Diabetes Mellitus
Tom Salter
F1 Warwick Hospital
Clinical Scenario
This is Mr Balls he has presented to his GP feeling
tired for 3 months...
What are you going to ask?
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Follow a Hx taking pattern that’s comfortable
Narrow down to a system
Have about 5 set questions in mind
R/O serious pathology
Don’t forget social and ICE
Clinical Scenario
• 52 years old lethargic & tired 3/12
• thirsty & drinking more than normal for 2/52
• no other significant symptoms
• Hypertension on Ramipril only
• No known allergies
• Works as librarian, drinks socially, non-smoker
Clinical Scenario
What do you think is wrong with the patient?
What would you like to examine?
O/E:
• Obese (BMI 32)
• Systems examinations otherwise unremarkable
Clinical Scenario
• What are your differentials and why?
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Diabetes Mellitus
Chronic kidney disease
Diabetes insipidus
Thyroid disease (Hypothyroidism)
Clinical Scenario
Investigations
• Bedside
▫ Urine dipstick (glucose and ketones), BM, ECG
• Simple
▫ Glucose, FBC (?anaemia), U+Es (?CKD), LFTs (fatty
liver, albumin), TFT,
▫ Urine MC&S, albumin and ?PCR (?CKD)
• Radiological
▫ ?CXR, ?USS Kidney
• Special tests
▫ ?Fluid deprivation test
Clinical Scenario
Management
Remember the blurb... “Managed in an MDT
approach...”
• GP, Practice nurse, district nurses, OTs
dietician, retinal screening service, MDT diabetic
foot clinic, consultant.
• Have a rough idea what each member does!
Clinical Scenario
• Conservative
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Smoking cessation – help and advice
Lifestyle – weight loss, low GI diet, exercise
Foot care
Eye checks
• Medical
▫ Oral/Tablet control
▫ Insulin
▫ Control BP, cholesterol and other risk factors
• Surgical
▫ Islet cell transplants
▫ Rx of Complications e.g. amputation
Diabetes Medical Management
Metformin:
Mode of action
Suppresses hepatic gluconeogenesis
Increases insulin sensitivity
Effects
Reduces diabetic complications,
Reduces serum levels of LDL and Triglycerides
Particularly important in overweight pts
GI side effects, CI if eGFR <30ml (caution if <45)
Diabetes Medical Management
Sulfonylureas:
Mode of action
Increase insulin secretion by Beta cells
Need underlying insulin production
Effects
Reduce circulating glucose (risk of hypos)
Generally avoided if overweight
Increased risk of hypos if renal impairment
Diabetes Medical Management
DPP-4 inhibitors:
Mode of action
Reduce circulating glucagon levels
Effects
↑insulin secretion
↓gastric emptying ↓blood glucose
Continue only if >0.5% ↓ in HbA1c
Diabetes Medical Management
Thiazolidinediones (glitazones):
Mode of action
Activates nuclear receptors called PPARs effecting gene
transcription
Effects
Decreased insulin resistance
Increased free fatty acid & glucose metabolism
Weight gain (↑ appetite)
Pioglitazone only now (Rosi. ↑ CHD and MIs)
Diabetes Medical Management
Insulin
NICE recommends (3)..
Cont. Metformin & Sulfonylurea
1st: Intermediate NPH (porcine) insulin ON or BD
Or long-acting OD if difficulty injecting
2nd: Biphasic BD
particularly if HbA1c >9% or problem with hypos
3rd: Add mealtime boluses as appropriate or consider switch
to basal bolus or add thiazolidenedione
Nice T2DM Mx guidelines: http://bit.ly/GIVIAW
Insulin in Type 1
• How does the insulin Mx differ?
▫ Loss of intrinsic insulin secretion – Basal-bolus
insulin or S/C pumps needed
▫ Usually a younger presentation
▫ S/C pumps may allow a more normal daily routine
▫ Pumps require good compliance
Diagnosis Criteria
• What are the diagnostic criteria for diabetes?
▫ Fasting Glucose level >7.0 mmol/L
▫ Random Glucose level >11.1 mmol/L
▫ One reading if symptomatic or two if
asymptomatic
▫ Also now HbA1c of 48 mmol/mol (6.5%) can be
used for diagnosing diabetes (<6.5% does NOT
exclude the diagnosis)
Diagnosis Criteria
• Impaired Glucose Tolerance
▫ 7.8 mmol/L - 11.0 mmol/L
▫ 2 hours post 75g oral glucose tolerance test
▫ Greater risk of CVD and DM than IFT
• Impaired Fasting Tolerance
▫ 6.1 mmol/L - 6.9 mmol/L
▫ Fasting serum glucose
Prognosis
• 75% of those with T2DM will die of heart disease
• 15% of a CVA
• The mortality rate from CVD is 5x higher in
those with DM (1)
• Over 60% of T1DM patients will NOT suffer
serious complications. Especially if no
complications by 10- 20 years post-diagnosis (5)
Complications of Diabetes
• Cardiovascular:
▫ Ischaemic heart disease, Cerebrovascular disease,
Peripheral vascular disease
• Renal:
▫ Diabetic nephropathy caused by hyperfiltration of
glucose and atheromatous changes to the blood
vessels of the kidneys
Complications of Diabetes
• Neuropathic:
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Neuropathy of any nerve!
Autonomic (GU, GI, postural hypotension)
peripheral sensorimotor e.g glove and stocking
mononuritis incl. CNs
Charcot’s foot, diabetic ulcers
PAIN
Complications of Diabetes
• Retinopathy:
▫ Background
▫ Pre-proliferative
▫ Proliferative
• Maculopathy:
Acute complications
HONK
▫ a hyperosmolor hyperglycaemic non-ketotic state
▫ T2DM
▫ Usually as a result of dehydration and illness
▫ Inability to take diabetic medication
▫ Symptoms weakness, cramps, visual impairment,
confusion seizures +/- nausia & vomiting (less
than DKA)
Acute complications
HONK
Management:
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A-E approach
Fluid resuscitation with normal saline
Electrolyte replacement esp. potassium
Insulin (aiming for SLOW reduction of serum
glucose, approx 3mmol/hr)
▫ Senior guidance for insulin sliding scale
▫ VTE prophylaxis
Acute complications
DKA
▫ Ketonaemia (>3 mmol/L), or ketonuria (>2+)
▫ Bicarbonate <15 mmol/L or venous pH <7.3
▫ Blood glucose >11 mmol/L or known DM (not a
good indicator of severity)
▫ Caused by infections, non-compliance, acute
illnesses (e.g. PEs, thyroid disease etc), CVD/MI
Acute complications
DKA
Symptoms:
polydipsia, polyuria, nausea & vomiting, abdominal pain
Management:
Correct dehydration with IV crystaloids
Reduce glucose 3mmol/L/hour
Regularly monitor potassium (ECG)
Do not routinely give bicarbonate or phosphate
Treat the underlying illness
Continue to monitor fluid balance & electrolytes 1-2 hourly
Summary
1. Diagnosis >7.0mmol/L (fasting)
>11.1mmol/L (random)
2. Minimise risk factors and maintain tight
control
3. Diabetes complications: Heart, Kidneys, Eyes &
Nerves PLUS DKA in T1DM, HONK in T2DM
References
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http://www.patient.co.uk/doctor/diabetes-mellitus
http://www.patient.co.uk/doctor/management-of-type-2-diabetes
http://bit.ly/GIVIAW (NICE)
http://bit.ly/GKfqM1 (NICE)
http://emedicine.medscape.com/article/117739-overview