T5-L2: Diabetes Flashcards
What hormone do Islets of Langerhans produce in the greatest quantity?
Insulin - via the Beta cells (75%)
- Alpha cells produce glucagon (25%0
- delta Cells Produce Somatosatin (5%)
- F cells produce pancreatic polypeptide
What is C-peptide?
It is a byproduct of the production of Insulin. It is produced in equal quantities to Insulin and so can be used as a diagnostic measure when looking at the levels of Insulin in the blood.
Insulin is synthesised from pro-insulin from the endoplasmic reticulum. It is cleaved at multiple sights leading to equal producing of insulin and C-peptide.
What are the affects of insulin?
Metabolic effects - Increase glucose uptake. It also inhibits gluconeogenesis and glycogenolysis.
Pancreatic effects - High insulin levels reduce the glucagon secretions from alpha cells.
Vascular, Growth and cancer affects - Has vasodilatory properties.
How do we diagnose diabetes?
- Fasting glucose of greater than 7 mmol/L
- Random glucose of greater than 11mmol/L
- Two separate reading posts OGTTT of greater than 11.1 mmol/L
- HbA1c - greater than 48mmol/L
How do we diagnose prediabetes with HbA1c?
≥41 and <48 mmol/mol = pre-diabetes - these patients can be advice of lifestyle changes to delay the onset of diabetes
What the epidemiology of Type 1 diabetes?
- Autoimmune destruction of insulin producing beta cells in the islets of Langerhans
- Occurs at any age (but peaks around puberty)
- Equal sex incidence but after 15% years of age, there is a two fold increase in the prevalence in men
Common in the developing world
What is the pathogenesis and risk factors for Type 1 diabetes?
Pathogenesis
- Due to autoantibodies as a result of humeral immunity
- Exposure/trigger to environmental factors
- AutoimmunityRisk factors
- Family History - Genetics - HLA Class II - DR4-DQ8 and DR3-DQ2 (genetic susceptibility)
- Perinatal factors - Low birth weight
- Viral infections e.g. respiratory and enteroviruses
Diet - cows milk
What is the presentation of Type 1 diabetes?
• Rapid onset (often few weeks)
• Weight loss + osmotic symptoms + low energy - e.g. thirst, polyuria, polydipsia and nocturia
• Abdominal pain - usually when you already have diabetic ketoacidosis
• Often slim
Present as diabetes ketoacidosis (DKA)
What autoantibodies can we detect in Type 1 diabetes?
- Insulin autoantibodies
* Glutamic acid decarboxylase autoantibodies ( GAD) - GAD65 is the one we measure more common in T1DMN
What is the presentation of Type II Diabetes?
• Often overweight
• Symptoms present over few months
• Minimal weight loss ( unless left for long period)
• Can present with complications such as vision loss or foot ulcers or fungal infection
Can also present in state of Hyperosmolar Hyperglycemia State (HHS) or HONK - high blood glucose without the acidosis
What are the management options for Type II Diabetes?
- Lifestyle - exercise, change in diet and weight loss
- Oral therapy - Metformin is the first line
- Insulin
What is the criteria for gestational diabetes?
- Diabetes diagnosed in pregnancy
- New diabetes not present prior to pregnancy
- Hyperglycaemic first detected in pregnancy
Fasting glucose above > 5.6 mmol/litre OR 2 hours plasma glucose level of 7.8mmol/litre. This is DIFFERENT from normal diabetes diagnosis.
What are the risk factors for gestational diabetes?
Risk factors:
- BMI of over 30 - Previous macrosomic baby - baby over 4.5 kg - Previous gestational diabetes - Family history of diabetes - Ethnic minority
What are the consequences of gestational diabetes?
Short term consequences:
- Macrosomia - Pre-eclampsia - Stillbirth - Neonatal morbidity Long term consequences - Obesity in the child - Development of T2DM in the mother
What is MODY?
Mature onset diabetes of the young (MODY) - has further subsets. It is a AD condition and the most common cause of monogenetic diabetes and accounts for 2 in 5 cases of diabetes.
