Background: Milk supplementation increases serum IGF-I concentrations in healthy children and the effect is attributed to elevation of insulin and/or direct effects of milk proteins. Low serum IGF-I concentrations are common among children with short stature and may be associated with GH deficiency but poor nutrition/malabsorption may also contribute. Effects of nutritional supplementation on serum IGF-I is poorly studied in short children.
Aim: To investigate whether 7 days high protein nutritional supplementation increases serum IGF-I levels in short prepubertal children with low IGF-I and whether an increase is more pronounced in children with nutritional deficiency.
Methods: Short (height SDS <−2 SDS), prepubertal 3-13 year-old children with serum IGF-I concentrations <−1 SDS were given a milk based protein supplementation of 18g/10 kg body weight and day during 7 days. Food consumption was assessed (3-day food record) and IGF-I and other hormones were measured at baseline and at the end of the intervention.
Results: 14 of 17 patients finished the 7 days intervention. Protein intake increased from 2.97±0.58 to 4.45±0.68 g/kgxday (P<0.001) while fat energy percentage decreased (P=0.005). Intake of total or weight based energy and carbohydrate energy percentage were unchanged. Children increased their mean body weight by 0.39±0.29 kg (P<0.001) and mean BMI SDS increased from −0.94±0.74 to −0.70±0.76 (P<0.001). Gender and age corrected serum IGF-I concentrations increased from −1.16±0.3 SDS to −0.86±0.49 SDS (P=0.015) corresponding to an increase of 11.1±14.7% (P=0.017). Insulin release was increased as suggested by suppression of SHBG (160±23.2 versus 136±35.4; P<0.008). Serum IGFBP-3 concentrations did not change (0.39±0.94 versus 0.26±0.76 SDS, P=0.37). Markers of nutritional state at baseline or changes during the intervention (weight SDS, BMI SDS, 3-day energy or protein intake and IGF-I/IGFBP-3 ratio) did not correlate. Neither did these variables correlate with IGF-I changes apart from weight SDS at baseline that tended to correlate (r=−0.51, P=0.063).
Conclusion: Protein intake is important for serum IGF-I concentrations even in short children with low IGF-I and may have a therapeutic potential by affecting height long term. The short term IGF-I response to a high protein nutritional supplementation may be of clinical relevance as a marker of nutritional deficiency while other commonly used nutritional markers did not correlate.
27 Sep 2018 - 29 Sep 2018