Diabetes Mellitus Flashcards
What is required to diagnose Type 1 DM?
Unequivocal hyperglycaemia with acute metabolic decompensation OR
Repeated measurements that are abnormal OR 1 abnormal measurement + symptoms
- fasting blood glucose > 7.0 mmol/L
- casual glucose >11mmol/ L
- 2 hour post challenge glucose >11mmol/ L
What is required to diagnose impaired fasting glucose?
Fasting glucose 6.1 – 6.9 mmol/L AND
2 hour post challenge glucose <7.8mmo//L
What is required to diagnose impaired glucose tolerance?
Fasting glucose 6.1 – 6.9 mmol/L AND
2 hour post challenge glucose 7.8- 11.0 mmo//L
A symptomatic patient has a RPG >11.1 OR FPG>7.7. What is the conclusion?
DM
A symptomatic patient has a RPG<7.7 OR FPG<6. What is the conclusion?
Not DM
A symptomatic patient has a RPG 7.7-11.1. What is the conclusion?
do the LEGIT test of FPG
- If FPG is btwn 7.7-11.1 = do OGTT
- If FPG > 11.1 = DM
A symptomatic patient has a FPG 6-7. What is the conclusion?
do OGTT to confirm
- If 7.7 11.1 = DM
[Hx taking in a diabetics patient] What is the relevant history (exclude PMH, drug hx, social hx, fam hx) to take?
1) Duration of DM
2) Type 1/ 2 DM
3) Diagnosis
- What were the presenting symptoms at that time?
- When was it diagnosed?
- How was diagnosis made: if he remembered fasting/ drinking any sweet drinks
4) Control
- Home capillary glucose monitoring?
- Last HbA1c?
- Symptoms of hyperglycemia: polyuria, polydipsia, nocturia, LOW?
- Regular follow up?
5) Compliance / Current Management
- Follow-up: where, who, frequency
- What drugs are you taking?
- Do you take your drugs regularly?
- Compliance to medications and follow-up 🡪 if not, why?
- Regular foot and eye screening
- What is your diet like? Do you exercise?
6) Complications * ask about pre-existing complications + screen for them
[Hx taking in a diabetics patient] What are the relevant complications of diabetes to screen for in the history?
- emergencies
- microvascular
- macrovascular
Emergencies
- DKA: Polyuria, polydipsia, LOW, abdominal pain, N&V
- HHS: Polyuria, polydipsia, LOW, confusion, LOC
- Hypoglycemia: giddiness, drowsiness, tremulousness, LOC, seizure
Microvascular
- Diabetic retinopathy: blurring of vision, laser treatment
- Peripheral neuropathy: glove and stocking distribution (tends to be length dependent)
- Autonomic neuropathy: ARU, gastroparesis, early satiety, imbalance, postural hypotension
- Nephropathy: proteinuria, oliguria, anasarca (pedal edema, SOB)
Macrovascular
- IHD: exertional dyspnoea, chest pain, effort tolerance, signs of ACS
- CVD: (increased risk of stroke/ TIA!): weakness/numbness, blurring of vision, facial droop, instability, confusion, inability to express self; transient episodes?
- PAD (peripheral arterial dz): ulcers, claudication, infections
[Hx taking in a diabetics patient] What is the relevant past medical hx to ask?
Metabolic syndrome: obesity, dyslipidaemia, HTN
Women: any history of gestational diabetes, polycystic ovarian syndrome (PCOS)
DM type 1: history of associated autoimmune disorders e.g. Graves’ disease, vitiligo
Causes of 2o diabetes: Cushing’s syndrome, Acromegaly, PCOS
[Hx taking in a diabetics patient] What is the relevant drug hx to ask?
- Drug allergies
- Current medications
- TCM/over the counter drugs?
[Hx taking in a diabetics patient] What is the relevant social hx to ask?
- Occupation, shift work
- Caregiver
- Smoking
- Alcohol
[Hx taking in a diabetics patient] What is the relevant fam hx to ask?
- DM
- HTN, HLD, CVS disease, Stroke, CKD
- Other autoimmune - condition
[PE taking in a diabetics patient] What would you look out for on general inspection of a patient with diabetes?
Parameters: HR, BP (postural hypotension in autonomic neuropathy)
Age, BMI: clues of T1/T2
Evidence of dehydration (osmotic diuresis, DKA)
Signs of secondary diabetes
- Abnormal endocrine facies (eg. Cushing’s syndrome, acromegaly)
- Pigmentation (eg haemochromatosis – bronze diabetes)
Signs of autoimmune disease (eg. Vitiligo, Graves)
Signs of DKA
- Patient may be comatose/delirious due to dehydration, acidosis, plasma hyperosmolality
- Kussmaul’s breathing (deep laboured breathing seen in DKA)
[PE taking in a diabetics patient] What would you look out for on inspection of a diabetic patient’s legs?
Hairless and atrophied skin (small-vessel vascular disease and resultant ischaemia)
Superficial skin infections
- Boils
- Cellulitis
- Fungal infections
Diabetic dermopathy: Small rounded plaques with raised borders lying in a linear fashion over shins
Necrobiosis lipoidica diabeticorum
- Yellowish brown plaques usually found over shins; surrounded by red active margin
- Plaques may ulcerate
Charcot’s joints
- Grossly deformed disorganised joints
- Due to loss of proprioception or pain or both 🡪 causing recurrent & unnoticed injury
Ulcers (toes or pressure areas of feet due to ischaemia + peripheral neuropathy)
[PE taking in a diabetics patient] What would you palpate on palpation of a diabetic patient legs?
Palpate injection sites for:
- Fat atrophy
- Fat hypertrophy
Check for peripheral vascular disease
- Feel for peripheral pulses
- Temperature of feet
- Capillary return
Neurological examination
- Assess formally for peripheral neuropathy including dorsal column loss (diabetic pseudotabes) – will cause loss of proprioception, light touch, pain
- DM causes predominantly sensory loss
- Because Diabetic Neuropathy is length dependent and sensory axons are longer than motor
- Motor function generally maintained
Tap reflexes – reduced/ absent
[PE taking in a diabetics patient] What would examine for in a diabetic patient’s upper limbs?
Signs of Hyperlipidaemia: xanthelasma
- Nails: signs of Candida infection
- Acanthosis Nigricans (axilla; related to severe insulin resistance)
- Blood pressure lying and standing (diabetic autonomic neuropathy causes postural hypotension)
[PE taking in a diabetics patient] What would examine for in a diabetic patient’s eyes?
Signs of Hyperlipidaemia: xanthelasma
Test visual acuity (retinal disease, glaucoma, cataract)
Fundoscopy
1) Rubeosis (new blood vessel formation over iris 🡪 cause glaucoma)
2) Cataracts
3) Non-proliferative retinal changes: Micro-aneurysms, Dot /blot haemorrhages, Cotton wool spots, Hard exudates
4) Proliferative changes (in response to ischaemia in retina): New vessel formation, Vitreal haemorrhage, Scar formation, Retinal detachment, Laser scars (small brown or yellow spots)
Cranial Nerves
- Diabetic CN 3 palsy from ischaemia which spares pupil
- Other CNs may be affected by CVA
- Rhinocerebral mucormycosis: periorbital, perinasal swelling and CN palsies
[PE taking in a diabetics patient] What would examine for in a diabetic patient’s ears?
Malignant otitis externa usually due to Pseudomonas aeruginosa
[PE taking in a diabetics patient] What would examine for in a diabetic patient’s mouth?
Evidence of Candida infection
[PE taking in a diabetics patient] What would examine for in a diabetic patient’s neck and shoulders?
Examine carotid arteries for evidence of vascular disease
Scleroedema diabeticorum: diffuse cutaneous infiltration causing bilateral thickening (+ reddening) of skin of upper back and shoulders
Acanthosis nigricans a/w insulin resistance
- Dark patches of skin, may have odour
- Found in skin folds: posterior and lateral folds of the neck, the armpits, groin, navel, forehead etc
- a/w hyperinsulinemia 2’ to IR
Goitre due to grave’s (a/w T1DM)
[PE taking in a diabetics patient] What would examine for in a diabetic patient’s abdomen?
Palpate for hepatomegaly (fatty infiltration, or due to haemochromatosis)
Lipodystrophy – excessive loss of fat and inability to produce it properly
What are the investigations to be performed in a diabetic patient?
Rule out secondary Causes
- 24-hour urine cortisol / Dexamethasone suppression test: for Cushing’s
- IGF1 levels: for acromegaly
Confirming Diagnosis
- Fasting glucose
- OGTT
To assess control: HbA1c
Complications
- Urine Albumin/Cr ratio (or UPCr) 🡪 positive indicates diabetic nephropathy. Since albumin and Cr fluctuates based on hydration, by taking Cr into consideration 🡪 negatives fluid status
- UECr / Rena panel: assess for CKD
- Fundoscopy
- Nerve testing / Diabetic Foot Screen
- Ankle- brachial index (ABI): simple, noninvasive, widely used test that detects peripheral arterial disease (PAD)
- ECG +/- Trops if symptomatic
- Lipids, BP
What can cause falsely low HbA1c?
Increased RBC turnover, Hypersplenism, Blood loss, Anaemia, Blood transfusion
