L28 Background hyperlipidemia

Cholesterol is not water soluble, therefore it cannot circulate in the blood., and it needs to be packaged and carried by lipoproteins.

High Density Lipoproteins (HDL)​ are 'good' cholesterol and we should have more than 1.0 mmol/L.

Functions of lipoproteins: Chylomicrons and VLDL: Deliver [blank_start]TAG[blank_end] to different cells in the body​. LDL: Delivers cholesterol to [blank_start]cells[blank_end] in the body where it can be used for the [blank_start]synthesis[blank_end] of membranes and [blank_start]steroid[blank_end] hormones​. HDL: Involved in reverse cholesterol transport – [blank_start]excess[blank_end] cholesterol is brought back to the [blank_start]liver[blank_end] by HDL​, and [blank_start]removed[blank_end] from the body by the liver.

Primary dyslipidaemias: Genetically determined but also influenced by [blank_start]environmental[blank_end] factors, i.e. familial hypercholesterolaemia is a genetic disorder where [blank_start]LDL[blank_end] is raised. Secondary dyslipidaemias: Secondary to [blank_start]other[blank_end] disorders, or as a result of other [blank_start]drug[blank_end] therapies. Can be treated if the underlying cause is treated.

Select all the medications (and not the conditions) that can cause secondary hypercholesterolaemia.

Pathophysiology of atherosclerosis: 1. Presence of [blank_start]hypercholestrolaemia[blank_end] and [blank_start]injury[blank_end] of endothelial lining of the coronary artery and/or other blood vessels.​ 2. Subendothelial migration of [blank_start]monocytes[blank_end] – accumulation of [blank_start]fatty[blank_end] streaks, containing lipid rich [blank_start]macrophages[blank_end] and [blank_start]T[blank_end]-cells. 3. Migration and proliferation of [blank_start]smooth[blank_end] muscle cells​. 4. Smooth muscle cells + [blank_start]fibroblasts[blank_end] secrete collagen, elastin, proteoglycans, and glycoproteins – creating a [blank_start]fibrous[blank_end] cap around the necrotic tissue​. 4. Presence of atherosclerotic [blank_start]plaques[blank_end] results in narrowing of blood vessels causing [blank_start]reduction[blank_end] of blood flow​. 5. Plaque ruptures, causing formation of a [blank_start]thrombus[blank_end]

Reference ranges for lipids​: Total cholesterol: < [blank_start]4[blank_end] mmol/L​ LDL cholesterol: < [blank_start]2.0[blank_end] mmol/L​ HDL cholesterol: ≥ [blank_start]1.0[blank_end] mmol/L ​ Triglycerides: <[blank_start]1.7[blank_end]mmol/L​