6 7 8 9 10 11 12 13 14 15 16 17 18 0
10 20 30 40 50 60 70
%
yr
Figure 11. Common variances of relative fat content metric and plastic indices (open bars = metric index, full bars = plastic index).
By the scaling of vertical axis of the two figures it seems to be obvious, the com-mon biological content of relative fat and body weight or body mass index (this final one contains the body weight too) was remarkably greater then the common variances of estimated fat and growth type characteristics, but none of the mentioned measures and indices are not independent from body fat content.
The deviation between chronological age and biological development may reach the magnitude of years in teenagers. There are a number of situations in which is necessary to determine biological development by more precise means than simply referring to calendar age. This is particularly so when children have to be characterised by their physical performance, above all before and during puberty.
Age determination is also important when final adult height has to be predicted.
A taller stature is of advantage in most sports. Stature was less significant for the par-ticipants of the Olympic Games in 1960 than either Munich or in more recent times.
Obviously, stature is also bound to be increasing importance in the detection of sport talents. So we are facing a period when suitably sensitive and routinely applicable meth-ods are determined. With regard to non-X-ray procedures for the estimation of adult sta-ture are of interest.
These methods are, however, less accurate when transferred to other countries.
The purpose of the present part of this thesis was to adapt a method (Mészáros et al., 1984; 1986) by which morphological age could be suitably estimated in Hungarian children and adolescents.
Procedure:
A nation-wide representative sample is required to construct a diagram of height, body weight and plastic index with interpolated points for every quarter of a year. The calculated means and also the interpolated values representing the growth patterns of Cypriot boys are summarised in Table11. The mean stature of young adults was taken as 100%; percent values of height were assigned to every point of the chart.
These data and chronological age (expressed in decimal system) were used to es-timate morphological age in a following manner:
a) Decimal age is calculated by subtracting the birth date from the data of study by the suggestions of the International Biological Program (Weiner and Lourie, 1969). The original table for the decimal system transformation can be seen in the Table 1 of the appendices.
b) Three other estimates of age are derived by using Table 11 – one for the sub-ject’s stature, one for weight, and one for the plastic index obtained for the ti-me of the study. Each of these estimates is expressed as the accurate to the nearest quarter of a year.
Table 11. Standards for the estimation of morphological age and prediction of young adult stature
Age BH BH% BM BM% PLX PLX%
18.00 174.62 100.00 71.40 100.00 86.75 100.00 17.75 174.49 99.75 70.89 99.29 86.66 99.90 17.50 174.35 99.67 70.39 98.59 86.57 99.79 17.25 174.22 99.60 69.88 97.87 86.48 99.69 17.00 174.08 99.52 69.37 97.16 86.39 99.59 16.75 173.61 99.25 68.45 95.87 85.94 99.07 16.50 173.13 98.98 67.53 94.58 85.49 98.55 16.25 172.66 98.71 66.61 93.29 85.04 98.03 16.00 172.18 98.43 65.69 92.00 84.59 97.51 15.75 171.24 97.90 64.98 91.01 84.12 96.97 15.50 170.30 97.36 64.26 90.00 83.64 96.41 15.25 169.36 96.82 63.55 89.01 83.17 95.87 15.00 168.42 96.28 62.83 88.00 82.69 95.32 14.75 166.98 95.45 61.50 86.13 81.89 94.40 14.50 165.54 94.64 60.17 84.27 81.08 93.46 14.25 164.09 93.81 58.83 82.39 80.28 92.54 14.00 162.65 92.99 57.50 80.53 79.47 91.61 13.75 161.49 92.32 56.50 79.13 78.83 90.87 13.50 160.32 91.65 55.50 77.73 79.19 91.29 13.25 159.16 90.99 54.49 76.32 77.54 89.38 13.00 157.99 90.32 53.49 74.92 76.90 88.65 12.75 156.07 89.22 51.60 72.27 75.88 87.47 12.50 154.16 88.13 49.72 69.64 74.86 86.29 12.25 152.24 87.03 47.83 66.69 73.84 85.12 12.00 150.32 85.94 45.94 64.34 72.82 83.94 11.75 148.87 85.11 44.69 62.59 72.03 83.03 11.50 147.42 84.28 43.45 60.85 71.25 82.13 11.25 145.96 83.44 42.20 59.10 70.46 81.22 11.00 144.51 82.61 40.95 57.35 69.67 80.31 10.75 142.93 81.71 39.51 55.34 68.95 79.48 10.50 141.31 80.79 38.06 53.31 68.24 78.66 10.25 139.70 79.87 36.62 51.29 67.52 77.83 10.00 138.05 78.92 35.17 49.26 66.80 77.00 9.75 137.08 78.37 34.53 48.36 66.45 76.60 9.50 136.10 77.81 33.89 47.46 66.09 76.18 9.25 135.13 77.25 33.24 46.55 65.74 75.78 9.00 134.15 76.69 32.60 45.66 65.38 75.37 8.75 132.99 76.03 31.80 44.54 64.88 74.79 8.50 131.83 75.37 31.01 43.43 64.39 74.22 8.25 130.66 74.70 30.21 43.71 63.89 73.65 8.00 129.50 74.03 29.41 41.19 63.39 73.07 7.75 127.80 73.06 28.25 39.57 62.60 72.16 7.50 126.11 72.10 27.08 37.93 61.82 71.26 7.25 124.41 71.12 25.92 36.30 61.03 70.35 7.00 122.71 70.15 24.74 34.65 60.24 69.44 6.75 121.74 69.60 24.36 34.12 59.88 69.03 6.50 120.77 69.04 23.99 33.60 59.52 68.61 6.25 119.79 68.48 23.61 33.07 59.19 68.23 6.00 118.82 67.93 23.23 32.54 58.80 67.78
Where: BH = height, BH% = the age group height expressed as a percentage of young adult stature, BM
PLX = plastic index, PLX% = the age group plastic index expressed as a percentage of young adult plastic index mean.
c) Morphological age is found as the arithmetic mean of these four estimates of age.
d) Correction is necessary when the subject’s actual stature is near to the value of children more than 1 year older or younger. The correction means a 5%
reduction of the estimated morphological age when the subject is much taller than his peers or vice versa. The correction is 8% when the subject’s actual stature is near to the value of children more than 2 years older or younger.
This makes the evaluation more realistic for children who inherited tall or small stature. The estimation of morphological age should rely on only three estimators when the age derived from the body weight is seriously biased by excessive obesity.
e) Prediction of young adult stature: From the actual age, one has to look up the percent (BH% in Table 11) assigned to this age. Young adult stature can be obtained by multiplying the actual stature by 100 and dividing by this per-centage. The final height of the individual will vary between the -1 and +2 centimetre range around the calculated young adult height.
Figure 12 contains the age-related trends of height, body mass and plastic index.
All the values are expressed in a percentage of young adult mean. The figure indicates the relative weights of the estimator variables.
6 7 8 9 10 11 12 13 14 15 16 17 18 30
40 50 60 70 80 90 100
yr
%
body m as s plas tic inde x
body he ight
Figure 12. Relative age group differences in height, plastic index and body weight (all
The linear correlations of the fit are very strong in case of all the three esti-mators.
Linear regression lines:
Relative height increase = 50.21 + 2.96 age r = 0.996 Relative body mass increase = -9.69 + 6.30 age r = 0.991 Relative plastic index increase = 48.44 + 3.02 age r = 0.995
It can be recognised easily the body height and plastic index have a similar rela-tive weight during the estimation procedure. Since, the range of relarela-tive body mass is remarkably wider than those of the stature and plastic index we can conclude the body weight is more sensitive during the calculation of morphological age in spite of the fact that it is more sensitive for the various effects of the environment. Consequently, the calculation is more precise if it based on four estimation variables.
Chapter 6. DISCUSSION
Introduction
Human body structure, composition and shape reach adult status in the course of growth and maturation under the interactive effects of hereditary and environmental fac-tors. The prevailing mental and bodily conditions of any population are exactly mirrored by the children that live in the same region. So by regular and well designed child stu-dies one gets a reliable picture of the whole society (Tanner, 1990; Cameron, 2006). In some European countries economic and social changes affected many people adversely.
Concurrently, we also have to face processes that are characteristic of consumer socie-ties, a gradual decrease of habitual physical exercise and its consequences manifested by unfavourable changes of body composition and physique. During the 20th century body size in the human populations changed rapidly first in the industrialised countries and later in the majority of the developing countries too. This change of the body measurements and proportions is called as secular trend or secular growth change and the most remarkable phenomenon of it is the increase of adult height in each following generations (Eveleth and Tanner, 1976; Malina, 2004). Taking into account the above summarised results and facts, it seems to be obvious that the correct evaluation of the human biological status of a given population requires the results of the previous invest-igations. Since, our data collection is the first in our country this possibility of compari-sons is missing unfortunately.