ELFH: Diabetes Flashcards
What is diabetes?
Diabetes can be described as a syndrome of hyperglycaemia (high blood sugar levels) and abnormal metabolism arising due to a disturbance in the overall action of insulin.
What cells secrete insulin?
Beta larger hand cells of the pancreas, in response to raised blood glucose levels
action of insulin?
The action of insulin is to increase the cellular uptake of glucose for direct use or to be stored in tissues in the form of glycogen (for example, liver).
This cellular uptake promotes metabolism of glucose (glycolysis, Krebs cycle and oxidative phosphorylation to make adenosine triphosphate (ATP)) in preference to the breakdown of fats and proteins.
Thus insulin will keep our blood glucose levels at relatively constant levels.
What happens in he absence of insulin?
When there are reduced insulin levels or the cells cannot respond at the insulin receptor complex:
blood sugar levels will rise
fat breakdown will be released, forming fatty and keto acids (low pH and fruity breath in excess)
proteins will also be broken down to promote gluconeogenesis (muscle mass reduction)
Both of these last 2 events provide an alternative source of metabolic raw components to produce ATP in the absence of glucose.
Type 1 diabetes?
- arises as a result of an autoimmune destruction of the beta Langerhans cells in the pancreas, possibly as a result of a preceding viral infection
- predominantly develops in childhood
- associated with other autoimmune diseases
- there is no strong association with family history, although there is some association with human leukocyte antigen (HLA) profile, for example, HLA DR3 or DR4
- results in absolute absence of any insulin
Type 2 diabetes?
- occurs due to a reduction in response to insulin at the insulin receptor or a reduced insulin secretion. Rarely absolute insulin absence
- risk increases with age and has association with weight gain and obesity in particular. It appears to be related to over demand and malfunction of the pancreas or reduced sensitivity of the receptors
- there is a strong family history association with little HLA association
- in the UK, the Asian population is most affected
- may manifest itself during pregnancy, Cushing’s disease, steroid medication and thiazide diuretics
How may T2D manifest?
Pregnancy
Cushings disease
Steroids
Thiazide diuretics
What are the accepted diabetes diagnostic blood sugar levels in a fasting blood glucose test?
Under 7.0mmol
What glucose levels can diabetes be diagnosed?
random blood glucose levels are greater than 11.1mmol.
Why is diabetes so dangerous to human health?
Reduced life expectancy
Deleterious effect on cellular function, particuarly white cell population, predisposing to infections
The state of diabetes results in the accelerated atheromatous deposits in the arterial network, especially the microvasculature which become significantly narrowed, resulting in a reduction over time to the supply of oxygenated haemoglobin at a cellular level (ischaemia) and eventually a complete block (infarction).
- dentists should be aware that the dental pulp can minifst the same changes in the micro circulation as the rest of the body
What are the systemic effects of diabetes on the body?
Eyes - ischaemic and infarction - loss of retinal function
Kidneys - ischaemic and infractive small vessel damage to the kidneys is a major cause of renal failure
Skin - slower wound healing as a result of reduced blood supply , predisposition to infection
Nerves - severely affect blood supply to individual nerves (lead to loss of function)
- can also affect hand and foot senses
are you predisposed to infection fo you have diabetes/
yes
describe the appearance fo skin in some diabetic pts?
The skin also develops lumpy ‘lipohypertrophy’ at the site of repeated injections.
diabetic retinopathy?
Ischaemic and infarction easing to. Loss f retinal function
Signs of diabetes?
Hyperglycaemia diuresis
Polyuria and subsequent thirst
Polydipsia
Weight loss
effect of untreated diabetes?
Protein breakdown and loss of muscle madd alongside fat breakdown and ketoacidosis
cardiovascular events associated with diabetes?
Stroke, MI, and tissue infarction in lower limbs, resulting n amputation
describe the type of infection associated with diabetes?
Opportunistic infection
E.g. genital infections and poor wound healing
aim of diabetes tx?
The aim of treatment is to keep the blood glucose as constant as possible as this is associated with reduced development of complications.
Management of T1D?
Type I diabetes will require insulin injections (Figure 1). Usually insulin is mixed with retarding agent (zinc or protamine) to calibrate the release over a longer period.
Recent developments have included human insulin which works quickly but also wears off after a shorter period.
Management of T2D?
Change in diet:
reduce fat
increase complex carbohydrate
regular meals with snacks to prevent wild swings in glucose levels
Oral hypoglycaemics:
- sulphonylureas, such as glibenclamide, increase insulin release and improve receptor responses. Beware of hypoglycaemia and increased appetite
- biguinides, such as metformin, reduce hepatic glucose production and increase insulin sensitivity, reduce appetite and are useful in obese patients
- alpha-glucosidase inhibitors, such as acarbose, impair carbohydrate digestion and slow absorption. May cause bloating and flatulence
- THhiazolidnediones, such as pioglitazone, increase insulin sensitivity by activating the peroxisome proliferator-activated receptor gamma (PPARγ), which will enhance the transcription of glucose transporter molecules glut-1 and glut-4. Beware liver problems.
How often to finger prick?
Up to 4 times a day for 2 days per week
How to achieve a Long term picture of glucose control?
glycosylated haemoglobin (HbA1c) will indicate how long Hb has been circulating in raised blood sugar levels over the previous 6 to 12 weeks. Normal levels are 4% to 8%.
DKA?
Diabetic ketoacidosis
What is DKA?
DKA develops when there is an absolute absence of insulin. This releases the previously inhibited protein and fat breakdown which is now required to replace the glucose supply which cells are unable to access without insulin.
Thus, the blood glucose levels will become very high (>20mmol/l). This can be precipitated by stress, infection, surgery or forgetting to take insulin.
High glucose will promote an osmotic diuresis and dehydration. Lipolysis will result in ketoacid build up and a metabolic acidosis with Kussmaul breathing (air hunger) and ‘fruity breath’.
Protein breakdown is accelerated by the activation of gluconeogenesis.
Catabolic events as a result of DKA?
- hyperglycaemia
- metabolic acidosis
- raised urea and electrolytes due to dehydration
- low total body potassium due to diuresis although as insulin levels are lowered, (facilitating intra-cellular potassium movement), the serum potassium will be raised
- raised white cell count
how might diabetes affect oral health?
- increased infections, for example, poor wound healing following extractions, - -recurrent dental abscess
- opportunistic infections, for example, oral candidiasis and unusual fungal infections such as mucormycosis
susceptibility to periodontal diseaseespecially if poorly controlled - salivary gland dysfunction, for example, sialosis and reduced function leading to xerostomia
- oral dysesthesia (burning mouth)
- lichenoid responses to oral hypoglycaemia
disputed grinspan syndrome (lichen planus, diabetes and high blood pressure) - increase in active dental caries
- traumatic oral ulcers
First signs of diabetes the dentist could spot orally?
significant periodontal disease
xerostomia (Figure 1)
oral dysesthesia
poor wound healing
dental abscesses
opportunistic infections
hypoglycaemic event
hyperglycaemic event
poor general health
When should you have appointments for a diabetic pt?
Appointments should be made first thing in the morning. This reduces the chances of patients becoming hypoglycaemic if they miss their morning insulin or medication. Keep vigilant for autonomic dysfunction such as dizziness on sitting the patient up, which may indicate orthostatic hypotension.
Can sedation be administered without problems?
Masks symptoms of hypoglycaemia
LA and diabetic pt?
the sympathetic nervous system may be activated, thereby raising the blood glucose levels
Do you need to treat infections promptly with diabetic pt?
Treat infections promptly and effectively to reduce the risk of ketoacidotic events developing
Tings to watch out for after extraction and diabetic pt?
Dry socket
Wound healing
Periodontal care and diabetes?
Effective periodontal care will improve the metabolic control for people with diabetes
Better effect in T1D
In DKA, which of the following will develop?
B
C
E
F
Which of the follwong oral signs and symptoms are associated with diabetes?
A. False. Patients may develop a dry mouth.
B. True. Fatty infiltration of the salivary glands.
C. True. Increased risk of ascending salivary gland infection.
D. False. No association with neoplastic disease.
E. False. Has been proposed but as yet unproven.
F. True. People with diabetes are prone to opportunistic infections due to impaired white cell function.
G. False.
H. True. Neuropathy may affect the cranial nerves.
Suspicions that a patient may have undiagnosed diabetes may be raised by which of the following tests in the dental surgery?
A. False. This is a hospital-based investigation.
B. False. This is another hospital/GP surgery based test.
C. True. Finger pricking can be performed to reveal a random blood glucose level.
D. False. There is no direct diagnostic association with blood pressure.
E. False. Although urinalysis can be easily performed in primary dental care, it is usual for this to be performed in a secondary care facility.
F. True. A cranial nerve examination can determine if any neuropathy developing.
