Objective: We aimed to investigate prospective associations between milk bioactives related to metabolic health (glucose, insulin, leptin, C reactive protein [CRP], and interleukin 6 [IL-6]) and incident formula initiation at 3 and 6 months postpartum. Design: This study included 363 mother-infant dyads who were fully breastfed at 1 month and participated in the prospective Mothers and Infants Linked for Healthy Growth study from pregnancy to 6 months postpartum. Associations between milk glucose, leptin, insulin, CRP, and IL-6 at 1 and 3 months and incident formula feeding (FF) at 3 and 6 months, respectively, were tested using multiple logistic regression, adjusting for numerous potential confounders such as maternal age and prepregnancy body mass index. Results: At 3 months postpartum, 1-month glucose (odds ratio [OR] 0.45 [95% confidence interval (CI): 0.27-0.75], p ≤ 0.01) and smaller decreases in glucose from 1 to 3 months (OR 0.51 [95% CI: 0.28-0.92], p = 0.03) were associated with lower odds of FF, whereas 1-month leptin (OR 2.30 [95% CI: 1.30-4.07], p < 0.01) and larger increase in insulin (OR 1.86 [95% CI: 1.23-2.81], p < 0.01) and leptin (OR 2.17 [95% CI: 1.29-3.68], p < 0.01) from 1 to 3 months were associated with increased odds of FF. At 6 months, insulin increases (OR 2.08 [95% CI: 1.03-4.17], p = 0.04) were associated with higher odds of FF. Conclusions: In a cohort of women with established lactation, 1-month milk glucose, insulin, and leptin predicted initiation of FF at 3 months. Early milk composition may provide a window into mammary gland function, allowing identification of women at risk of not meeting their breastfeeding goals.
Bibliographical noteFunding Information:
We would like to acknowledge and thank all the women and health care providers who contributed to the MILk study. We also acknowledge the valuable assistance of Neely Miller and Kristin Sandness and the resources of the Center for Neuro-behavioral Development, Rebecca Hollister from the Center for Pediatric Obesity at the University of Minnesota, the Clinical and Translational Research Services support team at the Clinical and Translational Science Institute at the University of Minnesota (supported by grant no. UL1TR002494 from the National Institutes of Health’s National Center for Advancing Translational Sciences), laboratory resources from the University of Oklahoma Health Sciences Center, and Elisabeth Seburg at the HealthPartners Institute.
This study used data from MILk study. The MILk study is supported by an NIH/NICHD grant (R01HD080444). K.E.J. received support from NIDCR (T90DE0227232). E.M.N. was supported by the NIH/NIDDK grant (T32DK083250).
D.R.J., D.A.F., L.H., E.O.K., and E.W.D. report grant funding from the National Institute of Child Health and Human Development (NICHD) during the conduct of this study. National Institute of Dental and Craniofacial Research (NIDCR). E.M.N. reports funding on a grant from the National Institute of Diabetes and Digestive and Kidney Diseases (NIDDK). No other conflicts of interest or financial disclosures were reported.
© Copyright 2021, Mary Ann Liebert, Inc., publishers 2021.
- human milk
- metabolic health