Diabetes Flashcards
ILO 8.8a: be familiar with the underlying disease processes of the common medical disorders affecting the body
what is diabetes mellitus?
- blood sugar levels too high
- body cannot take up glucose properly
- pancreas does not produce enough insulin
- OR body does not respond to insulin
what is type 1 DM?
- insulin deficiency
- autoimmune destruction of pancreatic beta cells
what does destruction of pancreatic beta cells lead to?
3
- hyperglycaemia
- ketoacidosis
- low c-peptide levels (indicating low insulin secretion)
what is ketoacidosis?
- when body cells cannot access glucose due to a lack of insulin
- cells start to metabolise fat which results as ketones as end product
only occurs in T1DM
what are the circulating antibodies present in T1DM?
3
- GAD - glutamic acid decarboxylase
- ICA - islet cell antibodies
- IAA - insulin autoantibodies
what are the symptoms of DM?
4
- polyuria
- polydipsia
- tiredness
- unintentional weight loss
what are the symptoms of diabetic ketoacidosis?
8
- polydipsia
- polyuria
- confusion
- blurred vision
- stomach pain
- nausea and vomiting
- sweet/fruity breath
- loss of consciousness
how can you treat early signs of diabetic ketoacidosis (DKA)? what happens if it is not treated early?
- insulin and fluids
- if not treated early, sent to hospital urgently
what is latent autoimmune diabetes (LADA)? which antibody is it associated with?
- diabetes onset in adults older than 30 years old
- GAD associated
- may masquerade as ‘non-obese’ type 2
describe the natural history of beta cell loss in T1DM
- when beta cell function is high = normoglycaemia
- as cells are destroyed, pt transitions through impaired glucose tolerance (IGT)
- as beta function decreases further, pt enteres a diabetic category
- pt. enters a non-insulin requiring stage where they still have some functioning beta cells
- then enters a insulin for control stage
- and finally until they require insulin for survival as beta cell function is so low, not enough insulin is produced
what is type 2 DM?
- insulin resistance
- diabetes associated with family history and social history
- transitions through impaired glucose tolerance
what are the rarely acute presentations of T2DM?
- polyuria, polydipsia, tiredness
- unusual infections
- diabetic complications e.g. cardiovascular
what are the effects of T2DM?
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- impaired glucose tolerance (IGT)
- hyperinsulinaemia
- hypertension
- oesity with abdominal distribution
- dyslipidaemia (high LDL, low HDL)
- procoagulant epithelial markers
- early and accelerated atherosclerosis
how would you be able to tell if T2DM was not well controlled?
the patient takes additional insulin medication with the oral medication when unable to maintain glycaemic control with:
* behavioural change
* body weight reduction
* oral hypoglycaemic agents
what is insulin resistance?
- defect in insulin synthesis, secretion and action
- beta cell response to hyperglycaemia is inadequate
- results in elevated basal insulin levels
- failure of gluconeogenesis suppression
- insulin stimulated glucose uptake is impaired
what is medication induced diabetes? what medications?
medicine which interferes with the **secretion of insulin or glucagon, or alters the uptake of glucose **
* corticosteroids (prednisolone, hydrocortisone)
* immune suppressants (cyclosporin)
* cancer medication (imatinib, nilotinib)
* antipsychotics (clozapine, olanzapine, quetiapine)
* antivirals (protease inhibitors)
what other medical conditions are related to diabetes?
- endocrine diseases - Cushing’s, Acromegaly, Phaeochromocytoma (adrenaline tumour)
- pregnancy - gestational diabetes
describe the four investigations for diabetes and the criteria for diagnosis of T2DM
- random sugar test - blood sugar tested at random time so no need to fast before - +11.1mmol/L on 2 occasions
- fasting sugar test - blood sugar tested after fasting - +7.0mmol/L
- glucose tolerance test - patient fasts before test then drinks glucose solution and blood glucose is measured - +11.1mmol/L
- HbA1C (glycated haemoglobin) - average blood sugar levels over previous 2-3 months - +48mmol/L
what are the normal values for each of the investigations for T2DM?
- HbA1C - 41mmol/L and below
- fasting glucose - 6.0mmol/L and below
- 2 hour plasma glucose - 7.7mmol/L and below
what is the group inbetween diabetes and normal when investigating blood sugar levels? what are the values?
impaired or pre-diabetes
what are the differences between T1DM and T2DM?
how would you manage diabetes mellitus generally?
- structured education - make appropriate to patient’s needs
- healthy living advice - dietary advice, living interventions, personalised diabetes plan
- blood glucose management - explain targets and the need to maintain them
- consider prevention to reduce risk from associated disease - antiplatelets, statins, antihypertensives
what are the different insulin regimes?
- basal-bolus: more injections so better control
- split-mixed: fewer injections so poorer control
how would you manage T1DM?
- nutrition - carbohydrate counting
- exercise - planned activity, understand individual response to exercise
- monitoring - initially need regular checks until pt is familiar with their personal response to food and exercise
- insulin - subcutaneous injection with different preparations and time to act
how would you manage T2DM?
- lifestyle - weight loss, diet, exercise
- medication - biguanides, DDP-4 inhibitors, GLP-1 mimetics, sulphonylureas
- surgery - gastric vertical banding - bariatric surgery
what does metformin (biguanides) do?
- enhance cell insulin sensitivity
- reduce hepatic gluconeogenesis
what are some acute diabeteic complications?
3
- hypoglycaemia
- hyperglycaemia
- ketoacidosis
what are some chronic diabetic complications?
- cardiovascular disease
- peripheral vascular disease
- increased risk of infection
- retinopathy
- neuropathy
- nephropathy
when does hypoglyaemia occur? what should you do when someone has a hypoglycaemic episode?
- blood glucose below 4mmol/L
- give them something to eat or drink that will increase blood sugar
- if someone becomes unconscious, give glucagon injection then food/drink when consciousness regained
what are the macrovascular complications with diabetes?
- coronary artery disease
- peripheral ischaemia (PVD)
- stroke
- hypertension
what are the microvascular complications with diabetes?
- nephropathy (renal disease)
- retinopathy (eye disease)
- neuropathy (nerves)
what are the infection complications with diabetes?
- UTI
- pneumonia
- skin/soft tissue infections
- fungal infections - candida
how do diabetic ulcers form?
- sustained hyperglycaemia leads to increased glycated haemoglobin and the formation of advanced glycation end products (AGEs)
- AGEs increase oxidant stress and lead to the production of free radicals which cause tissue damage i.e. diabetic ulcers
- they also bind to cell surface receptors (RAGEs) and cause increased permeability and increased adhesion molecule expression of endothelial cells, increased chemotaxis and increased production of TNFa and IL-6 from macrophages, and increased production of MMPs and reduced collagen formation by fibroblasts
what occurs with diabetic neuropathy?
- general sensation - ‘glove and stocking’ = numbness, tingling or pain in hands or feet
- motor neuropathy - weakness and wasting of muscels
- autonomic regulation - hyperglycaemia awareness lost, postural reflexes, bladder and bowel dysfunction
what are the problems with surgery for diabetic people?
- fasting is a problem - need insulin to prevent ketoacidosis, need carboydrates to prevent hypoglycaemia
- metabolic changes associated with surgery - hormone changes aggravate diabetes (adrenaline, cortisol, GH), more glucose production and less muscle uptake, metabolic acidosis more likely
what are the oral manifestations with DM?
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- dry mouth
- burning mouth
- fungal infections
- enlarged salivary glands
- periodontal disease
- impaired wound healing
- halitosis
- taste alteration
what should you be aware of when treating a diabetic person as a dentist?
- timing of dental treatment - morming visit after breakfast, bring snack
- risk of hypoglycaemia
- reduce stress - increases adrenaline, which interferes with insulin activity and may cause a hypoglycaemic event
- be aware of diabetic complications - neuropathy, dehydration, retinopathy
- be aware of increased infection risk
- be aware of poor wound healing
- link between DM and periodontal disease
