Insulin-like growth factor 1 (IGF-1) is an important growth factor in childhood. We aimed to investigate the impact of food supplements for the treatment of moderate acute malnutrition (MAM) on serum IGF-1 (sIGF-1). Secondary analysis of a randomised 2 × 2 × 3 factorial nutrition trial was performed. Children aged 6-23 months with MAM received 2093 kJ/d as lipid-based nutrient supplement (LNS) or corn soy blend (CSB), containing either dehulled soya or soya isolate and different quantities of dried skimmed milk (0 %, 20 % or 50 % of total protein) for 12 weeks. The trial was double-blind with regard to soya and milk but not to matrix (LNS v. CSB). sIGF-1 was measured at inclusion and after 12 weeks of supplementation. Of 1609 children enrolled, 1455 (90 %) had sIGF-1 measured at both time points. During supplementation, sIGF-1 increased 6·7 (95 % CI 6·1, 7·3) ng/ml compared with an expected age-dependent decrease of 0·3 (95 % CI 0·2, 0·4) ng/ml. Children who received LNS v. CSB had a lower increase in sIGF-1 (-8 %, 95 % CI - 12, -3). The effect of LNS was partly attenuated when sIGF-1 was corrected for inflammation. Children who received soya isolate compared with dehulled soya had a higher increase in sIGF-1 (6 %, 95 % CI 1, 12). Milk content did not affect sIGF-1. Overall, sIGF-1 increased during supplementation. The lower increase with LNS v. CSB was only partly explained by increased inflammation with LNS and needs further investigation. Isolate v. dehulled soya led to a higher increase which may be due to antinutrients in dehulled soya.
Keywords: Inflammation; Insulin-like growth factor-1; Lipid-based nutrient supplement; Low-income country; Moderate acute malnutrition.