Diabetes: Aetiology, DIagnosis and Presentation Flashcards
1
Q
2025 prediction of total number with diabetes in UK
A
> 5 million
2
Q
Typical Symptoms of Diabetes
A
Osmotic symptoms: Polyuria Polydipsia Nocturia Weight loss Fatigue Blurred vision Pruritis Recurrent UTIs/Genitourinary infections
3
Q
Why do you get osmotic symptoms in diabetes?
A
- hyperglycaemia
- glucose has osmotic effect
4
Q
What are some diabetes acute emergencies?
A
HHS = hyperosmolar hyperglycaemic syndrome DKA = diabetic ketoacidosis
5
Q
Diabetes complications
A
- skin infections = staphylococcal skin abcesses, oral, genital candidiasis
- foot problems = ulcers, neuropathic pain
- retinopathy = on routine eye test
- acute MI/stroke = whilst in hospital
6
Q
Difference in presentation of type 1 vs. type 2
A
1 = more acute, emergency 2 = subacute/insidious/non-specific
7
Q
Methods of diagnosis
A
- FPG (fasting plasma glucose)
- RPG (random plasma glucose)
- OGTT (oral glucose tolerance test)
- HbA1C
8
Q
How does OGTT work?
A
- fast for min. 9 hours
- check FPG
- give 75g glucose
- check 2 hour PG
9
Q
How does HbA1c work?
A
- glycated Hb
- measure for average glucose control over 3 month period
- normal <42mmol/mol
- depends of age/co-morbidities
- <53 mmol/mol indicates well controlled diabetes
10
Q
How to diagnose a patient with no symptoms?
A
2 diagnostic tests required (2 FPG/HbA1C) but only 1 abnormal OGTT
11
Q
How to diagnose a patient with symptoms
A
1 diagnostic test is enough
12
Q
FPG values
A
- diabetes = ≥7mmol/L
- normal ≤ 6
- impaired glucose tolerance <7
- impaired fasting glucose = 6.1-6.9
13
Q
2 hour PG values
A
- diabetes = ≥ 11.1mmol/L
- impaired glucose tolerance = 7.8-11
- normal <7.8
- impaired fasting glucose <7.8
14
Q
RPG values
A
- diabetes = ≥11.1mmol/L
- normal = ≤ 7.8
15
Q
HbA1c values
A
diabetes = ≥ 48mmol/mol or 6.5%
- normal <42/5.9%%
- impaired glucose tolerance 4.2-4.7 (6-6.4)
16
Q
Type 1 and 2 differences
A
Type 1 - ketosis prone - insulin deficient - autoimmune (GAD and ICA antibodies) - acute onset - non obese - juvenile onset <35 yrs - HLA DR3 and DR4 - FH positive in 10% - 50% concordance in monozygotic twins Type 2 - non ketosis prone - insulin resistance and or deficiency - non autoimmune as metabolic link - insidious onset - obesity associated - >35 years but common below this age - no HLA relation - FH positive in 30% - 100% concordance in monozygotic twins
17
Q
2ndry causes of diabetes
A
- pancreatic disease
- endocrine disease
- drug induced
- genetic defects of B cell function
- genetic defect of insulin action
- infections
- genetic syndromes
- gestational diabetes
18
Q
Pancreas exocrine causes of diabetes
A
- pancreatitis
- trauma/pancreatectomy
- neoplasia
- CF
- haemochromatosis/thalassaemia
- fibrocalculous pancreatopathy
19
Q
Endocrine diseases causing 2ndry diabetes
A
- acromegaly (GH)
- Cushing’s (cortisol)
- Glucagonoma (glucagon)
- Phaechromocytoma (catecholamines)
- Hyperthyroidism (thyroid hormone)
- Conn’s (aldosterone)
20
Q
Drugs inducing diabetes
A
- glucocorticoids
- Beta blockers
- thiazide diuretics
- tacrolimus (= NODAT)
- atypical antipsychotics = olanzapine, risperidone, clozapine
21
Q
Infections causing diabetes
A
Congenital rubella
CMV
22
Q
Pathogenesis of type 2 diabetes
A
- heterogenous
- environ = obesity, poor physical activity
- diabetogenic = genes contributing
- various combos of insulin resistance and beta cell failure
- exacerbated by hyperglycaemia = glucose toxicity as poorer B cell function so reduced insulin secretion so lowering glucose may help B cell function
- pro-inflammatory cytokines from adipocytes contribute from adipocytes contribute to resistance
- no autoimmunity
- B cell mass relatively preserved
- alpha cell population increased so excess glucagon relative to insulin
- post receptor insulin resistance
- late in disease = amyloid peptide deposition in pancreatic islets so dementia link
23
Q
Metabolic syndrome
A
- central obesity (waist circumference increased)
- bp abnormalities
- glucose abnormalities
- lipid abnormalities
24
Q
Who should be screened?
A
- obese/overweight
- strong FH
- history of gestational diabetes
- south Asian x 6 increased risk
- Afro-Caribbean x 2 increased risk
- known vascular disease (CHD, PVD, cerebrovascular disease)
- patients on steroids/atypical anti-psychotic therapy/transplants
- unexplained foot ulcers/recurrent candida/skin abscesses
25
Q
Aetiology of T1D?
A
- pancreatic B cell destruction
- leads to absolute insulin deficiency
- autoimmune destruction of pancreatic islets (ICA and GAD antibodies positive)
- may be antibody negative/idiopathic
26
Q
LADA
A
- latent autoimmune diabetes in aduts =
- diagnosed in adulthood
- non acute
- ICA or GAD positive
- require insulin fairly soon after diagnosis
- concordance in monozygotic twins
- environ factors = 5-7 years, puberty, seasonal variations, europid populations
