Complications of Diabetes Flashcards
What are some acute complications of diabetes?
- hypoglycemia (most frequent in type 1)
Cause:
- taking too much insulin or oral meds
- skipping meals or eating too little
- more physical activity then usual
- alcohol consumption (decreases liver gluconeogenesis) - diabetic ketoacidosis
- hyerosmolar hyperglycemic state (HHS)
What are the autonomic and neuroglycopenic symptoms of hypoglycemia?
Autonomic:
- tremor
- palpitations
- sweating
- anxiety
- nausea
- skin pallor
- hunger
- paresthesias (tingling)
Neuroglycopenic:
- difficulty concentrating
- dizziness
- weakness
- drowsiness
- irritability
- blurred vision
- confusion
- seizure
- loss of consciousness
What are the severity levels of hypoclycemia?
- mild - autonomic symptoms. Able to self-treat.
- moderate - auto and neuro symptoms. Able to self-treat.
- severe - requires assistance. May lose consciousness. PG is typically <2.8mmol/L.
What are the normal responses to hypoglycemia in the body?
- decrease insulin secretion.
- increase glucagon secretion
- increase in catecholamine release
2+3 = gluconeogenesis and glycogenolysis.
- also triggers symptoms which leads to treatment.
What is hypoglycemia unawareness?
- autonomic symptoms absent d/t:
1. autonomic dysfunction in patients with long-standing diabetes
2. frequent hypoglycemia that decreases the normal response to hypoglycemia
How do you treat hypoglycemia?
15g of glucose ingested or glucagon injection or glucose gel tablet if unconscious.
What are some causes of hyperglycemia?
- infection
- diet changes
- stress (emotional and physical)
- not taking medications as prescribed
- drug interactions
- disease progression
Somogyi effect (low glucose overnight and then a sudden increase at dawn with a surge in hormones)
What is diabetic ketoacidosis and its main causes?
An acute life-threatening condition, mainly affecting people with type 1 diabetes.
Main causes:
1. inadequate insulin therapy
2. new-onset type 1 diabetes or ketosis-prone diabetes
3. stress or illness (sympathetic response)
4. drugs that stimulate glucose metabolism
What are the defining features of DKA?
- hyperglycemia (>14mmol/L)
- ketone synthesis resulting in…
- metabolic acidosis (arterial blood pH <7.3
What are the manifestations of DKA?
- polyuria, polydipsia
- dehydration (can cause hypotension and tachycardia)
- electrolyte imbalances (Na and K lost in urine and vomit)
- abdominal pain, nausea and vomiting (not well understand)
- Kussmaul respirations (compensation for acidosis)
- fruity breath (ketones)
- confusion, drowsy, progression to coma
Symptoms evolve rapidly within 24 hours.
How does the bicarbonate buffer system work?
Release of additional H+ ions to decrease increase blood pH.
What is hyperosmolar hyperglycemic state and how does it differ from DKA?
Presence of hyperosmolarity, hyperglycemia and altered mental status.
DKA also involves ketones and blood acidity.
What are advanced glycation end products (AGEs)?
Excess glucose binds to endothelial cells and basement membrane proteins forming harmful AGEs.
These cause endothelial injury and thickening and weakening of vessel walls.
Contribute to microvascular disease (damage to small blood vessels) and macrovascular disease (medium/large vessels).
In microvascular disease, what does damage to small blood vessels cause:
- neuropathy
- retinopathy
- nephropathy
What is diabetic neuropathy?
Most common microvascular disease caused by AGEs (advanced glycation end products).
50% of patients with diabetes develop peripheral neuropathy; 90% develop autonomic neuropathy
risk factors = chronic hyperglycemia, long-standing diabetes, advanced age, dyslipidemia, obesity, smoking, CKD and vascular disease.
Caused by:
1. impaired blood flow to nerves causes nerve damage.
- osmotic damage to Schwann cells affecting nerve conduction.
What is diabetic peripheral neuropathy?
Early = small sensory fibres = neuropathic pain, tingling sensations
Late = large sensory fibres = sensory deficits, loss of vibration and proprioception
Motor fibres (less common)
What is diabetic autonomic neuropathy?
Cardiovascular:
- Early = reduced HR variability
- Late = resting tachycardia, postural hypotension
- silent MI, arrythmia
NOTE: blunted autonomic symptoms such as sweating and tachycardia in response to hypoglycemia contribute to hypoglycemia unawareness.
GI:
- stomach hypomotility (gastroparesis)
- colon hypomotility (constipation)
- esophageal hypomotility (dysphagia)
Urogenital:
- neurogenic bladder (incontinence)
- erectile dysfunction, female sexual dysfunction
What happens to the brain in hyper/hypoglycemia.
BBB mostly protects the brain from hyperglycemia (although has been shown to increase the risk of cognitive impairment and dementia).
Risk to CNS is with hypoglycemia.
Describe diabetic retinopathy.
Damage to small blood vessels of the retina causes microaneurysms and hemorrhage (causing edema and scarring)
A leading cause of blindness in adults
+ glaucoma and cataracts are common complications
What does macrovascular disease involve?
- coronary artery disease
- cerebrovascular disease
- peripheral vascular disease (foot ulcers and amputation)
Complications of chronic hyperglycemia (AGEs), elevated blood lipids, and other risk factors for atherosclerosis.
