-Caribbean origin. People of south Asian and African-Caribbean origin also have an increased risk of developing complications of diabetes, such as heart disease, at a younger age than the rest of the population.

Other risks

Your risk of developing type 2 diabetes is also increased if your blood glucose level is higher than normal, but not yet high enough to be diagnosed with diabetes. This is sometimes called pre-diabetes, and doctors sometimes call it impaired fasting glycaemia (IFG) or impaired glucose tolerance (IGT).

Pre-diabetes can progress to type 2 diabetes if you do not take preventative steps, such as making lifestyle changes. These include eating healthily, losing weight if you are overweight, and taking plenty of regular exercise. Women who have had gestational diabetes during pregnancy also have a greater risk of developing diabetes in later life.

Symptoms

The symptoms of diabetes include feeling very thirsty, passing more urine than usual, and feeling tired all the time. The symptoms occur because some or all of the glucose stays in your blood and is not used as fuel for energy. Your body tries to get rid of the excess glucose in your urine. The main symptoms, which are common to both type 1 diabetes and type 2 diabetes, are:

• urinating more often than usual, particularly at night
• feeling very thirsty
• feeling very tired
• unexplained weight loss
• itching around the penis or vagina, or frequent episodes of thrush
• cuts or wounds that heal slowly
• blurred vision – caused by the lens of the eye becoming dry.

The signs and symptoms of type 1 diabetes are usually obvious and develop very quickly, often over a few weeks. These signs and symptoms are not always as obvious, however, and it is often diagnosed during a routine check-up. This is because they are often mild and develop gradually over a number of years. This means you may have type 2 diabetes for many years without realising it. Early diagnosis and treatment for type 2 diabetes is very important as it may reduce your risk of developing complications later on.

You must see your doctor/ GP as soon as possible, if you think you may have diabetes.

Hyperglycaemia

Type 2 diabetes occurs when the pancreas, a large gland behind the stomach, cannot produce enough insulin to control your blood glucose level, or when the cells in your body do not respond properly to the insulin which is produced. This means your blood glucose levels may become very high, a condition also known as hyperglycaemia. Hyperglycaemia can occur for several reasons, including:

• eating too much
• being unwell
• ineffective diabetes medication, or not taking enough.

Hyperglycaemia causes the main symptoms of diabetes, which include extreme thirst and frequent urination. It is important for diabetes to be diagnosed early, so treatment can be started as soon as possible. If you experience the symptoms of diabetes, you must visit your family doctor/ GP as soon as possible. They will ask about your symptoms, and may request blood and urine tests.

Your urine sample will be tested for glucose. Urine does not normally contain glucose, but glucose can overflow through the kidneys and into your urine if you have diabetes. If your urine contains glucose, a specialised blood test known as glycated haemoglobin (HbA1c) can be used to determine whether you have diabetes.

Glycated haemoglobin (HbA1c)

In people who have been diagnosed with diabetes, the glycated haemoglobin (HbA1c) test is often used to show how well their diabetes is being controlled. The HbA1c test gives your average blood glucose levels over the previous two to three months. The results can indicate whether the measures you are taking to control your diabetes are working. If you have been diagnosed with diabetes, it is recommended you have your HbA1c measured at least twice a year. However, you may need to have your HbA1c measured more frequently if:

• you have recently been diagnosed with diabetes
• your blood glucose remains too high
• your treatment plan has been changed.

Unlike other tests, such as the glucose tolerance test (GTT), the HbA1c test can be carried out at any time of day and does not require any special preparation, such as fasting. However, the test cannot be used in certain situations, such as during pregnancy. The advantages associated with the HbA1c test make it the preferred method of assessing how well blood glucose levels are being controlled in a person with diabetes. HbA1c can also be used as a diagnostic test for diabetes, and as a screening test for people at high risk of diabetes.

HbA1c as a diagnostic test

In 2011 the World Health Organization (WHO) recommended that HbA1c could also be used to help diagnose type 2 diabetes in people who are not known to have the condition. An HbA1c level of 6.5% (48mmol/mol) or above indicates type 2 diabetes. Although there is no fixed point to indicate when someone has pre-diabetes, a UK expert group has recommended that an HbA1c level of 6-6.4% (42-47 mmol/mol) would indicate that a person has a high risk of developing diabetes.

A glucose tolerance test (GTT), sometimes known as an oral glucose tolerance test (OGTT), can show if your body is having problems processing glucose. Before having the test, you will be asked not to eat or drink certain fluids for 8-12 hours. You may also need to avoid taking certain medications before the test, as they may affect the results. A blood sample will be taken before the test and your blood glucose will be measured. You will then be given a sweet glucose drink. After drinking the glucose drink, your blood glucose will be measured again after two hours. As you will have a long time to wait between blood tests, you may want to take something to read or listen to.

Test results

The results of the GTT will show whether you have impaired glucose tolerance (IGT) or diabetes. This will be based on the amount of glucose in your blood both before and after drinking the glucose drink. Blood glucose is measured in millimoles per litre, often written as mmol/l. For someone without diabetes, the amount of glucose in their blood should be:

• less than 6 mmol/l before the test
• less than 7.8 mmol/l two hours after the test.

If you have IGT, the amount of glucose in your blood will be:

• 6-7 mmol/l before the test
• 7.9-11 mmol/l two hours after the test

If you have diabetes, the amount of glucose in your blood will be:

• more than 7 mmol/l before the test
• more than 11 mmol/l two hours after the test.

If your test results indicate you have IGT, you may be advised to make lifestyle changes, such as eating more healthily and taking more exercise. Medication to lower your blood glucose level may also be recommended. If your results indicate you have diabetes, it is likely medication will be prescribed. This will lower your blood glucose level and help keep it under control.

Treatment for diabetes aims to keep your blood glucose levels as normal as possible and control your symptoms to prevent health problems developing later in life. If you have been diagnosed with type 2 diabetes, your personal doctor/ GP will be able to explain your condition in detail and help you understand your treatment. They will also closely monitor your condition to identify any health problems that may occur. If there are any problems, you may be referred to a hospital-based diabetes care team.

Making lifestyle changes

If you are diagnosed with type 2 diabetes, you will need to look after your health very carefully for the rest of your life. This may seem daunting, but your diabetes care team will be able to give you support and advice about all aspects of your treatment. After being diagnosed with type 2 diabetes, or if you are at risk of developing the condition, the first step is to look at your diet and lifestyle and make any necessary changes. Three major areas that you will need to look closely at are:

• eating healthily
• losing weight if you are overweight
• exercising regularly.

You may be able to keep your blood glucose at a safe and healthy level without the need for other types of treatment.

Diet

Increasing the amount of fibre in your diet and reducing your sugar and fat intake, particularly saturated fat, can help prevent type 2 diabetes, as well as manage the condition if you already have it. You should:

• increase your consumption of high-fibre foods, such as wholegrain bread and cereals, beans and lentils, and fruit and vegetables
• choose foods that are low in fat – replace butter, ghee and coconut oil with low-fat spreads and vegetable oil
• choose skimmed and semi-skimmed milk, and low-fat yoghurts
• eat fish and lean meat rather than fatty or processed meat, such as sausages and burgers
• grill, bake, poach or steam food instead of frying or roasting it
• avoid high-fat foods, such as mayonnaise, chips, crisps, pasties, poppadoms and samosas
• eat fruit, unsalted nuts and low-fat yoghurts as snacks instead of cakes, biscuits, bombay mix or crisps.

If you are overweight or obese (i.e. if you have a body mass index (BMI) of 30 or over), you must lose weight by gradually reducing your calorie intake and becoming more physically active. Losing 5-10% of your overall body weight over the course of a year is a realistic initial target. You should aim to continue to lose weight until you have achieved and maintained a BMI within the healthy range, which is:

• 18.5-24.9kg/m² for the general population
• 18.5-22.9kg/m² for people of south Asian or Chinese origin – south Asian includes people from Bangladesh, Bhutan, India, Indian-Caribbean, Maldives, Nepal, Pakistan and Sri Lanka.

If you have a BMI of 30kg/m² or more (27.5kg/m² or more for people of south Asian or Chinese origin), you need a structured weight loss programme, which should form part of an intensive lifestyle change programme. To help you achieve changes in your behaviour, you may be referred to a dietititian or a similar healthcare professional for a personal assessment and tailored advice about diet and physical activity.

Physical activity

Being physically active is very important in preventing or managing type 2 diabetes. For adults who are 19-64 years of age, it is recommended a minimum of:

• 150 minutes (2 hours and 30 minutes) of moderate-intensity aerobic activity (such as cycling or fast walking), per week, which can be taken in sessions of 10 minutes or more, and
• muscle-strengthening activities on two or more days a week which work all major muscle groups – the legs, hips, back, tummy (abdomen), chest, shoulders and arms.

An alternative recommendation is to do a minimum of:

• 75 minutes of vigorous-intensity aerobic activity, such as running or a game of tennis every week, and
• muscle-strengthening activities on two or more days a week that work all major muscle groups – the legs, hips, back, abdomen, chest, shoulders and arms.

In cases where the above activity levels are unrealistic, even small increases in physical activity will be beneficial to your health and act as a basis for future improvements. You must reduce the amount of time spent watching television or sitting in front of a computer. Going for a daily walk (for example, during your lunch break) is a good way of introducing regular physical activity into your schedule.

If you are overweight or obese, you may need to be more physically active to help you lose weight and maintain weight loss. Your doctor, diabetes care team or dietitian can give you more information and advice about losing weight and becoming more physically active.

Complications

If diabetes is not treated, it can lead to a number of other health problems. High glucose levels can damage blood vessels, nerves and organs. Even a mildly raised glucose level which does not cause any symptoms can have long-term damaging effects.

Heart disease and stroke

If you have diabetes, you are up to five times more likely to develop heart disease or have a stroke. Prolonged, poorly controlled blood glucose levels increase the likelihood of atherosclerosis, where the blood vessels become clogged up and narrowed by fatty substances.

This may result in poor blood supply to your heart, causing angina, which is a dull, heavy or tight pain in the chest. It also increases the chance that a blood vessel in your heart or brain will become blocked, leading to a heart attack or stroke.

Nerve damage

High blood glucose levels can damage the tiny blood vessels in your nerves. This can cause a tingling or burning pain that spreads from your fingers and toes up through your limbs. It can also cause numbness, which can lead to ulceration of the feet. Damage to the peripheral nervous system, which includes all parts of the nervous system that lie outside the central nervous system, is known as peripheral neuropathy. If the nerves in your digestive system are affected, you may experience nausea, vomiting, diarrhoea or constipation.

Diabetic retinopathy

Diabetic retinopathy is when the retina, the light-sensitive layer of tissue at the back of the eye, becomes damaged. Blood vessels in the retina can become blocked or leaky, or can grow haphazardly. This prevents light fully passing through to your retina. If it is not treated, it can damage your vision. Annual eye checks are usually organised by a regional photographic unit. If significant damage is detected, you may be referred to a doctor who specialises in treating eye conditions (ophthalmologist).

The better you control your blood glucose levels, the lower your risk of developing serious eye problems. Diabetic retinopathy can be managed using laser treatment if it is caught early enough. However, this will only preserve the sight you have rather than improve it.

Kidney disease

If the small blood vessels of your kidney become blocked and leaky, your kidneys will work less efficiently. It is usually associated with high blood pressure, and treating this is a key part of management. In rare, severe cases, kidney disease can lead to kidney failure. This can mean a kidney replacement, treatment with dialysis, or sometimes kidney transplantation becomes necessary.

Foot problems

Damage to the nerves of the foot can mean small nicks and cuts are not noticed and this, in combination with poor circulation, can lead to a foot ulcers. About 1 in 10 people (10%) with diabetes get a foot ulcer, which can cause a serious infection. If you have diabetes, you must look out for sores and cuts which do not heal, puffiness or swelling, and skin that feels hot to the touch. You should also have your feet examined at least once a year.

If poor circulation or nerve damage is detected, you must check your feet every day and report any changes to your doctor, nurse or podiatrist.

Sexual dysfunction

In men with diabetes, particularly those who smoke, nerve and blood vessel damage can lead to erection problems. This can usually be treated with medication. Women with diabetes may experience:

• a reduced sex drive (loss of libido)
• less pleasure from sex
• vaginal dryness
• less ability to orgasm
• pain during sex.

If you experience a lack of vaginal lubrication or find sex painful, you can use a vaginal lubricant or a water-based gel.

Miscarriage and stillbirth

Pregnant women with diabetes have an increased risk of miscarriage and stillbirth. If your blood glucose level is not carefully controlled during the early stages of pregnancy, there is also an increased risk of the baby developing a birth defect. Pregnant women with diabetes will usually have their antenatal check-ups in hospital or a diabetic clinic, ideally with a doctor who specialises in pregnancy care (an obstetrician).

This will allow your care team to keep a close eye on your blood glucose levels and control your insulin dosage more easily, as well as monitoring the growth and development of your baby.

Looking after your eyes

The diabetic eye screening programme (if your country has one) will arrange for you to have your eyes checked every year. Everyone who is on a diabetes register will be given the opportunity to have a digital picture taken of the back of their eye. You must speak to your doctor to register.

Living with Diabetes

If you have type 2 diabetes, it is important to look after your own health and wellbeing, with support from those involved in your care. Caring for your health will make treating your diabetes easier and minimise your risk of developing complications of diabetes. Self care for type 2 diabetes includes:

• maintaining good physical and mental health
• preventing illness or accidents
• effectively dealing with minor ailments and long-term conditions.

Your diabetes care team

As type 2 diabetes is a long-term condition, you will be in regular contact with your diabetes care team. Your doctor or diabetes care team will also need to check your eyes, feet and nerves regularly because they can also be affected by diabetes. You should also be tested regularly (at least once a year), to check how well your diabetes is being controlled over the long term. A blood sample will be taken from your arm, and the HbA1c test will be carried out. It measures how much glucose is in the red blood cells, and gives your blood glucose levels for the previous two to three months.

Healthy eating

Eating a healthy, balanced diet is very important if you have diabetes. However, you do not need to avoid certain food groups altogether. You can have a varied diet and enjoy a wide range of foods as long as you eat regularly and make healthy choices. You can make adaptations when cooking meals, such as reducing the amount of fat, salt and sugar you eat, and increasing the amount of fibre.

You do not need to completely exclude sugary and high-fat foods from your diet, but they should be limited. The important thing in managing diabetes through your diet is to eat regularly and include starchy carbohydrates, such as pasta, as well as plenty of fruit and vegetables. If your diet is well balanced, you should be able to achieve a good level of health and maintain a healthy weight.

Regular exercise

As physical activity lowers your blood glucose level, it is very important to exercise regularly if you have diabetes. Like anyone else, you should aim to do at least 150 minutes (2 hours and 30 minutes) of moderate-intensity aerobic activity, such as cycling or fast walking, every week. However, before starting a new activity, speak to your doctor or diabetes care team first. As exercise will affect your blood glucose level, your care team may have to adjust your insulin treatment or diet to keep your blood glucose level steady.

Do not smoke

If you have diabetes, your risk of developing a cardiovascular disease, such as a heart attack or stroke, is significantly increased. As well as increasing this risk further, smoking also increases your risk of many other serious smoking-related conditions, such as lung cancer. If you want to give up smoking, your doctor can provide you with advice, support and treatment to help you quit.

Limit alcohol intake

If you have diabetes and decide to drink alcohol, avoid drinking more than the recommended daily amounts, and never drink alcohol on an empty stomach. Depending on the amount you drink, alcohol can cause either high or low blood glucose levels (hyperglycaemia or hypoglycaemia). Drinking alcohol may also affect your ability to carry out insulin treatment or blood glucose monitoring, so always be careful not to drink too much. Men and women are advised not to regularly drink more than 14 units a week. 

Keeping well

People with long-term conditions, such as type 2 diabetes, are encouraged to get a flu jab each autumn to protect against flu (influenza). A pneumoccocal vaccination, which protects against a serious chest infection called pneumococcal pneumonia, is also recommended.

Foot care

If you have diabetes, you are at greater risk of developing problems with your feet, including foot ulcers and infections from minor cuts and grazes. This is because diabetes is associated with poor blood circulation in the feet, and blood glucose can damage the nerves.

To prevent problems with your feet, keep your nails short and wash your feet daily using warm water. Wear shoes that fit properly, and see foot care specialists (a podiatrist or chiropodist) regularly so any problems can be detected early. Regularly check your feet for cuts, blisters or grazes as you may not be able to feel them if the nerves in your feet are damaged. You must see your doctor if you have a minor foot injury which does not start to heal within a few days.

Regular eye tests

If you have type 2 diabetes, you should be invited to have your eyes screened once a year to check for diabetic retinopathy. Diabetic retinopathy is an eye condition where the small blood vessels in your eye become damaged. It can occur if your blood glucose level is too high for a long period of time (hyperglycaemia). Left untreated, retinopathy can eventually lead to sight loss. People with diabetes should also see their optician every two years for a regular eye test. Diabetic eye screening is specifically for diabetic retinopathy and cannot be relied upon for other conditions.

Source: NHS Choices.