Diabetes Flashcards
DIabetes is characterised by…
…increased urine production.
Two types of diabetes:
Diabetes mellitus and insipidus
Whats diabetes mellitus characterised by?
1) persistent glucosuria
- Excretion of glucose in urine
- Due to hyperglycemia (high blood [glucose])
Diabetes insipidus: caused by …
…inadequate secretion of vasopressin (AVP) by the pituitary gland or failure of kidneys to respond to AVP
AVP produced when we are…
…dehydrated causing the kidneys to absorb more water leading to concentrated urine to be produced.
Lack of AVP leads to …
…very dilute urine production and extreme thirst (polydipsia)
Whats type 2 diabetes due to?
due to insulin resistance &/or inadequate insulin production
Whats type 1 diabetes due to?
Type 1: β-cells of endocrine pancreas destroyed
Whats gestational diabetes?
Hormonal changes and insulin resistance due to pregnancy
Whats diabetes MODY?
- Maturity Onset Diabetes of the Young
- No associated with obesity, but inherited due to string risk factors
Whats double diabetes?
Has both type I and II
Whats steroid diabetes?
due to taking steroid anti-inflammatory drugs
Whats secondary diabetes?
due to another medical condition
Only type I and II diabetes mellitus are …
…well defined
Type I diabetes mellitus Characterised by …
…absolute deficiency of insulin secretion
Causative element of type 1 diabetes?
No one definitive causative element, but there is involvement of:
- Autoimmune components involved in the destruction of pancreatic islet cells
- Genetics
- Exposure to viruses and other environmental factors
Type I diabetes mellitus risk factors?
- Family history: E.g. parent or sibling
- Genetics: Variants of HLA-DQA1, HLA-DQB1 and HLA-DRB1 genes
- Geography: T1DM incidence increases travelling away from the equator
- Age: Two noticeable peaks in children – a) 4 - 7 years old, b) 10 - 14 years old
Type II diabetes mellitus Caused by a combination of:
- Resistance to insulin action
- Inadequate compensatory insulin secretory response
In inadequate compensatory insulin secretory response (type 2 diabetes):
- Hyperglycemia sufficient to cause pathologic and functional changes in various target tissues exists, but without clinical symptoms – asymptomatic
- Asymptomatic hyperglycemia may be present for a long period of time before diabetes is detected
The world health organisation defines several other causes which are:
1) The world health organisation defines several other causes
- 7.3.1 Genetic defects of beta-cell function
- 7.3.2 Genetic defects in insulin action
- 7.3.3 Diseases of the exocrine pancreas
- 7.3.4 Endocrinopathies
- 7.3.5 Drug- or chemical-induced diabetes
- 7.3.6 Infections
- 7.3.7 Uncommon but specific forms of immune-mediated diabetes mellitus
- 7.3.8 Other genetic syndromes sometimes associated with diabetes
2) Lead to classification of type 3(a-h) diabetes mellitus by some
In 2008, Monte and Wands, put forward a proposal that Alzheimer’s disease could be termed …
…type 3 diabetes.
In 2008, Monte and Wands, put forward a proposal that Alzheimer’s disease could be termed type 3 diabetes.
Their reasoning is based on the observation that …
…insulin resistance within the brain is feature of Alzheimer’s disease.
Diabetes is a group of …
…metabolic diseases, characterized by hyperglycemia due to defects in:
- Insulin secretion
- Insulin action
- Insulin secretion AND insulin action
Chronic diabetes hyperglycemia results in long-term damage, dysfunction and failure of organs, e.g.:
Eyes
Kidneys
Nerves
Heart
Blood vessels
Pathogenic processes involved in the development of diabetes include
- Autoimmune destruction of the pancreatic b-cells that results in insulin deficiency
- Abnormalities resulting in resistance to insulin action
Deficient insulin action on target tissues results in …
…abnormalities in metabolism of macronutrients such as carbohydrates, fat, and protein.
Deficient insulin action results from:
- Inadequate insulin secretion, and/or
- Diminished tissue responses to insulin
Impaired insulin secretion and defects in insulin action frequently …
…coexist in patients.
- It is unclear which abnormality, if either alone, is the primary cause of the resultant hyperglycemia
Symptoms of marked hyperglycemia include:
- Polyuria
- Polydipsia
- Weight loss (sometimes with polyphagia - excessive eating or appetite)
- Blurred vision
WHats polyuria?
production of abnormally large volumes of dilute urine
Whats polydipsia?
increased thirst
Chronic hyperglycemia may also be accompanied by:
- Impaired growth
- Susceptibility to certain infections
Acute, life-threatening consequences of uncontrolled diabetes are hyperglycemia with:
- Ketoacidosis
- Non-ketotic hyperosmolar syndrome (very high blood glucose levels without keto acidosis causes osmotic problems)
Whats ketoacidosis ?
acidification of the blood due to high levels of ketones
WHats Non-ketotic hyperosmolar syndrome?
very high blood glucose levels without keto acidosis causing osmotic problems
Long-term complications of diabetes include:
1) Retinopathy with potential loss of vision
2) Nephropathy leading to renal failure
3) Peripheral neuropathy with risk of foot ulcers, amputations, and Charcot joints
4) Autonomic neuropathy causing symptoms in the following systems:
- Gastrointestinal
- Genitourinary (and sexual dysfunction)
- Cardiovascular
Diabetic patients also have an increased incidence of:
- Atherosclerotic CVD
- Peripheral arterial disease (PAD)
- Cerebrovascular disease
- Hypertension
- Abnormalities of lipoprotein metabolism
- Alzheimer’s disease
Patients at increased risk of developing inadequate compensatory insulin secretory response can be identified by:
1) Autoimmune pathologic process occurring in the pancreatic islets
2) Markers of the immune destruction of the β-cell include:
- Islet cell autoantibodies
- Autoantibodies to insulin
- Autoantibodies to GAD (GAD65)
- Autoantibodies to tyrosine phosphatases (IA-2 and IA-2b)
3) Genetic markers (HLA genes)