Background: Postpartum demands of caring for a newborn, breastfeeding, and sleep deprivation result in little time for self care of type 1 diabetes (T1D). Data are limited on the efficacy, safety and feasibility of closed loop insulin delivery postpartum.

Methods: We performed an open label, controlled pilot trial randomizing women to hybrid closed loop insulin delivery Medtronic MiniMed™ 670G/770G in auto mode or sensor augmented insulin pump (SAP) therapy in the first 12 twelve postpartum weeks. The primary outcome was the percent time in target glucose range of 70-180 mg/dL (3.9-10.0 mmol/L). Mixed models analysis assessed between group differences in glucose measures from median start time of closed loop (8 days) to 12wks postpartum.

Results: Twenty women were recruited. Two withdrew prior to randomization. The remaining 18 women completed 12 weeks of postpartum follow up in their assigned randomization group. Overall baseline mean age, duration of T1D and first pregnancy A1c was 32 years, 22 years and 6.9% respectively. Analyses adjusted for first pregnancy A1c and was intention to treat. Time in range did not differ between groups (79 ± 8.0% versus 80 ± 6.4% p =.079). Time below 70mg/dL (3.9 mmol/L) and 54mg/dL (3.0 mmol/L) was less for women randomized to closed loop versus SAP (1.6 ± .72 % vs 5.3 ± 3.3 % p <0.001 and .23 ± .16 % vs .95 ± .82 % p = 0.002 respectively). Time above 180 mg/dL (10 mmol/L) was not different between groups 19.5 ±8.7% vs 15.9 ±7.8% p = .823. Mean glucose was 146 ± 13 and 133 ± 14 mg/dL p <.001 for closed loop and SAP groups respectively. No episodes of diabetic ketoacidosis or severe hypoglycemia occurred in either group.

Conclusions: Closed loop insulin delivery postpartum was associated with less hypoglycemia than SAP and slightly higher mean glucose. There were no safety concerns. Time in target glucose range was high, minimizing the potential for further improvement with closed loop. These findings are reassuring for the use of closed loop insulin delivery postpartum because of its’ potential to reduce hypoglycemia.


L.E.Donovan: Research Support; Dexcom, Inc., Medtronic, Tandem Diabetes Care, Inc., Inner Analytics. D.Feig: Advisory Panel; Novo Nordisk Canada Inc., Speaker's Bureau; Sanofi, Novo Nordisk Canada Inc. P.Lemieux: Other Relationship; Dexcom, Inc. H.R.Murphy: Advisory Panel; Medtronic, Research Support; Dexcom, Inc. R.C.Bell: None. R.J.Sigal: Research Support; Novo Nordisk. J.Ho: None. J.M.Yamamoto: None.


Calgary Health Trust

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