Zinc supplementation increases growth and circulating insulin-like growth factor I (IGF-I) in growth-retarded Vietnamese children
Ninh, N.X.; Thissen, J.P.; Collette, L.; Gerard, G.; Khoi, H.H.; Ketelslegers, J.M.
American Journal of Clinical Nutrition 63(4): 514-519
1996
ISSN/ISBN: 0002-9165 PMID: 8599314 DOI: 10.1093/ajcn/63.4.514Document Number: 313938
Growth, incidence of infections and circulating insulin-like growth factor I (IGF-I) concentrations were assessed in 146 growth-retarded Vietnamese children 4-36 months old paired according to age, sex, commune, Z scores for weight and for height, and number of siblings, and were randomly assigned to receive zinc 153 micro mol (10 mg)/day or a placebo for 5 months. Weight, height and episodes of infection were recorded each month and plasma IGF-I was measured 1 and 5 months after the start of Zn supplementation. Multiple-linear-regression analysis for paired data showed that Zn supplementation increased weight (+0.5+or-0.1 kg; P<0.001) and height (+1.5+or-0.2 cm; P<0.001) after 5 months compared with placebo treatment. The relative risk of infectious episodes in Zn-treated subjects was reduced 3-fold for diarrhoea (P=0.012) and 2.5-fold for respiratory infections (P=0.057). The probability of having at least 2 episodes of diarrhoea or respiratory infection was 2.9- and 3.2-fold lower, respectively, in Zn-treated than in placebo-treated children. Plasma IGF-I concentrations increased in Zn-treated subjects between 1 and 5 months (P=0.018), whereas they did not change in placebo-treated subjects (P=0.584). After 1 month, IGF-I concentration (mean+or-s.d.) in Zn-treated subjects was 2.8+or-0.3 compared with 1.9+or-0.2 nmol/litre in placebo-treated subjects (P=0.021). After 5 months, the values were 3.4+or-0.5 (Zn-treated) and 2.0+or-0.3 nmol/litre (placebo-treated; P=0.044). It is suggested that Zn deficiency may limit growth in nutritionally deprived children.