Week 4 Flashcards
What is diabetes
A disease of high glucose but also blood pressure and lipids
Common and expensive
Associated with significant morbidity
It’s training and support can be managed well
Symptoms of diabetes
Weight loss
Tiredness
Infection- candidiasis (thrush), urine
Osmotic symptoms- polyuria, thirst, blurred vision, tiredness
Coma
Some have no symptoms
Diagnosing diabetes mellitus
Urine testing
Measuring blood insulin
Blood glucose values (repeat if they have no symptoms)
Oral glucose tolerance test- gold standard
Glycated haemoglobin- HbA1c : 48mmol/mol reflects previous 10 weeks of ambient circulating glucose
What blood glucose levels indicate diabetes
Random glucose >_ 11.1mmol/l
Fasting glucose >_ 7.0mmol/l
What is an oral glucose tolerance test
Fasting state
Measure glucose- time 0
75g glucose drink over 5 mins
Wait 2 hours
Measure glucose - time 2 hrs
What causes diabetes
Insulin deficiency
Insulin resistance
Or a combination
What is insulin
Moves glucose out of blood stream for storage/ building
Major anabolic hormone
Maintains supply of glucose to tissues
Regulates metabolism in muscle
Promotes protein synthesis
Inhibits breakdown of fat
What do pancreatic beta cells do
Secrete insulin
Found in islet of Langerhans in pancreas
What is proinsulin
A substance produced by pancreas which is converted to insulin
It’s a prohormone precursor to insulin made in beta cells of the islets of Langerhans in pancreas
What’s a prohormone
A committed precursor of a hormone consisting of peptide hormones synthesised together that has a minimal hormonal effect by itself
What is a precursor
A substance from which another- usually more active or mature substance is formed
Classification of diabetes
Two main types:
Type 1 diabetes
Type 2 diabetes
Gestational diabetes- during pregnancy some women have such high levels of blood glucose that their body is unable to produce enough insulin to absorb it all
Type 1 diabetes
Where the body’s immune system attacks and destroys the cells that produce insulin
Absolute insulin deficiency
Can present any age usually <40
Usually normal weight or slim
Dramatic onset
Family history less common
Presence of ketones in urine and breath
Insulin required to sustain life
Type 2 diabetes
Where the body doesn’t produce enough insulin or the body’s cells don’t react to insulin
Insulin resistance
Relative insulin deficiency
8% population -more common
Onset typically >40 but getting younger
Genetic predisposition
Associated with obesity
Insidious onset of symptoms, insulin not required to sustain life
No ketones as insulin is present
Cause of type 1 diabetes
Autoimmune (Insulitis)- an inflammation of the islets of Langerhans- the body’s T lymphocytes attack and destroy the beta cells that produce insulin
Cause of type 2 diabetes
Insulin resistance (mainly in skeletal muscle and liver)
Beta cell dysfunction leading to a relative reduced insulin secretion
High glucose levels
“The 3 steeds of a diabetics chariot” Elliott Joslin
Diet, exercise, insulin —— glucose control
Glucose control in diabetes
Type 1- lifestyle, insulin
Type 2- lifestyle, reduce insulin resistance, increase glucose excretion, increase insulin
Types of insulins
Meal time insulins- soluble (Actrapid, Humulin S), Rapid acting insulin (Aspart (Novorapid), Lispro (humalog), glulisine (Apidra))
Longer acting insulins- Zinc insulins ( Insulatard, Humulin I), Long acting (Determir (levermir), glargine (Lantus), Glargine U300 (toujeo), Degludec (tresiba))
Other medication to lower glucose
Tablets- Insulin sensitisers, insulin secretogogues, gut absorption, glucose excretion, incretin breakdown inhibitors
Injection- incretin mimetic
Medication other than insulin
Blood pressure: ACE inhibitors, beta blockers, calcium channel blockers, diuretics
Lipids: statins, fibrates
Complications of diabetes
Platelet dependent thrombosis
Microvascular- retinopathy, cataracts, glaucoma, nephropathy, neuropathy
Macrovascular- stroke, cerebrovascular disease, transient ischemic attack, cognitive impairment, coronary heart disease, peripheral vascular disease, feet wounds likely to heal slow contributing to gangrene
Hyperglycaemia and hypoglycaemia
Hearing impairments