Hi Erwitchin.
Thanks for your questions about Lp(a).
This is a classic example of why I always encourage people to give the units when discussing their Lp(a) levels, and this is likely why you might have some confussion about this.
Lp(a) is measured in either mg/dL or nmol/L. They vary by an approximate factor of 2.4x for most people, so units of measurement are important here.
The good news is that your level of 20.7 should not pose an elevated risk, whether or not that is a mg/dL value or nmol/L value.
In mg/dl elevated risk generally starts at about >30mg/dl. So, 20.7mg/dl would be well below this threshold and should not be of any concern to you, if in fact your measurement was in mg/dL.
In nmol/L elevated risk generally starts at 75nmol/L. If your 20.7 measurement was in nmol/L, you are very far below the threshold at which it would be of concern. So, either way, you are good.
I would not worry about that. The short online Lp(a) book that you linked was quirky in many respects. It is far from the best source on Lp(a) and actually contradicts itself in a couple of places. For example, in the introduction they state: "To date, no specific therapy exists for the treatment of elevated Lp(a)". A few paragraphs below this, they go on to list several specific treatment options for elevated Lp(a). It had me wondering if the book was in part AI generated.
If one has borderline LDL, there would be an indication to keep an eye on it and possibly to incorporate some lifestyle choices that could move you below the "borderline" level. However, with Lp(a), there is really nothing you can do to lower it, in terms of lifestyle, so no action is needed on your part. And, by the same token, if you had a 2 week vacation in which you indulged in cheeseburgers and pizza, it is not something that will push your Lp(a) above the "borderline" into increased risk.
So, once again, units matter when it comes to Lp(a) measurement,, But in your case, 20.7 is not of concern, regardless of which unit measurement your lab is using.