Long Lasting Effects of Breastfeeding on Metabolism in Women with Prior Gestational Diabetes

Background & Aims: Breastfeeding improves glucose tolerance in the early postpartum period of women with prior gestational diabetes GDM, but it is unclear whether future risk of metabolic alterations, like type 2 diabetes, is reduced. The aim of this study was to investigate the effect of lactation, three years after pregnancy, on glucose and lipid metabolism in women with prior gestational diabetes. Materials & Methods: A population of women with prior gestational diabetes (Carpenter and Coustan Criteria) was evaluated with comparison of results for “lactating” [BF] versus “nonlactating women” [non BF]. Breast feeding was defined [BF] if lasting? 4 weeks. In each woman a 75-g oral glucose tolerance test (OGTT) was performed to analyze the glucose tolerance, insulin sensitivity/resistance and b-cell function. Fasting serum was used to study their lipid profile (total cholesterol, high-density lipoprotein [HDL] cholesterol, low-density lipoprotein [LDL] cholesterol, and triglycerides), apolipoprotein B, apolipoprotein A1, homocysteine, fibrinogen, hsCRP, uric acid, microalbuminuria. Statistics: Paired and Un-paired t-test, Mann-Whitney and χ2 tests were used, as appropriate. Results: A total of 81 women were evaluated (62 [BF] and 19 [non BF]). Maternal age (37.1 ± 4.6 vs 37.4 ± 4.9 years), body mass index (26.3 ± 5.6 vs 26.4 ± 5.3 kg/m2), parity (1.9 ± 0.8 vs 1.7 ± 0.8) and length of follow-up (32.2 ± 20.2 vs 32.1 ± 20,0) were not different between the two groups. No effect was visible on glucose tolerance, HOMA-IR and other b-cell function indexes as well as hs-CRP (not significantly lower in non BF), uric acid, total cholesterol, HDL and LDL cholesterol. Levels of significance were only reached for “HOMA-IS” [BF] 1.0 ± 0.7 vs [non BF] 0.6 ± 0.4, p = 0.04) and triglycerides [BF] 83.8 ± 46.7 vs [non BF] 123.2 ± 94.0 mg/dl, p = 0.02). Conclusions: Breastfeeding does not improve the glucose tolerance of our women with prior GDM three years after delivery, even though lower levels of triglycerides and improved insulin sensitivity are still visible. Corresponding author.