Hybrid closed-loop insulin therapy prevents low night-time blood glucose levels among breastfeeding mothers with type 1 diabetes: Study

This study aimed to describe the relationship between breastfeeding episodes and maternal glucose levels, and to assess whether this differs with closed-loop vs open-loop (sensor-augmented pump) insulin therapy. Infant-feeding diaries were collected at 6 weeks, 12 weeks and 24 weeks postpartum in the trial of postpartum closed-loop use in 18 women with type 1 diabetes.

Continuous glucose monitoring (CGM) data were used to identify maternal glucose patterns within the 3 h of breastfeeding episodes. Generalised mixed models adjusted for breastfeeding episodes in the same woman, repeat breastfeeding episodes, carbohydrate intake, infant age at time of feeding and early pregnancy HbA1c. Results: CGM glucose remained above 3.9 mmol/l in the 3 h post-breastfeeding for 93% (397/427) of breastfeeding episodes.

There was an overall decrease in glucose at nighttime within 3 h of breastfeeding (1.1 mmol l−1 h−1 decrease on average; p=0.009). A decrease in nighttime glucose was observed with open-loop therapy (1.2 ± 0.5 mmol/l) but was blunted with closed-loop therapy (0.4 ± 0.3 mmol/l; p<0.01, open-loop vs closed-loop). There is a small decrease in glucose after nighttime breastfeeding that usually does not result in maternal hypoglycaemia; this appears to be blunted with the use of closed-loop therapy.

Reference:

Donovan, L.E., Bell, R.C., Feig, D.S. et al. Glycaemic patterns during breastfeeding with postpartum use of closed-loop insulin delivery in women with type 1 diabetes. Diabetologia 67, 2154–2159 (2024). https://doi.org/10.1007/s00125-024-06227-z