What is Diabetes ?

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What is Diabetes ?

• Diabetes Mellitus is a metabolic disorder where the body’s ability to use sugar, fat and protein is affected due to a decrease in the production of insulin or due to a resistance to insulin.
• Both of these lead to an increase in blood glucose concentration and glycosuria.

How does Diabetes develop ?

• The hormone insulin, which is made in the pancreas, helps control levels of the sugar glucose, which is required to fuel many chemical processes.
• In a healthy person, when food is digested, glucose levels in the bloodstream rise. The pancreas then releases insulin which helps the body’s cells take up glucose. Insulin also helps convert glucose into glycogen which is stored in the liver and muscles until needed for fuel.
• Hormones regulate the release of insulin by causing blood sugar levels to drop, which in turn causes the pancreas to secrete less insulin.
• However in a person with diabetes mellitus, either the pancreas produces insufficient levels of insulin or the body is unable to use the insulin it makes. After food is digested the pancreas cannot produce enough insulin and the body is forced to break down fats instead of glucose for energy. Poisonous chemicals called ketones are excreted in the urine and also build up in the bloodstream leading to ketoacidosis, a serious condition that may result in a coma or death. If the body is unable to use insulin properly glucose is locked out of cells and circulates through the body without being absorbed. High levels of sugar in the blood and urine impair the body’s ability to fight infections and may lead to ketoacidosis.

Estimates from the World Health Orginisation and other sources suggest:

• 1 There are 200 million cases worldwide.
• 2 In the U.K. there are two million cases (5% of the total population, rising to 10% in the elderly)
• 3 The incidence of both types of diabetes has doubled every 20 years since 1945.
• 4 The disease reaches epidemic proportions in some ethnic groups.

What is the Pancreas ?

• The pancreas combines both exocrine and endocrine functions
• Exocrine tissue is responsible for the secretion of enzymes which are transported in ducts to the duodenum, where they play a vital role in the digestion of food.
• The endocrine function of the pancreas is concerned with the secretion of hormones. Clusters of endocrine tissue, the Islets of Langerhans, are found scattered throughout the pancreas.
• There are two principal ypes of cells contained within the islets : Beta cells, which secrete insulin, and Alpha cells, which secrete glucagons. Each has a role in the regulation of blood glucose.

What is the Endocrine System ?

• The Endocrine System is associated organs and tissues of the body that collectively release substances known as hormones, which are released directly into the bloodstream for transport to their respective target organs
• It is one of the two major control systems of the body, the other being the nervous system.

What are the Symptoms ?

• All of the following symptoms can be an indication of the onset of Diabetes Mellitus :

1. Weight reduction, occurring in Type 2 is caused by the loss of fluids and fat because of the body’s inability to break down carbohydrates.
2. Polyuria, passing large amounts of urine.
3. Polydipsia, increasing thirst.
4. Disturbances in vision, i.e blurred vision.
5. Vaginal Thrush.
6. Lethargy.

• About half of people affected with Type 2 are undiagnosed for some years until high glucose levels are detected in samples of blood or urine during medical tests.

How is it Diagnosed ?

• The patient may present themselves feeling unwell with any of the above symptoms
• They may be asymptomatic with associated complications or asymptomatic alone.
• Diabetes may be diagnosed following the discovery that a patient has glycosuria or ketonuria (glucose and ketones in the urine) or both.
• • This would be followed by a random blood test or more accurately a fasting blood test.
  • The patient is fasted to receive a more accurate result as if you have something to eat your body will be absorbing glucose from digested food and your plasma glucose is likely to be higher than if you have been fasted.
• The ideal blood glucose should be between 4 and 7 mmols/l.

Types of Diabetes

• There are 5 types of Diabetes Mellitus, the first two being the most common :

1. Type 1 – Insulin Dependent Diabetes Mellitus (IDDM)
2. Type 2 – Non Insulin Dependent Diabetes Mellitus (NIDDM)
3. Gestational Diabetes
4. Maturity onset diabetes of the young (MODY)
5. Secondary Diabetes-eg steroids, acromegaly, chronic pancreatitis, cystic fibrosis

• Type 1 is Insulin Dependent Diabetes Mellitus or juvenile- onset diabetes
  • This type of diabetes commonly occurs in children and young adults and progresses rapidly
  • It is caused by failure of the pancreas to produce insulin and without insulin the result is fatality.
• Type 2 is Non Insulin Dependent Diabetes Mellitus and is also known as maturity-onset diabetes
  • This type, as it’s name suggests, usually affects people over the age of 40 and progresses gradually
  • In this type the pancreas has not ceased to produce insulin, it is the quantity that is insufficient, or the hormone is not stimulating the glucose uptake in muscles and tissues required for energy
  • The patient may go on to require insulin but can survive without it
• Gestational Diabetes can be brought on by the changes in the body due to pregnancy
  • A percentage of these patients will go on to develop Type 2 Diabetes later in life

Treatment and Management

• The aim of the treatment in all types of diabetes is to keep the blood glucose level as normal as possible by administering insulin or by oral hypoglycaemics and dietary modification.

Insulin

• In type 1 diabetes the patient is controlled on insulin and dietary therapy which allows the sugar produced by the body to be used as energy. It can only be given by injection and comes from two sources :
  • 1 Human insulin which does not come from people. It is made in a laboratory.
  • Animal insulin which is extracted from pork pancreas cells and purified.

• Types of insulin:

1. Fast (clear)
2. Long acting (cloudy)
3. Ready made mixtures of short and medium acting
   1. for example 30/70 mix means 30% fast and 70% slow, like human mixtard 30 or humulin m3.
   2. (This insulin should always be shaken prior to administration to ensure an accurate mixture of the two components is given.)
4. Humalog
   1. rapid acting insulin that can be given at the time of eating

• Insulin delivery
  • Insulin is given by subcutaneous injection with the needle inserted
  • at right angles to the skinto it’s full depth
  • in either the upper arms, upper thighs, the abdominal wall or the buttocks
  • Sites must be rotated on a regular basis to avoid fat hypertrophy
  • leading irregular release of insulin into the blood stream and unstable blood sugars.
• Insulin timing
  • Insulin should be administered 30 minutes before a meal (except humalog which should be administered at or just after a meal)
  • Once insulin has been administered food should always be taken to avoid a hypoglycaemic attack.

• Insulin Storage
  • Insulin can be kept at room temperature for up to one month
  • New vials should be stored in the door of the fridge
  • The insulin should never be allowed to freeze
  • Visual checks of the vial should be made and if crystals can be seen on the glass, dispose of the vial, as the insulin would be inefficient.
  • Never allow insulin to be stored in the hold of an aircraft for this reason.
• Pen Device Needles
  • The needles do not need to be changed after every injection
  • They can last up to 2-3 days
  • The needle should be changed every time a new vial is inserted into the pen and if the needle becomes bent or touches something other than the person’s skin.

Oral Hypoglycaemics

• In type 2 diabetes the patient is controlled on dietary therapy alone or oral hypoglycaemic therapy and dietary therapy or insulin and dietary therapy

• Dietary modification is the mainstay of treatment
  • Diet is formulated on an individual basis which involves a reduced calorie diet which is low in fat and refined carbohydrate and high in fibre
  • This should slow down the rate of glucose absorption, reducing obesity and as a result the demand for insulin should be reduced and cell sensitivity to insulin improved
  • When combined with oral hypoglycaemics or insulin the patient will need to be aware of carbohydrate intake to avoid hypoglycaemic attacks.

• Oral hypoglycaemic medication can only be effective if the Beta cells (found in the islets of langerhans in the pancreas), which produce insulin are capable of secreting some insulin
• Oral hypoglycaemic agents belong to 3 main groups :

1. Sulphonylureas-
   1. these stimulate your pancreas to produce more insulin to lower your blood glucose level.
   2. This type of tablet is usually used for people who are of normal weight or underweight as it may stimulate weight gain
   3. These tablets may cause your face to flush if you drink alcohol
   4. Sulphonylureas may also cause hypoglycaemia
   5. Examples are: glipizide, gliclazide, glibenclamide, tolazamide, tolbutamide, which are very short acting and normally given to the elderly, and chlorpropamide, which is very long acting so precautions have to be taken peri-operatively.
2. Biguanides-
   1. the only tablet in this group is metformin
   2. It helps insulin to use the sugar in your body more effectively
   3. It is usually used for people who are overweight as it does not encourage weight gain
   4. It can cause diarrhoea and abdominal pain and as a result should be taken with or after food
   5. The dose should be built up slowly
   6. It will not cause hypoglycaemia.
3. Alpha Glucosidase Inhibitors
   1. the only tablet in this group is acarbose
   2. It delays the rate at which sugars are digested, in turn this slows down the rate at which your blood glucose level rises after you have eaten
   3. Acarbose itself will not cause hypoglycaemia but may cause wind or soft, smelly stools
   4. If a patient has an episode of hypoglycaemia whilst on acarbose they must be given oral glucose and not sucrose

How is it Monitored ?

1. Blood glucose monitoring
2. Urinalysis for ketones if patient feels unwell or Blood sugars are >17 mmols/l
3. HBA1c

• These can be carried out in hospital and by the patient at home to enable correct treatment.
• When testing a patient’s blood sugar level it is important to note the following to gain an accurate test result :

1. Ensure patient’s hands are clean and warm.
2. Let the drop of blood fall onto test strip, do not smear.
3. Take the sample from the sides of the last three fingers on hand, never take from the pads of the fingers. This is important as diabetic patients can suffer from peripheral neuropathy and by taking samples from the pads of the fingers it may exacerbate it.

• In all cases of diabetes education is vital to both the individuals and their families with the emphasis now on a multidisciplinary, patient-centered approach, and much closer collaboration between primary and secondary care.

Complications of Diabetes

• If diabetes is poorly controlled it can lead to many complications :

1. Hypoglycaemia
2. Hyperglycaemia
3. Ketoacidosis
4. Neuropathy
5. Diabetic foot
6. Nephropathy
7. Diabetic retinopathy
8. Large vessel disease such as stoke, heart attack, peripheral vascular disease

Hypoglycaemia is a condition in which blood glucose is lower than the normal fasting range of 3.5 mmol/l.

• In reality symptoms of hypoglycaemia rarely occur until the blood glucose falls below 3 mmol/l
• Hypos may be caused by
  • too little food
  • missed or late meals
  • more exercise than usual (hypo occurs much later than exercise.)
  • too much insulin
  • alcohol
  • hot weather
  • injecting into a "fatty lump"

• Patients may experience some of the following symptoms :
  • Headaches early in the morning are a result of hypos during the night
  • Lack of concentration
  • Dizziness
  • Unsteady gait
  • Slurred speech
  • Sweating
  • Irrational behaviour

• Treatment
  • If the patient is conscious they should take 3 glucose sweet
  • These will raise blood glucose levels within a few minutes
  • Repeat this if no improvement after 5-10 minutes
  • To prevent the blood glucose falling again, this should be followed by a carbohydrate snack- milk, sandwich, biscuit or fruit.
  • If the patient is unconscious a thick glucose gel, hypostop can be administered into the side of their mouth and is absorbed through the cheek, so it does not need to be swallowed
  • in some cases intramuscular glucagon or intravenous glucose is required
  • Again once the patient is conscious this should be followed by a carbohydrate snack

• Hyperglycaemia
  • refers to high blood sugar levels and dehydration with the absence of ketones
  • In these cases where ketones are not present the patient may require extra insulin and to increase their fluid intake.
• Ketoacidosis
  • could be defined as uncontrolled hyperglycaemia and hypoinsulinaemia accompanied by dehydration and acidosis
  • It can occur in patients with undiagnosed diabetes or due to an infection, myocardial infarction, stroke, failure to take sufficient insulin, surgery or trauma in a diabetic person
  • The symptoms are :

  • Polyuria
  • Polydipsia
  • Lethargy/weakness
  • Nausea/vomiting
  • Abdominal colic
  • Muscle cramps
  • The patient may also have halitosis due to ketones being present.

  • The patient is treated with an insulin infusion and an intravenous infusion until blood sugar levels are stable, there is no ketonuria and blood urea, electrolytes and plasma osmolality return to normal.
  • It is important to realize that if severe enough, hypoglycaemia, hyperglycaemia and ketoacidosis can all lead to a state of unconsciousness, a coma, requiring nasogastric tube to prevent aspiration as gastric dilation often occurs.

• Neuropathy is a disease process of nerve degeneration and loss of function effecting either sensory or motor nerves and results in a loss of sensation.
  • The types of neuropathy which may occur are :

1 Peripheral neuropathy which principally affects the lower extremities and plays a part in the cause of the diabetic foot.

2 Polyneuropathy which refers to widespread neuropathic changes which affect many nerves.

3 Mononeuropathies. It is possible for a single nerve to display evidence of damage eg third and sixth cranial nerve palsies.

4 Autonomic neuropathies. Damage within the autonomic nervous system causing a wide range of symptoms, eg silent myocardial infarction, impotence, postural hypotension, diarrhoea, small pupils and poor dilation.

• Diabetic foot as stated above can occur as a result of neuropathic and also vascular changes and can lead to an ischaemic foot which if severe enough can lead to amputation. Therefore it is important that diabetics are seen regularly by a chiropodist.
  • Not all people who have diabetes have problems with their feet, but having diabetes may put your feet at risk of damage
  • Your feet may become numb so you do not feel pain if your feet are damaged
  • Therefore it is important to wear footwear at all times, check your shoes regularly for ridges etc, do not ignore slight injuries, avoid very hot baths and hot water bottles and never treat corns or calluses yourself.

• Nephropathy- the kidneys of people with diabetes are vulnerable as damage to the capillaries in the glomeruli can occur and the filtering capacity reduced and impaired renal function.
  • Hypertension, a common feature in diabetes can contribute to kidney damage and can also result from kidney damage.

• Diabetic retinopathy results from changes in the small blood vessels of the retina and can be classified as :
  • Background retinopathy or non-proliferative retinopathy
  • Maculopathy
  • Proliferative retinopathy

• Background retinopathy is common in people who have had diabetes for some time and rarely causes a major threat to vision.
• Maculopathy occurs when the blood vessels in the retina begin to leak
  • If the macula is affected central vision will gradually get worse
  • It is very rare for someone with maculopathy to lose all their sight.
• Proliferative retinopathy
  • Sometimes diabetes can cause the blood vessels in the retina to become blocked
  • If this occurs new blood vessels are formed in the eye
    • Unfortunately these vessels grow on the surface of the retina and into the vitreous
    • As a result they bleed easily and cause scar tissue to form, which pulls and distorts the retina
    • It is rarer than background retinopathy and without treatment total loss of vision can occur (treatment involved is laser therapy).

• Large Vessel Disease
  • Small vessels disease results in the damage are the eyes, kidney and nerves
  • Large vessel disease results in strokes, heart atttacks and peripheral vascular disease
  • In the eye it can cause ocular ischaemia
  • It is paramount that all people with diabetes and encouraged to never smoke as heart attack is the commonest cause of death in diabetes

 Management of Diabetes Pre- and Post- operatively

• During hospital admission it is important to try and maintain stable blood glucose levels
• This can be difficult due to a change in the patient’s routine i.e. diet, exercise and the patient may be required to fast for surgery or investigations.
• Blood sugars do not have to be ‘good’ if it is the patient's normal levels as long as there are no peaks and troughs.
• Prior to surgery the patient takes their insulin or oral hypoglycaemics as per their normal routine
• Nursing staff should monitor blood sugar levels four times daily using ward glucose meter and medical staff should obtain a laboratory random blood glucose and electrolyte levels
• The patient will normally be first on the operating list and have to fast from 12 midnight the night prior to surgery
• An infusion of 500ml dextrose 4% and saline 0.18% and insulin infusion (50 units of actrapid in 50ml 0.9% saline) via sliding scale (see appendix) is commenced at approximately 7am on the day of surgery to maintain stable blood sugar levels
• Once commenced (by two trained nurses) the patients blood sugar is checked hourly and the insulin infusion adjusted, if required, as per sliding scale by either two trained nurses or one trained nurse and a student nurse.
• After surgery, when the patient is able to eat, the usual dose of subcutaneous insulin should be administered 30 minutes prior to eating and insulin infusion and intravenous infusion discontinued 30 minutes after the injection
• Patients who take oral hypoglycaemic drugs should have their hypoglycaemic agents recommenced at this stage
• Venflons should be left in situ until first post operative day
• Do not discard infusion until patient is tolerating fluids and diet