Atherosclerosis in Children
Atherosclerosis is actually quite common in children and young adults, with a morbidity (prevalence) approaching 20% of the population having early lesions of atheroma (found as a result of autopsies of those who have died as a result of non-cardiac cause and verified by modalities such as intravascular ultrasound and non-invasive vascular ultrasound).
What is cholesterol? Cholesterol is absorbed from the gut and taken up by low-density lipoproteins (LDL), transported to the liver where it enters the bloodstream. LDL carries fat molecules in the bloodstream to cells to be metabolized. High Density lipoproteins (HDL) carry fat molecules that are excreted by the cells.
Excess cholesterol is recycled back through the liver. This feedback mechanism is what keeps low-density cholesterol levels within normal range and defects in this feedback mechanism are one of the reasons there are abnormal levels of low-density lipids.
Keep in mind that cholesterol is vital to the normal functioning of the body. HDL is considered “good” cholesterol and LDL is considered “bad” cholesterol. Think of this pneumonic: LDL is “lousy” cholesterol and HDL is “healthy” cholesterol.
In children, extremely high levels of cholesterol are most often associated with genetic hyperlipidemia, whereas modest increases are highly associated with dietary and lifestyle habits. Furthermore, chronic infections are highly associated with the inflammation of arterial walls, which in turn leads to the deposition of cholesterol in the arteries. Examples of these infections include chronic respiratory infections, Kawasaki disease, human papillary virus (HPV), Chlamydia, lupus, rheumatoid arthritis and vasculitis.
Cholesterol is used by the body to repair damage, think of it like the repair “glue” that the body uses to fix things that go wrong. Inflammation of the arterial walls causes the body to lay down a layer of cholesterol in order to cap the damage. An interesting fact is that this inflammatory process is highly vascularized and is somewhat like a living organism. It grows (very slowly), therefore the body lays down more cholesterol until at some point a significant stenosis develops.
Another interesting fact is that almost half of people who die of heart disease have normal cholesterol levels. Hence, there is a lot of controversy about the subject of cholesterol.