Diabetes Mellitus - Type 1 Flashcards
Define Type 1 Diabetes Mellitus
Chronic metabolic hyperglycaemic condition caused by absolute insufficiency of pancreatic insulin production, causing impaired carbohydrate, protein and fat metabolism
Aetiology of Type 1 Diabetes Mellitus
Destruction of the pancreatic insulin-producing beta cells -> absolute insulin deficiency
Often autoimmune process against beta cells (90%)
Hyperglycaemia arises when 90% of the beta cells have been destroyed
Epidemiology of Type 1 Diabetes Mellitus
Accounts for 5-10% of all diabetic cases
Accounts for >85% of diabetes cases under 20
Highest incidence children 10-14
Symptoms of Type 1 Diabetes Mellitus
Patient: young, lean appearance
Polyuria, polydipsia Weight loss Nocturia Fatigue Blurred vision
+symptoms of complications:
DKA (abdo pain, nausea + vomiting, drowsiness, confusion, coma)
Neuropathy (painless leg ulcers, loss of sensation)
Signs of DKA and neuropathy due to Type 1 Diabetes Mellitus on examination
DKA: Tachypnoea, Kussmaul breathing (deep + rapid) Ketotic breath Dry mucous membranes Reduced skin turgor
Neuropathy: Painless leg ulcers Loss of sensation (monofilament+vibration) Weak/absent dorsalis pedis pulse Cranial nerve palsy Diplopia
Investigations for Type 1 Diabetes Mellitus
Fasting plasma glucose >6.9
Random plasma glucose >11.1
Oral glucose tolerance test >11.1
HbA1c >48
Urinary ketones: T1DM ABPI: suggests PAD Urinary albumin excretion: may be increased (end-organ damage) ECG: ?ischaemia Fundoscopy: retinopathy
Fasting C peptide: low or undetectable
Autoimmune markers: +ve
Fasting lipid profile: normal
Serum creatinine + eGFR: ?renal insufficiency
Conservative Management for Type 1 Diabetes Mellitus
Smoking cessation Physical activity Nutritional advice (DAFNE programme) Self-monitoring of blood glucose levels (at least 4x a day) Hypoglycaemia avoidance
HbA1c monitoring every 3-6 months
Medical management for Type 1 Diabetes Mellitus
Insulin therapy
- Basal-bolus (2x daily insulin detemir) + rapid acting insulin before meals (lispro, aspart, glulisine)
- Continuous SC insulin infusion (insulin pump_
- Mixed insulin regimens
- sliding scale (hospital use)
Complications of Type 1 Diabetes Mellitus
Microvascular: retinopathy, neuropathy, nephropathy
Macrovascular: cardiovascular, cerebrovascular, peripheral vascular disease
Hypoglycaemia with insulin therapy
Diabetic Ketoacidosis
What is hypoglycaemia define as and how is it managed
Plasma glucose < 3 mmol/L = severe
Able to swallow -> 50g oral fast-acting glucose e.g. lucozade, sugar, 3 dextrose tablets
Reduced consciousness -> IM glucagon ± IV glucose
No improvement after 10 mins -> IV glucose (dextrose)
-> when safe switch to oral carbohydrate
What are the stages of Type 1 Diabetic retinopathy + their management
- Background retinopathy
Hard exudates | Microaneurysms | blot haemorrhages
=> Warn about warning signs + improve glucose control - Pre-proliferative
Cotton wool spots/soft exudates
=> Pan-retinal photocoagulation - Proliferative
Visible new vessels on disk or elsewhere
=> Pan-retinal photocoagulation - Maculopathy
Hard exudates near the macula | microaneurysms | blot haemorrhages
Can threaten direct vision
=> Grid photocoagulation
Describe Type 1 Diabetic nephropathy and its management
HTN + progressively increasing proteinuria and deteriorating kidney function
Histological: mesangial expansion, BM thickening, glomcerulosclerosis
=> diabetic control | BP control | RAAS inhibition = ACEi | Smoking cessation
Describe the different types of Type 1 Diabetic neuropathy
Peripheral: longest nerves supply the feet, common in taller people, no sense of injury -> infection -> does not heal
Mononeuropathy: sudden motor loss (wrist, foot drop, CN palsy)
Autonomic: loss of sympathetic/parasympathetic innervation to system
Mononeuritis multiplex: random combo of peripheral nerve lesions
Radiculopathy: pain over spinal nerve, often dermatomes
Prognosis for Type 1 Diabetes Mellitus
Untreated = fatal due to DKA
Poor control = risk factor for many chronic complications
Intensive glycaemia control decreases complication rates, even if for a few years
Cardiovascular disease is the major cause of death