Breastfeeding prevents Asian moms with GDM from becoming lifelong diabetics

Breastfeeding has benefits that extend beyond the babies’ health, with a recent study showing that mothers who nurse for at least 6 months are better protected against long-term dysglycaemia, particularly those with a history of gestational diabetes mellitus (GDM), in an Asian setting.

“This is the first study conducted on women in Singapore to understand the role of breastfeeding in reducing long-term type 2 diabetes mellitus (T2DM) and prediabetes risk following a diagnosis of GDM,” according to the investigators.

“We find that the protective effect of breastfeeding to reduce diabetes risk is associated with a longer breastfeeding duration, even after controlling for the mother’s age at delivery, parity at recruitment, a family history of diabetes at recruitment, previous GDM, the prepregnancy body mass index (BMI), and perinatal tobacco smoking exposure, as supported,” they added.

The investigators looked at 116 women participating in the Growing Up in Singapore Towards healthy Outcomes (GUSTO) study. All of them had been diagnosed with GDM in the index pregnancy and were followed for 4 to 7 years for the development of dysglycaemia, assessed via the oral glucose tolerance test (OGTT).

Over a median of 5.1 years, 51 (44.0 percent) women had abnormal postpartum glucose tolerance test results, with 13 (11.2 percent) being positive for T2DM and 38 (32.8 percent) for prediabetes. Relative to those with normal glucose tolerance, women with dysglycaemia group were older, had higher parity, more likely to have a family history of T2DM, and had greater BMI both prior to and after pregnancy.

Unadjusted Poisson regression models showed an inverse association between dysglycaemia risk and breastfeeding duration of ≥6 months (vs 1 month: incidence rate ratio [IRR], 0.50, 95 percent confidence interval [CI], 0.27–0.91; p=0.02). This association persisted despite controlling for potential confounders (IRR, 0.42, 95 percent CI, 0.22–0.80; p=0.008). [Nutrients 2021;13:408]

Reports on the effects of long-term breastfeeding on the risk of dysglycaemia in women with previous GDM in and outside Asia have been mixed, the investigators noted. Some described a benefit, while others did not. [Diabetologia 2016;59:S187; Salud Cienc 2014;20:581-585; PLoS ONE 2016;11:e0157272; J Clin Transl Endocrinol 2014;1:38-43]

“Our results further corroborate findings from the Shanghai Women’s Health Study, conducted in a predominantly Chinese population,” with the increased duration of lifetime breastfeeding protective against T2DM risk after more than 4 years of follow-up, they pointed out. [Diabetologia 2008;51:258-266]

The reasons for such are not known for certain, but “may suggest that the effects of breastfeeding manifest in a more complex way than a purely short-term physiological response to breastfeeding,” according to the investigators.

“It may also offer additional intergenerational benefits through impeding the risk of metabolic disease and disrupting the ongoing vicious cycle of offspring obesity and a future risk of diabetes,” they added. [J Pediatrics 2011;158:872]

Taken together, the data support the consideration of public health programmes aimed at increasing breastfeeding intensity and duration, especially in Singapore, where diabetes prevalence is high at 8.6 percent. [https://www.moh.gov.sg/resources-statistics/singapore-health-facts/disease-burden]

“Pregnancy holds a unique opportunity to identify women at risk of abnormal insulin sensitivity in the long term through the diagnosis of GDM. Moreover, breastfeeding after pregnancy is a low-cost intervention that may improve future maternal cardio-metabolic risk,” the investigators said.