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Understanding Diabetes

Final Year CUCMS

Teaching module

Dr Nor ShuhailaHPJ

What is diabetes?

• Condition with elevated blood glucose

• Diabetics have sugar lying around in their circulation but are unable to utilize it fully due to certain factors:-o No insulin or not enough

insulino Enough insulin but

unable to function well o Insulin resistance

GLUCOSE HOMEOSTASIS

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Classification (WHO)• Type 1 (5-25% of cases): Pancreatic islet cell deficiency

– Autoimmune (anti-glutamic acid decarboxylase, islet cell and insulin antibodies

– Idiopathic

• Type 2 (75-95% of cases): Defective insulin action or secretion– Insulin resistance– Insulin secretory defect

• Others:-– Genetic defects of cells function

• Maturity Onset Diabetic of the Young (MODY) – chromocomal defects

– Genetic defects of insulin action• Leprechaunism

– Diseases of exocrine pancreas• Pancreatitis• Pancreatectomy

– Secondary DM (Cushing’s, Acromegaly, Phaeochromocytoma etc)

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The Development of Type 2 Diabetes

Causes of type 2 diabetes

Genetically induced cell mal function and/ or insulin resistance

Mi ld hyperglycaemia

Obesity Environmentalfactors

Type 2 DM

cel l

malfunction Insulin res istance

Who is at risk? Case

• Mr. AB, 40 yr old man

• No past history of any illness

• On routine annual health check advocated by his company, he was found to have a fasting blood glucose of 6.89 mmol/l.

• Upon further questioning, he has positive FH of DM– Both parents diabetics

– Elder brother, aged 54 yrs, also diabetic

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Case

• Does Mr. AB has diabetes?a. YES

b. NO

c. PROBABLY AT RISK

• How do you diagnose diabetes?

• What one other test would you recommend?

Case

• Mr. AB returned 2 weeks later for a repeat blood glucose test

– FBS 6.5 mmol/l

– OGTT 9.0 mmol/l

• So does he have diabetes?

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Case

• Mr. AB was advised to watch his diet and start cutting down his glucose intake.

• 1 year later, he presented to his private doctor near his home with 2 months history of feeling easily tired.

• What are your differentials?

Differential diagnosis of lethargy

• Anaemia

• Diabetes

• Hypothyroidism

• Chronic renal failure

• Addison’s disease

• Cardiomyopathy/ cardiac failure

• Depression

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Case

• What other questions would you like to ask Mr. AB?

Symptoms of diabetes

Complications of diabetes

• Majority asymptomatic

• 48% pts over 30 yrs of age are unaware that they have diabetes.

Complications of diabetes

• Macrovascular– Coronary artery disease

– Cerebrovasculardisease

– Peripheral vascular disease

• Microvascular– Nephropathy

– Retinopathy

– Neuropathy

– Dermopathy

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Case

• Mr. AB admitted that he has been getting up 3 to 4 times at night to pass urine.

• He is also often thirsty at those times and drinks a glass of water each time.

• He has been overweight since secondary school but has noticed that he is losing weight and feeling weak over the 2-month period.

• Despite that his appetite is excellent.

Case

• Further questioning revealed that he had been having pain in both of his feet which is worse at night; sometimes keeping him awake.

• It was burning in nature and sometimes his toes felt numb.

• His vision was blurry at times, especially in the afternoon.

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Case

• As mentioned earlier, both his parents and elder brother were diabetics. In addition, his mother was on dialysis for renal failure.

• He is not on any medications. He denies taking traditional medicines.

• He is married with 3 children.

• He smokes 10 cigarettes per day for past 15 years. He does not drink alcohol.

Assessment of the newly diagnosed patient: HISTORY

• Duration of symptoms e.g. thirst, polyuria, weight loss

• Possible secondary causes of DM e.g. acromegaly, Cushing’s

• Family history

• Presence of complication of DM

• Risk factors for developing complications egsmoking, hypertension, hyperlipidaemia

Case

• Weight 90 kg, height 160 cm. BMI?

• Pink

• Xanthelasma, no tendon xanthomata

• No Cushingoid/ acromegalic features

• BP 145/96 mmHg, PR 84 bpm reg

• CVS S1S2

• Lungs clear

• PA soft, non-tender, BS+

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Case

• No pitting pedal oedema

• Peripheral pulses all well palpable

• Reduced sensation to light touch and pin prick over the toes and dorsum of both feet up to ankles, and hands up to wrists.

• Absent ankle jerks.

• Fundoscopy: dot and blot haemorrhage.

Diabetic retinopathy The diabetic eyeBackground retinopathy

Glaucoma Cataract

Maculopathy

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The diabetic foot

Left ankle joint is deformed – Charcot’s joint.Evidence of diabetic dermopathy.Distal muscles of the lower limb are wasted.Absence of body hair.

Neuropathic and Ischaemic feet

of a diabetic.

Assessment of the newly diagnosed patient: EXAMINATION

• Body mass index (BMI)– Weight in kg divide by (height in meters)2

• Clues for secondary causes

• CVS (BP and peripheral pulses)

• Signs of autonomic and peripheral neuropathy– Postural hypotension

– Loss of ankle reflex, distal muscle wasting and sensory loss

• Eyes – for retinopathy

• Skin – dermopathy, granuloma annulare, necrobiosislipoidicadiabeticorum

Case

• What can you deduce from the history and physical examination?

• Mr. AB has symptoms of diabetes.

• Mr. AB has complications of diabetes– Retinopathy

– Peripheral neuropathy

• Mr. AB has associated co-morbidities: smoking, hypertension, hyperlipidaemia

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What investigations would you like to do for Mr. AB?

a. FBS

b. HbA1c

c. RP

d. LFT

e. UFEME

f. ECG

g. All of the above

Assessment of the newly diagnosed patient: INVESTIGATION

• Renal profile – look for renal impairment

• Liver function test – fatty liver

• Thyroid function – associated thyroid disease

• Lipid profile – diabetic dyslipidaemia

• Urine for ketones, protein and if negative, for microalbuminuria

• ECG in all type 2 diabetics

How will you manage Mr. AB?

• Non-pharmacological– Educate on diabetes (diabetes

educator)

– Diet (dietitian)

– Exercise ( at least 150 mins/ week)

– Weight loss if obese (5 – 10% over 6 month)

• Pharmacological– Oral anti-diabetic medications/

Insulin

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Aim of management Dietary advice: standard diabetic diet

• < 10% of its energy in the form of saturated fat (< 8% if hyperlipidaemic)

• < 30% from all fats• 50-60% as carbohydrate which is mostly complex

cabohydrate, high fibre• Sugar limited to about 25g/ day• Sodium content < 6 g/ day in most people or < 3g/

day if hypertensive• If overweight, reduce total intake to aid weight

reduction • Alcohol consumption (empty calories) – reduce if

overweight or hypertriglyceridaemia

Case

• Investigations are as follows:

• RBS 15 mmol/l

• FBS 9 mmol/l

• HbA1c 7.8%

• BU 5.6 Na 141 K 4.5 Creat 89

• ALT 45 AST 40 Alb 38

• TC 6.1 LDL 5.0 HDL 0.9 Tg 2.9

• UFEME prot 1+

• ECG LVH COMMENT

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Treating to target!

Case

• So Mr. AB has diabetes.

• Which medication would you give to Mr. AB?

a. Gliclazide

b. Metformin

c. Acarbose

d. Rosiglitazone

e. All of the above

Indications for oral hypoglycaemic agents

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Case

• Mr. AB was started on Metformin 250 mg BD which was increased to 500 mg BD and subsequently 1 gm BD as his blood glucose was not adequately controlled.

• At 3 months, his results were as follows:

– FBS 11.0 mmol/l

– HbA1c 8.4%

• What is the next step of management?

How many classes of OADs are there?

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Case

• Mr. AB was given combination of Metforminand Glibenclamide 1g/10 mg BD.

• HbA1c 8.5%, FBS 10 mmol/l after 3 months.

• What are you going to do?

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Insulin therapy• Required in all type 1 DM• In type 2 DM to achieve better glycaemic control or

for the relief of hyperglycaemic symptoms.• Most insulin is in a biosynthetic human form (from

yeast/ bacteria) at a standard concentration U100 (100 units/mL).

• Can be given by s/c or i/v routes.• Standard insulins come as 10ml vials for use with a

0.5 ml or 1.0 ml syringe or as 1.5 ml or 3.0 ml cartridges for use in pen devices.

• Insulin itself is unmodified/ neutral or mixed with agents such as zinc to alter its onset of action, peak effect and duration of action.

Insulin: summaryTypes of insulin Examples Peak activity (hrs) Duration of action

(hrs)

Insulin analogue

Humalog (lispro)

Insulin Apartate (Novorapid)

0.5 - 1.5

(so inject and eat simultaneously)

< 6

Short acting

(soluble insulins)

Human Actrapid

Humulin S

1- 3

Onset 30 mins after injection (so eat 20-30 mins after)

< 8

Intermediate

acting (isophane insulins)

Human insulatard

Human monotard

4 – 8

(zinc added to it)

Onset 1-2 hrs after injection.

8 – 14

Long acting Human Ultratard

Insulin Glargine (Lantus)

6 – 24

Peakless

< 36

24 hrs

Biphasic/ premixed insulins

• Combinations of soluble/ neutral and isophane insulins (mixtard)

• Amount of soluble insulin varies from 10-50%; 30% being the most popular.

• Depending on its monocomponents, onset is normally at 30 mins, peak effect at 2-6 hrs and duration 8-12 hrs.

• Insulin analogue biphasic preparation also available.

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Insulin regimes (1)• Twice daily free mixing

– 2/3 isophane, 1/3 soluble

– 2/3 of both pre-breakfast and 1/3 pre-evening meal

– problems of mixing them, pre-lunch hypos or pre-dinner hyperglycaemia.

• Twice daily fixed mixture– Mixtard 30/70 (30% soluble/ 70% isophane)

– Not ideal for pre-lunch control

– Indicated for type 2 DM with poor control.

– Reasonable starting dose 10-15 units pre-breakfast, 5-10 units pre-dinner.

Insulin regimes (2)

• Basal bolus regime– Soluble insulin/ insulin analogue pre-meals (3X) with pre-bed

isophane

– Adv: more flexible with meal times

– Larger no. of injections and need frequent capillary blood glucose monitoring.

– Reasonable starting dose e.g 4-6 iu pre-meals, 6-8 iu pre-bed.

– If on insulin analogues, 2X daily isophane needed especially if there is a long gap between lunch and evening meal.

Insulin regimes (3)

• Continuous s/c insulin infusion – Used in USA– Insulin pumps– Potential problems: pump failure, ketoacidosis and cannula

site infections.– Soluble insulin given continuously via a s/c cannula into

the anterior abdomen.

• Insulin and oral agent mixtures– BIDS – bed time insulin, day time tablets (isophane pre-

bed to give acceptable fasting sugars), starting dose 10 iu/night

– Insulin plus metformin (2g/day) – to reduce insulin requirements and improve control without further weight gain often seen if the insulin is continually increased.

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