Investigations
Your Organisational Guidance
ebpracticenet urges you to prioritise the following organisational guidance:
Évaluation du risque cardiovasculaire en première lignePublished by: Domus MedicaLast published: 2010Cardiovasculaire risicobepaling in de eerste lijnPublished by: Domus MedicaLast published: 2020Globaal Cardiovasculair RisicobeheerPublished by: Domus MedicaLast published: 2007Gestion globale des risques cardiovasculairesPublished by: Domus MedicaLast published: 2007Évaluation du risque cardiovasculaire en première lignePublished by: Domus MedicaLast published: 20201st investigations to order
lipid profile
Test
Consists of total cholesterol (TC), triglycerides, and LDL-, HDL-, and non-HDL-cholesterol.
TC, non HDL, and HDL can be measured in the non-fasting state. Accuracy of LDL-cholesterol is preserved between fasting and non-fasting situations when the Martin-Hopkins formula is used, whereas estimated LDL-cholesterol by older methods (Friedewald formula) commonly underestimates LDL-cholesterol at low levels.[36] Non-HDL-cholesterol (which is calculated by the formula TC-HDL-cholesterol) is an independent marker of cardiovascular events and can be measured in non-fasting states.[34][35]
TC values vary by 10% and triglycerides by up to 25% from day to day, even in the absence of disease.[46]
Plasma or serum can be used, with plasma cholesterol being approximately 3% higher than the serum value.[47]
Acute illnesses can influence the lipid profile. Triglycerides increase and cholesterol levels decrease in inflammatory states. In particular, lipid profiles change significantly 24 hours after an acute myocardial infarction, and measurement should either be performed acutely or postponed until after recovery.[48]
Result
TC >5.18 mmol/L (>200 mg/dL); LDL-cholesterol >2.6 mmol/L (>100 mg/dL); non-HDL-cholesterol <3.4 mmol/L (<130 mg/dL); HDL-cholesterol <1.04 mmol/L (<40 mg/dL) for men and <1.29 mmol/L (<50 mg/dL) for women; triglycerides >1.7 mmol/L (>150 mg/dL)
serum thyroid-stimulating hormone (TSH)
Test
Routine TSH test is used to assess for hypothyroidism as an underlying cause of elevated lipid levels.
Result
elevated in primary hypothyroidism; may be low in secondary hypothyroidism
lipoprotein(a)
Test
Lipoprotein(a) is an LDL particle with apolipoprotein(a) covalently bound to apolipoprotein B of LDL.
Result
values >50 mg/dL or >125 nmol/L are considered high (above the 80th percentile)
Investigations to consider
genetic testing
Test
Genetic testing can help to confirm a diagnosis of familial hypercholesterolaemia, though a pathogenic variant in the most common genes is only identified in 30% to 80% of individuals with clinical familial hypercholesterolaemia (FH).[40] More importantly, when these genes are identified, it facilitates cascade screening of family members, which is critical. Even when a gene is not identified, screening of first-degree relatives with lipid testing should be performed.[40][42] Another important reason to perform genetic testing is for prognostication. Individuals with severe hypercholesterolaemia and an FH mutation have an odds ratio for coronary artery disease that is 22-fold higher than those with LDL-C 3.4 mmol/L (<130 mg/dL), as compared with an odds ratio that is 6-fold higher in those with severe hypercholesterolaemia and similar LDL-C levels but no FH mutation.[43]
Result
identification of pathogenic variant
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