TITLE:
Glucose and Insulin Levels are Increased in Obese and Overweight Mothers’ Breast-Milk
AUTHORS:
Suman Ahuja, Mallory Boylan, Sybil L. Hart, Carmen Román-Shriver, Julian E. Spallholz, Barbara C. Pence, Barbara G. Sawyer
KEYWORDS:
Breast-Milk, Glucose, Insulin, Obesity
JOURNAL NAME:
Food and Nutrition Sciences,
Vol.2 No.3,
May
17,
2011
ABSTRACT: Objective: To analyze the relationships between mothers’ pre-pregnancy body mass index (BMI) and levels of glucose and insulin in breast-milk. Methods: Participants were 32 breast-feeding mothers who were assigned to either normal weight (group 1: n = 21, BMI between 18.5 and 24.9 kg/m2) or overweight/obese (group 2: n = 11, BMI ≥ 25 kg/m2) based on their pre-pregnancy BMI. Breast-milk samples were collected at six weeks postpartum. Glucose and insulin concentrations were measured in the breast-milk samples. To control for any extreme dietary influences on breast-milk glucose concentrations, mothers completed 24-hour food recalls. Results: Mean milk-glucose values of groups 1 and 2 were 32.6 ± 21.8 mg/dL and 51.9 ± 20.5 mg/dL respectively. Milk-borne insulin values were 4.5 ± 7.6 µIU/mL and 30.1 ± 56.3 μ IU/mL, respectively. Independent-samples t tests found that glucose levels of group 2 were greater than those of group 1, t(30) = 2.43, p = 0.02; and milk-borne insulin was greater in group 2 than in group 1, t(30) = 2.075, p = 0.05. Mothers’ pre-pregnancy BMI was found correlated with both breast-milk glucose (r = 0.483, p = 0.005) and insulin (r = 0.565, p = 0.001). Conclusion: This study found that in comparison with normal weight mothers, over-weight/ obese mothers have higher concentrations of glucose and insulin in their breast-milk. Further studies are needed to explain the underlying mechanisms, and possible consequences of infant exposure to higher levels of glucose and insulin in breast-milk.