Infant formula and diabetic risks : a systematic review

Background There is growing evidence suggest the link between health and feeding practice in early postnatal period, which is a critical window for development. Given the rate of type 2 diabetes is increasing and infant feeding is modifiable, understanding the association between infant feeding and subsequent diabetic risks may provide a potential effective strategy to combat the epidemic. Objective Systematically review the association of infant formula feeding and subsequent diabetic risks. Methods The PubMed electronic database was used for literature searching. English papers assessing the association between formula feeding and major clinical markers of type 2 diabetes including diagnosis of type 2 diabetes, fasting glucose concentration, HbA1c and insulin resistance were included. Results Data were extracted from 15 studies (four randomized controlled trials, four cross-sectional studies and seven cohort studies). All four randomized controlled trials, three cross-sectional studies and three cohort studies reported higher diabetic risks in formula-fed participants comparing to breast-fed participants. No association between infant feeding and diabetic risks was reported in the remaining five studies. All but two included studies were conducted in western countries, including the USA, Canada, the UK, France and the Netherlands. The two studies in non-western setting also found higher fasting glucose concentration in formula-fed infants. Two RCTs suggested that lower protein formula had protective effects on diabetic risks compared with higher protein formula. Only one study assessed but found no dose-response association between infant formula consumption and later diabetic risks. Among all 11 observational studies, only 6of them adjusted for maternal socioeconomic position, which was an important confounder, especially in western countries where mothers of high socioeconomic position are more likely to choose breastfeeding and breastfeed for longer, and the risk of type 2 diabetes (T2DM) was lower among those with higher SEP, therefore the published benefits of breastfeeding on preventing T2DMin such settings might be overestimated if SEP was not adjusted. Conclusion The current evidence suggested that in comparison with breast-fed individuals, formula-fed individuals may have greater subsequent diabetic risks, indicated by higher fasting glucose, insulin resistance or lower insulin sensitivity. However, published evidence is not strong due to the possible residual confounding from SEP. Further epidemiological studies are needed to assess the potential health impact of infant feeding in subsequent health, especially in the Asia countries where breastfeeding maybe less socially pattern and the rate of diabetics is on an increase.published_or_final_versionPublic HealthMasterMaster of Public Healt