Insulin requirements and carbohydrate to insulin ratio in normal weight, overweight, and obese women with type 1 diabetes under pump treatment during pregnancy: a lesson from old technologies

Aim:The primary aim of this study was to assess insulin requirements and carbohydrateto insulin ratio (CHO/IR) in normal weight, overweight, and obese pregnant women withtype 1 diabetes across early, middle, and late pregnancy.Methods:In this multicenter, retrospective, observational study we evaluated 86 of 101pregnant Caucasian women with type 1 diabetes under pump treatment. The womenwere trained to calculate CHO/IR daily by dividing CHO grams of every single meal byinsulin units injected. Since the purpose of the study was to identify the CHO/IR able toreach the glycemic target, we only selected the CHO/IR obtained when glycemic valueswere at target. Statistics: SPSS 20.Results:We studied 45 normal weight, 31 overweight, and 10 obese women. Insulinrequirements increased throughout pregnancy (p < 0.0001 and <0.001 respectively) inthe normal and overweight women, while it remained unchanged in the obese women.Insulin requirements were different between groups when expressed as an absolute value,but not when adjusted for body weight. Breakfast CHO/IR decreased progressivelythroughout pregnancy in the normal weight women, from 13.3 (9.8–6.7) at thefirst stageof pregnancy to 6.2 (3.8–8.6) (p = 0.01) at the end stage, and in the overweight womenFrontiers in Endocrinology | www.frontiersin.orgFebruary 2021 | Volume 12 | Article 6108771Edited by:Elena Succurro,University of Magna Graecia, ItalyReviewed by:Cristina Bianchi,Azienda Ospedaliero-UniversitariaPisana, ItalyMaria Grazia Dalfra’,University of Padua, Italy*Correspondence:Camilla Festacamillafesta1@gmail.comSpecialty section:This article was submitted toObesity,a section of the journalFrontiers in EndocrinologyReceived:27 September 2020Accepted:14 January 2021Published:25 February 2021Citation:Festa C,Fresa R,Visalli N,Bitterman O,Giuliani C,Suraci C,Bongiovanni M andNapoli A (2021)Insulin Requirements andCarbohydrate to Insulin Ratio inNormal Weight, Overweight, andObese Women With Type 1Diabetes Under Pump TreatmentDuring Pregnancy: A LessonFrom Old Technologies.Front. Endocrinol. 12:610877.doi: 10.3389/fendo.2021.610877ORIGINAL RESEARCHpublished: 25 February 2021doi: 10.3389/fendo.2021.610877 from 8.5 (7.1–12.6) to 5.2 (4.0–8.1) (p = 0.001), while in the obese women it remainedstable, moving from 6.0 (5.0–7.9) to 5.1 (4.1–7.4) (p = 0.7). Likewise, lunch and dinnerCHO/IR decreased in the normal weight and overweight women (p < 0.03) and not in theobese women. The obese women gained less weight than the others, especially in earlypregnancy when they even lost a median of 1.25 (−1−1.1) kg (p = 0.005). In earlypregnancy, we found a correlation between pregestational BMI and insulin requirements(IU/day) or CHO/IR at each meal (p < 0.001 and p = 0.001, respectively). In latepregnancy, a relationship between pre-gestational BMI and CHO/IR change was found(P = 0.004), as well as between weight gain and CHO/IR change (p=0.02). Thesignificance was lost when both variables were included in the multiple regressionanalysis. There was no difference in pregnancy outcomes except for a higher pre-termdelivery rate in the obese women.Conclusion:Pre-gestational BMI and weight gain may play a role in determining CHO/IRduring pregnancy in women with type 1 diabetes under pump treatment.