Received: 18 January 2020 | Revised: 21 March 2020 | Accepted: 24 March 2020 DOI: 10.1111/ppe.12682 ORIGINAL ARTICLE The importance of maternal insulin resistance throughout pregnancy on neonatal adiposity Rodrigo A. Lima1 | Gernot Desoye2 | David Simmons3,4 | Roland Devlieger5 | Sander Galjaard5,6 | Rosa Corcoy7,8 | Juan M. Adelantado7,8 | Fidelma Dunne9 | Jürgen Harreiter10 | Alexandra Kautzky-Willer10 | Peter Damm11 | Elisabeth R. Mathiesen11 | Dorte M. Jensen12,13 | Lise-Lotte T. Andersen12,14 | Mette Tanvig12,14 | Annunziata Lapolla15 | Maria G. Dalfra15 | Alessandra Bertolotto16 | Urszula Manta17 | Ewa Wender-Ozegowska17 | Agnieszka Zawiejska17 | David J. Hill18 | Frank J. Snoek19 | Judith G. M. Jelsma20 | Mireille van Poppel1 1 Institution of Sport Science, University of Graz, Graz, Austria 2 Department of Obstetrics and Gynecology, Medizinische Universitaet Graz, Graz, Austria 3 Western Sydney University, Campbelltown, New South Wales, Australia 4 The Institute of Metabolic Science, Addenbrooke’s Hospital, Cambridge, UK 5 KU Leuven Department of Development and Regeneration: Pregnancy, Fetus and Neonate, Gynaecology and Obstetrics, University Hospitals Leuven, Leuven, Belgium 6 Division of Obstetrics and Prenatal Medicine, Department of Obstetrics and Gynaecology, Erasmus MC, University Medical Centre Rotterdam, Rotterdam, The Netherlands 7 Institut de Recerca de l´Hospital de la Santa Creu i Sant Pau, Barcelona, Spain 8 CIBER Bioengineering, Biomaterials and Nanotechnology, Instituto de Salud Carlos III, Zaragoza, Spain 9 Galway Diabetes Research Centre and College of Medicine Nursing and Health Sciences, National University of Ireland, Galway, Ireland 10 Gender Medicine Unit, Endocrinology and Metabolism, Department of Internal Medicine III, Medical University of Vienna, Vienna, Austria 11 Departments of Endocrinology and Obstetrics, Faculty of Health and Medical Sciences, Center for Pregnant Women with Diabetes, Rigshospitalet, Institute of Clinical Medicine, University of Copenhagen, Copenhagen, Denmark 12 Department of Gynecology and Obstetrics, Odense University Hospital, University of Southern Denmark, Odense, Denmark 13 Department of Clinical Research, Faculty of Health Sciences, Steno Diabetes Center Odense, Odense University Hospital, University of Southern Denmark, Odense, Denmark 14 Department of Clinical Research, Faculty of Health Sciences, University of Southern Denmark, Odense, Denmark 15 Universita Degli Studi di Padova, Padua, Italy 16 Azienda Ospedaliero Universitaria – Pisa, Pisa, Italy 17 Department of Reproduction, Poznan University of Medical Sciences, Poznan, Poland 18 Recherche en Santé Lawson SA, Bronschhofen, Switzerland 19 Department of Medical Psychology, Amsterdam Public Health research institute, Amsterdam UMC, Vrije Universiteit Amsterdam, Amsterdam, The Netherlands 20 Department of Public and Occupational Health, Amsterdam Public Health Research Institute, Amsterdam UMC, Vrije Universiteit Amsterdam, Amsterdam, The Netherlands This is an open access article under the terms of the Creative Commons Attribution License, which permits use, distribution and reproduction in any medium, provided the original work is properly cited. © 2020 The Authors. Paediatric and Perinatal Epidemiology published by John Wiley & Sons Ltd Paediatr Perinat Epidemiol. 2021;35:83–91. wileyonlinelibrary.com/journal/ppe | 83 | 13653016, 2021, 1, Downloaded from https://onlinelibrary.wiley.com/doi/10.1111/ppe.12682 by Readcube (Labtiva Inc.), Wiley Online Library on [11/04/2023]. See the Terms and Conditions (https://onlinelibrary.wiley.com/terms-and-conditions) on Wiley Online Library for rules of use; OA articles are governed by the applicable Creative Commons License 84 LIMA et al. Correspondence Rodrigo A. Lima, Institute of Sport Science, Abstract University of Graz, Graz, Austria. Background: Although previous studies evaluated the association of maternal health Email: rodrigoantlima@gmail.com parameters with neonatal adiposity, little is known regarding the complexity of the Funding information relationships among different maternal health parameters throughout pregnancy and This study was funded by the European Union 7th Framework (FP7/ 2007–2013) its impact on neonatal adiposity. under Grant Agreement no. 242187. Objectives: To evaluate the direct and indirect associations between maternal insulin Additional funding was provided by the Netherlands Organisation for Health resistance during pregnancy, in women with obesity, and neonatal adiposity. In addi- Research and Development (ZonMw) tion, associations between maternal fasting glucose, triglycerides (TG), non-esterified (grant 200310013), in the Netherlands. In Poland, additional funding was obtained fatty acids (NEFA), and neonatal adiposity were also assessed. from Polish Ministry of Science (grants Methods: This is a longitudinal, secondary analysis of the DALI study, an interna- 2203/7, PR/2011/2). In Denmark, additional funding was provided by Odense tional project conducted in nine European countries with pregnant women with University Free Research Fund. In Spain, obesity. Maternal insulin resistance (HOMA-IR), fasting glucose, TG, and NEFA were additional funding was provided by CAIBER 1527-B-226. The study sponsors were not measured three times during pregnancy (<20, 24-28, and 35-37 weeks of gestation). involved in the design of the study; the Offspring neonatal adiposity was estimated by the sum of four skinfolds. Structural collection, analysis, and interpretation of data; writing the report; or the decision to equation modelling was conducted to evaluate the direct and indirect relationships submit the report for publication. among the variables of interest. Results: Data on 657 mother-infant pairs (50.7% boys) were analysed. Neonatal boys exhibited lower mean sum of skinfolds compared to girls (20.3 mm, 95% CI 19.7, 21.0 vs 21.5 mm, 95% CI 20.8, 22.2). In boys, maternal HOMA-IR at <20 weeks was di- rectly associated with neonatal adiposity (β = 0.35 mm, 95% CI 0.01, 0.70). In girls, maternal HOMA-IR at 24-28 weeks was only indirectly associated with neonatal adiposity, which implies that this association was mediated via maternal HOMA-IR, glucose, triglycerides, and NEFA during pregnancy (β = 0.26 mm, 95% CI 0.08, 0.44). Conclusions: The timing of the role of maternal insulin resistance on neonatal adi- posity depends on fetal sex. Although the association was time-dependent, maternal insulin resistance was associated with neonatal adiposity in both sexes. KEYWORDS endocrinology, gynaecology, insulin, lipid metabolism, obesity 1 | BAC KG RO U N D neonatal adiposity, some aspects still require further evaluation. First, it is crucial that the entire pregnancy period is taken into ac- Maternal obesity is associated with neonatal1-4 and childhood adi- count. Fetal development depends on the maternal metabolic profile posity, and childhood obesity2,5 is not only associated with a higher throughout the whole pregnancy period,6-13 illustrated by the fact chance of obesity, but also premature death and disability in adult- that obese women or women who develop gestational diabetes have 5 hood. While maternal insulin resistance and fasting glucose have a larger fetuses already by 20 weeks of gestation.14,15 Second, there 6-13 positive association with neonatal adiposity, the role of maternal is evidence that neonatal girls might be more insulin resistant than triglycerides and non-esterified fatty acids on neonatal adiposity boys,16,17 and mechanisms underlying the relationship between ma- remains controversial.6-8,11 It is unclear whether such associations ternal metabolism and neonatal adiposity might differ depending on are causal, in the causal pathway or a consequence of the metabolic the neonatal sex.18 pathways involved. The aim of this investigation was to evaluate the direct and in- Shapiro et al6 reported that HOMA-IR, glucose, but not tri- direct associations between insulin resistance during pregnancy glycerides and non-esterified fatty acids at 24-32 weeks of gesta- and neonatal adiposity, as measured by sum of skinfolds. In addi- tion mediated the association between maternal pre-pregnancy tion, the direct and indirect associations between fasting glucose, body mass index (BMI) and neonatal adiposity. Although this study6 triglycerides, non-esterified fatty acids, and neonatal adiposity provided relevant insights regarding the possible underlying mech- were also assessed. This is a novel approach because it assesses anisms in the relationship between maternal metabolic profile and the complexity of the relationships among different maternal health | 13653016, 2021, 1, Downloaded from https://onlinelibrary.wiley.com/doi/10.1111/ppe.12682 by Readcube (Labtiva Inc.), Wiley Online Library on [11/04/2023]. See the Terms and Conditions (https://onlinelibrary.wiley.com/terms-and-conditions) on Wiley Online Library for rules of use; OA articles are governed by the applicable Creative Commons License LIMA et al. 85 parameters throughout pregnancy and its impact on neonatal adi- posity. Although the observational design does not allow to assert Synopsis on causality, it is a valuable approach for generating hypothesis to be tested in clinical trials. Study question How is the synergic relationship of maternal insulin re- 2 | M E TH O DS sistance, fasting glucose, triglycerides, and non-esterified fatty acids with neonatal adiposity in pregnant women 2.1 | Design and participants with obesity? This is a longitudinal, secondary analysis of the DALI study What's already known which was a multicentre parallel randomised trial conducted in Maternal insulin resistance and fasting glucose have a nine European countries (Austria, Belgium, Denmark, Ireland, positive association with neonatal adiposity, and the role Italy, Netherlands, Poland, Spain, and United Kingdom) during of maternal triglycerides and non-esterified fatty acids on 2012-2015. Pregnant women with a pre-pregnancy body mass neonatal adiposity remains controversial. index (BMI) of ≥29 kg/m 2 , before 20 weeks of gestation, with a singleton pregnancy, and aged ≥18 years were invited to par- What this study adds 19 ticipate. Exclusions included diagnosis with early gestational The association between maternal insulin resistance and diabetes mellitus (GDM), pre-existing diabetes, and chronic neonatal adiposity differed depending on the infant sex. medical conditions. The study was prospectively registered While adiposity in boys was associated directly with ma- as a randomised controlled trial (RCT) on 21 November 2011 ternal insulin resistance in the beginning of pregnancy, (ISRCTN70595832). adiposity in girls was associated with maternal insulin re- sistance at 24-28 weeks of gestation via a chain of relation- ships through fasting glucose, triglycerides, and free fatty 2.2 | Randomisation, masking, and interventions acids. Using a computerised random number generator, women were ran- domised to one of the following groups, pre-stratified for site: (a) healthy eating; (b) physical activity; (c) healthy eating + physical activity; (d) baseline (<20 weeks), 24-28 weeks, and at 35-37 weeks of gestation. healthy eating + physical activity + vitamin D; (e) healthy eating + physi- Body mass index (BMI) was calculated as weight in kg divided by the cal activity + placebo; (f) vitamin D; (g) placebo; and (h) control. Staff square of height in metres. involved with measurements, but not participants, were blinded to the After fasting for 10 hours, blood was collected in three different intervention. Since methodology has been extensively described else- periods during pregnancy (<20, 24-28, and 35-37 weeks of gestation). where,19 only variables of interest will be detailed in this manuscript. The procedures were identical in all pregnancy periods. All the sam- ples were centrifuged and separated aliquots (1000 or 250 μL) placed in microrack tubes and stored at −20 or −80°C in the central trial labo- 2.3 | Measurements ratory, prior to analysis, in Graz, Austria. The maternal plasma concen- trations of fasting glucose, triglycerides, and non-esterified fatty acids 2.3.1 | Neonatal adiposity were quantified. For insulin and leptin, commercially available en- zyme-linked immunosorbent assays (ELISAs) were used. Insulin resis- Triceps, subscapular, supra-iliac, and quadriceps skinfolds were meas- tance was derived from homeostasis model assessment (HOMA-IR).20 ured with a Harpenden skinfold calliper, and values summed. Each skinfold measurement was repeated once, and if a difference of more than 0.2 mm was registered, a third measurement was performed and 2.3.3 | Covariates the average of the three was taken. Time between birth and meas- urements was registered in hours—neonatal age at the measurement. Information on possible covariates was collected in the baseline questionnaire or from medical files: intervention groups, maternal age, gestational age during pregnancy (<20, 24-28 and 35-37 weeks), 2.3.2 | Maternal measurements maternal ethnicity (European descent and non-European descent), maternal education (low [