Pancreatic Beta Cell Function in Infants Varies by Maternal Weight

The Asian Indian Beta Cell function (ABCs) in Infants Study examined the associations of maternal weight on infant pancreatic beta cell function across 7 months postpartum. Pregnant women aged 18-35 years were recruited in Hyderabad, India. Women were classified by first trimester weight as underweight (UW), BMI < 18.5 kg/m²; normal weight (NW), BMI 18.5-22.9 kg/m²; or overweight (OW), BMI 23.0 through <28.5 kg/m². At age > 7 months, infants had an oral glucose tolerance test (OGTT, 1.75 g glucose/kg bodyweight) following a 3 h fast. Infant blood samples were assayed for C-peptide and glucose. Infant beta cell function (HOMA2-B; disposition index, DI) and insulin resistance (HOMA2-IR) were compared across maternal weight groups. Mothers (UW n = 63; NW n = 43; OW n = 29) had similar age at delivery and second trimester 50 g glucose challenge test results. Cord HOMA2-B values were 51% greater for I_UW (83.5, SD 55.2) and 44% greater for I_OW (79.9, SD 60.8) vs. I_NW (55.4, SD 51.5), forming a U-shaped relationship between maternal weight and HOMA2-B. No qualitative differences in HOMA2-IR were found at birth. However, at 7 months postpartum, HOMA2-IR changed most within I_UW (-64% median reduction) and changed the least in I_OW (-7% median reduction). At seven months postpartum, DI was higher in I_UW vs. the other groups (geometric mean I_UW 1.9 SD 2.5; I_NW 1.3 SD 2.6 or vs. I_OW mean 1.2 SD 3.7), reflecting a +49% difference in DI. Evidence from this study illustrates adaptations in the pancreatic functional response of infants associated with the maternal nutritional environment.