Diabetes Mellitus Flashcards
What is diabetes mellitus?
Elevated blood glucose concentration (hyperglycaemia) which leads to damage of small and large blood vessels causing cardiovascular disease
Three main presentations of diabetes mellitus
Polyuria
Polydipsia
Weight loss
Why do people with diabetes present with polydipsia + polyuria?
- hyperglycaemia overwhelms the kidneys
- glucose levels in urine + draws water out
- this causes polyuria + dehydration
- dehydration causes polydipsia
Diagnosis of diabetes
Lab tests:
- oral glucose intolerance test
- HBA1c >48mmol/mol (6.5%)
- fasting glucose >7mmol/L
Symptoms + 1 abnormal test or asymptomatic + 2 abnormal tests
What is the difference between [glucose] + HbA1c?
- [glucose]: immediate measure of glucose levels in that current moment in time
- HbA1c: % of glycated haemoglobin - average blood sugar over the last 3 months
What are the blood glucose levels for:
- non diabetic
- pre diabetic
- diabetic
- non diabetic: <5.5mmol/L
- pre diabetic: 5.6-6.9mmol/L
- diabetic: >7mmol/L
Compare and contrast the feature of type 1 and type 2 diabetes
Type 1:
- Childhood
- Sudden onset
- Ketoacidosis
- No C peptide - insulin not produced
- Autoimmunity
- Recent weight loss
Type 2:
- Middle age
- Gradual onset
- Non-ketoacidosis
- C-peptide detectable - insulin still produced
- Not autoimmunity
- Often no weight loss
What is type 1 diabetes?
Autoimmune disease
Destroys beta cells in pancreas which secretes insulin
Presentation of diabetes mellitus type 1
- Rapid onset weight loss
- Polyuria
- Polydipsia
- Presence of ketones > acetone smell on breath
- Increased venous plasma glucose
- Vomiting due to ketoacidosis in late presentation
Management of type 1 diabetes mellitus
- s.c. insulin
- monitoring dietary carb intake
- monitor blood sugars upon waking, at each meal + before bed
- monitor + manage complications - regular clinics
- pancreas/islet transplant
- closed loop system/artificial pancreas
What is a closed loop system/artificial pancreas?
combination of continuous glucose monitoring + insulin pump
- devices communicate to automatically adjust insulin based on glucose readings
What is the basal bolus regime of insulin?
involves a combination of a:
- basal/long acting insulin once a day
- bolus/short acting insulin 30 mins before each meal
Advantages + disadvantages of insulin pumps
Advantages:
- better blood glucose control
- more flexibility with eating
- less injections
.
Disadvantages:
- difficulties learning to use the pump
- must be attached at all times
- blockage in infusion set
- risk of infection
Two types of insulin pumps
- tethered pumps: replaceable | attach to patient’s belt or waist with tube connecting to the pump
- patch pump: disposable | sits directly on the skin
What is type 2 diabetes?
combination of insulin resistance + reduced insulin production
Pathophysiology of type 2 diabetes mellitus
- repeated exposure to glucose + insulin makes the cells resistant to the effects of insulin
- more insulin is required to simulate glucose uptake in cells
- over time the pancreas becomes fatigued + damaged > reduced insulin output
Risk factors of type 2 diabetes
- older age
- ethnicity (black african, Caribbean, south asian)
- family history
- obesity
- sedentary life style
- high carb diet
Presentation of type 2 diabetes
- Polyuria
- Polydipsia
- fatigue
- opportunistic infections e.g. thrush
- slow wound healing
- acanthosis nigricans
What is acanthosis nigricans?
velvety darkening appearance of the skin
often at the neck, axilla + groin
associated with insulin resistance
What is the HbA1c for pre-diabetes + diabetes?
- pre diabetes: 42-47mmol/mol (5.7-6.4%)
- diabetes: >48mmol/mol (6.5%)
management of type 2 diabetes
- weight loss
- exercise
- low glycaemic index, high fibre diet
- a structed education program
- antidiabetic drugs
- monitoring + managing complications - clinics
Pharmacological management of type 2 diabetes - step wise
- first line: metformin
- add SGLT-2 inhibitor once settled on metformin if existing CVD or heart failure
- if GI adverse effects with metformin, trial modified release
- second line: add sulfonylurea, pioglitazone, DPP-4 inhibitor or SGLT-2 inhibitor
- third line: triple therapy (*metformin + 2 second line drugs) | insulin therapy
Treatment targets of HbA1c for new type 2 diabetics + those with >1 antidiabetic medications
- new: 48mmol/mol (6.5%)
- >1 antidiabetic drug: 53mmol/mol (7%)
Monitoring of diabetes
- HbA1c every 3-6 months
- capillary blood glucose (finger prick test)
- flash glucose monitoring: e.g FreeStyle Libre
- continuous glucose monitoring
Outline flash glucose monitoring
example
- uses a sensor on the skin that measures glucose level of interstitial fluid in the s.c. tissue
- 5 min lag behind blood glucose
- to read results, phone is swiped over sensor to collect reading
- replacement sensor ever 2 weeks
- FreeStyle Libre
Acute complications of diabetes
Hyperglycaemia:
- metabolic decomposition
- diabetic ketoacidosis in type 1
- hyperosmolar hyperglycaemic syndrome in type 2
.
Hypoglycaemia:
- coma - brain is glucose dependent
Chronic complications of diabetes
Macro and micro vascular disease
Macro vascular disease:
- stroke
- heart attack
- hypertension
- peripheral ischemia > diabetic foot ulcers
Micro vascular disease:
- retinopathy
- nephropathy
- peripheral neuropathy
How to recognise diabetic retinopathy
- blurred/fluctuating vision
- floaters or dark spots in visual fields
- fundoscopy findings
Fundoscopy findings of diabetic retinopathy
- hemorrhages - red spots
- hard exudates - yellow plaques
- cotton wool spots - ischaemia
- micro-aneurysms
- new vessels on retina
What is proliferative diabetic retinopathy?
Insufficient retinal perfusion results in the production of vascular endothelial growth factor (VEGF) which results in the development of new vessels on the retina (neovascularisation).
Management of diabetic retinopathy
- control blood glucose
- control blood pressure
- regular follow up
- smoking cessation
- injections of anti-vascular endothelial growth factor into the eye
- pan retinal photocoagulation
What does pan retinal photocoagulation on fundoscopy?
clusters of burn marks on retina created by the laser during treatment
Drug management of CKD in diabetes patients
ACR >3: ACEi
- ACR >30: SGLT-2 inhibitors
Pharmacological options for neuropathic pain in diabetes
- amitriptyline: tricyclic antidepressant
- duloxetine: SNRI antidepressant
- gabapentin: anticonvulsant
- pregabalin: anticonvulsant
Management of diabetic foot ulcers
- assess wound + classify
- control blood glucose
- offloading pressure e.g. total contact cast
- ensure wound is kept clean + moist
- antibiotics if infected
- daily foot inspection
- encourage well fitting shoes
- regular foot clinics
Infection related complications of diabetes mellitus
- UTIs
- pneumonia
- skin + soft tissue infections (esp. in feet)
- fungal infections e.g. oral + vaginal candidiasis
What suppressed ketone production?
Insulin
What is needed in the presence of ketones?
Immediate insulin therapy
Why do patients with type 1 diabetes need immediate referral?
- insulin suppressed ketone production
- lack of insulin > ketones produced
- ketoacidosis if not treated rapidly
What is metabolic syndrome?
Group of the most dangerous risk factors of cardiovascular disease:
- diabetes + raised fasting plasma glucose
- abdominal obesity
- hypertension
- high cholesterol
What is needed for a person to have metabolic syndrome?
Waist >94 cm for men >80 cm for women
PLUS 2 from:
- raised triglycerides
- reduced HDLs
- raised fasting blood glucose
- raised blood pressure
What causes metabolic syndrome?
Insulin resistance
Central obesity
Genetics
Inactivity
Ageing
Why does insulin need to been given as an injection not orally?
Insulin is a peptide hormone
it would get broken down in GI tract into amino acids if it was taken orally
What is hyperosmolar hyperglycaemic state?
- Rare complication of DM2
- Characterised by hyperosmolality, hyperglycaemia + absence of ketones
What characterises hyperosmolar hyperglycaemic state?
- Hyper osmolality (water loss > very conc. blood)
- Hyperglycaemia
- Absence of ketones
What distinguishes DKA + hyperosmolar hyperglycaemic state?
Absence of ketones in HHS
Presentation of hyperosmolar hyperglycaemic state
- polyuria
- Polydipsia
- weight loss
- dehydration
- tachycardia
- hypotension
- confusion
Treatment of hyperosmolar hyperglycaemic state
- IV fluids
- careful monitoring
- involve seniors
What test can be done to work out if insulin is from an endogenous or exogenous source?`
serum C-peptide
Outline the form insulin is released in by the pancreas to insulin that is used in the body
preproinsulin > proinsulin > insulin + C-peptide
Presentation of diabetic ketoacidosis
- sweet smelling breath
- dehydrated
- hyperglycaemia
- potassium imbalance
- metabolic acidosis
- N+V
- altered consciousness
- hypotension
When should you suspect diabetic ketoacidosis?
- blood glucose >11mmol/L
AND - polyuria, Polydipsia, abdominal pain, lethargy, acetonic breath, confusion
Diagnosis of DKA
Hyperglycaemia
Ketosis >3mmol/L
Acidosis
Test results which suggest diabetic ketoacidosis
- +++ ketones in urine or blood
- venous blood pH <7.3
- HCO3 <15mmol/L
- hyperglycaemia >11mol/L
- (potassium imbalance)
What are possible precipitating factors to diabetic ketoacidosis?
Infection
Trauma
Non adherence to insulin treatment
Drug drug interactions
Treatment of diabetic ketoacidosis
FIG PICK
- IV Fluids
- Insulin infusion
- Glucose monitoring
- add Potassium to fluids + monitor
- Infection: treat any underlying cause
- Chart fluid balance
- monitor Ketones, pH + bicarbonate
Complications during DKA treatment
- hypoglycaemia
- hypokalaemia
- cerebral oedema
- pulmonary oedema
What is the target HbA1c of a someone with type 2 diabetes?
48mmol/mol (6.5%)
Or 53mmol/mol (7%) if at risk of hypoglycaemia
Screening for diabetic retinopathy
How often is this done?
Diabetic eye screening at diagnosis
Every 2 years if at low risk, every year otherwise
Factors affecting accuracy of HbA1c
- anything that affects lifespan of RBCs
- increased HbA1c: iron/B12 deficiency, splenectomy, CKD (due to reduced EPO), alcoholism, high doses of aspirin
- decreased HbA1c: B12/iron/EPO injection, chronic liver disease, splenomegaly, RA, pregnancy
Autonomic complications of diabetes
- postural hypotension
- ED + sexual dysfunction
- bloating, nausea, vomiting
- reduced sweating
- urinary symptoms - hesitancy, reduced frequency, urinary retention
