Lecture 7: T2DM Flashcards
What is the effect of obesity on insulin secretion
- The molecules released from adipose tissue are commonly referred to as adipokines
- Enlargement of adipose tissue depots seen in obesity can lead to dysregulated adipokine secretion, representing a potential pathophysiological link between obesity and type 2 diabetes
- It is apparent that some adipokines have beneficial effects whereas others have detrimental properties. The balance is dysregulated in obesity leading to the contribution to β-cell failure
Name the different types of diabetes mellitus and their prevalence
Type 1 - makes up 10% of all diabetes cases
Type 2 - makes up 90% of all diabetes cases
Other (1%) - includes monogenic diabetes (neonatal and gestational)
What is the lifetime risk of T2DM for individuals with one parent affected?
40% risk
What is the lifetime risk of T2DM for individuals with both parent affected?
70% risk
Describe insulin resistance
- This is the inability of metabolic tissues to respond to insulin.
- It occurs naturally as people age and become more heavier.
- Present for years before onset of type 2 diabetes (prediabetes or early onset).
When does insulin resistance develop into Type 2 diabetes mellitus
It becomes a problem when the compensatory mechanism from the beta cells (hyperinsulinaemia) causes the beta cells to fatigue resulting in hypergylcaemia
Why does the β-cell eventually succumbs to rising insulin resistance- leading to T2DM
The enlargement of adipose tissue deposits seen in obesity can lead to dysregulated adipokine secretion. Which adipokine has implications of the development of insulin resistance?
- Leptin
- Adiponectin
- TNFα
- Resistin
Describe how leptin has implications on insulin resistance
- An increase of fat mass is associated with an increase of leptin
- Leptin functions in the central nervous system and is involved in the control of food intake and energy expenditure
Describe how adiponectin has implications on insulin resistance
Reduces levels of free fatty acids
Describe how TNF-alpha has implications on insulin resistance
Insulin receptor signalling interference
Describe how resistin has implications on insulin resistance
enhances hypothalamic stimulation of glucose
production
acanthosis nigricans is associated with which receptor mutation
Insulin receptor gene mutations
What is acanthosis nigricans?
Which condition does this point you to?
It is a brown to black hyperpigmentation of the skin.
It is usually found in body folds, such as the armpits.
Indiciates Type 2 diabetes mellitus
Describe how glucotoxicity can interfere with insulin secretion
Glucose themselves can be a negative factor as it can impair beta cell function
Describe how glucokinase deficiency can interfere with insulin secretion
Glucokinase deficiency can impair insulin secretion
In T2DM, patients are at a higher risk of a cardiovasular event. Controlling glucose levels has a low impact on reducing the risk.
Which other values must we control in patients with type 2 diabetes to reduce their risk of a CV event?
Blood pressure + cholesterol etc
Controlling these values far outweights the ability of controlling glucose alone to reduce the risk of a CV events
In normal renal glucose handling, 90% of glucose is reabsorbed by which receptor in the kidney?
SGLT -2
In normal renal glucose handling, 90% of glucose is reabsorbed by SGLT2. The remaining glucose (10%) is reabsorbed where and by which receptor?
Remaining glucose is reabsorbed by SGLT1 (10%) in the descending loop of Henle
