Diabetes Mellitus Flashcards
Types of Diabetes Mellitus
- Type 1
- Type 2
- MODY - maturity onset diabetes of the young
- Pancreatic diabetes - pancreatitis, surgery, cancer
- Endocrine diabetes - acromegaly, Cushing’s
- Malnutrition related diabetes
Define Diabetes Mellitus
A disease in which the body is unable to produce/respond to insulin normally, resulting in abnormal carbohydrate metabolism and increased blood glucose
Type 1 pathology
Autoimmune disease in which beta cells are destroyed resulting in cessation of insulin production. Glucose can’t be transported into cells -> high blood glucose
Type 2 pathology
Peripheral insulin resistance -> more insulin produced to have same effect (beta cell hyperplasia), normoglycaemia -> amylin secretion by beta cells -> beta cell hypoplasia and hypotrophy -> decreased insulin production -> high blood glucose
RF T2DM (10)
- > 40yrs
- Men
- South Asian, Black-Caribbean, Black-African (>25y)
- Obesity
- Hypercholesterolaemia
- Sedentary lifestyle
- Family history
- HTN
- Smoking & alcohol
- PCOS (polycystic ovary syndrome)
Diagnosis of T2DM
- Symptoms and 1 abnormal blood glucose test (fasting>7mmol/L, random >11.1mmol/L)
- 2 abnormal blood glucose tests (as above, oral glucose tolerance test 2h >11.1mmol/L)
- Abnormal HbA1c
HbA1c level ranges
Normal <42mmol/mol
Pre-diabetic 42-47mmol/mol
Diabetic >48mmol/mol
When to avoid HbA1c
- Pregnancy
- Type 1
- Children
- Haemoglobinopathies
Symptoms of hyperglycaemia
- Polydipsia
- Polyphagia
- Glycosuria
- Polyuria
Explain symptoms of hyperglycaemia
High blood glucose damages nephrons, causing glycosuria. High osmolarity of filtrate draws in water - polyuria. Dehydration from polyuria causes polydipsia. Cells starved of glucose causes hunger and weight loss due to lipo and proteolysis.
Diagnosis of T1DM
- Fasting glucose (8h w/o food) >7mmol/L
- Random glucose >11.1mmol/L
- Hyperglycaemic symptoms with 1 or more of
- Ketoacidosis
- Rapid weight loss
- Onset <5y/o
- BMI<25
- FHx of autoimmune disease
RF T1DM (2)
- HLA-DR3, HLA-DR4 gene (FHx autoimmune disease)
2. PMH of autoimmune disease
T1DM treatment
Insulin
T2DM management
- Lifestyle and diet modification (low sat fat, sugar, high starch-carb)
- Monotherapy - metformin
- Dual therapy (if HbA1c >58mmol/mol)
- Metformin + DDP4 inhibitor
- Metformin + pioglitazone
- Metformin + sulphonylurea (SU)
- Metformin + SGLT-2i
- Triple therapy (if HbA1c >58mmol/mol)
- Metformin + DDP4 inhibitor + SU
- Metformin + pioglitazone + SU
- Metformin + SU/pioglitazone + SGLT-2i
- Insulin based therapy
Metformin
Biguanide. Increases insulin sensitivity and helps with weight
SE: nausea, diarrhoea (try modified release), abdominal pain
Avoid if eGFR <36mL/min - risk of lactic acidosis
DPP4-inhibitors
E.g Sitagliptin
Block DDP4 action - enzyme that destroys incretin
Pioglitazone
Increases insulin sensitivity
SE: hypoglycaemia, fractures, fluid retention, increase LFT
CI: CCF, osteoporosis, increasing weight/oedema
Sulphonyurea
Increase insulin secretion
SE: hypoglycaemia
SGLT-2i
Selective sodium-glucose co-transporter 2 inhibitor.
Blocks reabsorption of glucose in the kidneys and promotes secretion of excess glucose in urine
Annual diabetic review (9)
- HbA1C test
- BP
- BMI
- Plasma lipids
- Visual acuity and retina state
- Urine test for proteinuria, microalbuminuria
- Renal function blood test - creatinine
- Check condition of feet, pulses, neurology
- Review of CV RF
Define hypoglycaemia
Plasma glucose <3mmol/L
Causes of hypoglycaemia (diabetic) (4)
- Insulin or SU treatment
- Increased activity
- Missed meal
- Accidental/non-accidental overdose
Symptoms of hypoglycaemia
Autonomic: sweating, anxiety, hunger, tremor, palpitations, dizziness, tachycardia
Neuroglycopenic: confusion, drowsiness, visual trouble, seizures, coma
Complications of diabetes (8)
- Vascular disease
- Nephropathy
- Diabetic retinopathy
- Cataracts - senile or snowflake
- Rubeosis iridis (new vessels on iris - lead to glaucoma)
- Metabolic complications
- Diabetic feet
- Neuropathy
Treatment of hypoglycaemia (3)
- 15-20g quick-acting carbohydrate snack and recheck blood glucose after 10-15mins
- If conscious but uncooperative, squirt glucose gel in gums and teeth
- Glucose IVI or glucagon 1mg/IVI
3 key features of Diabetic Ketoacidosis (DKA)
- Hyperglycaemia
- Raised plasma ketones
- Metabolic acidosis
Pathogenesis of DKA
- Insufficient insulin -> unrestrained gluconeogenesis in the liver
- Dehydration due to osmotic diuresis in the kidneys as a result of hyperglycaemia
3, Peripheral lipolysis -> lots of FFAs in the blood -> converted into ketones in the liver -> metabolic acidosis
Clinical features of DKA (7)
- Dehydration (reduced tissue turgor pressure -> skin takes longer to snap back into place)
- Vomiting and abdominal pain (electrolyte disturbance)
- Sunken eyes and dry tongue
- Low BP
- Kussmaul’s breathing (deep and rapid - respiratory compensation)
- Fruity breath (ketones)
- Low body temp
DKA investigations
- Blood glucose >11mmol/L
- Ketonaemia - finger prick sample measuring b-hydroxybutyrate
- Acidaemia - pH < 7.35
- Urine dipstick - glycosuria and ketouria
- U&E - creatinine and urea high, serum potassium high (low insulin allows to shift out cells), low total body potassium (osmotic diuresis)
Management of DKA
- Fluid replacement - NaCl 0.9%
- IV glucose - 6 units/hour
- Electrolytes
Symptoms of diabetic neuropathy (8)
- Numbness or reduced ability to feel temp/pain in fingers and toes, glove and stocking distribution
- Tingling/burning sensation
- Sharp pains or cramps
- Hypersensitivity
- Muscle weakness
- Hyporeflexia - particularly in ankle
- Loss of balance and coordination
- Foot issues - ulcers, infection, amputation
Symptoms of diabetic retinopathy (6)
- Spots or floaters in vision
- Blurred vision
- Fluctuating vision
- Impaired colour vision
- Dark or empty areas in vision
- Vision loss
Investigations for diabetic retinopathy
Fundoscopy - cotton wool spots and flare haemorrhages
Pathophysiology of diabetic nephropathy (3)
- Glomerular disease
- Ischaemic renal lesions
- Ascending UTIs
