Cookies help us deliver our services. By using our services, you agree to our use of cookies. More information

Healthy reference population

From Bioblast
Revision as of 09:28, 6 February 2020 by Gnaiger Erich (talk | contribs)


high-resolution terminology - matching measurements at high-resolution


Healthy reference population

Description

A healthy reference population, HRP, establishes the baseline for the relation between body mass and height in healthy people of zero underweight or overweight, providing a reference for evaluation of deviations towards underweight or overweight and obesity. The WHO Child Growth Standards on height and body mass refer to healthy girls and boys from Brazil, Ghana, India, Norway, Oman and the USA. The Committee on Biological Handbooks compiled data on height and body mass of healthy males from infancy to old age (USA), published before emergence of the fast-food and soft-drink epidemic. Four allometric phases are distinguished with distinct allometric exponents. At heights above 1.26 m the allometric exponent is 2.9, equal in women and men, and significantly different from the exponent of 2.0 underlying the concept of the body mass index, BMI [kg/m2].

Abbreviation: HRP

Reference: Body mass excess

Work in progress by Gnaiger E 2020-02-05 linked to a preprint in preparation on BME and mitObesity.

The HRP database

  • The WHO Child Growth Standards are based on large samples with similar numbers of girls and boys in longitudinal (N=1737 children) and cross-sectional studies (N=6669). The studies were conducted between 1997 and 2003 (WHO 2006 Acta Paediatr; WHO 2006 Geneva: World Health Organization; De Onis 2007 Bull World Health Organization).
  • Anthropometric studies carried out on adults since the 1960ies are prone to reflect the impact of high-caloric nutrition on allometric relationships, referring us to earlier time points for a HRP. The original studies in the CBH dataset (N=17523; Zucker 1962) were published between 1931 and 1944 and thus apply to a population (USA) before emergence of the fast-food and soft drink epidemic, and with a lifestyle demanding a balanced physical activity without the impact of local war or economic disaster on starvation. The CBH dataset includes men only, but it is emphasized that "evidence indicates that curves for females (not represented) are identical in slope and position with those of males".


From BMI to BME

Four allometric phases

The Committee on Biological Handbooks (1962) distinguishes three allometric phases from newborns to adults, with breaks of standing heights at 0.74 m (10 kg) and 1.21 m (22 kg), and corresponding allometric power functions in the equations


 Eq. 1:  ln M° = ln B + A·ln H
 Eq. 2:  ln H = ln β + α·ln M°
Range of H α β A B
- 0.74 m 0.34 0.3360 2.941 24.73
0.74 - 1.21 m 0.63 0.1726 1.587 16.26
1.21 - 1.8 m 0.35 0.4110 2.857 12.68
By comparison, analysis of the WHO database on height and body mass of children (De Onis 2007 Bull World Health Organization; further details: healthy reference population) reveals four allometric phases. The WHO Child Growth Standards on height and body mass of children and adolescents is based on a particularly quality-controlled selection of healthy populations, and agreement is within 1 % with the Biological Handbooks data in the region of overlap at heights >1.26 m. Therefore, these data sets were combined to establish a baseline of the healthy reference population for evaluation of body mass excess, distinguishing four allometric phases:
HRP M-H.png
Figure 1: Four phases of the allometric relationship between body mass, M°, and height, H, in the healthy reference population (HRP), and shift of M at body mass excess, BME, indicating underweight (BME = -0.2 and -0.1) or overweight (BME = 0.2) and increasing degrees of obesity (BME = 0.4 to 1.0).
Range of H α β A B
0.45 - 0.62 m 0.3240 0.3373 3.086 28.60
0.63 - 1.02 m 0.5869 0.2034 1.704 15.08
1.03 - 1.26 m 0.4591 0.2894 2.178 14.89
1.27 m - 0.35 0.4110 2.857 12.68


"The WHO Child Growth Standards depict normal growth under optimal environmental conditions and can be used to assess children everywhere, regardless of ethnicity, socio-economic status and type of feeding" (WHO 2006 Acta Paediatr). The HRP is characterized by three allometric phases in childhood to early adolescence (up to 1.26 m height), and a final phase with an exponent of 2.867 (=1/0.35) at heights above 1.26 m, equal in women and men (Fig. 1; green line for M° at BME=0).
At any given height, the personal body mass may deviate from the reference body mass, M°, in the HRP for the same height. This difference is the excess body mass, ME = M-M°. When normalized for M°, we obtain the simple definition of the body mass excess, BME = ME/M°. By this definition, the BME equals zero in the HRP at all heights. For comparison, it is instructive to calculate the BMI as a function of height in the HRP, defining this as the BMI° or precision-BMI at BME=0. The normal BMI of 20 kg·m-2 is obtained in the HRP at H=1.7 m and M°=57.7 kg/x. If this normal BMI would represent a general index independent of height, it should be constant for the HRP, which is clearly not the case, neither for adults nor children (Fig. 2).
HRP-BMI.png
Figure 2: Precision-BMI of the HRP, BMI°, with the BMI°=20 kg·m-2 at the height of 1.70 m in the healthy reference population (dashed lines). The circle marks the harmonization point between the BMI of 20 kg·m-2 (normal) and the precision-BMI°. For persons smaller than 1.7 m, the BMI° is below 20 kg·m-2, such that a BMI of 17.9 instead of 20 kg·m-2 is the precision reference at a height of 1.5 m. On the other hand, at a height of 1.9 m a BMI of 22 instead of 20 kg·m-2 is the precision reference (dotted lines).
The concept of body mass excess, BME, is simple and easy to communicate to the general public. In contrast, neither the BMI nor the concept of a precision-BMI can be explained easily. With the BMI firmly established by convention in the WHO, however, it is important to harmonize the concepts of BME and BMI. Fig. 2 provides the first step for harmonization by assigning to the height of 'reference man' (Sender 2016 PLOS Biol) the BMI of 20 kg·m-2 as BMI°. BME cutoff points for overweight and obese are then obtained for BMI cutoffs of 25 and 30 kg·m-2 at heights of 1.79 and 1.85 m, respectively.
» Further details: BME cutoff points).
Figure 3: Growth curves and allometry of body mass and height in girls and boys from 5 to 19 years (WHO 2006). (a) and (b): Height and body mass as a function of age. The curves are very similar up to 13 years. (c) and (d) Body mass and precision-body mass index, BMI°, as a function of height. Three allometric phases are indicated by the shaded areas. The BMI does not yield an index that is independent of height.
Figure 3 is based on the WHO Child Growth Standards (De Onis 2007 Bull World Health Organization). It illustrates the limitation of the BMI as an index of overweight and obesity. The precision body mass index, BMI°, is claculated for the healthy reference population (HRP), in which neither underweight nor overweight prevails and which, therefore, should be characterized by a constant index. This is achieved by the body mass excess, BME, which relates the actual body mass, M, to the reference body mass, M°, at a given height, BME=(M-M°)/M°. The BME is constant at 0.0 for the HRP for both sexes independent of height. In contrast, the increase of the precision BMI° from 15 to 21 kg·m-2 from 1.0 to 1.8 m represents a confounding factor which explains the necessity of adjusting the BMI cutoff points. Instead of a focus on adjusted BMI cutoff points (De Onis 2019 Public Health Nutrition), overweight and obesity should assessed in terms of the BME and BME cutoff points.



References HRP

  1. WHO Multicentre Growth Reference Study Group (2006) WHO child growth standards based on length/height, weight and age. Acta Paediatrica Suppl 450:76-85. - »Bioblast link«
  2. WHO Multicentre Growth Reference Study Group (2006) WHO child growth standards: length/height-for-age, weight-for-age, weight-for-length, weight-for-height and body mass index-for-age: Methods and development. Geneva: World Health Organization:312 pp. - »Bioblast link«
  3. de Onis M, Borghi E, Arimond M, Webb P, Croft T, Saha K, De-Regil LM, Thuita F, Heidkamp R, Krasevec J, Hayashi C, Flores-Ayala R (2019) Prevalence thresholds for wasting, overweight and stunting in children under 5 years. Public Health Nutrition 22:175-9. - »Bioblast link«
  4. de Onis M, Onyango AW, Borghi E, Siyam A, Nishida C, Siekmann J (2007) Development of a WHO growth reference for school-aged children and adolescents. Bull World Health Organization 85:660-7. - »Bioblast link«
  5. Zucker TF (1962) Regression of standing and sitting weights on body weight: man. In: Altman PL, Dittmer DS, eds: Growth including reproduction and morphological development. Committee on Biological Handbooks, Fed Amer Soc Exp Biol:336-7. – Anthropometry, H and M°, of the healthy reference population, HRP; based on [3.1-3.5]. - »Bioblast link«
    1. Bayley N, Davis FC (1935) Growth changes in bodily size and proportions during the first three years. Biometrika 27:26-87.
    2. Gray H, Ayres JG (1931) Growth in private school children. Behavior Res Fund Monog, Univ Chicago Press, Chicago:282 pp. – With averages and variabilities based on 3110 measurings on boys and 1473 on girls from the ages of one to nineteen years.
    3. Meredith HV (1935) Univ Iowa studies in child welfare 11(3).
    4. Peatman JG, Higgons RA (1938) Growth norms from birth to the age of five years: a study of children reared with optimal pediatric and home care. Am J Diseases Children 55:1233-1247.
    5. Simmons KW (1944) Monographs Soc Research in Child Develop 9(1).


Publications: BME and height

» Height of humans
 Reference
Bosy-Westphal 2009 Br J NutrBosy-Westphal A, Plachta-Danielzik S, Dörhöfer RP, Müller MJ (2009) Short stature and obesity: positive association in adults but inverse association in children and adolescents. Br J Nutr 102:453-61.
De Onis 2007 Bull World Health Organizationde Onis M, Onyango AW, Borghi E, Siyam A, Nishida C, Siekmann J (2007) Development of a WHO growth reference for school-aged children and adolescents. Bull World Health Organization 85:660-7.
Gnaiger 2019 MiP2019
Erich Gnaiger
OXPHOS capacity in human muscle tissue and body mass excess – the MitoEAGLE mission towards an integrative database (Version 6; 2020-01-12).
Hood 2019 Nutr DiabetesHood K, Ashcraft J, Watts K, Hong S, Choi W, Heymsfield SB, Gautam RK, Thomas D (2019) Allometric scaling of weight to height and resulting body mass index thresholds in two Asian populations. Nutr Diabetes 9:2. doi: 10.1038/s41387-018-0068-3.
Indian Academy of Pediatrics Growth Charts Committee 2015 Indian PediatrIndian Academy of Pediatrics Growth Charts Committee, Khadilkar V, Yadav S, Agrawal KK, Tamboli S, Banerjee M, Cherian A, Goyal JP, Khadilkar A, Kumaravel V, Mohan V, Narayanappa D, Ray I, Yewale V (2015) Revised IAP growth charts for height, weight and body mass index for 5- to 18-year-old Indian children. Indian Pediatr 52:47-55.
Zucker 1962 Committee on Biological Handbooks, Fed Amer Soc Exp BiolZucker TF (1962) Regression of standing and sitting weights on body weight: man. In: Growth including reproduction and morphological development. Altman PL, Dittmer DS, eds: Committee on Biological Handbooks, Fed Amer Soc Exp Biol:336-7.


MitoPedia concepts: MiP concept 


Labels:






MitoPedia:BME