Lecture 14 Flashcards
What is diabetes?
When blood glucose is too high (hyperglycaemia) and over years leads to damage of the small and large blood vessels causing premature death from cardiovascular diseases.
What are the types of diabetes?
Type 1
Type 2
Why is diabetes a major health concern?
- risk of amputation
- leading cause of blindness in working age
- 1/4 develop kidney disease
- life expectancy is reduced
What is the largest epidemic in human history?
Type 2 diabetes- due to the environment, not genetics
How is glucose obtained from food?
- after eating, your body breaks down food into glucose
- glucose is a sugar which is the body’s main source of energy
- as blood glucose rises, body sends signal to pancreas which releases insulin
- insulin binds to an insulin receptor, allowing glucose to pass through
Why does blood glucose rise?
- inability to produce insulin due to beta cell failure
- insulin production is adequate but insulin resistance prevents insulin from working effectively= obesity
What is type 1 diabetes caused by?
Autoimmune beta cell destruction
immune response to self antigens
What does type 1 diabetes cause?
Pancreas does not secrete enough insulin
= ABSOLUTE INSULIN DEFICIENCY
Why does type 2 diabetes develop?
-pancreas may not produce ENOUGH insulin
=RELATIVE INSULIN DEFICIENCY
-cells do not use insulin properly (insulin resistance: insulin can’t fully unlock cells to allow glucose to enter)
How does diabetes mellitus (hyperglycaemia) present?
-polyuria (large production of urine)
-polydipsia (drinking lots of water)
-blurred vision
Due to inadequate energy utilisation (as energy is being excreted in the urine)
-tiredness
-weakeness
-weight loss
How do you diagnose diabetes?
Labatory confirmation
- fasting glucose test
- oral glucose tolerance test (take a glucose drink and blood glucose levels is monitored at regular intervals after: if they have diabetes then the blood glucose will remain higher than should be)
- HbA1c (measurement of glucose attached to haemoglobin)
Symptomatic: 1 abnormal test
Asymptomatic: 2 abnormal tests
What is the fasting glucose test?
Don’t eat/drink 8-10 hours before the test
- diabetic: 7 mmol or above
- normal: 5.5mmol or below
What is a theory as to why incidence of type 2 diabetes is increasing?
We are not as exposed to pathogens, so immune system is more immature and finds it hard to differentiate between self anitgens and non-self antigens
What are the symptoms of type 1 diabetes?
- rapid onset weightloss (weeks)
- polyuria/polydipsia
- late presentation: vomiting due to ketoacidosis
What does the patient clinically present with in type 1 diabetes?
- elevated venous plasma glucose
- presence of ketones (breakdown products of fat)
- young <30 yo
How do you treat type 1 diabetes?
Exogenous insulin
- subcutaneous injections several times a day
- can have a pump- continuous insulin infusion
What does ketone production suggest?
Absence of insulin
-presence of ketones is an indication for immediate insulin therapy
What supresses ketone production?
Insulin (in presence of starvation there may be some ketones in healthy people)
What is ketoacidosis?
- deficiency of insulin
- enhanced lipolysis= uncontrolled ketosis
- large quantities of ketone bodies
Why does type 2 diabetes develop?
Insulin resistance
- obesity
- genetic influences
- physical inactivity
- muscle and liver fat deposition
How can you treat type 2 diabetes?
-very low calorie diets
-bariatric surgery
Fall in liver fat content return of normal sensitivity to insulin and decreases pancreatic fat normalising B cell function
What are the symptoms of type 2 diabetes?
Variable due to slower rise in blood glucose
- may have polyuria, polydipsia, weight loss
- NO urinary ketones
What age group is affected
Over 40 years
increasingly seen in younger people
How do you treat type 2 diabetes?
Weight loss (lifestyle)
- can use insulin
- non-insulin therapies
What should you look for in patients with type 2 diabetes?
- other vascular risk factors- BP, lipids, smoking, exercise, diet
- surveillance for chronic complications
Give some examples of non-insulin therapies:
- metformin
- thiazolidinediones
- sulphonylureas
What are some acute complications of diabetes?
Hyperglycaemia -diabetic ketoacidosis in type 1 -hyperosmolar non-ketotic syndrome in type 2 Hypoeglycaemia -coma
What some chronic complications of diabetes?
- macrovascular/large vessel disease
- cerebrovascular, cardiovascular, peripheral vascular disease
- stroke, heart attack, intermittent claudication, gangrene
- microvascular/capillary disease
- retinopathy > blindness
- nephropathy > renal replacement therapy
- neuropathy
- erectile dysfunction
- foot ulceration
- diarrhoea/constipation
What is the metabolic syndrome?
Cluster of the most dangerous risk factors associated with cardiovascular disease
-diabetes
-raised fasting plasma glucose
-abdominal obesity
-high cholesterol
-high BP
Confer a marked increase in cardiovascular risk
What must a person clinically have to have the metabolic syndrome?
-waist measurement >94cm men, >80cm women
Plus any 2 of these:
-raised triglyceride >1.7mmol/l
-reduced HDL cholesterol <1 men, <1.2mmol/l women
-raised BP >135/85
-raised fasting blood glucose >5.6mmol/l
