Genetic Risk Factors and Gene–Lifestyle Interactions in Gestational Diabetes

Paralleling the increasing trends of maternal obesity, gestational diabetes (GDM) has become a global health challenge with significant public health repercussions. In addition to short-term adverse outcomes, such as hypertensive pregnancy disorders and fetal macrosomia, in the long term, GDM results in excess cardiometabolic morbidity in both the mother and child. Recent data suggest that women with GDM are characterized by notable phenotypic and genotypic heterogeneity and that frequencies of adverse obstetric and perinatal outcomes are different between physiologic GDM subtypes. However, as of yet, GDM treatment protocols do not differentiate between these subtypes. Mapping the genetic architecture of GDM, as well as accurate phenotypic and genotypic definitions of GDM, could potentially help in the individualization of GDM treatment and assessment of long-term prognoses. In this narrative review, we outline recent studies exploring genetic risk factors of GDM and later type 2 diabetes (T2D) in women with prior GDM. Further, we discuss the current evidence on gene–lifestyle interactions in the development of these diseases. In addition, we point out specific research gaps that still need to be addressed to better understand the complex genetic and metabolic crosstalk within the mother–placenta–fetus triad that contributes to hyperglycemia in pregnancy

Distinct Changes in Placental Ceramide Metabolism Characterize Type 1 and 2 Diabetic Pregnancies with Fetal Macrosomia or Preeclampsia

Disturbances of lipid metabolism are typical in diabetes. Our objective was to characterize and compare placental sphingolipid metabolism in type 1 (T1D) and 2 (T2D) diabetic pregnancies and in non-diabetic controls. Placental samples from T1D, T2D, and control pregnancies were processed for sphingolipid analysis using tandem mass spectrometry. Western blotting, enzyme activity, and immunofluorescence analyses were used to study sphingolipid regulatory enzymes. Placental ceramide levels were lower in T1D and T2D compared to controls, which was associated with an upregulation of the ceramide degrading enzyme acid ceramidase (ASAH1). Increased placental ceramide content was found in T1D complicated by preeclampsia. Similarly, elevated ceramides were observed in T1D and T2D pregnancies with poor glycemic control. The protein levels and activity of sphingosine kinases (SPHK) that produce sphingoid-1-phosphates (S1P) were highest in T2D. Furthermore, SPHK levels were upregulated in T1D and T2D pregnancies with fetal macrosomia. In vitro experiments using trophoblastic JEG3 cells demonstrated increased SPHK expression and activity following glucose and insulin treatments. Specific changes in the placental sphingolipidome characterize T1D and T2D placentae depending on the type of diabetes and feto-maternal complications. Increased exposure to insulin and glucose is a plausible contributor to the upregulation of the SPHK-S1P-axis in diabetic placentae

Large maternal waist circumference in relation to height is associated with high glucose concentrations in an early-pregnancy oral glucose tolerance test : A population-based study

Publisher Copyright: © 2023 The Authors. Acta Obstetricia et Gynecologica Scandinavica published by John Wiley & Sons Ltd on behalf of Nordic Federation of Societies of Obstetrics and Gynecology (NFOG).Introduction: To explore the role of maternal anthropometric characteristics in early-pregnancy glycemia, we analyzed the associations and interactions of maternal early-pregnancy waist circumference (WC), height and pre-pregnancy body mass index (BMI) with plasma glucose concentrations in an oral glucose tolerance test (OGTT) at 12–16 weeks’ gestation. Material and Methods: A population-based cohort of 1361 pregnant women was recruited in South Karelia, Finland, from March 2013 to December 2016. All participants had their WC, weight, height, HbA1c, and blood pressure measured at 8–14 weeks’ gestation and subsequently underwent a 2-h 75-g OGTT, including assessment of fasting insulin concentrations, at 12–16 weeks’ gestation. BMI (kg/m2) was calculated using self-reported pre-pregnancy weight. Maternal WC ≥80 cm was defined as large. Maternal height ≥166 cm was defined as tall. Data on gestational diabetes treatment was extracted from hospital records. Results: In the total cohort, 901 (66%) of women had an early-pregnancy WC ≥80 cm, which was associated with higher early-pregnancy HbA1c, higher concentrations of fasting plasma glucose and serum insulin, higher post-load plasma glucose concentrations, higher HOMA-IR indices, higher blood pressure levels, and higher frequencies of pharmacologically treated gestational diabetes, than early-pregnancy WC 0.5 was positively associated with both fasting and post-load plasma glucose concentrations at 12–16 weeks’ gestation, even when adjusted for age, smoking, nulliparity, and family history of type 2 diabetes. The best cut-offs for WHtR (0.58 for 1-h plasma glucose, and 0.54 for 2-h plasma glucose) were better predictors of post-load glucose concentrations >90th percentile than the best cut-offs for BMI (28.1 kg/m2 for 1-h plasma glucose, and 26.6 kg/m2 for 2-h plasma glucose), with areas-under-the-curve (95% confidence interval) 0.73 (0.68–0.79) and 0.73 (0.69–0.77), respectively, for WHtR, and 0.68 (0.63–0.74) and 0.69 (0.65–0.74), respectively, for BMI. Conclusions: In our population-based cohort, early-pregnancy WHtR >0.5 was positively associated with both fasting and post-load glucose concentrations at 12–16 weeks’ gestation and performed better than BMI in the prediction of post-load glucose concentrations >90th percentile. Overall, our results underline the importance of evaluating maternal abdominal adiposity in gestational diabetes risk assessment.Peer reviewe

Macronutrient intake during pregnancy in women with a history of obesity or gestational diabetes and offspring adiposity at 5 years of age

Background/objectives The impact of maternal macronutrient intake during pregnancy on offspring childhood adiposity is unclear. We assessed the associations between maternal macronutrient intake during and after pregnancy with offspring adiposity at 5 years of age. Additionally, we investigated whether gestational diabetes (GDM), BMI, or breastfeeding modified these associations. Subjects/methods Altogether, 301 mother-child dyads with maternal prepregnancy BMI >= 30 and/or previous GDM participated in the Finnish Gestational Diabetes Prevention Study (RADIEL) and its 5 years follow-up. Macronutrient intakes (E%) were calculated from 3-day food records collected at 5-18 weeks' gestation, in the third trimester, and at 12 months and 5 years after pregnancy. Offspring body fat mass (BFM) and fat percentage (BF%) at 5 years were measured by bioimpedance. Statistical analyses were multivariate linear regression. Results Mean (SD) prepregnancy BMI was 33(4) kg/m(2). GDM was diagnosed in 47%. In normoglycemic women, higher first half of pregnancy n-3 PUFA intake was associated with lower offspring BFM (g) (ss -0.90; 95% CI -1.62, -0.18) and BF% (ss -3.45; 95% CI -6.17, -0.72). In women with GDM, higher first half of pregnancy n-3 PUFA intake was associated with higher offspring BFM (ss 0.94; 95% CI 0.14, 1.75) and BF% (ss 3.21; 95% CI 0.43, 5.99). Higher SFA intake in the third trimester and cumulative intake across pregnancy (mean of the first half and late pregnancy) was associated with higher BFM and BF% (across pregnancy: ss 0.12; 95% CI 0.03, 0.20 and ss 0.44; 95% CI 0.15, 0.73, respectively). Higher carbohydrate intake across pregnancy was associated with lower BFM (ss -0.044; 95% CI -0.086, -0.003), and borderline associated with BF% (ss -0.15; 95% CI -0.31, 0.00). Conclusions The macronutrient composition of maternal diet during pregnancy is associated with offspring BFM and BF% at 5 years. GDM modifies the association between prenatal n-3 PUFA intake and offspring anthropometrics.Peer reviewe

Skin Autofluorescence in Young Adult Offspring of Women with Type 1 Diabetes : A Cross-Sectional Case-Control Study

Introduction: Offspring born to women with type 1 diabetes pregnancies have an elevated risk for early-onset obesity and type 2 diabetes compared with offspring born to women without diabetes. Skin autofluorescence (SAF) is a marker of accumulated advanced glycation end products (AGEs) and it has been shown to predict type 2 diabetes, cardiovascular disease, and mortality in the general population. The aim of this study was to evaluate whether maternal type 1 diabetes influences the SAF value in young adult offspring. Methods: This cross-sectional case-control study included 78 offspring of women with type 1 diabetes (cases) and 85 control participants (controls). All study participants, aged 18-23 years, were invited to participate in a clinical assessment including laboratory tests and questionnaires. SAF was assessed using the AGE reader from the dominant forearm of each participant. Results: The mean SAF value did not differ between the cases (1.61 [standard deviation (SD) 0.37]) arbitrary units [AU]) and the controls (1.64 [SD 0.41] AU) (p = 0.69). After adjusting for glycated hemoglobin A(1c), body fat percentage, smoking, and season the mean SAF value did not differ between the cases and the controls (p = 0.49) but differed between men and women (p = 0.008), without any interaction observed (p = 0.78). Conclusion: SAF values did not differ between the young adult offspring of women with type 1 diabetes and offspring born to mothers without diabetes. Surprisingly, young adult women showed higher SAF values than men in both case and control groups.Peer reviewe

Genetic risk of type 2 diabetes modifies the effects of a lifestyle intervention aimed at the prevention of gestational and postpartum diabetes

Aims/hypothesis The aim of this study was to assess the interaction between genetic risk and lifestyle intervention on the occurrence of gestational diabetes mellitus (GDM) and postpartum diabetes. Methods The RADIEL study is an RCT aimed at prevention of GDM and postpartum diabetes through lifestyle intervention. Participants with a BMI >= 30 kg/m(2) and/or prior GDM were allocated to intervention and control groups before pregnancy or in early pregnancy. The study visits took place every 3 months before pregnancy, once in each trimester, and at 6 weeks and 6 and 12 months postpartum. We calculated a polygenic risk score (PRS) based on 50 risk variants for type 2 diabetes. Results Altogether, 516 participants provided genetic and GDM data. The PRS was associated with higher glycaemic levels (fasting glucose and/or HbA(1c)) and a lower insulin secretion index in the second and third trimesters and at 12 months postpartum, as well as with a higher occurrence of GDM and glycaemic abnormalities at 12 months postpartum (n = 356). There was an interaction between the PRS and lifestyle intervention (p=0.016 during pregnancy and p=0.024 postpartum) when analysing participants who did not have GDM at the first study visit during pregnancy (n = 386). When analysing women in tertiles according to the PRS, the intervention was effective in reducing the age-adjusted occurrence of GDM only among those with the highest genetic risk (OR 0.37; 95% CI 0.17, 0.82). The risk of glycaemic abnormalities at 12 months postpartum was reduced in the same group after adjusting additionally for BMI, parity, smoking and education (OR 0.35; 95% CI 0.13, 0.97). Conclusions/interpretation Genetic predisposition to diabetes modifies the response to a lifestyle intervention aimed at prevention of GDM and postpartum diabetes. This suggests that lifestyle intervention may benefit from being tailored according to genetic risk.Peer reviewe

Prevention of gestational diabetes through lifestyle intervention: study design and methods of a Finnish randomized controlled multicenter trial (RADIEL)

Background Maternal overweight, obesity and consequently the incidence of gestational diabetes are increasing rapidly worldwide. The objective of the study was to assess the efficacy and cost-effectiveness of a combined diet and physical activity intervention implemented before, during and after pregnancy in a primary health care setting for preventing gestational diabetes, later type 2 diabetes and other metabolic consequences. Methods RADIEL is a randomized controlled multi-center intervention trial in women at high risk for diabetes (a previous history of gestational diabetes or prepregnancy BMI &ge;30&nbsp;kg/m2). Participants planning pregnancy or in the first half of pregnancy were parallel-group randomized into an intervention arm which received lifestyle counseling and a control arm which received usual care given at their local antenatal clinics. All participants visited a study nurse every three months before and during pregnancy, and at 6&nbsp;weeks, 6 and 12&nbsp;months postpartum. Measurements and laboratory tests were performed on all participants with special focus on dietary and exercise habits and metabolic markers. Of the 728 women [mean age 32.5&nbsp;years (SD 4.7); median parity 1 (range 0-9)] considered to be eligible for the study 235 were non-pregnant and 493 pregnant [mean gestational age 13 (range 6 to 18) weeks] at the time of enrollment. The proportion of nulliparous women was 29.8% (n&thinsp;=&thinsp;217). Out of all participants, 79.6% of the non-pregnant and 40.4% of the pregnant women had previous gestational diabetes and 20.4% of the non-pregnant and 59.6% of the pregnant women were recruited because of a prepregnancy BMI &ge;30&nbsp;kg/m2. Mean BMI at first visit was 30.1&nbsp;kg/m2 (SD 6.2) in the non-pregnant and 32.7&nbsp;kg/m2 (SD 5.6) in the pregnant group. Discussion To our knowledge, this is the first randomized lifestyle intervention trial, which includes, besides the pregnancy period, both the prepregnancy and the postpartum period. This study design also provides an opportunity to focus upon the health of the next generation. The study is expected to produce novel information on the optimal timing and setting of interventions and for allocating resources to prevent obesity and diabetes in women of reproductive age.</p

Higher pulse wave velocity in young adult offspring of mothers with type 1 diabetes : a case-control study

Background Offspring of mothers with type 1 diabetes have an increased risk for acquiring early onset cardiovascular disease (CVD). Arterial stiffness, measured as pulse wave velocity (PWV), is a non-invasive biomarker for CVD risk assessment. Our aim is to determine whether PWV is increased in young adult offspring of mothers with type 1 diabetes. Methods This is a case-control study carried out in the hospital district of Helsinki and Uusimaa, Finland. 75 offspring of mothers with type 1 diabetes (cases) and 84 offspring of mothers without diabetes (controls), aged 18-23 years, were enrolled in this study. All participants attended clinical assessments, including questionnaires and laboratory tests. Carotid-femoral PWV (cfPWV), carotid-radial PWV (crPWV), and PWV ratio were measured from each participant using the Complior Analyse mechanotransducer (Alam Medical, France). Student's t-test and chi-squared test were used to assess differences between the groups. Stata 17.0, StataCorp LP (College Station, TX, USA) statistical package was used for the analysis. Results We did not observe any differences in conventional CVD risk factors: systolic blood pressure, LDL, Hb(A1c), and smoking between cases and controls. We detected higher cfPWV in cases 6.5 (SD +/- 1.2) m/s than in controls 6.2 (SD +/- 0.7) m/s, p = 0.049, after adjustments for BMI, smoking, mean arterial pressure, height, and pulse rate was made. We did not observe any difference between cases and controls regarding crPWV or PWV ratio. Additionally, we detected no sex differences. Conclusions We report a novel finding of signs of increased arterial stiffness already in young adult offspring of mothers with type 1 diabetes compared to matched offspring of mothers without diabetes. Our finding suggests that exposure to an adverse intrauterine environment of type 1 diabetes mothers may affect the vascular health of offspring already in young adulthood. Additional research within this topic is warranted.Peer reviewe

Genetic risk of type 2 diabetes modifies the effects of a lifestyle intervention aimed at the prevention of gestational and postpartum diabetes

Aims/hypothesis The aim of this study was to assess the interaction between genetic risk and lifestyle intervention on the occurrence of gestational diabetes mellitus (GDM) and postpartum diabetes.Methods The RADIEL study is an RCT aimed at prevention of GDM and postpartum diabetes through lifestyle intervention. Participants with a BMI >= 30 kg/m(2) and/or prior GDM were allocated to intervention and control groups before pregnancy or in early pregnancy. The study visits took place every 3 months before pregnancy, once in each trimester, and at 6 weeks and 6 and 12 months postpartum. We calculated a polygenic risk score (PRS) based on 50 risk variants for type 2 diabetes.Results Altogether, 516 participants provided genetic and GDM data. The PRS was associated with higher glycaemic levels (fasting glucose and/or HbA(1c)) and a lower insulin secretion index in the second and third trimesters and at 12 months postpartum, as well as with a higher occurrence of GDM and glycaemic abnormalities at 12 months postpartum (n = 356). There was an interaction between the PRS and lifestyle intervention (p=0.016 during pregnancy and p=0.024 postpartum) when analysing participants who did not have GDM at the first study visit during pregnancy (n = 386). When analysing women in tertiles according to the PRS, the intervention was effective in reducing the age-adjusted occurrence of GDM only among those with the highest genetic risk (OR 0.37; 95% CI 0.17, 0.82). The risk of glycaemic abnormalities at 12 months postpartum was reduced in the same group after adjusting additionally for BMI, parity, smoking and education (OR 0.35; 95% CI 0.13, 0.97).Conclusions/interpretation Genetic predisposition to diabetes modifies the response to a lifestyle intervention aimed at prevention of GDM and postpartum diabetes. This suggests that lifestyle intervention may benefit from being tailored according to genetic risk.</p