What is Diabetes? Flashcards
What is diabetes?
Disease that occurs when your blood glucose is too high = insufficient insulin to maintain glucose homeostasis
Why do different types of diabetes develop?
Type 1 = absolute insulin deficiency
Type 2 = relative insulin deficiency, inadequate insulin production and/or insulin release
MODY = failure of insulin synthesis, release or activity
What is diabetes mellitus?
Group of metabolic diseases characterised by hyperglycaemia = results from defects in insulin secretion or action (or both)
What is the diagnostic criteria for diabetes?
HbA1c = 48m/m or above
Fasting glucose = 7.0 mmol/L or above
2hr glucose in OGTT = 11.1 mmol/L or above
Random glucose = 11.1 mmol/L or above
What is the diagnostic criteria for impaired/pre-diabetes?
HbA1c = 42-47m/m or above
Fasting glucose = 6.1-6.9 mmol/L or above
2hr glucose in OGTT = 7.8-11.0mmol/L or above
What is the ADA criteria for diagnosing diabetes?
FPG >= 7.0mmol/L
2hr PG >= 11.1mmol/L during OGTT
A1C >= 48m/m
Patient with classic symptoms of hyperglycaemia or hyperglycaemic crisis, or random PG >= 11.1 mmol/L
What is the ADA classification of diabetes?
Type 1 = due to autoimmune beta cell destruction, usually leading to absolute insulin deficiency
Type 2 = due to progressive loss of beta cell insulin secretion
What is the ADA classification for gestational diabetes mellitus?
Diabetes diagnosed in the second or third trimester that was not clearly overt diabetes prior to gestation
What does the ADA as some other causes of diabetes?
Monogenic diabetes syndrome = neonatal diabetes, MODY
Disease of exocrine pancreas = cystic fibrosis
Drug/chemical induced = glucocorticoids
What is the WHO classification of type 1 diabetes?
Pancreatic beta cell destruction, usually characterised by presence of anti GAD/anti-islet cell antibodies
What is the WHO classification of type 2 diabetes?
Diagnosed if a person doesn’t have type 1 diabetes, monogenic diabetes or other medical condition/treatment suggestive of secondary diabetes
What is the pathogenesis of type 1 diabetes?
Innate immune cells enter pancreatic islets (priming)
T cells arrive from lymph nodes and insulitis ensues
Destructive insulitis occurs = without onset will cause disease onset
What is the typical presentation of type 1 diabetes?
Pre-school or pre-pubescent (small peak in late 30s), usually lean, acute onset, severe symptoms and weight loss, ketonuria (metabolic acidosis), no evidence of microvascular disease at diagnosis, immediate and permanent requirement for insulin
What is the clinical presentation of type 2 diabetes?
Middle aged/elderly, usually obese, pre-diagnosis duration of 6-10 years, insidious onset over weeks to years, ketonuria minimal/absent, managed initial by diet (then tablets), evidence of microvascular disease in 20% at diagnosis
How dos diabetes present?
Thirst, polyuria, thrush, weakness/fatigue, blurred vision, infections, possible weight loss, signs of complications if type 2 (neuropathy, retinopathy)
What is stage one of type 1 diabetes?
Characteristics = autoimmunity, normoglycaemia, pre-symptomatic
Diagnostic criteria = multiple autoantibodies, not IGT or IFG
What are the characteristics of stage 2 of type 1 diabetes?
Autoimmunity, dysglycaemia, pre-symptomatic
What is the diagnostic criteria for stage 2 of type 1 diabetes?
Multiple autoantibodies, IFG and/or IGT for dysglycaemia, FPG is 5.6-6.9mmol/L, 2hr PG is 7.8-11.0mmol/L, A1c is 39/47m/m or >= 10% increase in A1c
What is stage 3 of type 1 diabetes?
Characteristics = new-onset hyperglycaemia, symptomatic
Diagnostic criteria = clinical symptoms, diabetes by standard criteria
What are the risk factors when considering testing for diabetes in overweight or obese individuals?
First degree relative affected High risk ethnicity History of CVD Hypertension HDL cholesterol < 0.9mmol/L and/or triglycerides > 2.82 mmol/L Women with polycystic ovary syndrome Physical inactivity Other clinical conditions associated with insulin resistance
What are high risk ethnicities for developing diabetes?
African American, Latino, Native American, Asian Americans, Pacific Islander
How often should patients with pre-diabetes be tested for diabetes?
Yearly
How should women diagnosed with gestational diabetes be tested for diabetes?
Lifelong testing at least every three years
When should regular patients be tested for diabetes?
Should begin at age 45 = if results are normal, testing should be repeated at least every three years
What are the risk factors for type 2 diabetes?
Obesity (central), family history, gestational diabetes, age, ethnicity (African, afro-Caribbean, Asian), history of MI/stroke, medications (antipsychotics), IGT/IFG
What score on the ADA risk calculator would indicate a patient is at risk of type 2 diabetes?
A score of five or more
What should be considered in asymptomatic patients at risk of type 2 diabetes?
Screening for type 2 diabetes with an informal assessment of risk factors or validated tools
What tests should be done for type 2 diabetes?
Fasting plasma glucose, 2hr plasma glucose during 75g oral glucose tolerance test (OGTT), A1C
What should also be identified and treated in patients with diabetes?
CV disease risk factors
When should testing for type 2 diabetes be considered in children?
If they are overweight or obese, and if they have additional risk factors for diabetes
What are some discriminatory tests that can be done for diabetes?
Autoimmune markers, ketones, C-peptide
What are the autoimmune markers that can be used for diabetes?
Islet cell autoantibodies, autoantibodies to GAD65, insulin, tyrosine phosphatases IA-1 and IA-2 beta, ZnT8
What does type 1 diabetes have a genetic link with?
Strong HLA association with linkage to DQA DGB genes
What is LADA?
Latent autoimmune diabetes in adults
How is LADA distinguished from other forms of diabetes?
Late onset type 1 diabetes is probably quite common in patients presenting with “typical” type 2 diabetes
If there is ketosis, then its type 1 diabetes
What is idiopathic type 1 diabetes?
Diabetes of no known aetiology = patients have permanent insulinopenia and are prone to DKA, but have no evidence of beta cell autoimmunity
How do most patients with idiopathic type 1 diabetes present?
Most are of African or Asian ancestry = suffer from episodic DKA and exhibit varying degrees of insulin deficiency between episodes
What are the genetic features of idiopathic type 1 diabetes?
Strongly inherited and has no HLA association
What is type 3 diabetes?
Gestational diabetes = any degree of glucose intolerance arising or diagnosed during pregnancy
What conditions are grouped under type 4 diabetes?
Pancreatic and endocrine diseases, drug induced diabetes, genetic diseases, abnormalities in insulin and its receptor
What are some examples of pancreatic and endocrine disease that cause diabetes?
Pancreatic = chronic or recurrent pancreatitis, haemochromatosis, cystic fibrosis Endocrine = Cushing's syndrome, acromegaly, phaechromocytoma, glucagonoma
What are some genetic diseases and drugs that can induce diabetes?
Genetic diseases = cystic fibrosis, myotonic dystrophy, Turner’s syndrome
Drugs = glucocorticoids, diuretics, beta blockers
What are the risk factors for monogenic diabetes?
Strong family history, associated features (renal cysts etc), young onset, GAD negative, C-peptide positive
What is HbA1C?
Measure of average blood glucose over the past two to three months
What are some rapid acting and long acting insulin analogues?
Rapid = Humalog, novorapid, apidra Long = lantus, levemir
What are some short and intermediate acting insulin analogues?
Short (soluble) = Humulin S, actrapid, insuman rapid
Intermediate (isophane) = insulatard, Humulin I, insuman basal
What are some examples of rapid acting analogue-intermediate mixtures?
Humalog mix 25 or 50, novomix 30
What are some examples of short acting-intermediate mixtures?
Humulin M3, insuman comb 15,25 or 50
What are some complications of diabetes?
Macrovascular = heart disease stroke
Microvascular = retinopathy, neuropathy, nephropathy
Psychiatric = anxiety depression
Peripheral vascular disease, kidney failure, blindness
