The Corpulence Index (CI) (also Ponderal Index (PI) or Rohrer's Index) is a measure of
corpulence, or of leanness in other variants, of a person
[''Foods and Nutrition Encyclopedia'', Audrey H. Ensminger, Marion Eugene Ensminger. p. 1645] calculated as a relationship between mass and height.
[EXSS 323: LAB 1 - BIOMECHANICS TOOLS: Computers, Algebra and Trig]
Oregon State University
It was first proposed in 1921 as the "Corpulence measure" by Swiss physician
Fritz Rohrer and hence is also known as Rohrer's Index. It is similar to the
body mass index, but the mass is normalized with the third power of body height rather than the second power.
[ In 2015, Sultan Babar showed that CI does not need to be adjusted for height after adolescence.][
:
with in kilograms and in metres, giving a measure with the same ]dimensions
In physics and mathematics, the dimension of a mathematical space (or object) is informally defined as the minimum number of coordinates needed to specify any point within it. Thus, a line has a dimension of one (1D) because only one coordin ...
as density
Density (volumetric mass density or specific mass) is the substance's mass per unit of volume. The symbol most often used for density is ''ρ'' (the lower case Greek letter rho), although the Latin letter ''D'' can also be used. Mathematical ...
. The corpulence index yields valid results even for very short and very tall persons, which is a problem with BMI — for example, an ideal body weight for a person 152.4 cm tall (48 kg) will render BMI of 20.7 and CI of 13.6, while for a person 200 cm tall (99 kg), the BMI will be 24.8, very close to the "overweight" threshold of 25, while CI will be 12.4.
Because of this property, it is most commonly used in pediatrics.[ACC/SCN NUTRITION POLICY PAPER No. 19 - Glossary](_blank)
by Lindsay H. Allen and Stuart R. Gillespie (For a baby, one can take crown-heel length for the height.) The normal values for infants are about twice as high as for adults, which is the result of their relatively short legs. It does not need to be adjusted for age after adolescence. It has also been shown to have a lower false positive rate in athletes.
The corpulence index is variously defined (the first definition should be preferred due to the use of SI-units kg and m) as follows:
Significance
* It plays a role in assessing whether the intrauterine growth restriction
Intrauterine growth restriction (IUGR), or fetal growth restriction, refers to poor growth of a fetus while in the womb during pregnancy. IUGR is defined by clinical features of malnutrition and evidence of reduced growth regardless of an infant's ...
of a child is symmetrical or asymmetrical.
* CI has been shown to have higher sensitivity, specificity, and positive and negative predictive values than body mass index for determining adiposity
Adipose tissue, body fat, or simply fat is a loose connective tissue composed mostly of adipocytes. In addition to adipocytes, adipose tissue contains the stromal vascular fraction (SVF) of cells including preadipocytes, fibroblasts, vascular ...
.
* It is used to calculate ''ectomorphy'' in the Heath–Carter formula.
See also
* Body adiposity index
* Body mass index
* Waist-to-height ratio
A person's waist-to-height ratio (WHtR), occasionally written WtHR or called waist-to-stature ratio (WSR), is defined as their waist circumference divided by their height, both measured in the same units. It is used as a predictor of obesity-re ...
References
{{reflist
External links
Online Ponderal Index Calculator
which uses the first definition.
Ponderal Index Calculator
which uses metric values. (German site)
Android App for Corpulence Index
Apple app for Corpulence Index
Medical terminology
Body shape
Classification of obesity
Human body weight
Pediatrics