What is atherogenic index of plasma?
Your triglycerides are the fat your liver sends round from the sugar, fat and alcohol you took in, and your HDL are the particles that bring cholesterol back out of the vessel wall. With belly fat and insulin resistance those two move against each other: the triglycerides rise and the HDL falls. The atherogenic index of plasma catches those two movements in one number, by dividing the triglycerides by the HDL and taking the logarithm of the result. That logarithm is the only difference from the ordinary triglyceride/HDL ratio, and it mainly changes how the result looks. A division above one becomes a positive number, a division below one becomes negative, and zero means your triglycerides and your HDL are exactly the same size. A negative result is therefore not a deficit but a property of the scale, and it is also the healthy side. Because the logarithm compresses large differences, a sizeable change in the division underneath looks modest on this scale. The index appears on no Dutch report; you calculate it with the calculator on this page, from triglycerides and HDL in mmol/L. The result has no unit and no agreed normal value: the paper that introduced the name in 2001 published no division, and whoever later devised categories for it chose them themselves. Below zero is the healthy side, and the lower, the better.
Why is atherogenic index of plasma relevant?
The index puts together the two fat values that respond most strongly to how you live. Triglycerides go down with less sugar, less alcohol, losing weight and exercise; HDL goes up with exercise, losing weight and stopping smoking. Anyone who changes their lifestyle therefore sees the index move on two sides at once, and that makes it a sensitive measure of the gain from that change. The second reason is that the combination says something the separate numbers say less sharply. High triglycerides with a low HDL is the fat pattern of belly fat and insulin resistance, the forerunner of type 2 diabetes, and it goes together with small, dense LDL particles that lodge more easily in the vessel wall. An index above zero is therefore an early signal that the sugar balance needs attention, often years before the fasting glucose moves. The honest limitation is that the index is mainly a research measure. In the Netherlands nobody prints it, the risk estimate works with LDL and non-HDL, and there is no agreed division: two studies from 2026 set their boundaries at 0.21 and 0.5, or derive their own boundary of 0.3661. So read the index as a summary of two numbers you already have, not as a result with a norm.
How atherogenic index of plasma is worked out
What counts beside the number:
- The separate values of triglycerides and HDL, because the same index belongs to several combinations
- Whether you were drawn fasting, because the triglycerides in the numerator rise for hours after a meal
- How much belly fat you carry, how much you exercise and how much sugar and alcohol you drink, because those steer both numbers
- Your fasting glucose and HbA1c, because an index above zero is often the first sign that the sugar balance is moving along
- LDL and non-HDL, the measures the risk estimate works on and which the index says nothing about
- Your earlier results from the same lab, because without an agreed boundary your own course is the reference point
There is no agreed normal value for this index, and in the Netherlands nobody prints it. The paper that introduced the name, Dobiášová and Frohlich in 2001, describes 1433 people from 35 cohorts and reports correlations, not a division. Anyone who later uses categories chooses them themselves, and two studies from 2026 show how far apart that goes: one splits at low below 0.21, moderate from 0.21 to 0.5 and high above 0.5, the other derives its own boundary and lands on 0.3661. So no division appears here. What does stand: below zero your triglycerides are lower than your HDL, and that is the healthy side. To do something with the same two numbers that does appear on a Dutch report, look at the triglyceride/HDL ratio, the same division without the logarithm.
AIP = log10(triglycerides / HDL cholesterol), both in mmol/l
The logarithm is what sets this index apart from the ordinary triglyceride/HDL ratio: it compresses the same two figures onto a scale around zero, where a result below zero means your HDL is larger than your triglycerides and above zero the reverse holds. The input is the same; the scale is not. It takes two figures from the same lipid profile.
log10( ÷ ) =
Atherogenic index of plasma high or low: what it means
A low index is favourable, and below zero means only that your HDL is larger than your triglycerides. Being drawn fasting rather than non-fasting lowers the triglycerides and with them the index; anyone who drinks less sugar and alcohol, exercises and loses weight sees the numerator fall and the denominator rise; and a high HDL makes the denominator larger without anything changing about the triglycerides. With a low index always check whether LDL itself sits below the limit that fits your risk, because the index says nothing about that. A high index means your triglycerides sit above your HDL. The most common explanation first: having eaten or drunk recently, because triglycerides rise for hours after a meal while HDL stays still; belly fat and insulin resistance, the pattern in which the liver makes more triglycerides and HDL falls; type 2 diabetes, in which that same pattern is locked in; alcohol, which makes the liver produce extra triglycerides; and rarely oestrogen therapy, which lifts the triglycerides. What you do about it: cut soft drinks, fruit juice and sweets, because sugar is converted into triglycerides in the liver, drink less alcohol, eat oily fish, fibre and unsaturated fat, and lose weight if you carry belly fat. Exercise, also vigorously, because that lowers the triglycerides and lifts HDL. Stop smoking. Count on six to twelve weeks before the index shows the change, and then have blood drawn fasting, otherwise you compare two different moments. Read the index beside the triglycerides and HDL themselves, because the same result belongs to several combinations, beside the triglyceride/HDL ratio, which is the same division without the logarithm, beside non-HDL and LDL, which the risk estimate works on, and beside fasting glucose and HbA1c, which show whether the sugar balance is already moving along.
What lowers it
Favourable: the triglycerides fall or the HDL rises, and the logarithm compresses both movements.
| Cause | How often |
|---|---|
| Drawn fasting rather than non-fastingTriglycerides rise for hours after a meal and HDL does not, so a fasting draw gives a lower numerator than a draw after breakfast | Often |
| Treating the underlying causeLess sugar and alcohol, losing weight, exercise and better-controlled diabetes lower the triglycerides and lift HDL, so the index falls on two sides | Sometimes |
| A high HDLMakes the denominator larger without anything changing about the triglycerides; check whether LDL itself sits below the limit that fits your risk | Sometimes |
What raises it
Your triglycerides sit above your HDL: usually through the draw, and structurally through the pattern of belly fat and insulin resistance.
| Cause | How often |
|---|---|
| Having eaten or drunk recentlyTriglycerides rise after every meal and stay high for hours, while HDL stays still; the most common reason for an unexpectedly high index | Often |
| Belly fat and insulin resistanceThe liver makes more triglycerides and HDL falls, so both sides of the division move the wrong way; often years before the glucose moves | Often |
| Type 2 diabetesThe same pattern of high triglycerides with a low HDL, and the stronger the worse the sugars are controlled | Often |
| AlcoholThe liver converts alcohol into triglycerides; even a few glasses a day lifts the numerator | Sometimes |
| Oestrogen therapyOestrogen in tablet form makes the liver produce more triglycerides | Rare |
How does an atherogenic index of plasma blood test work?
- Referral
- Not needed. The index follows from two values that sit in every lipid profile, and you calculate it with the calculator on this page; in the Netherlands nobody prints it.
- Fasting
- Yes, because the triglycerides in the numerator rise for hours after a meal. Eight to twelve hours without food and only water to drink, and no alcohol the evening before.
- When
- In the morning, fasting, on an ordinary day with no party the evening before. Six to twelve weeks after a change in diet, weight or alcohol to see the effect.
- The draw
- One tube of blood from a vein in your arm. Triglycerides and HDL come from the same tube, and fasting glucose can go straight in with it.
- Repeating
- Once a year, or six to twelve weeks after a change in lifestyle. Compare with your previous fasting lipid profile and see which of the two numbers moved.
- Which test
- Atherogenic index of plasma is in the Heart health test (€69) and in .
- Where to draw
- You can draw at 250+ locations near you, no referral needed. See the locations
Frequently asked questions
What is the atherogenic index of plasma?
The logarithm of your triglycerides divided by your HDL, AIP for short. Through that logarithm the result lands on a scale around zero, and it can also be negative. The two numbers underneath are the same as for the triglyceride/HDL ratio, and they sit in every lipid profile. It is a calculation from research, not a test a Dutch lab prints.
What is a healthy atherogenic index of plasma?
Below zero: then your triglycerides are lower than your HDL, the picture of someone who exercises, drinks little sugar and alcohol and carries no belly fat. There is no agreed normal value; the paper that introduced the index published no division, and later boundaries such as 0.21 and 0.5 are choices of the researchers themselves. The lower, the better, and your own course is the reference point.
Why can my index be negative?
Because the logarithm of a number below one is negative. If your triglycerides are lower than your HDL, the division is smaller than one and the index lands below zero. That is a property of the scale and not of your blood, and it is also the healthy side: nothing is lacking.
What does a high atherogenic index of plasma mean?
That your triglycerides sit above your HDL. The most common reason is that you had eaten or drunk shortly before the draw, because triglycerides rise for hours after a meal. Structurally it is the pattern of belly fat and insulin resistance: the liver makes more triglycerides and HDL falls, often years before the fasting glucose moves. Less sugar and alcohol, exercise and losing weight bring the index down on two sides.
Do I need to fast?
Yes. The triglycerides in the numerator move strongly with what you ate and drank shortly before, HDL hardly at all, so a non-fasting draw lifts the index without anything changing in your profile. Eight to twelve hours without food, only water, and no alcohol the evening before.
What is the difference from the triglyceride/HDL ratio?
Only the logarithm. Both use exactly the same two numbers from the same lipid profile; the index compresses the result onto a scale around zero and the ratio leaves it as it is. Because the logarithm compresses large differences, a sizeable change in the ratio looks modest on the index.
What do I do with an index above zero?
Cut soft drinks, fruit juice and sweets, because sugar is converted into triglycerides in the liver, drink less alcohol, eat oily fish, fibre and unsaturated fat, exercise vigorously too and lose weight if you carry belly fat. Count on six to twelve weeks and then have blood drawn fasting. Also look at your fasting glucose and HbA1c, because the pattern of high triglycerides with a low HDL is the forerunner of type 2 diabetes.
Why is this index on the site if nobody prints it?
Because you meet it in calculations and reports from outside the Netherlands and then want to know where the number comes from. The page explains the calculation and points to the two values that do appear on your report and have a band behind them. For the risk estimate Dutch doctors work with LDL and non-HDL, not with this index.
Which tests include atherogenic index of plasma?
Atherogenic index of plasma is in the comprehensive test (€229) and in .
Related biomarkers
Read on
Sources
- 1.Dobiášová M, Frohlich J, The plasma parameter log (TG/HDL-C) as an atherogenic index, Clinical Biochemistry. 2001. pubmed.ncbi.nlm.nih.gov
- 2.Mehta S, Baxi RK, Rathi PM, Atherogenic dyslipidemia as a novel cardiovascular risk stratification tool in chronic obstructive pulmonary disease, Monaldi Archives for Chest Disease. 2026. pubmed.ncbi.nlm.nih.gov
- 3.Li GA, Huang J, Wang YJ, The atherogenic index of plasma is associated with subclinical cardiac systolic dysfunction among obese patients, Frontiers in Nutrition. 2026. pubmed.ncbi.nlm.nih.gov
- 4.CVRM, Dutch multidisciplinary guideline on cardiovascular risk management, module on estimating cardiovascular risk. 2024. richtlijnendatabase.nl
- 5.Star-shl, determination guide: triglycerides. 2026. star-shl.nl
- 6.Unilabs, determination guide: HDL cholesterol. 2026. bepalingenklapper.nl
Educational information only, not medical advice. Consult a healthcare professional for clinical decisions.
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