Efficacy of lipid nutrient supplements on growth and micronutrient status in infants

Abstract

Background: Stunting or linear growth failure occurs as result of poor maternal nutrition and suboptimal health and/or feeding practices. Small-quantity lipid-based nutrient supplements (SQ-LNS) are promising home fortificants used to prevent stunting and micronutrient deficiencies in children aged 6-23 months, but evidence so far is inconclusive. Aim: The study investigated the factors associated with stunting at age 6 months and evaluated the efficacy of SQ-LNS A and SQ-LNS B on linear growth and iron status among 6-month old infants followed for 6 months. Methods: Baseline variables were explored to determine the factors associated with stunting at age 6-months old. The randomised controlled trial (RCT) was conducted between September 2013 and July 2015 in North West Province, South Africa. The infants were randomised to SQ-LNS A with essential fatty acids (EFAs), SQ-LNS B with EFAs, docosahexaenoic acid (DHA) and arachidonic acid (ARA), phytase, powder milk and lysine and a control group. Home visits to monitor adherence and morbidity were conducted weekly. Length-for-age (LAZ), weight-for-length (WLZ) and weight-for-age (WAZ) z-scores (WHO classification) were determined at baseline and age 8, 10 and 12 months. Blood samples (4ml) were analysed for haemoglobin (Hb), plasma ferritin (PF), soluble transferrin receptor (sTfR), C-reactive protein (CRP), alpha-2 acid glycoprotein (AGP), at baseline and end. Socio-economic, breastfeeding and complementary feeding practices were assessed by questionnaire. Generalised linear, quantile, linear splines and logistic regression analysis were used. Results: At baseline stunting, underweight, wasting and overweight affected 28.5%, 11.1%, 1.7% and 10.1% of infants respectively. Stunting was the predominant form of malnutrition and was inversely associated with birth weight (kg) (OR 0.12, 95% CI 0.07 to 0.20, P<0.001), and maternal height (cm) (OR 0.94, 95% CI 0.91 to 0.98, P=0.001) while male sex was significantly associated with higher odds of stunting (OR 1.73, 95% CI 1.10 to 2.70, P=0.017). The RCT show that SQ-LNS B had overall positive effects on LAZ (P=0.036) compared to the control, this was mainly driven by significant intervention effects at age 8 and 10 months, as at age 12 months (trial end) the intervention effect disappeared. There were positive effects on Hb for both SQ-LNS A (P=0.027) and SQ-LNS B (P=0.005) groups. The results also show that the risk of anaemia, iron deficiency and iron deficiency anaemia was significantly lower in SQ-LNS A and SQ-LNS B groups compared to the control. Conclusions: The cross-sectional results showed that stunting (28.5%) was associated with lower birth weight, shorter maternal height and male sex. The intervention showed that both SQ-LNS A and SQ-LNS B did not show an effect on growth at 12 months of age. However, SQ-LNS B showed better linear growth at age 8 and 10 months old compared to the control. In addition, both SQ-LNS A and SQ-LNS B significantly decreased the risk of infants for iron deficiency and iron deficiency anaemia. This trial was registered at http://clinicaltrials.gov as INTC01845610.