Type 2 Diabetes Mellitus

Question 1

how is it diagnosed?

Answer 1

a diagnosis of exclusion

• check if it’s T1DM (give insulin for life)
• check for something more unusual
• if nothing else comes up = T2DM

Question 2

who gets it?

Answer 2

prevalence of diabetes peaks at 65-69 years old in Scotland - risk increases with age
if parent has T2DM - 40% lifetime risk
9/10 people with T2DM are overweight/obese

Question 3

pathophysiology

Answer 3

polygenic common complex disease

many genetic variants contribute to risk BUT age and BMI have a huge impact

obesity and lack of activity result in adiposity - increased free fatty acids and adipokines, lead to insulin resistance (fatty acids deposited in liver and muscle)

it is a progressive disease mainly due to deterioration in beta-cell function (with a small increase in insulin resistance over time)

Question 4

effect on beta cells

Answer 4

normal beta cells - cause a compensatory increase in insulin production causing euglycaemia
vulnerable beta cells (caused by lipotoxicity) - cause an inability to respond to an produce more insulin

Question 5

what % of people with T2DM have insulin resistance?

Answer 5

90% - although insulin resistance is not just associated with DM

Question 6

what else other than DM is insulin resistance associated with?

Answer 6

hypertension
hyperlipidaemia
hyperglycaemia (even in absence of diabetes)
Polycystic ovarian syndrome (PCOS)
collectively these are known as insulin resistance syndrome

Question 7

how can it present?

Answer 7

blurred vision
recurrent UTIs
tiredness
polyuria

Question 8

what would cause a need to screen for T2DM?

Answer 8

overweight/obese
family history of T2DM
or concurrent illness e.g. glucose measure in work up for heart disease

Question 9

what is the onset of it?

Answer 9

unlike T1DM it is usually slow onset - there may be a phase of ‘prediabetes’ or frank diabetes present years before presentation

Question 10

acute presentation?

Answer 10

can present acutely with DKA

Question 11

the ‘stereotype’ patient

Answer 11

usually middle aged/elderly, though can have young onset (children/young adults) in very obese and/or high risk ethnicity
obese and sedentary although can be non-obese esp. if elderly

Question 12

do they need insulin

Answer 12

typically non-insulin dependent (but can progress to insulin dependent)

Question 13

aims of management?

Answer 13

treat symptoms

prevent microvascular complications (control glucose, aim for HbA1c <7% [53mmol/mol])

prevent cardiovascular complications (control BP, cholesterol and antiplatelet therapy)

screen for complications - early while treatable (eye disease - laser, neuropathy - podiatry, kidney disease - BP management, ACEi)

Question 14

steps of management

Answer 14

diagnosis 
therapeutic lifestyle change (10-15% weight loss can result in remission)
monotherapy 
combination therapy (not insulin)
combination therapy with insulin

Question 15

Therapeutic lifestyle - diet & exercise

Answer 15

aim for realistic targets with weight maintenance/modest weight loss (i.e. 5-10kg in one year - this can improve health outcomes)
initial guidance on healthy eating - normal intake of unrefined carbohydrate, reduce refined sugar intake, reduce fat intake, increase fruit and veg intake, reduce salt, safe and sensible alcohol consumption
encourage active lifestyle

Question 16

ideal use of lifestyle intervention

Answer 16

to prevent diabetes in the 1st place - lifestyle intervention 1/2s the odds of developing T2DM
lowering HbA1c - helps reduce CV risk/ long-term risks and helps control symptoms

Question 17

what is the target HbA1c for T2DM?

Answer 17

7.0% (53mmol/mol)
target of 6.5% may be more appropriate at diagnosis, the targets should also be considered on an individual basis in order to balance benefit and harm (esp. hypoglycaemia and weight gain)

Question 18

what factors make it harder to reach glycaemia targets?

Answer 18

younger
female
obese
not at BP or lipid targets

Question 19

when insulin treatment should be used

Answer 19

most T2DM patients produce plenty of insulin until late in disease - insulin treatment different to T1DM - less use of basal-bolus insulin therapy and more use of basal insulin
used when people fail non-insulin therapies (once daily NPH insulin (immediate acting), mixed insulin (Humulin M3) or basal/bolus (e.g. lantus/novorapid))

Question 20

drug treatments?

Answer 20

1st line = metformin (SU if intolerant) in addition to lifestyle measures
2nd line = add SU or SGLT2i or DDP-4i or pioglitazone in addition to lifestyle measures
3rd line = add another oral agent from a different class: SU or SGLT2i or DDP-4i or pioglitazone in addition to lifestyle measures
GLP-1 agonist and basal insulin can also be used

Question 21

sick day rules

Answer 21

BG normally rises in response to stress and illness
short-term hyperglycaemia can be tolerated and managed at home if no dehydration and oral fluids are being tolerated
should normally continue oral diabetes medication
severe infection or dehydration stop metformin
admit to hospital if severely dehydrated or severe (intractable) vomiting

Question 22

What medications should be stopped if major vomiting/diarrhoea or fever, sweats and shaking in T2DM patients?

Answer 22

ACEi 
ARBs
diuretics 
metformin 
NSAIDs