Semester 2 Summary
Glucose Homeostasis
Blood glucose 3.4-5.8mmol/L
Glycogen- glycogenesis and glycogenolysis
Fat- lipogenesis and lipolysis
Protein- gluconeogenesis and proteolysis
Insulin- secreted by β cells decrease BG
Glucagon- secreted by α cells increases BG
Cortisol- glucocorticoid increases BG
Adrenaline- increase BG and fatty acids
Growth hormone- secreted by APG increases BG and fatty acid+protein
synthesise
Somatostatin- secreted by δ cells from raised glucose+amino acids. Inhibits
digestion, absorption and secretion of pancreatic hormones
Pancreatic polypeptide- secreted by F cells in response to raised amino acids
reducing appetite
GLP-1- secreted from ileum from L cells. Increases insulin secretion and slow
absorption from GIT
Insulin Secretion
GLUT-4 uptake glucose into β cells
Glucose metabolised into ATP
Increase ATP opens ATP dependant potassium channels
Potassium gate closed so cell depolarises
Voltage gated calcium channels open
Calcium influx causes calcium release from ER
Vesicles containing insulin by exocytosis
GLP-1
Incretin gut hormone
Increases insulin secretion, inhibits glucagon secretion, stimulates β
proliferation and slow GI absorption
Receptors are GPCRs act via Gs causing cAMP rise in β cells and gene expression
like GLUT-2
Rapidly hydrolysed by DPP-4
Diabetes Mellitus
, Primary diabetes mellitus- type 1 and 2
Secondary diabetes mellitus- pancreatic disease, endocrine disease or drug
induced
Gestation diabetes- 2nd or 3rd trimester
Type 1
Polyuria, polydipsia, weight loss, blurred vision, DKA, hyperventilation, muscle
catabolism, high BG, hyperosmolality and potassium loss
DKA- ketone bodies, acetoacetate and hydroxybutyrate created from fat
breakdown
DKA symptoms- polyuria, polydipsia, nausea, tiredness, abdominal pain, dry
mouth, ketone breath, confusion and tachycardia
Type 2
Bacteria infections, HONK (hyperosmolar non-ketotic) but not many
HONK- endogenous insulin inhibits hepatic ketogenesis but not hepatic
glycogenolysis and glucogenesis
HONK symptoms- polydipsia, polyuria, dry skin and drowsiness
Diagnosis
Random venous >11.1mmol/L
Fasting venous >7.0mmol/L
GTT >11.1mmol/L
Complications
, Microvascular
Endothelial of retina, kidney and PNS allows glucose to enter cell without insulin
Retinopathy- blurred vision, cataracts and glaucoma. Small haemorrhages and
harden exudates causes no blood supply an new fragile vessels form and break
Risk- high BG, high BP, nephropathy and smoking
Treatment- good GP and BP control, screening and laser treatment
Nephropathy- HbA1c aim <7% target <6% and BP<120/70mmHg
Proteinuria- albumin in urine
High BP- ACEIs (captopril and ramipril) and CCBs (amlodipine and felodipine
renoprotective)
Neuropathy- decreased vibrational sense, tingling and itching
Autonomic nerve damage- orthostatic hypotension, diabetic diarrhoea and
erectile dysfunction
Treatment- BG and BP control, analgesics, wound management and foot
inspection
Diabetic foot- peripheral vascular and neuropathy
Risk factors- ulceration, amputation and poor BG or BP control
Macrovascular Disease
Statins if high risk of CV disease mainly type 1
Target 140/80 or 130/80 if related disease
Risk- retinopathy, nephropathy, high BP/BG and cholesterol
Treatment- antihypertensive if BP over 130/80
Type 1 Therapeutics
Rapid acting- Novorapid, Humalog or Apidra
