Week 2 Flashcards
What are the two core defects of type II diabetes?
Insulin resistance and beta-cell dysfunction
In type II diabetes: what does ectopic fat accumulation and increase FFA circulation + increase inflammatory mediators (CRP) cause?
Inhibition of insulin via serine kinases responsible for phosphorylation of insulin receptor substrate-1 (IRS-1)
What disease of females causes insulin resistance?
Polycystic ovarian syndrome
In the initial phase of type II diabetes - what do the beta cells initially compensate for?
Increasing insulin resistance
What are glucotoxicity and lipotoxicity a result of?
Insulin resistance - and they both lead to declining beta-cell function
Which of the two are more likely to get type II diabetes - apples or pears?
Apples
At time of diagnosis of type II diabetes - what four complications are commonly already present?
- Retinopathy
- Erectile dysfunction
- Neuropathy
- Nephropathy
In what way is family history relevant to type II diabetes?
50% genetic
What is the therapy staircase of type 2 diabetes?
- Diet and exercise
- Oral monotherapy - metformin
- Oral combination
- Injecting insulin
Name a biguanide?
Metformin
What class of drugs are glicazide, glibenclamide and glimeparide?
Sulphonylureas
Name a thiazolidinedione?
Pioglitazone
How does metformin work?
Improves sensitivity to insulin
What is the usual starting dose for metformin?
500mg twice a day
If a patient is struggling to tolerate metformin what can be done?
Moved to slow release tablets (XR) or start low and go slow
Does metformin reduce HbA1c?
Yes
Does metformin prevent microvascular complications and macrovascular complications>
Yes
Name two other conditions that metformin is good for other than diabetes?
PCOS
NAFLD
Give five side effects of metformin
- GI - anorexia, nausea, vomiting, diarrhoea,ando pain and taste disturbance
- Interference with vit B12 and folic acid absorption
- Lactic acidosis
- Liver failure
- Rash
When should metformin be avoided or stopped in relation to renal toxicity?
When eGFR is less than thirty ml/min or serum creatinine is greater than 150 umol/l
Half dose if eGFR 30-45 ml/min
When should metformin be discontinued in relation to liver toxicity?
When advanced cirrhosis or risk of lactic acidosis e.g. encephalopathy or alcohol excess
What is first line agent for T2DM?
Metformin
In what way is the effect of SUs better than metformin in relation to hyperglycaemia management?
Results in more rapid reduction in hyperglycaemia than insulin sensitisers
What is the main concern with SUs?
Acceleration of beta cell demise
Do SUs prevent microvascular and macrovascular complications?
Yes for microvascular but NO for macrovascular
What is there a big risk of with SUs in particular with elderly/frail, alcohol excess and liver disease?
Hypoglycaemia
What drug class is used first line in underweight T2DM because of adverse affect weight gain?
SUs
What drug class should be considered as the preferred option after metformin or in those intolerant of metformin?
SUs
What drugs are PPARgamma agonists?
Thiazolidinediones (TZDs)
Give two adverse effects of TZDs?
- Heart failure - fluid retention
2. Weight gain
What drugs increase the risk of hip fracture by 20% per year of use?
Glitazone
What is the incretin effect?
If sugar is injected through veins the insulin levels rise less than by mouth.
Name two incretins?
GIP from K cells
GLP-1 for L cells
What enzyme breaks down GIP and GLP-1?
DPP-IV
What hormones increase satiety and decrease appetitie?
Incretin hormones
What class of drugs do exenatide, exendin LAR, liraglutide and lixisenatide belong to?
GLP-1 receptor agonists
Give four benefits of GLP-1 receptor agonists?
- promote insulin secretion from pacnreas without hypoglycaemia
- Suppress glucagon
- Decrease gastric emptying
- Reduce appetite - weight loss
What class of drugs do vildagliptin, sitagliptin, saxagliptin and linagliptin belong to?
DPP-IV inhibitors
Give two benefits DPP-IV inhibitors?
- Promote insulin secretion from pancreas without hypoglycaemia
- Suppress glucagon
What class of drugs do dapagliflozin, canagliflozin and empagliflozin?
SGLT2 inhibitors
What drugs decrease uptake of sugar by about one quarter?
260g - SGLT inhibitors
Give two adverse effects of SGLT inhibitors?
- Increase in thrush
2. Urine infections
Name three insulin secretagogues?
- Sulphonylureas
- DPP4 inhibitors
- GLP-1RA
How do sulfonylureas, incretin mimetics, glinides, DPP-4 inhibitors all work?
Insulin dependent action - increasing secretion of insulin
How do biguanides and TZDs work?
Insulin dependent action - decreasing insulin resistance and reducing hepatic glucose output
How do alpha-glucosidase inhibitors work?
Slowing glucose absorption from the GI tract - insulin independent action
How do SGLT2 inhibitors work?
Enhancing glucose excretion by the kidney - insulin independent action
What does increased ATP:ADP ratio within a cell do?
Closes ATP sensitive K+ channels causing membrane depolarisation
In relation to the kATP channel what makes up the octomeric complex?
4 potassium inward rectifier 6.2 subunits (Kir6.2) and 4 sulphonylurea receptor 1 subunits (SUR1)
In relation to the kATP channel what do the tetramer of Kir6.2 subunits form?
A potassium selective ion channel
In relation to the kATP channel what do SUR1 subunits regulate?
Potassium channel activity
In relation to the kATP channel - what substance binds to each of the Kir6.2 subunits to close the channel causing depolarisation of the beta cell?
ATP
In relation to the kATP channel - what binds to the SUR1 subunit to open the channel, maintaining the resting potential and inhibiting insulin secretion?
ADP-Mg
What drugs appear to act by displacing the binding of ADP-Mg from the SUR1 subunit?
Sulfonylureas
What drugs act similarly to sulfonylreas and bind to SUR1 at a distinct benzamido site?
Glinides
When are glinides taken?
Before meals
Name a GLP-1 analogue?
Extenatide
How are incretin analogues administered?
Subcutaneously
What diabetic drugs have adverse effects of flatulence, loose stools, diarrhoea, abdo pain and bloating?
Alpha-glucosidase inhibitors such as acarbose
How does metformin work?
Reduces hepatic gluconeogenesis by stimulating AMP-activated protein kinase (AMPK)
What drug increases glucose uptake and utilisation by skeletal muscle, reduces carbohydrate absorption and increases fatty acid oxidation?
Metformin
What sort of infections can hyperglycaemia cause?
Fungal infections
How is insulin normally secreted to account for about 50% of insulin produced?
At a low basal rate
What type of insulin analogue is Levemir?
Long acting
Name a rapid acting anaolguie?
Novorapid
In relation to insulin adjustment - what is the target for pre meal?
3.9 - 7.2 (4-7) mmol/l
In relation to insulin adustment - what is the target for 1-2 hours after the beginning of a meal?
Name two classes of prandial insulins?
- Insulin analogues
2. Soluble insulin
What is the onset of action, peak action and duration of insulin analogues such as Novorapid, Humalog and Apidra?
Onset of action - 10-15 minutes
Peak action - 60-90 minutes
Duration - 4-5 hours
What is the onset of action, peak and duration of soluble insulins such as Actrapid and humulin S?
Onset - 30-60 minutes
Peak 2-4 hours
Duration - 5-8 hours
What should most patients with type I diabetes be on?
Analogue based insulin
What types of insulin are Insulatard and Humulin I?
Isophane ‘basal’ insulins - peak of activity is 4-6 hours after administration
Name two analogue based insulins?
Lantus
Levemir
Who is advanced carbohydrate counting for?
- Those on MDI
2. Those on SCII pumps
What are the two components of advanced carbohydrate counting?
- Insulin to carbohydrate ration (ICR)
2. Insulin sensitivity factor (ISF) also known as correction factor (CF)
What is the ratio of insulin: CHO?
1 unit of insulin per 10g CHO
What type of insulin do insulin pumps administer?
Short acting
What is the background insulin dictated by with insulin pumps?
Basal rate
What is a measure of average blood glucose over a prolonger period of time such as 6-8 weeks?
HbA1c
What is the HbA1c target?
48 mmol/mmol
Give four factors that affect insulin absorption/action?
- Temperature
- Injection site
- Injection depth
- Exercise
In what two conditions is IV insulin indicated?
DKA and HHS
What inheritance does MODY have?
Autosomal dominant
What are the two distinct types of MODY?
- Transcription factor (HNF-1alpha)
2. Glucokinase
What type of MODY: onset at birth, stable hyperglycaemia, diet treatment and complications are rare?
Glucokinase mutations
What type of MODY: onset as young adult, progressive hyperglycaemia, 1/3 diet, 1/3 OHA, 1.3 insulin and ocmplications are frequent?
Transcription factor mutations
When is insulin required in neonatal diabetes?
Within the first 3 months of life
What are MODY HNF1alpha sensetivie to?
SU treatment - GCK does not need treatment
What do these symptoms suggest - shaking, sweating, anxious, dizzin ess, hunger, tachycardia, impaired vision, weakness, headache and irritable?
Symptoms of hypoglycaemia
What is the immediate treatment of hypoglycaemia?
Consume 15-20 grams of glucose or simple carbohydrates and recheck BG after 15 minutes
If injection is present - what is the treatment of immediate, severe hypoglycaemia?
Glucagon 1 mg injected into buttock, arm or thigh
What is the term for a disordered metabolic state that usually occurs in the context of an absolute or relative insulin deficiency accompanied by an increase in the counter-regulatory hormones i.e. glucagon, adrenaline, cortisol and growth hormone.
Diabetic ketoacidosis
In relation to DKA pathophysiology - what four effects occur as a result of insulin deficiency and stress hormone activation?
- Lipolysis increase
- Glucose utilisation decrease
- Proteolysis increase
- Glycogenolysis increase
What is the ketonaemia for DKA diagnosis?
> 3mmol/L or significant ketonuria >2+ on standard urine stick
What is the BG for DKA diagnosis?
> 11 mmol/L or known diabetes
What is the bicarbonate for DKA diagnosis?
Give four common precipitants of DKA?
- Non-adherence with treatment
- Newly diagnosed
- Infection
- Illicit drugs or alcohol
Give two osmotic related symptoms of DKA?
- Thirst and polyuria
2. Dehydration
Give four ketone body related symptoms of DKA?
- Flushed
- Vomiting
- Abdo pain
- Kussmaul’s respiration
Is amylase raised in DKA?
Very frequently