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Brief Reports

Indian Pediatrics 2000;37: 990-997

Insulin Like Growth Factor-I, Insulin Like Growth Factor Binding Protein-3 and Acid Labile Subunit Levels in Healthy Children and Adolescents Residing in Mumbai Suburbs


Rajbinder Kaur Dehiya
Deepa Bhartiya
Chhaya Kapadia
Meena P. Desai

From the Cell Biology Department, Research Society, B.J. Wadia Hospital for Children and Institute of Child Health, Acharya Donde Marg, Parel, Mumbai 400 012, India

Reprint requests: Dr. Deepa Bhartiya,Cell Biology Department, B.J. Wadia Hospital for Children, Acharya Donde Marg, Parel, Mumbai 400 012, India

Manuscript received: June 17, 1999;
Initial review completed: August 10, 1999;
Revision accepted: March 21, 2000

The actions of growth hormone (GH), a major regulator of growth, are mediated via Insulin like Growth Factor-1 (IGF-1), produced by the liver(1). Almost 95% of IGF-1 in circulation is present in a 150 kDa complex, with its binding protein-3 (IGFBP-3) and another protein, Acid Labile Subunit (ALS,2). This complex stabilizes IGF-1, prolongs its half-life and also regulates its bio-availability to growing tissues(2). These peptides viz., IGF-1, IGFBP-3 and ALS appear to be more stable than GH (which is pulsatile in nature), show minimum diurnal variation and are being used to screen for GH deficiency(3) in an easier manner than the conventional GH measurement. They are also being studied in cases of GH insensitivity(4), intrauterine growth retardation(5), polycystic ovarian syndrome(6) and central precocious puberty(7).

It is a well established fact that children of developing countries do not attain same level of growth as their Western counterparts. Compari-sons with the European countries show that even affluent Indians are shorter and lighter(8,9). It has been shown in the past, that using Western percentiles, there would be unnecessary investigation for short stature in a third of our normal population(10). Recently, Khadagwat et al.(11) found that Agarwal charts(8,9) were better representative of growth of normal Indian children than the NCHS or ICMR charts (the latter were based on Indian children of low socio-economic status families and the study was conducted four decades ago).

Since IGF-1, IGFBP-3 and ALS are essentially involved in postnatal growth, we have analyzed their levels in healthy children and adolescents (from birth to 20 years of age) residing in Mumbai suburbs and have also made comparisons between present study data and that available for Western population.

  Subjects and Methods

The study population included 434 children/adolescents (new-born to 20 years of age; atleast 10 males and 10 females per year of age). Samples from healthy full-term new borns, delivered normally after uncomplicated preg-nancies and weighing more than 2.5 kg at birth, were collected from a maternity hospital. To collect samples from older children/adolescents, camps were organized in large residential complexes in Mumbai suburbs. The children included, belonged to well-to-do higher to middle class families with monthly income over Rs. 5000. We worked on the premise that our study population had maximum growth potential, since they did not belong to low socio-economic status families. Nutrition was not a limiting factor in our population was further confirmed by plotting the heights and weights of our study group on Agarwal's growth charts(8,9) generated on children belonging to affluent class of our community. Almost 90% of our children had their heights and weights falling within the 3rd and 97th percentile of Agarwal charts. As weight for height is the best anthropometric index of nutrition, using EPIINFO software, we found 96% of our children above 10 years of age to be more than 90% of mean weight for height by NCHS standards. However, in age group below 10 years, 50% of present study children were more than 50% of mean weight for height by NCHS standards. The children had no history of systemic illness and also no obvious problem in growth/height. None of the girls included in the study had delayed onset of menses. Two ml of blood was collected and the serum was stored in aliquots at –70°C till further analysis.

Measurement of IGF-1, IGFBP-3 and ALS: Commercial kits from Diagnostic Systems Laboratories, USA were used to measure all the three peptides.

Statistical Analysis: Body Mass Index (BMI) was calculated using the formula Weight (kg)/Height2 (meters). Data was analyzed using the Statistical Analysis Software (SAS, North Carolina, USA). Correlation between the peptides and various clinical parameters such as age, weight, height and BMI were studied by multivariate analysis. Graphs were made using the Microsoft Excel Software. Statistical significance of difference between the present study and the Western population(12) was determined by the Students "t" test (two-tailed). A ‘p’ value of less than 0.05 was considered statistically significant.

  Results

Levels of all the three peptides, from birth to 20 years of age, are shown in Tables I-III. A steady increase in the circulatory levels of all the three peptides with age was observed. IGF-1 levels in circulation, showed more dramatic alterations in both the sexes, compared to IGFBP-3 and ALS. Almost a thirty fold increase in IGF-1 and a five fold increase in IGFBP-3 levels was noticed at 12-14 years in girls and 15 years in boys followed by a decline. Circulatory levels of ALS showed a seven and a nine fold rise at 14 years in girls and 17 years in boys, respectively, followed by a decline thereafter.

Multivariate analysis with age and BMI as the independent variables revealed that all the three peptides correlated significantly with BMI in females and with age in males.

On comparison of IGF-1 and IGFBP-3 levels (mean ±SE) obtained in present study with the Western population , IGF-1 levels were observed to be lower in the present study population (Fig. 1) than their Western counterparts, at all ages in both the sexes, IGFBP-3 levels showed considerable overlap between the two popula-tions except at birth, where IGFBP-3 levels were significantly lower in the present study group.

  Discussion

In the present study, circulatory levels of IGF-1, IGFBP-3 and ALS were studied in Indian children residing in Mumbai suburbs. Unlike IGFBP-3 and ALS, IGF-1 showed more dramatic changes with age. Though levels increased gradually till 10 years of age, a thirty-fold rise was observed during adolescent years. Early peaks were observed in girls (12-14 years) as compared to boys (15 years) in accordance with the earlier sexual maturation in girsl(13). Interestingly ALS levels peaked later in both girls (14 years) and boys (17 years).

In agreement with earlier studies conducted in healthy Japanese(1). Caucasians(13), and Spanish(14) children, the present data revealed distinct age related alterations in the circulatory levels of all the three peptides. However, peak values of IGF-1 were attained at different ages in all the three groups.

Environment and genetics are the major factors that regulate the physical growth of an individual. Vijayaraghavan et al.(15) had earlier reported that well-to-do Indian girls, without any apparent dietary and environmental constraints were as tall and heavy as American girls up to 12 years of age and considerable deviations were noted in adolescent period. The differences in the growth curves of Indian and American girls emerged and widened to result in a difference of 5 cm at the 18th year, a difference which occurred almost entirely between the 12th and 18th year of age. Although, the number of observations per year are less in the present study, it is of interest to note that IGF-1 levels were lower at all ages, as compared to the Western norms, and achieved statistical signi-ficance in the post-pubertal period (Fig. 1).

Extensive studies need to be carried out to evaluate the clinical usefulness of these peptides in Indian children having various endocrine defects.

Table I__Levels of IGF-1, IGFBP-3 and ALS in Children (New-born to Five Years)

Age
(Yr)
n Mean SD Range

Percentiles

  5th 10th 25th 50th 75th 90th 95th
IGF-1
0 20 14.1 4.7 9.6-26 9.8 10.5 12 12.8 13.5 20.5 26
1 20 23.1 16.7 10.5-66 10.5 10.5 14 19 20 66 66
2 20 43.8 27.9 9-120 9 20 23.5 39.5 47.5 79 120
3 20 48.1 29.5 10-120 16 17 23 33.5 68 90 120
4 20 49.3 24.1 12.5-105 12.5 16 34 47.5 58 92 105
5 22 67.7 57.8 16.5-260 27 29 30 52.5 72 145 180
IGFBP-3
0 20 1090.3 342.1 520-1950 562.5 642.5 930 1025 1275 1550 1825
1 20 1496.7 482.5 830-2150 830 830 1000 1500 1850 2100 2100
2 20 2478.1 705.9 1550-4000 1550 1650 1925 2400 2975 3500 4000
3 20 2200 991.3 670-4500 800 940 1650 2000 2700 3700 4500
4 20 2522.2 927.4 1050-4500 1050 1350 1850 2300 3300 3550 4500
5 22 2525.5 963.7 1010-4800 1450 1450 1600 2450 3100 3550 4000
ALS
0 20 4.1 2.2 1.1-11 1.3 1.8 2.8 3.9 4.7 7.1 9.1
1 20 7.9 4.8 1.7-16.5 1.7 1.7 4.5 6.4 11 16.5 16.5
2 20 11.1 6.4 1.8-30 1.8 5.5 7.3 9.9 12.8 17 30
3 20 11.5 5.3 3.9-21.5 3.9 5.6 6.3 11.5 13.5 21.5 21.5
4 20 14.2 5.8 7.4-27 7.4 7.8 9.2 12.5 19 22.5 27
5 22 13.7 5.8 4.4-25 6.6 8 10 11.5 17.5 23 24

Table II__Levels of IGF-1, IGFBP-3 and ALS in Girls (Six to Twenty Years).

Age
(Yr)

n Mean SD Range

Percentiles

  5th 10th 25th 50th 75th 90th 95th

IGF-1

6 10 91.4 54.7 31-190 31 31 48 80 135 190 190
7 10 96.2 45.4 38-190 38 38 77 90 105 190 190
8 10 113.2 53.4 28-195 28 42 79 105 147.5 190 195
9 10 217.6 189.1 51-650 51 51 105 145 280 650 650
10 11 139.4 65.8 39-290 73 86 89.5 105 162.5 210 290
11 10 262.2 151.3 58-465 58 58 147.5 250 380 465 465
12 11 393.6 182.3 92-640 135 145 205 470 520 620 640
13 11 401.4 135.6 100-650 145 280 285 420 490 500 650
14 10 413 147.8 155-670 155 202.5 350 422.5 490 615 670
15 10 309.5 93.1 86-445 120 190 265 300 365 427.5 445
16 10 302 70.6 135-390 200 220 240 300 380 385 390
17 10 221.8 55.7 115-300 122.5 122.5 195 230 250 300 300
18 10 306.5 107.9 170-490 170 187.5 205 297.5 400 465 490
19 11 244 119.4 99-510 99 105 145 255 310 320 510
20 10 262.5 114.0 150-605 150 152.5 160 205 360 415 470

IGFBP-3

6 10 3464.3 1263.8 1950-4500 1950 1950 2300 3100 4500 5400 5400
7 10 3100 617.0 1450-2900 2100 2100 2550 3400 3650 3700 3700
8 10 3245 755.9 1800-4100 1800 2100 2850 3400 3900 4100 4100
9 10 3700 1883.7 1650-7000 1650 1650 2550 2600 4400 7000 7000
10 11 3618.2 1050.3 1800-4800 1800 2200 2900 3600 4650 4650 4800
11 10 4027.8 1243.3 1900-6700 1900 1900 3800 4000 4100 6700 6700
12 11 5331.8 1917.6 2600-9000 2600 3200 3900 5000 6900 7200 9000
13 11 4572.7 1466.4 2900-7000 2900 3200 3300 4000 5900 6700 7000
14 10 4565 949.3 3500-6400 3500 3500 3600 4725 5100 5900 6400
15 10 4305 938.8 3050-6400 3050 3275 3800 4150 4500 5800 6400
16 10 4150 548.2 3050-5100 3400 3525 3800 4075 4500 5025 5100
17 10 4600 1209.3 3500-7000 3500 3500 3500 4500 4950 7000 7000
18 10 4485 1078.3 2650-6600 2650 3025 3700 4550 4950 5850 6600
19 11 3663.6 1142.0 1850-5000 1850 2000 2900 3500 4650 4900 5000
20 10 3650 992.2 2500-5800 2550 2575 2700 3600 4500 5100 5400

ALS

6 10 19.4 6.2 11.0-28 11 11 14.5 18 25.5 28 28
7 10 18.7 6.4 9.4-27 9.4 9.4 15.5 20.5 23 27 27
8 10 17.7 5.6 7-27.5 7 10 14.5 18 20 25.3 27.5
9 10 22.4 7.1 12-31.5 12 12 18.5 24 27 31.5 31.5
10 11 21.5 7.8 10.5-32 10.5 12 14.5 21 31 32 32
11 10 28.4 9.9 8.4-37 8.4 8.4 22 34 35 37 37
12 11 27.6 6.5 16.5-41 16.5 22 24 26 32 34 41
13 11 28.9 9.0 16.5-47 16.5 19.5 23 27.5 31 42 47
14 10 34.0 6.8 23.5-44.5 23.5 26 31 31.5 41 43.8 44.5
15 10 32.5 5.9 26.5-47 26.5 27.3 29 30 34 41 47
16 10 31.8 7.9 21-44.5 21 21 27 33 37 40.8 44.5
17 10 23.4 3.6 17.5-29 17.5 17.5 21 24 25 29 29
18 10 27.4 7 15-40 15 18.8 23 28 30 37 40
19 11 25.1 5.6 13-30 13 20.5 20.5 27.5 30 30 30
20 10 24.1 8.1 10.5-36 10.5 14 19 22.8 32 35.5 36

Table III__Levels of IGF-1, IGFBP-3 and ALS in Boys (Six to Twenty Years)

Age n Mean SD Range

Percentiles

(Yr)   5th 10th 25th 50th 75th 90th 95th
IGF-1
6 10 104.7 61.7 14-230 41 42 55 88 130 207 230
7 10 64.1 20.8 39-98 39 39 47 68 79 98 98
8 11 81.8 39.5 26-140 26 36 40 84 117.5 130 140
9 10 134.2 56.7 43-210 43 43 100 137.5 165 210 210
10 10 108.4 38.4 40-155 40 45 92 122.5 130 151.3 155
11 12 163.8 100.6 43-320 43 51 91 117.5 262.5 310 320
12 13 184.4 108.2 54-350 54 85 90 140 310 330 350
13 10 154.3 82.4 56-310 65 67.5 100 118.8 215 277.5 310
14 11 265.6 164.6 38-560 68 86 107.5 250 370 475 560
15 11 370 98.7 230-580 230 260 275 380 415 460 580
16 10 360 84.6 160-480 160 235 360 362.5 410 455 480
17 10 299.3 165.5 100-580 102.5 108.8 140 270 450 535 580
18 10 316 132.8 140-640 140 170 240 310 350 500 640
19 10 286.5 92.1 190-415 180 185 220 242.5 390 402.5 415
20 10 265.7 106.6 65-410 65 65 240 255 330 410 410
IGFBP-3
6 10 3175 713.5 1850-4000 1850 2200 2550 3150 3900 3950 4000
7 10 2014.3 480.2 1450-3700 1450 1450 1650 2100 2200 2900 2900
8 11 3286.4 1189.8 1850-5300 1850 1850 1900 3400 4200 4900 5300
9 10 3644.4 1224.9 2000-6200 2000 2000 2800 3500 4000 6200 6200
10 10 3495 950.6 2400-5900 2400 2600 3100 3300 3800 4900 5900
11 12 4004.2 1368.6 2200-6600 2200 2250 3050 3650 5200 5400 6600
12 13 3996.2 767.7 2650-5300 2650 3200 3500 3900 4600 5000 5300
13 10 4185 996.7 2450-5900 2450 2825 3800 4100 4900 5600 5900
14 11 4372.7 1528.0 2100-7600 2100 2750 3650 4200 4700 6300 7600
15 11 4768.2 1432.2 2900-7000 2900 3400 3650 4300 6600 6600 7000
16 10 4433.3 1023.8 2900-6200 2900 2900 3850 4350 4900 6200 6200
17 10 3815 884.1 2100-5400 2100 2575 3200 3925 4200 4875 5400
18 10 4145 1199.0 1250-5400 1250 2250 3900 4350 4950 5250 5400
19 10 3950 793.7 2650-5300 2650 2975 3500 3950 4100 5200 5300
20 10 3971.4 994.9 2750-5900 2750 2750 3400 3650 4300 5900 5900
ALS
6 10 15.8 4.3 10-21.5 10 10.5 12.5 15.3 21 21.3 21.5
7 10 14.4 3.17 10.5-19.5 10.5 10.5 10.5 15.5 15.5 19.5 19.5
8 11 16.4 5.1 6.8-23 6.8 11 13 17 22 22 23
9 10 21.3 7.0 12.5-31 12.5 12.5 15.5 21.5 25.5 31 31
10 10 20 4.4 15.5-30 15.5 16 16.5 18.8 21 27 30
11 12 21.6 7.8 9.4-30 9.4 10 14.3 24.5 28 30 30
12 13 22.9 4.3 16-29.5 16 17.5 19 23 25 29 29.5
13 10 21.5 6.3 8.8-34 8.8 13.15 18.5 22.3 24 29 34
14 11 24 6.4 10.5-33 10.5 19 20.5 24 30 32 33
15 11 29 4.9 21.5-35 21.5 23 23 30 34 34 35
16 10 29.4 8.2 21-46 21 21.3 23 27.8 37 41.5 46
17 10 31.6 10.9 18-50 18 20.5 24 27 39 48.5 50
18 10 30.9 8.5 16.5-42 16.5 17.8 26.5 31.5 35.5 42 42
19 10 27.8 6.1 19-41 19 21.5 25 26 29 37.5 41
20 10 25.6 7.6 11.5-37 11.5 11.5 23 26 28.5 37 37


Fig. 1. Comparison of IGF-1 levels (mean ± SE).

  Acknowledgement

We wish to acknowledge the guidance and support of Dr. Sudha Gangal, Director, Research Society and Dr. N.C. Joshi, Dean, Bai Jerbai Wadia Hospital for Children; Deepak, Shamim and Lata helped us in the field work.

Contributors: MPD helped in designing the study. DB co-ordinated the study (designing, interpretation of data, drafting of manuscript); she will act as the guarantor for the paper. RKD helped in sample collection, performing the tests, data compilation and in drafting the paper. CK assisted in field work.

Funding: Department of Science and Technology, New Delhi. ALS kits were provided as gift by Diagnostic Systems Laboratory, USA.
Competing interests:
None stated.

Key Messages

  • Circulatory levels of IGF-1, IGFBP-3 and ALS were studied in healthy Indian Children and adolescents (0-20 years of age).

  • Data generated may be used as reference while evaluating cases of GH disorders.

  • Difference exist in circulatory levels of IGF-1 in Indian compared to Western age-matched population.

  References
  1. Kawai N, Kanzaki S, Takano-Watou S, Tada C, Yamanaka Y, Miyata T, et al. Serum free Insulin-like Growth Factor-1 (IGF-1), total IGF-1 and IGF binding protein-3 concentrations in normal children and children with growth hormone deficiency. J Clin Endocrinol Metab 1999; 84:82-89.

  2. Juul A, Moller S, Mosfeldt-Laursen E, Rasmussen MH, Scheike T, Pedersen SA, et al. The acid-labile subunit of human ternary insulin-like growth factor binding protein complex in serum: Hepatosplanchnic release, diurnal varia-tion, circulating concerntrations in healthy subjects and diagnostic use in patients with growth hormone deficiency. J Clin Endocrinol Metab 1998; 83: 4408-4415.

  3. Rosenfeld RG, Albertsson-Wikland K, Cassorla F, Frasier SD, Hasegawa Y, Hintz RL, et al. Diagnostic controversy: The diagnosis of childhood growth hormone deficiency revisited. J Clin Endocrinol Metab 1995; 80: 1532-1540.

  4. Savage MO, Blum WF, Ranke MB, Postal-Vinay MC, Cotterill AM, Hall K et al. Clinical features and endocrine status in patients with growth hormone insensitivity (Laron syndrome). J Clin Endocrinol Metab; 1993; 77: 1465-1471.

  5. Frank GR, Cheung PT, Horn JA, Alfaro MP, Smith EP, Chernausk SD. Predicting the growth response to growth hormone in patients with intrauterine growth retardation. Clin Endocrinol 1996; 44: 679-685.

  6. Nobel F, Dewailly D. Puberty and polycystic ovarian sysndrome; The insulin/insulin-like growth factor hypothesis. Fertility sterility 1992; 58: 655-666.

  7. Juul A, Scheike T, Nielsen CT, Krabbe S, Muller J, Skakkebaek NE. Serum insulin-like growth factor (IGF-1) and IGF-binding protein 3 levels are increased in central precocious puberty: Effects of two different treatment regimens with gonadotropin-releasing hormone agonists, without or in combination with an antiandrogen (Cyproterone Acetate). J Clin Endocrinol Metab; 1995; 80: 3059-3067.

  8. Agarwal DK, Agarwal KN, Upadhaya SK, Mittal R, Prakash R, Rai S. Physical and sexual growth patterns of affluent Indian children from 5 to 18 years of age. Indian Pediatr 1992; 29: 1203-1268.

  9. Agarwal DK, Agarwal KN. Physical growth of Indian affluent children (birth-6 years). Indian Pediatr 1994; 31: 377-413.

  10. Colaco P, Desai M. Identification of a child with short stature. Indian Pediatr 1990; 27: 1159-1164.

  11. Khadgawat R, Dabadghao P, Mehrotra RN, Bhatia V. Growth charts suitable for evaluation of Indian Children. Indian Pediatr 1998; 35: 859-865.

  12. Diagnostic System Laboratories, Inc. Kit inserts for IGF-1 (Catalogue no: DSL 2800), IGFBP-3 (Catalogue no : DSL 6600) and ALS (Catalogue no: DSL-10-8200).

  13. Juul A, Bang P, Hertel NT, Main K, Dalgaard P, Jorgensen K, et al. Serum insulin-like growth factor-1 in 1030 healthy children, adolescents and adults; Relation to age, sex, stage of puberty, testicular size and body mass index. J Clin Endocrinol Metab 1994; 78: 744-752.

  14. Argente J, Barrios V, Pozo J, Munoz MT, Hervas F, Stene M, et al. Normative data for insulin-like growth factors (IGFs), IGF-binding proteins, and growth hormone- binding protein in a healthy Spanish pediatric population: Age- and sex-related changes. J Clin Endocrinol Metab 1993; 77: 1522-1528.

  15. Vijayaraghavan K, Singh D, Swaminathan MC. Heights and weights of well-nourished Indian school children. Indian J Med Res 1971; 59: 648-654.

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