Diabetes Mellitus Flashcards
What is the difference between diabetes mellitus and diabetes insipidus?
Mellitus = deficiency of insulin Insipidus = deficiency of ADH
What is insulin?
A peptide hormone
51 amino acids
Where is insulin produced?
B cells of the islets of Langerhans of pancreas
What does insulin do?
Released into bloodstream, binds to cell membrane receptors, regulates glucose uptake and metabolism, increased glycogen synthesis
How is the release of insulin controlled?
mainly direct feedback - B cells absorb glucose via GLUT2, metabolic pathway releases pre-synthesised insulin
What acute conditions can insulin deficiency cause?
Hyperglycaemia
Ketosis
Acidosis
Hyperosmolar state (dehydration, coma, death)
What chronic conditions can insulin deficiency cause?
Cardiovascular disease
Nephropathy
Neuropathy
Retinopathy
Define type 1 DM
Autoimmune destruction of B cells
Define type 2 DM (NIDDM, obesity related, adult-onset diabetes)
Peripheral insulin resistance
Strong association with lifestyle
Insulin concentrations normal or high
What is gestational diabetes?
genetic predisposition, insulin resistance, caused by pregnancy, resolves with delivery
What are the risk factors for gestational diabetes?
Maternal age, family history of T2DM, african or north american, previous GD, previous baby over 4KG, smoking
What are the dangers of gestational diabetes?
Mother - greater risk of T2DM later in life, hypertension, pre-eclampsia/eclampsia, obstructed labour
Child - risk of T2DM later in life, risk of obesity, macrosomia, neonatal hypoglycaemia
What are the causes of secondary DM?
Chronic pancreatitis, cystic fibrosis, pancreatic surgery, endocrine disease, drug therapy.
What are the classic symptoms of T1DM?
Polyuria, polydipsia (thirst), hunger, weight loss.
What is polyuria?
High concentrations of glucose in the urine - leads to glycosuria which leads to osmotic polyuria.
