Lipid accumulation product calculator

The formula

The index uses a different waist starting point for men and women (Kahn 2005):

Men: LAP = (waist in cm - 65) × fasting triglycerides in mmol/L

Women: LAP = (waist in cm - 58) × fasting triglycerides in mmol/L

The result is in cm·mmol/L. The 65 cm and 58 cm values are the study's estimate of the smallest waist an adult would have, the size that holds mostly muscle, organs and spine with little stored fat. They were worked out from US adults aged 18 to 24 (Kahn 2005). If your lab reports triglycerides in mg/dL, we divide by 88.57 to get mmol/L; a waist in inches is multiplied by 2.54.

For example, a man with a 100 cm waist and fasting triglycerides of 1.5 mmol/L (about 133 mg/dL) has a LAP of (100 - 65) × 1.5 = 52.5. A woman with an 88 cm waist and triglycerides of 1.2 mmol/L (about 106 mg/dL) has a LAP of (88 - 58) × 1.2 = 36.

The study measured waist standing, level with the top of the right hip bone, at the end of a normal breath out (Kahn 2005). The formula gives zero or less at or below the minimum waist, so the calculator does not give a value there; in the study, five young men with a waist of 65 cm or less had their waist set to 66 cm (Kahn 2005).

Where your value falls among US adults

The paper sets no cutoff for a high or normal LAP. What it does report is how LAP was spread across US adults in NHANES III, by sex and age group (Kahn 2005):

Values in cm·mmol/L, from Table 2 of the paper (Kahn 2005). The calculator tells you which quarter of your group your value falls in. That is a comparison with other people, not a risk level. LAP rose with age in both sexes, and men's values rose faster than women's before age 50 (Kahn 2005).

What the study found

The study ranked everyone into quarters by LAP and, separately, by BMI. Nearly half of the US adults it represented landed in a different quarter for each (Kahn 2005). Those whose LAP quarter was higher than their BMI quarter had less healthy levels of seven blood fat measures, uric acid, heart rate and blood pressure than those whose BMI quarter was higher (Kahn 2005). Used as a continuous number, LAP was more strongly linked than BMI to nine of the 11 risk factors checked, though not to blood pressure (Kahn 2005).

All of these results come from measurements taken at the same time. The author wrote that LAP might predict heart disease better than BMI, but that this needed testing in studies that follow people over time, and that the paper should be seen mainly as a demonstration of the idea (Kahn 2005).

A research index, with limits

LAP needs a fasting blood test, and the author noted that the fasting and the blood draw can be a burden (Kahn 2005). It has no cutoff from its original study, the percentiles describe US adults measured in 1988 to 1994, and it does not diagnose metabolic syndrome, diabetes, fatty liver or heart disease. A high value is a reason to talk to your doctor about your waist size, triglycerides and other heart risk factors, not a diagnosis.

Related checks

The metabolic syndrome criteria checker uses waist size and fasting triglycerides with set cutoffs, plus blood pressure, HDL and blood sugar. The waist-to-height ratio and waist-to-hip ratio look at waist size on its own. The visceral adiposity index (VAI) adds BMI and HDL to waist and triglycerides. The TyG index calculator pairs fasting triglycerides with glucose, and the fatty liver index uses triglycerides, waist, BMI and GGT. For what triglyceride numbers mean, read triglycerides explained.