Endo top tier Flashcards
diabetes type 1 vs type 2
T1DM - insulin deficiency
T2DM - ineffective insulin + deficiency
diabetes diagnosis
fasting glucose: 7.0mmol/L
random glucose: 11.1mmol/L
OGGT: 11.1mmol/L
Hb1AC : 48mmol/mol , 6.5%normal
C peptide (down in type 1, normal in type 2) autoantibodies (present in type 1, not in type 2)
pre diabetes diagnosis
fasting glucose: 5.6-7.0
random glucose: 7.8-11.1
OGGT
Hb1AC: 42-47mmol/mol, 6-6.5%normal
fasting glucose test =
only water for 8 h
OGTT=
2 hours oral glucose tolerance test. 75g sugar drink given. blood taken 1 and 2h later
hb1ac =
proportion of haemoglobin with glucose stuck to it– measure of glucose levels over the last 2-3 months
type 1 vs type 2 diabetes symptoms
Type 1 symptom onset is acute
Type 2 symptom onset is gradual
diabetes symptoms
- Polydipsia, thirst
- Polyuria- nocturia, glycosuria, ketonuria
- Fatigue
- Dry skin
- Weight loss - lipid and muscle loss due to unrestricted gluconeogenesis
- Hunger - lack of usable energy source
- Infections
- – Recurrent thrush
- – Poor healing of wounds
- Blurred vision, esp at night (due to glucose/water in lens)
- Breath can smell of acetone smell (nail polish remover)/ pear drops (ketones- esp type 1
- Acanthosis nigricans = blackish pigmentation at the name of the neck and in the axillae – severe insulin resistance in DMT2
type 1 diabetes pathophysiology
Insulin deficiency due to autoimmune destruction of beta cells
— autoantibodies against insulin and islet cells
(high glucagon, more lipolysis, glycolysis, gluconeogensis, decreased peripheral glucose uptake, increased muscle breakdown)
so increased glucose conc, increased glucose lost in urine
Healthy at birth but damage to beta cells over time, eventually diabetes
type 1 diabetes untreated
high glucagon, high glucose
weak - muscle broken down
fat broken down (oxidised to ketone bodies)
prone to ketoacidosis
diabetes type 1 signs from investigations
dehydration
low BP
high levels of islet autoantibodies
no C peptide present (from pancreas)
diabetes type 1 risk factors
Northern european - especially finnish
Family history (HLA-DR3 , maybe other DRs?)
Associated with other autoimmune diseases (eg coeliac, graves, addison’s etc)
Vitamin D deficiency
ketoacidosis
free fatty acids and glucose levels high
these form acetyl coA
so increased ketones
ketones are strong acids so low blood pH. this impairs the ability of haemoglobin to bind to oxygen (dissoc curve shifted to the right)
+ pH dependant enzymes less effective
+ metabolic acidosis (high h+, low HCO3-)
+ breath smells of pear drops (=ketones)
causes of ketoacidosis
- Unknown, idiopathic
- Infection
- MI
- Treatment errors
- Undiagnosed diabetes (esp type 1)
Not really type 2, as even a small amount of insulin can halt breakdown of fat and muscle into ketones. So therefore, can occur in the very late stages where there is absolute insulin deficiency - Stopping insulin therapy
- Surgery
- Pancreatitis
ketoacidosis symptoms
Acute Polyuria Polydipsia , thirst May be unable to pass urine if not high water intake nausea , vomiting Weight loss Abdominal pain drowsiness/ confusion Weakness
ketoacidosis SIGNS
- Hyperventilation : Kussmaul’s respiration (deep rapid breathing)
- Dehydration: Urea and creatinine raised
- Hypotension
- Tachycardia
- Conscious disturbance, coma
- Breath smells of pear drops (ketones)
- Low body temperature
- Glycosuria, ketonuria
- Raised wbc maybe
ketoacidosis management
1 ABC (airways, breathing, circulation) 2 rehydration . no delay. In order to dilute acid and glucose 3 Insulin -- Stop new ketone production -- Stop glucose production in liver -- Lower glucose - convert to glycogen -- Monitor glucose 4 replace k+ -- Electrolytes -- K+ seems high (serum levels), but acc is in deficit because it moves out of cells to serum due to acidosis. It falls further with the rehydration (step 1) 5 Treat underlying cause
type 2 diabetes pathophysiology
- Impaired insulin secretion and insulin resistance in muscle and fat
- Beta cell mass reduces
- May have high levels of circulating insulin at the beginning, due to high levels of glucose from liver and reduced uptake– but this insulin is ineffective and inadequate at restoring hyperglycaemic state.
Then levels decrease due to secretory failure.
So insulin deficiency relative to increased demands causes hypersecretion by depleted beta cell mass → progresses to absolute insulin deficiency (where levels are low (not only relatively))
what is the viscous cycle of insulin resistance ? which type of diabetes
type 2
impaired glucose secretion (less insulin) and insulin resistance in muscle and fat (less effective insulin)
this causes impaired glucose tolerance, take up and clearance
this causes hyperglycaemia, this worsens glucose secretion and insulin resistance
diabetes risk factors
Modifiable:
- Obesity- high fat levels
- High cholesterol levels
- Sedentary lifestyle
- Low activity levels/ exercise
- Smoking
- High blood pressure
- medications - thiazide diuretic with beta blocker
Non–modifiable:
- Race: south asians, Chinese, middle-eastern, African-Caribbean or black African origin
- Gender (male>female)
- Genetic disposition
- Family history of diabetes
- Low birth weight
- History of gestational diabetes
gestational diabetes inc risk factors
- high blood sugar when foetus in pregnancy, usually disappears after birth
- Likely to have this if mum is overweight, south Asian, Black, African-Caribbean or Middle Eastern origin, had pregnancies with previous gestational diabetes/ large baby
- 40 yrs +
MODY=
MODY = maturity onset diabetes of youth
Dominant
type 2 risk factor
‘typical’ type 1 vs type 2 presentation
1 symptoms sudden young lean associated with other autoimmune diseases
2 symptoms sudden 30y+ overweight familial hypercholestrolemia often present hypertension alcohol family history
peptide C diabetes
from pancreas
not present in type 1
yes present in type 2