LDL/HDL Ratio: A Key Cholesterol Balance

The ratio is nothing more than your LDL cholesterol divided by your HDL cholesterol. LDL is the cholesterol carried out to the tissues, which can accumulate in the artery wall; HDL is the cholesterol carried back to the liver. The lab measures those two, divides one by the other and prints the result. No extra tube of blood goes in, and no extra information comes out: everything in the ratio was already somewhere else on your report.

That sounds harmless, but it leaves the ratio vulnerable in two ways, and both come up more often than average in athletes.

The first is the calculation error the ratio inherits. In most laboratories your LDL is not measured but calculated, with the Friedewald formula: total cholesterol minus HDL minus triglycerides divided by 2.2. With high triglycerides or a non-fasting sample that assumption no longer holds. The calculated LDL then comes out too low, so your ratio looks better than reality. A blood draw after a carbohydrate-heavy loading phase, or simply too soon after your last meal, is enough to produce that effect. The cholesterol/HDL ratio does not have this problem, because it uses two directly measured values.

The second is what is missing. VLDL particles and the remnants left over from them do carry cholesterol into the artery wall, but they appear in neither the numerator nor the denominator. Anyone with high triglycerides and reduced insulin sensitivity sees none of that reflected in this number. Non-HDL cholesterol does count those particles.

This is also a different number from the cholesterol ratio. The cholesterol/HDL ratio uses total cholesterol in the numerator; for that one the NVKC publishes a limit of 5, and preferably below 3.5. For the LDL/HDL ratio the NVKC publishes no limit, and the 3 that is often quoted is an international rule of thumb without a Dutch source. That is why this page shows no reference value.

If you track your blood values to perform better and recover better, this ratio tells you the least of all the lipid values, and that is where the guidelines stand. The European ESC/EAS guideline sets its targets on LDL cholesterol, with non-HDL cholesterol and ApoB as secondary goals; the Dutch NHG CVRM standard steers on LDL and non-HDL. For the LDL/HDL ratio, neither sets a goal.

There is also an arithmetic illusion built into it. An LDL of 3.0 mmol/l with an HDL of 1.0 mmol/l gives a ratio of 3.0. An LDL of 4.5 mmol/l with an HDL of 1.5 mmol/l also gives exactly 3.0. Identical number, and yet the second person carries fifty percent more atherogenic cholesterol. It is that absolute LDL which accumulates in the artery wall, so a ratio that looks good says nothing until you place the individual values next to it.

For athletes there is a trap of their own on top of that. Regular endurance training raises HDL slightly, while LDL often barely moves. The ratio falls, your result looks better, and the amount of harmful cholesterol has stayed exactly the same. The number flatters you, and that feels like progress when nothing has been won.

There is one situation in which this ratio is in fact sharper than its components: the use of anabolic androgenic steroids. Androgens push HDL down substantially and drive LDL up. Both halves of the fraction therefore move the wrong way at once, which makes the ratio swing harder and earlier than the LDL or the HDL on their own. As a within-person trend, measured under the same conditions, that is usable information, and it is the only place where this ratio earns its spot on your report. It gives no reason to dose or change anything yourself: discuss it with a doctor.

For everything else, let non-HDL or ApoB carry more weight. Non-HDL needs no formula, does not break at high triglycerides and requires no fasting. ApoB counts the number of harmful particles instead of their cargo. Both say something this ratio cannot.

You do not order this ratio separately. It falls out of a lipid panel automatically once the LDL and the HDL have been determined, so the real question is how you take that panel.

Fasting counts for more here than for most lipids. Total cholesterol and HDL barely change after a meal, but triglycerides do, and your LDL is calculated from them. So test fasted, and avoid a draw straight after a carbohydrate-heavy loading phase or a period of heavy drinking. Above roughly 4.5 mmol/l of triglycerides the formula is no longer valid and the ratio says nothing at all.

Also take your training load into account. A long endurance session can temporarily lower triglycerides and slightly raise HDL, for up to a few days afterwards. If you want to compare values between two training blocks, always test at a comparable point in the week and at the same laboratory. And wait a few weeks after an infection, surgery or a significant injury, because cholesterol falls temporarily in that period.

A newly abnormal result deserves a search for an underlying cause before you start adjusting your diet. An underactive thyroid raises LDL and is often missed, so have a TSH included.

Who you are and what you do also decide where your ratio lands by itself. In men HDL is on average lower than in women, so at the same LDL the ratio comes out structurally higher and the often quoted rule of thumb of 3 is in practice stricter for men. In women before menopause oestrogen keeps HDL higher, so the ratio comes out lower and comparing your number with your training partner's says little; around and after menopause LDL rises while HDL may slip slightly, so the ratio climbs faster than the LDL alone. Regular endurance training lets HDL rise slightly against an LDL that often stays flat, so the ratio falls without the atherogenic burden having fallen. Anabolic androgenic steroids push HDL down substantially and LDL up, so the ratio worsens steeply and early. And with high triglycerides or a non-fasting draw the calculated LDL comes out too low, so the ratio looks favourable when it should not.

Have every result assessed by a doctor, together with your individual values and your full risk profile.