There is little difference in most lipid parameters between fasting and non-fasting specimens after a typical meal (1-3). What is the effect of a meal on lipid measurements? Non-HDL cholesterol can be easily calculated by the formula: It does not require the patient to be fasting. Non-HDL compares favourably with LDL as a CVD risk marker, especially in patients with poor lipid particle clearance where the proportion of non-LDL particles This includes LDL as well as VLDL, IDL, and lipoprotein (a). The total of all atherogenic (apoB containing) particles can be expressed together as ?non-HDL cholesterol?. However, if the triglyceride is greater than 4.5 mmol/L, an LDL level cannot be calculated. In most laboratories LDL is calculated from the other lipid levels, and this calculation is valid in non-fasting samples if the triglyceride is less than 4.5 mmol/L. In Auckland there is consensus from experts that non-fasting lipids can be used to assess absolute risk, using algorithms such as PREDICT. Triglyceride is not part of the Framingham risk algorithm however evidence suggests non-fasting triglyceride levels are as good and possibly better at identifying patients with poor lipid particle clearance and who may be at increased CVD risk. Triglyceride increases after food but the average increase is small (about 0.3 mmol/L). Risk assessment using the Framingham formula (and related risk algorithms) uses the total cholesterol / HDL ratio, which does not change after a meal. This is valid for non-fasting as well as fasting samples.Ī non-fasting blood sample is acceptable for lipid tests in most cases. Non-HDL cholesterol = Total cholesterol - HDL cholesterol This calculation is only valid for fasting patients with serum triglyceride less than 4.5 mmol/L. LDL Cholesterol = Total Cholesterol - HDL Cholesterol - (TG x 0.456) Triglyceride: mg/100 mL x 0.0113 = mmol/LĬalculation of LDL- cholesterol is performed using the Friedwald formula: In a non-fasting patient, a non-HDL cholesterol at or above 5.7 mmol/L (220mg/dL) also suggests a possible genetic dyslipidaemia.Ģ014 63(25_PA):2889-2934.
Such patients can also have a mildly-moderately raised triglyceride level. In such patients a raised non-HDL cholesterol can reflect increased concentrations of these triglyceride-rich particles, with increased CVD risk, even if LDL appears reassuring.
diabetes, hypothyroidism, metabolic syndrome). These are usually present at low concentrations (0.8 mmol/L or less), but their concentration increases in clinical states of slow lipid particle clearance (e.g. LDL are the smallest and risk/treatment guidelines have primarily focused on LDL, however the precursor VLDL and IDL particles are now also recognised as atherogenic.
Non-HDL cholesterol is a measure of apoB containing particles (VLDL, VLDL remnants/IDL, LDL). 0.5 mL Paediatric Micro-PST Blood (Preferred)įor guidelines for interpretation and management of plasma lipids see the New Zealand Guideline Group websiteĪll risk factors need to be taken into account when interpreting plasma lipid levels.Īs a rough guide, the following levels are acceptable if no other major risk factors are present: