Diabetes Flashcards
Are all new-onset Diabetes in older people is type 2
No, if ketotic +/- poor response to oral hypoglycaemics and patient is slim or has a family/PMH of autoimmunity
THINK OF LATENT AUTOIMMUNE DIABETES IN ADULTS (LADA)
Measure Islet cell antibodies
Nevertheless it is a form of type 1 DM
Define Type 1 diabetes Mellitus
Usually occurs in adolescents or at any age.
It is the autoimmune destruction of pancreatic B cells causing in no insulin production.
patients must have insulin
prone to ketoacidosis (can present with it) and weight loss
Associated with HLADR3 or DR4 and can be with other autoimmune diseases
Define Type 2 diabetes Mellitus
It is the gradual resistant to insulin or the fail of secretion of enough insulin from pancreatic B cells or BOTH.
Formally non-insulin dependent DM (NIDDM)
usually in Asian men and the elderly
most are over 40s, but now many teenagers get it too
Stronger environmental association compared to T1DM
Cuases of Type 2 diabetes Mellitus
Obesity
Lack of exercise
calorie and alcohol excess
Maturity onset diabetes of the young (MODY)
A rare from of type 2 DM of autosomal dominant form.
Affects young people with +ve Fx
Investigations of Diabetes
Diabetic if:
Fasting plasma glucose >7mmol/L
Random plasma glucose (+ Symptoms) >11.1mmol/dL
Glycated Hemoglobin HbA1c >6.5% (48mmol)
What is impaired glucose tolerance test
fasting plasma glucose of <7mmol/L
and at 2h after oral glucose load –> 7.8-11 mmol/L
plasma glucose at 2h: >11.1mmol/L
Impaired fasting glucose
plasma glucose 5.6-6.9mmol/L
Other causes of DM
very important
Steroids
Anti-HIV drugs
newer antipsychotics
Thiazides
others:
Pancreatic: -itis, malignancy, surgery (90% otomy), trauma
Cushing’s disease
Congenital
Presentation of diabetes
T1DM T2DM Polydipsia Asymptomatic Polyuria complications - MI Reduced weight ketosis
Conservative treatment of DM
T1 and T2 the same
Diet Exercise Smoking cessation is BMI A HbA1c and blood glucose monitoring Decrease alcohol
Type 1 Medical treatment
Insulin thassss it
Type 2 Medical treatment
Metformin (biguanide) 1st line
What does Metformin do
Increases insulin sensitivity and helps weight
SE: Nausea, diarrohoea, abdominal pain, not hypoglycaemia
When to avoid Metformin
If eGFR <36mL/min
stop if tissue hypoxia (MI, Sepsis)
Morning before GA
Iodine contrast
When do you start adding more treatment for T2 diabetes
When HbA1c >53mmol/L at 16 weeks
Additional treatments for T2DM at 16 weeks
Sulfonylurea (gliclazide)
increases insulin secretion
SE: increases weight, hypoglycaemia (monitor glucose),
Additional treatments for T2DM at 6 months
If HbA1c >57mmol/L at 6 months consider
Insulin
Glitazone
sulfonylurea receptor binders
Glucagon like peptide analogues
a-glucosidase inhibitors
Complications of DM
Macrovascular - prevalent in the West as a whole
• Stroke - ↑ x2
• MI - ↑ x3-5
• Amputation for foot gangrene - ↑ x50
Microvascular - specific to DM; manifest 10-20 years after diagnosis:
• Diabetic retinopathy - ~1/3 pts develop eye problems; commonest cause of blindness in <65yo
• Diabetic nephropathy
• Diabetic neuropathy
• Diabetic foot ulcers
Diabetic ketoacidosis
Cataracts - changes in blood sugar cause osmotic changes in the lens
What is diabetes insipidus
A disorder cause by low levels of or insensitivity to antiduretic hormone (ADH) leading to polyuria
Glucose and the liver
The liver is the principal organ of glucose homeostasis which absorbs and stores glucose as glycogen
What is the major consumer of glucose
The brain and is not dependent to insulin
brain only uses glucose and ketones for energy, but prefers glucose
What does insulin do
promotes uptake of glucose by cells by activating glucose transporters (GLUT)
What happens to glucose in muscles
Stored as glycogen or metabolised to lactate or CO2 and water
Effects of insulin in the postprandial state
There will be increased insulin levels, therefore it will inhibit production of glucose from liver and promote entry of glucose to peripheral cells.
What is postprandial
After food
Where dose glucose come from
When you eat gut breakdown food into glucose in small intestine
Effects of insulin in the fasting state
The insulin levels will be low, therefore it will excite the liver to produce more glucose
What are hypoglycaemia symptoms
Confusion
Dizziness
Fainting
Coma
Factors that affect glucose levels
The WHALE factors Weigh Health - MH Age Level of activity Eating habits - diet
Define hypoglycaemia
Reduced levels of glucose in blood stream
Symptoms of hyperglycaemia
Thirsty
Polyuria - kidneys trying to flush glucose
Dehydration
increased apetite
weight gain may be
Define hyperglycaemia
Increased levels of glucose in blood stream
What is Diabetic ketoacidosis
acute emergency of T1DM
it is when the body is at stress (infection maybe) so more energy is required but not enough insulin (because of T1DM) therefore there could be hyperglycaemia but no uptake by cells, no insulin, and result in what is called starvation metabolism
to compensate the body starts breaking protein from muscles for amino-acids (proteolysis) and adipose for glycerol and free fatty acids (lipolyisis) all of these products are to taken to the liver for Gluconeogenesis (formation of new glucose). Then glucose is formed which is good, but a by-product is produced by gluconeogensis is Acetyl-COa. Acetyl-COa promotes ketogenesis which produces ketones. Ok ketones are good they give the brain energy, however too much ketones in the blood alter the bloods Ph causing metabolic acidosis (ketoacidosis)
glycogenolyisis also takes place independent of the above factors, here glycogen is broken down for glucose which is good as well.
However, although we were successful in producing more glucose, we cant use the glucose because of the lack of insulin, therefore we have hyperglycaemia.
Now, for the clinical presentation of diabetic ketoacidosis. One will have abdominal pain, nausea, and vomiting. These are caused by the release of inflammatory cytokines (released after lipolysis) causing irritation of the gut. After this vomiting dehydration occurs, but in ketoacidosis dehydration is severe. This is made worse with hyperglycaemia. Why? Because, with hyperglycaemia will not be able to reabsorb all of the glucose, causing glucosuria. When there is glucoseuria, glucose is osmosmotically active therefore it will suck more water with it and releasing it in the urine, thus less water levels in the body, thus dehydration (osmotic diuresis). Dehydration causes altered mental status, which is made worse with metabolic acidosis caused by increased ketone levels in the blood. Metabolic acidosis, if severe enough, can cause cardiac arrhythmias or abnormal heart rhythms that can be fatal.
Patient with MI and is found to have hyperglycaemia
Give insulin infusion then consider management of diabetes
