DYSLIPIDEMIA Flashcards
with constant excess caloric intake, what cell increases?
adipocytes (cells of adipose tissue)
what do adipocytes secrete?
adipokines
- a combination of hormones and cytokines - these are small immune system molecules (TNF - alpha)
what can an excess of TNF alpha increase?
free fatty acids in the bloodstream by causing some of the fat in adipose tissue to break down
what do the adipokines inhibit?
the clearance of VLDL (which is the main transporter of triglycerides (& cholesterol) in the bloodstream
what is the function of lipoproteins?
bodys mechanism for transporting lipids (fat) through the bloodstream (water based system)
what are the adipokines?
- angiotensinogen
- leptin
- resistin
- adiponectin
- TNF-alpha
what adipokine has anti-inflammatory and insulin sensitizing effects and is reduced with increased adiposity?
adiponectin
what is resistin?
(FOR INSULIN RESISTANCE)
is elevated in obesity and is an important link between obesity, insulin resistance and development of DM
- plays a role in development of atherscerlosis, CV, non alcoholic fatty liver disease and other disorders associated with obesity
what is leptin?
elevated in obesity and plays role in energy regulation and glucose homeostas
what does leptin inhibit?
apetite and food intake and stimulates energy expenditure
leptin resistance in obesity. is this an issue?
no
is a pro inflammatory adipokine an issue?
yes
what does leptin promote?
promotes production of other pro inflammatory cytokines from immune cells, which contributes to the overall ‘pro inflammatory state’ observed in obesity
what is excess leptin production stimulated by?
pro inflammatory cytokines, TNF alpha and IL-1 - resulting in vicious cycle of chronic inflammation in obesity
leptin has been shown to act on hypothalamus and evoke what?
sympathetic activation, leading to peripheral vasoconstriction, increase BP which contributes to hypertension
what is angiotensinogen?
synthesized by adipocytes in direct proportion to their adiposity
- eventually converted into the vasoactive compound angiotensin II by passing through the kidneys and lungs
what does angiotensinogen elevate?
BP by DIRECTLY promoting vasoconstriction and by INDIRECTLY increasing renal water retention by promoting release of aldosterone
angiotensin provides a link between?
increased adiposity/obesity and development of hypertension
what is adiponectin?
normally produces insulin sensitizing effects and reduces the production of TNF alpha by adipocytes
what happens to the beneficial effects of adiponectin?
they are reduced in obesity as the levels of adiponectin decline with increasing adiposity
what does adiponectin have beneficial effects on?
lipid metabolism
what is adiponectin is negatively correlated with?
triglycerides
what is adiponectin is positively correlated with?
HDL levels
what does adiponectin helps to enhance?
VLDL clearance
what is TNF alpha increase production of?
more VLDL by the liver, lowering levels of HDL in response to increased weight gain
what do the extra triglycerides and free fatty acids interfere with?
insulin signalling in muscle and liver tissue
what do the receptors on cells in skeletal muscle and adipose tissue signal to the cells?
signal the cells to take up glucose that is floating into the bloodstream from digestive system
high concentration of free fatty acids in the blood interfere with what?
signalling, preventing the cells from taking up glucose in response to insulin (this is beginning of insulin resistance)
does the pancreas produce greater or less insulin in response to insulin resistance?
much greater
can the pancreas compensate for insulin resistance?
yes, for a LITTLE WHILE.
it produces more insulin to compensate
what are the first symptoms presented with T2D?
elevated triglycerides and impaired glucose tolerance
why does the pancreas only compensate for insulin resistance for a little while?
the beta cells get exhausted from producing all the extra insulin and failure of beta cells is the point at which glucose levels in the blood begin to rise and hyperglycaemia results
