Week 7 - Endocrine Dysfunction and Diabetes Mellitus Flashcards
(18 cards)
Define Diabetes
A group of metabolic diseases with high levels of blood glucose over a prolonged period.
Define Type 1 Diabetes
Characterised by:
- Complete destruction of islet cells of the pancreas
- Inability to produce little to no insulin
Define Type 2 Diabetes
Characterised by:
- Insulin resistance at the target cells
- May progress to insufficient pancreatic insulin release and islet cell destruction.
What are the Risk Factors for Type 1 Diabetes
- Genetic
- Family history
What are the Risk Factors for Type 2 Diabetes
- Age
- Obesity
- Physical inactivity
- Ethnicity
Explain the Mechanism of Action of Insulin
- Secreted by the beta (β) cells of the pancreas
- Binds with the insulin receptor on the cell surface of the target cell.
Explain the Mechanism of Action of Metformin
- To improve insulin sensitivity, particularly in the liver and muscles.
- Reduce hepatic glucose production
What is the Pathophysiology of Type 1 Diabetes
- Lack of insulin caused by loss of beta cells
- Destruction of islet cells is related to genetic susceptibility, autoimmunity and environmental factors.
- Non-autoimmune type 1 diabetes can occur secondarily to other diseases such as pancreatitis.
Provide an Acute Complication of Type 1 Diabetes
Diabetic Keto-Acidosis (DKA)
- Infection or another metabolic demand for insulin but no insulin is produced or administered
List and Explain four symptoms of Type 1 Diabetes (DKA)
Polyphagia:
- Increased hunger which occurs because glucose do not enter cells which results in cells deprived of nutrients.
- This stimulates increased food intake.
Polyuria;
- Increased urine production due to Glucose in urine
- Glucose in the urine which leads to the osmotic effect in urine which draws water into the urine from the bloodstream.
Polydipsia:
- Increased thirst due to polyuria and dehydration.
Ketoacidosis:
- Increased metabolism of fats & proteins which leads to high levels of circulating ketones
What is the Pathophysiology of Type 2 Diabetes
- Insulin secretion by the pancreas increases to compensate for insulin resistance in peripheral tissues → hyperinsulinaemia.
- Continued overproduction leads to fatigue of pancreatic beta cells, reducing their insulin output.
- Over time, beta cells undergo apoptosis, resulting in a severe lack of insulin.
- This leads to persistent hyperglycaemia.
Provide an Acute Complication of Type 2 Diabetes
Hyperglycaemic Hyperosmolar State (HHS):
- Sufficient insulin to prevent breakdown of fat stores for production of glucose > ketoacidosis is avoided > hence blood pH can remain normal
List and Explain four symptoms of Type 1 Diabetes (HHS)
- High BGL
- Delirium
- Loss of Consciousness
- Polydipsia
- Polyuria
List three Chronic Complications Associated with Type 2 Diabetes
- Microvascular complications
- Macro-vascular complications (associated with larger diameter vessels)
- Neuropathies
What is the Pathophysiology of Microvascular
Microvascular Complication -Diabetic Nephropathy:
- High glucose levels damage glomerular capillaries, causing protein denaturation and hardening of the glomeruli, reducing blood flow.
- This leads to progressive kidney damage and may result in renal failure.
What is the Pathophysiology of Macrovascular
Macrovascular Complication - Cardiovascular Disease:
- Chronic hyperglycaemia causes a pro-inflammatory state leading to arterial endothelial dysfunction, including smooth muscle proliferation and impaired vasodilation.
- This contributes to atherosclerosis, worsened by altered lipid metabolism (↑LDL, ↑triglycerides, ↓HDL), increasing the risk of heart disease and stroke.
What is the Pathophysiology of Neuropathies
Neuropathic Complication - Peripheral Neuropathy:
- Glucose binds to neurons, altering their structure and function, damaging peripheral nerves.
- This causes numbness, tingling, and decreased sensation, increasing the risk of ulcers and infections, particularly in the lower limbs.
Explain the underlying pathophysiology of DKA relating to the signs and symptoms. (15 marks)
Read the table.
