Remnant cholesterol calculator

The formula

Calculated remnant cholesterol is total cholesterol minus LDL cholesterol minus HDL cholesterol, and it can be worked out from fasting or non-fasting cholesterol tests (Nordestgaard 2016 (EAS/EFLM)). It is the cholesterol in very low-density lipoproteins (VLDL), intermediate-density lipoproteins (IDL) and chylomicron remnants, which the consensus also calls triglyceride-rich lipoprotein cholesterol (Nordestgaard 2016 (EAS/EFLM)).

For example, total cholesterol of 200 mg/dL, LDL of 120 mg/dL and HDL of 50 mg/dL give 200 − 120 − 50 = 30 mg/dL. In mmol/L, 5.2 − 3.1 − 1.3 = 0.8 mmol/L. All three numbers must be in the same unit.

Remnant cholesterol is one part of non-HDL cholesterol (total minus HDL), which also contains LDL and lipoprotein(a) cholesterol (Nordestgaard 2016 (EAS/EFLM)). Your non-HDL cholesterol and its healthy range are on the LDL calculator.

Measured or calculated LDL matters

Many labs do not measure LDL directly but calculate it from the other three numbers. The consensus notes that if LDL is calculated (with the Friedewald equation), remnant cholesterol works out to triglycerides divided by 2.2 in mmol/L, or by 5 in mg/dL (Nordestgaard 2016 (EAS/EFLM)). In that case this calculator only restates your triglycerides. It tells you more when your LDL was measured directly or with a different equation. Your lab report usually says which method it used. The LDL calculator shows the Friedewald and Sampson (NIH) equations side by side.

The flag levels

The 2016 consensus suggests that lab reports flag calculated remnant cholesterol as abnormal at (Nordestgaard 2016 (EAS/EFLM)):

• 0.9 mmol/L (35 mg/dL) or higher on a non-fasting sample
• 0.8 mmol/L (30 mg/dL) or higher on a fasting sample

These are desirable levels for flagging, not a diagnosis. The consensus estimated that 27% of people in a Western or Northern European country would have a non-fasting remnant cholesterol at or above 0.9 mmol/L (Nordestgaard 2016 (EAS/EFLM)). The mg/dL values are the consensus's own, rounded to the nearest 5 mg/dL. After a normal meal, remnant cholesterol rose on average by at most 0.2 mmol/L (8 mg/dL), a change the consensus did not consider clinically significant (Nordestgaard 2016 (EAS/EFLM)).

If you are not sure whether you fasted, the calculator uses the non-fasting level.

What the research found

A 2013 Danish study of 73,513 people used gene variants that raise remnant cholesterol to test whether it causes heart disease (a Mendelian randomization design). A genetic increase of 1 mmol/L (39 mg/dL) in non-fasting remnant cholesterol went with a 2.8 times higher odds of ischemic heart disease, independent of lower HDL cholesterol. In ordinary observation, the same increase went with a 1.4 times higher risk. The authors wrote that the findings need to be confirmed with other gene variants or randomized trials (Varbo 2013).

These results describe groups of people, not your own chance of a heart attack. For that, use a calculator that also counts age, blood pressure, smoking and diabetes, such as the PREVENT heart risk calculator.

Related research indexes

Other markers from the same cholesterol test focus on triglycerides. The triglyceride to HDL ratio divides triglycerides by HDL, and the atherogenic index of plasma takes the logarithm of that ratio in mmol/L. See triglyceride levels for the adult triglyceride categories. None of these diagnoses a disease.

Getting the right numbers

Use total, LDL and HDL cholesterol from the same test and in the same unit. Your clinician will look at each of them against its own range (MedlinePlus). If you compare remnant cholesterol over time, use results taken the same way each time, fasting or not, and with the same LDL method.