1. Higher IGF-1 levels in Black vs White Children: Does Ghrelin Play a Role? Fida Bacha, MD Silva Arslanian, MD Children’s Hospital of Pittsburgh.

2. Background (3) Important black/white racial differences exist in several metabolic parameters. Black children compared with their white peers have: 1)higher insulin-like growth factor-1 (IGF-1) levels with lower insulin-like growth factor binding protein-1 (IGFBP-1) levels. Wong et al; J Pediatr 135: 296, 1999 2) higher bone mineral density. Yanoski et al; J Pediatr 137: 826, 2000 3) hyperinsulinemia / insulin resistance. Arslanian et al; Diabetes 51:3014, 2002 4) lower intra-abdominal adipose tissue. Goran et al; Am J Hum Biol 11: 201, 1999 Bacha et al; J Clin Endocrinol Metab 88: 2534, 2003

3. Study Population NW-W 6M/14F OB-W 4M NW-B 4M/5F OB-B 3M/1F Age (years)9.3 ± 1.210.6 ± 1.09.1 ± 1.18.6 ± 0.1 BMI (kg/m 2 ) 17.2 ± 0.426.4 ± 1.3**18.2 ± 0.631.9 ± 4.4** % Body Fat21.5 ± 1.241.7 ± 2.0**23.3 ± 3.045.0 ± 4.9** Mean Fasting Ghrelin (PM) 644.5 ± 94.6536.3 ± 50.3617.9 ± 116.8446.9 ± 108.0 Mean IGF-1 (ng/ml) 157.1 ± 10.3199.1 ± 27.3191.3 ± 12.2 † 141.3 ± 12.5* ** p<0.01 NW vs OB within the same race * p<0.05 NW vs OB within the same race † p= 0.05 NW-B vs NW-W

4. Figure 1: The relationship of body mass index to fasting Ghrelin levels. r=-0.3 p=0.03 (one tailed)

5. Ghrelin (PM) Figure 2: Ghrelin levels in black vs white children during 3-hr OGTT. Minutes In whites, mean suppression in ghrelin at 60 min : 158.3 ± 20.3 PM, p< 0.001 In blacks, mean suppression in ghrelin at 60 min : 83.7 ± 19.3 PM, p=0.001 * * Δ Ghrelin (PM) 0 50 100 150 200 P=0.015 BlacksWhites

6. Conclusion These preliminary results are consistent with our hypotheses of:  Decreased suppression of ghrelin in black vs white children in response to feeding.  Obese children seem to have less suppression in ghrelin levels in response to feeding compared with normal-weight youth. Whether or not this decreased suppression of ghrelin in obesity plays an orexigenic role remains to be determined.