Diabetes Flashcards
What is the role of insulin (6).
Skeletal muscles
- Stimulates glucose uptake & glycogen synthesis
Liver
- Supresses hepatic glucose output (inhibits glycogenolysis and gluconeogenesis)
Adipose Tissue
- Stimulates lipogenesis (storage of fats)
- Supresses lipolysis and proteolysis
Other
- Activates ATPase - uptake of K into cells
Cells and hormones secreted in the Islet of Langergans
- Alpha cells = glucagon
- Beta cells = insulin, amylin
- Delta cells = somatostatin
Role of glucagon
- Increases hepatic glucose output (via glycogenolysis, gluconeogenesis)
- Reduces peripheral glucose uptake
- Lipolysis
- Muscle glycogenolysis
What is glycogenolysis
Breakdown of glycogen into glucose
What is gluconeogenesis
Production of glucose
What is glycogenesis
Production of glycogen (using glucose)
What is glycolysis
Breakdown of glucose into pyruvate
What is lipogenesis
Synthesis and storage of FFA and triglycerides as fat in liver and adipose tissue
CHO metabolisms in fasting state
- Glucose from LIVER delivered to insulin-independent tissues (brain, RBCs)
- Insulin levels are low - this is sufficient to prevent breakdown of fat in insulin-sensitive tissues
- Muscles use FFA for energy
CHO metabolism after feeding state
- Rising BGL after eating stimulates insulin secretion and supresses glucagon
- Ingested glucose helps replenish glycogen stored in liver and muscle
What is Diabetes Mellitus?
Disorder of CHO metabolism characterised by hyperglycaemia
Name 8 complications of DM
- Microvascular (retinopathy, nephropathy, and neuropathy)
- Macrovascular (IHD, peripheral vascular disease, and CVD)
- DKA
- HHS
- Hyperglycaemia
- Other autoimmune disorders
- Opportunistic Infections
- Psychological complications, reduced QoL & life expectancy
Describe pathophysiology of DKA and why may you get hyperkalaemia
Ketoacidosis
- Shortage of insulin & hyperglycaemia
- Inc lipolysis (breaks down fat–>FFA)
- FFA is used as alternative energy source
- Liver uses FFA to produce ketone bodies
- Ketone bodies are used for energy but inc acidity of the blood (ketoacidosis)
Hyperkalaemia
- Extra H+ in blood goes to H/K pump and pumps K into blood
- Lack of insulin means reduced stimulation of ATPase so K is not pumped into cells
Signs, Symptoms, Investigations, Treatment of DKA
Signs and Symptoms
- hyperglycaemia related sx (polydipsia, polyuria, polyphagia, glycosuria)
- Osmotic diuresis
- GI upset - N+V, abdo pain, weight loss
- Fruit acetone breath
- Kussmaul breathing
Investigations
- Serum glucose and ketones
- U&E - look for hyperkalemia
- Urinalysis
- ABG - look for metabolic acidosis
- Others to consider - Chest Xray, ECG (any arrythmias)
Treatment and Management Fluid, electrolyte, insulin replacement 1. ABCDE + IV fluid must be done before insulin 2. IV insulin 3. Replacement of electrolytes
What is DKA?
(1. ) It is a medical emergency characterised by hyperglycaemia, ketonemia, acidemia (remember DKA = Diabetes, Ketonemia, Acidemia)
(2. ) Failure of lipolysis –> breaking down fat at a rate that is much too fast. The liver processes the fat into a fuel called ketones, which causes the blood to become acidic.
(3. ) More common in type 1
What is HHS? and RF?
- High serum osmolarity with little/no ketosis and extreme dehydration.
- Common in Type 2
- RF = infections, medications (diuretics, Bb, steriods), CV event, non-adherence to insulin, overconsumption of CHO.
Symptoms, Investigations, Treatment of HHS
Symptoms
- Hyperglycaemia related symptoms
- Dry mucosus mb + poor skin tugor
- Cognitive impairment (lethargy, disorientation, stupor)
- Blurred vision
- Tachycardia + Hypotension
Investigations
- BGL, ketones (rule out DKA), serum osmolarity
- ABG
Treatment
- IV fluids
- IV insulin
- Correction of electrolytes
What hypoglycaemia? And how does the body respond to this in a non-diabetic and diabetic.
- low BGL <3.9mmol/L. More common in T1DM due to over-administration of insulin.
- Normal response to hypo = protective mechanisms kick -> ADRENALIN + GLUCAGON -> INHIBITION OF INSULIN
- DM response to hypo = altered threshold leading to impaired awareness of low BGL. Body resets to 2.5mmol/L for mechanisms to kick in.