Diabetes: Common causes and Treatment

What is diabetes?

Diabetes affects 2.3 million people in the UK.

Diabetes is a condition where the blood sugar level is higher than normal.

There are two main types of diabetes.

• Type 1 diabetes or insulin-dependent diabetes. It is usually seen in young people.
• Type 2 diabetes - usually non insulin-dependent diabetes. It tends to affect adults over 40 and overweight people.

There are also other types of diabetes.

• Pregnancy diabetes. This is known as gestational diabetes. It's associated with pregnancy and symptoms usually disappear after the birth. If you get gestational diabetes, you have an increased risk of developing one of the main types of diabetes later in life.
• Secondary diabetes. This is when diabetes is caused as the result of another condition, eg inflammation of the pancreas, or by the use of certain medication such as diuretics or steroids (the most common cause).

How common is diabetes?

There are currently 2.3 milion people with diabetes in the UK. However, it's estimated that more than half a million people have the condition but are unaware of it.

The last 30 years has seen a threefold increase in the number of cases of childhood diabetes. This is especially worrying in respect of the rising numbers of children and teenagers with type 2 diabetes, usually only seen in older people, and which reflects obesity levels in young people.

Obesity levels have also risen and this has led to Type 2 diabetes, which is linked to diet, being seen for the first time in young people in Europe and America.

But obesity doesn't explain the increase in the numbers of Type 1 diabetes in children, who make up the majority of new cases.

What causes diabetes?

Insulin is a hormone produced by the pancreas gland in the abdomen. It controls the use of glucose within the body.

The blood sugar level will rise if:

• the pancreas produces little or no insulin(Type 1 diabetes)
• the pancreas produces insulin, but it's inadequate for the body’s needs and its effectiveness is reduced (Type 2 diabetes).

It's thought Type 2 diabetes is related to factors associated with a Western lifestyle, since it's most common in people who are overweight and who don't get enough exercise.

Gestational diabetes is brought about by the many hormone changes and demands placed upon the body during pregnancy.

Secondary diabetes is much like Type 2 diabetes. It's quite variable, depending on the underlying cause. It can be caused by damage to the pancreas (eg by alcohol), and drugs such as steroids and diuretics can impair insulin secretion from the pancreas.

Common symptoms of diabetes

Glucose is one of the body’s main fuels. If there isn't enough, blood sugar levels rise and glucose is secreted into urine. This causes:

• increased thirst
• frequent urination
• tiredness
• weight loss, although appetite often increases (especially in Type 1 diabetes)
• itchiness, especially around the genitals
• recurrent infections on the skin, eg boils.

People with Type 1 diabetes usually develop these symptoms within days or weeks.

In Type 2 diabetes, these symptoms often don't show for years. Many are diagnosed by chance through routine medical check-ups.

Heredity plays a part in diabetes, but only 10 per cent of people with Type 1 have a family history of diabetes. For Type 2, this rises to 30 per cent.

How is a diagnosis made?

Glucose levels are measured in blood samples. This is done using the following tests:

• random glucose test: glucose levels are taken at a random time on two occasions. Any figure above 11.1mmol/l is a diagnosis of diabetes
• fasting glucose test: the glucose level is measured after an overnight fast and on two different days. Above 7.0mmol/l is a diagnosis of diabetes.

You may only need to give one blood sample if you have other symptoms of diabetes.

Glucose tolerance test

If the diagnosis is still unclear from these tests, a glucose tolerance test can be carried out.

A glucose drink is given containing a standard amount of glucose (75g). Blood samples are taken before the drink is given and two hours later. The test is done after an overnight fast.

• A two-hour blood glucose level above 11.1mmol/l is a diagnosis of diabetes.
• A level below 7.8mmol/l is normal.

If the level falls between these values, it suggests a decreased tolerance for glucose.

This is known as impaired glucose tolerance (IGT).

Impaired glucose tolerance is more than just a pre-diabetic state.

People who have IGT are at increased risk of developing some of the conditions associated with diabetes, such as heart disease.

Pregnant women with IGT have an increased risk of miscarriage and stillbirth.

How is diabetes treated?

Diabetes is treated in two ways:

• a combination of healthy diet and exercise
• medication with tablets and/or insulin.

Insulin injections increase the amount of insulin in your body and bring down the blood sugar level. Insulin injections are used in Type 1 diabetes and in some cases of Type 2.

These can be given once a day as a long-acting insulin, or as shorter-acting injections given more frequently through the day, and can be used in combination with tablet treatment if necessary.

There are different types of oral medication for treating Type 2 diabetes:

• some increase the amount of insulin secreted by the pancreas
• some increase the action of insulin in the body
• some delay the absorption of glucose from the digestive system
• some suppress a hormone called glucagon, which is secreted by the pancreas and stops insulin from working.

Treatment for diabetes depends on the individual.

It starts the first time you give yourself an insulin injection or take a diabetes tablet, and continues through eating a well-balanced diet and starting an exercise programme.

To help you get the most out of treatment, consult your GP or hospital healthcare team, which should include a diabetes nurse specialist.

Blood sugar levels

Monitoring blood sugar levels is an important aspect of treatment, especially in Type 1 diabetes where levels can change markedly.

This can be done easily at home with a small blood glucose meter.

Depending on the reading, you may need to adjust your diet, the amount you exercise or your insulin intake.

Managing diabetes

In the long term, diabetes is monitored through routine check-ups by your doctor and/or annual check-ups at the hospital on an outpatient basis.

Their purpose is to determine if treatment is satisfactory and to look out for any evidence of longer-term complications such as eye or kidney disease.

Tests for these complications are usually done at the annual check-up, while routine check-ups may be carried out every three to six months.

Routine check-ups

• Blood sample to check the level of HbA1c (a measure of long-term glucose) in the blood.
• Evaluation of home glucose readings.
• Discussion of diet.
• Blood pressure.
• Weight check.
• Other tests and examinations as determined by your doctor.

Annual check-ups

• Blood sample to check the amount of HbA1c in the blood.
• Blood sample to determine the amount of fats in the blood.
• Blood sample to check kidney function and various salts in the blood (mainly sodium and potassium).
• Blood pressure.
• Urine sample to determine the presence of protein (albuminuria). The appearance of protein can indicate that the small blood vessels (capillaries) in the kidneys are beginning to be affected by the diabetes.
• Foot examination, including a check of various pulse points on the foot to assess circulation, and a check for vibration sensation to determine if there's any neuropathy (nerve damage) to the foot.
• Weight check.
• Measuring the waistline.
• Discussion of exercise habits.
• Discussion of smoking habits.

Long-term prospects

Both types of diabetes have the risk of complications.

Acute complications

• Low glucose level, caused by treatment with insulin or oral hypoglycaemic drugs that increase insulin secretion from the pancreas.
• Diabetic acidosis, a life-threatening condition caused by the lack of insulin.

Late-stage diabetic complications

• Retinopathy (eye disease) that can cause blindness.
• Diabetic kidney disease that can lead to kidney failure.
• Diabetic neuropathy (nerve disease) that can cause foot ulcers and foot infections.
• Atherosclerosis (hardening of the arteries), particularly in smokers and those with high blood pressure and abnormal fat levels in the blood.

Late-stage complications do not usually develop for 10 to 15 years with Type 1 diabetes.

In Type 2 diabetes, however, symptoms can appear close to the time of actual diagnosis because the disease may go undetected for longer.

Many studies now show that good glucose control can significantly reduce or even stop complications. This means keeping the blood sugar level as close to normal as possible.

Recent studies have also confirmed the need for people with diabetes to reduce their risk of atherosclerosis (fatty deposits in your arteries).

This is because if you have Type 2 diabetes, you have a four to five times greater risk of developing serious problems with your circulation that can lead to a heart attack or a stroke.

The main factors that increase your risk are:

• smoking
• high blood pressure
• raised levels of fats such as cholesterol in the blood.

By taking measures to address these issues, you will reduce your chance of developing complications such as heart disease.