From the Guidelines
Fasting is not necessary for an Lp(a) test, as lipoprotein(a) levels remain relatively stable regardless of food intake. Unlike some other lipid tests, Lp(a) levels are genetically determined and do not fluctuate significantly with meals 1. You can have your blood drawn for an Lp(a) test at any time of day, whether you've eaten recently or not. This differs from standard lipid panels, which typically require 9-12 hours of fasting for accurate results. The reason for this difference is that Lp(a) is composed of an LDL-like particle bound to apolipoprotein(a), and its levels are primarily determined by genetics rather than diet or recent food consumption.
Some key points to consider:
- Lp(a) screening should be considered, especially in patients with high cardiovascular risk 1.
- Non-fasting lipid profiles can provide acceptably accurate measures for risk calculation, with the exception of triglyceride levels greater than 4.52 mmol/L (>400 mg/dL) 1.
- Fasting lipid measures may still be necessary if the purpose is to measure or monitor triglyceride levels, but this is not the case for Lp(a) testing.
- The European Society of Cardiology recommends lipid assessment, including Lp(a) screening, in patients with rheumatoid arthritis, regardless of age, at least every 5 years in ‘low-risk RA’, and annually in ‘high-risk RA’ 1.
In terms of morbidity, mortality, and quality of life, not requiring fasting for Lp(a) testing can improve patient adherence and reduce the burden of testing, as patients do not need to take time off work or family to fast and return for a second visit 1. Overall, the current evidence suggests that fasting is not necessary for Lp(a) testing, and this can have a positive impact on patient outcomes.
From the Research
Fasting Requirements for Lipoprotein(a) Measurement
- There are no specific guidelines that require fasting for lipoprotein(a) (Lp(a)) measurement, as Lp(a) levels do not change significantly in response to normal food intake 2.
- A study found that median fasting Lp(a) levels were 17.3 mg/dL, while median levels at 3-4 hours since last meal were 19.4 mg/dL, with no significant difference (p = 0.38) 2.
- However, Lp(a) levels may be minimally increased at increased levels of C-reactive protein (CRP), a marker of inflammation 2.
Clinical Management of Lipoprotein(a) Levels
- Elevated Lp(a) is an independent risk factor for atherosclerotic cardiovascular disease (ASCVD), and testing for Lp(a) is not routinely incorporated into clinical practice 3.
- Current guidelines recommend testing for elevated Lp(a) in individuals at intermediate or high risk of ASCVD 3.
- A retrospective analysis found that the frequency of Lp(a) testing increased over a 5-year period, but the number of patients with abnormal Lp(a) levels who received subsequent referrals or new lipid-lowering medications was relatively low 4.
Therapies for Lowering Lipoprotein(a) Levels
- Several therapies are available for lowering Lp(a), including PCSK9 inhibitors, lipoprotein apheresis, and antisense oligonucleotides, but none are selective for Lp(a) and there is limited clinical trial data on their effectiveness in reducing ASCVD risk 5, 6.
- PCSK9 inhibitors can reduce Lp(a) levels by up to 30%, while antisense oligonucleotides have shown strong efficacy with up to 90% reductions in clinical trials 5, 6.