I’ve had the pleasure of hearing Dr David Diamond present three times in the past year. I have found the most thought provoking parts of his presentations to be on Familial Hypercholesterolemia (FH). At a conference in California on February 2nd, 2020, David reiterated some important, and little known, facts about FH. He also used a quotation about FH with which I am familiar. It comes from the British Heart Foundation (BHF) and it says: “If you don’t have treatment, 1 in 2 men and nearly 1 in 3 women with FH will develop coronary heart disease by the age of 55” (Ref 1).
Hearing David use this quotation reminded me that I had exchanged emails with the BHF about this statement back in February 2018. I checked the BHF literature when I got home, and their errors/falsehoods – not sure what to call this – have still not been corrected. I’ll report the exchange in full later in this note. First, let’s remind ourselves of what FH is and what the evidence is for the risk with which it is associated.
FH is a genetic condition caused by a gene defect on chromosome 19. The defect impairs the body’s ability to remove low density lipoproteins (LDL) from the blood stream, resulting in consistently high levels of LDL (and thus the cholesterol contained therein). There are two types of FH: Heterozygous FH is found in approximately 1 in 500 people; Homozygous FH is even rarer, occurring in approximately 1 in a million births (Ref 2).
Human cells have LDL receptors, so that they can receive LDLs from the blood stream and let them into the cell with all the vital lipids that they contain. With Heterozygous FH, the LDL receptor works to a slight extent and some vital lipids will get through to the cell. With Homozygous FH, the LDL receptor doesn’t work at all and so the cell doesn’t get the lipids that it needs. (One should immediately think: what damage will be done to all cells – including heart cells – if vital lipids are not able to reach the cell because of this genetic defect? High LDL levels in the blood stream are a marker of FH, but is that harmful in itself? Or is the issue the impact on the cell of the LDL not getting to where it’s needed?)