The genetic interface between gestational diabetes and type 2 diabetes

Functional genetic variants and susceptibility and prediction of gestational diabetes mellitus

The aetiological mechanism of gestational diabetes mellitus (GDM) has still not been fully understood. The aim of this study was to explore the associations between functional genetic variants screened from a genome-wide association study (GWAS) and GDM risk among 554 GDM patients and 641 healthy controls in China. Functional analysis of single nucleotide polymorphisms (SNPs) positively associated with GDM was further performed. Univariate regression and multivariate logistic regression analyses were used to screen clinical risk factors, and a predictive nomogram model was established. After adjusting for age and prepregnancy BMI, rs9283638 was significantly associated with GDM susceptibility (P < 0.05). Moreover, an obvious interaction between rs9283638 and clinical variables was detected (Pinteraction < 0.05). Functional analysis confirmed that rs9283638 can regulate not only target gene transcription factor binding, but it also regulates the mRNA levels of SAMD7 (P < 0.05). The nomogram model constructed with the factors of age, FPG, 1hPG, 2hPG, HbA1c, TG and rs9283638 revealed an area under the ROC curve of 0.920 (95% CI 0.902-0.939). Decision curve analysis (DCA) suggested that the model had greater net clinical benefit. Conclusively, genetic variants can alter women's susceptibility to GDM by affecting the transcription of target genes. The predictive nomogram model constructed based on genetic and clinical variables can effectively distinguish individuals with different GDM risk factors.

Association of gene polymorphisms of ACE, AGT, and ARNT-like protein 1 with susceptibility to gestational diabetes

Background and aims

Gestational diabetes mellitus is well-defined as glucose intolerance first documented during pregnancy. In this study, we examined the possible associations between I/D polymorphism of the angiotensin-converting enzyme gene, the M235T variant of angiotensinogen gene, and the rs7950226 polymorphism of the ARNT-like protein-1 (BMAL1) gene and the risk for diabetes in Egyptian pregnant women.

Subjects and methods

This study recruited 160 gestational diabetes cases and 165 controls. Genomic DNA was derived from peripheral blood leukocytes and ACE gene (I/D) genotyping was performed using the method of polymerase chain reaction and the polymerase chain reaction-based restriction fragment length polymorphism was used for identifying the M235T variant of AGT gene and the rs7950226 polymorphism of the BMAL1.

Results

The II, ID, and DD genotypes of the ACE gene have significant differences in cases compared to controls (P = 0.000 and X2 = 81.77). The M235T polymorphism of the AGT gene was increased with gestational diabetes risk. Furthermore, the AA genotype of the BMAL1 rs7950226 gene was significantly related to the gestational diabetes risk (P = 0.000 and X2 = 52.82). Furthermore, the allele frequencies of the three variants have significant variances between cases and control.

Conclusion

This study suggested significant associations between ACE (DD), AGT (TT), and BMAL1 rs7950226 (AA) gene polymorphisms with gestational diabetes susceptibility and there was a possibility to identify that II + MM + GG as protective haplotypes and DD + TT + AA as risk haplotypes for gestational diabetes.

Interaction of Polygenetic Variants for Gestational Diabetes Mellitus Risk with Breastfeeding and Korean Balanced Diet to Influence Type 2 Diabetes Risk in Later Life in a Large Hospital-Based Cohort

The etiologies of gestational diabetes mellitus (GDM) and type 2 diabetes mellitus (T2DM) are similar. Genetic and environmental factors interact to influence the risk of both types of diabetes. We aimed to determine if the polygenetic risk scores (PRS) for GDM risk interacted with lifestyles to influence type 2 diabetes risk in women aged >40 years in a large hospital-based city cohort. The participants with GDM diagnosis without T2DM before pregnancy were considered the case group (n = 384) and those without GDM and T2DM as the control (n = 33,956) to explore GDM-related genetic variants. The participants with T2DM were the case (n = 2550), and the control (n = 33,956) was the same as GDM genetic analysis for the interaction analysis of GDM genetic risk with lifestyles to influence T2DM risk. The genetic variants for the GDM risk were selected from a genome-wide association study (GWAS), and their PRS from the best model with gene-gene interactions were generated. GDM was positively associated with age at first pregnancy, body mass index (BMI) at age 20, and education level. A previous GDM diagnosis increased the likelihood of elevated fasting serum glucose concentrations and HbA1c contents by 8.42 and 9.23 times in middle-aged and older women. However, it was not associated with the risk of any other metabolic syndrome components. Breast-feeding (≥1 year) was inversely associated with the T2DM risk in later life. In the genetic variant-genetic variant interaction, the best model with 5-SNPs included PTPRD_rs916855529, GPC6_rs9589710, CDKAL1_rs7754840, PRKAG2_rs11975504, and PTPRM_rs80164908. The PRS calculated from the 5-SNP model was positively associated with the GDM risk by 3.259 (2.17-4.89) times after adjusting GDM-related covariates. The GDM experience interacted with PRS for the T2DM risk. Only in non-GDM women PRS was positively associated with T2DM risk by 1.36-times. However, long breastfeeding did not interact with the PRS for T2DM risk. Among dietary patterns, only a Korean-style balanced diet (KBD) showed an interaction with PRS for the T2DM risk. Participants with a low-PRS had the lowest serum glucose concentrations in the high KBD intake but not low KBD intake. In conclusion, participants with a high PRS for GDM risk are positively associated with T2DM risk, and breastfeeding for ≥1 year and consuming KBD offset the PRS for GDM risk to influence T2DM risk in middle-aged and older.

Gestational Diabetes Mellitus (GDM) Risk for Declared Family History of Diabetes, in Combination with BMI Categories

Whether categories of family history of diabetes can act as independent risk factors for gestational diabetes mellitus (GDM-1, -2) has not yet been established, and neither has it been established how categories of body mass index (BMI) affect these relationships. A group of 912 women without chronic diseases, recruited in the first trimester, was investigated: 125 (13.7%) women developed GDM-1 (treated with diet); 21 (2.3%) women developed GDM-2 (treated with insulin); and a control group consisted of 766 non-diabetic women. A multiple logistic regression was used to evaluate adjusted odds ratios (AOR (95% confidence intervals)) of GDM-1 and GDM-2 for declared diabetes in the parents or grandparents (separately). These relationships were investigated in the whole cohort and subgroups of pre-pregnancy BMI. (1) Some categories of the family history were independent risk factors of GDM-1 or GDM-2. Compared to ‘absence of diabetes in the family’, women with diabetes in the father had a 3.68-fold increase in GDM-1 risk (AOR-b = 3.68 (2.23–6.07)), and women with diabetes in the mother had a 2.13-fold increase in GDM-1 risk (AOR-b = 2.13 (1.1–4.14)) and a 4.73-fold increase in GDM-2 risk (AOR-b = 4.73 (1.26–17.77)). Women with diabetes in the grandmother had a 2.34-fold increase in GDM-1 risk (AOR-b = 2.34 (1.29–4.24)). (2) The cumulative assessment of diabetes in the parents and/or grandparents was not related to the intensification of the risk of GDM, except for the increased risk of GDM-1 for diabetes in both mother and grandmothers simultaneously (AOR-b = 8.80 (1.16–66.57)), however, this group was very small. (3) The analyses in the subgroups of BMI categories showed that diabetes in the father was also an independent risk factor of GDM in the subgroup of pregnant women with normal BMI. In the subgroups of overweight and/or obesity, the risk of GDM for paternal and maternal diabetes was approximately twice as high as compared to the results of pregnant women with normal BMIs. Additionally, apart from the maternal influence of diabetes, the results suggest a significant influence of diabetes in the father on the risk of GDM, even (interestingly) in lean pregnant women.

Long-term cardio-metabolic effects after gestational diabetes: a review

Women with GDM are at high risk of metabolic syndrome and type 2 diabetes (T2DM). A relationship with GDM and future development of cardiovascular disease (CVD) has been also recognized. Pregnancy and postpartum period in women with GDM give us the opportunity to identify the underlying, often unrecognized, CVD risk factors. Ideally, the postpartum follow-up of this women should be done by a multidisciplinary team to evaluate their cardio-metabolic risk and to counseling regarding lifestyle modification (healthy diet and regular physical activity) and breastfeeding that can reduce their risk. Longer follow-up of these women should be individualized, focusing attention on women at medium-high cardio-metabolic risk. The link between GDM and T2DM-CVD offers us a great opportunity for the diseases prevention.

Genetic Susceptibility to Gestational Diabetes Mellitus in a Chinese Population

Introduction: New genetic variants associated with susceptibility to obesity and metabolic diseases have been discovered in recent genome-wide association (GWA) studies. The aim of this study was to investigate the association of theses risk variants with gestational diabetes mellitus (GDM). Methods: We performed a case-control study including 964 unrelated pregnant women with GDM and 1,021 pregnant women with normal glucose tolerance (as controls). A total of 33 genetic variants confirmed by GWA studies for obesity and metabolic diseases were selected and measured. Results: We observed that FTO rs1121980 and KCNQ1 rs163182 conferred a decreased GDM risk in the dominant and additive model [additive model: OR (95% CI) = 0.79 (0.67-0.94), P = 0.007 for rs1121980; OR(95%CI) = 0.84 (0.73-0.96), P = 0.009 for rs163182], whereas MC4R rs12970134 and PROX1 rs340841 conferred an increased GDM risk in the dominant, recessive, and additive model [additive model: OR(95%CI) = 1.25 (1.07-1.46), P = 0.006 for rs12970134; OR(95%CI) = 1.22 (1.07-1.39), P = 0.002 for rs340841). With the increasing number of risk alleles of the four significant SNPs, GDM risk was significantly increased in a dose-dependent manner (P_trend < 0.001). And the significant positive associations between the weighted genetic risk score and risk of GDM persisted. Further function annotation indicated that these four SNPs may fall on the functional elements of human pancreatic islets. The genotype-phenotype associations indicated that these SNPs may contribute to GDM by affecting the expression levels of their nearby or distant genes. Conclusion: Our study suggests that FTO rs1121980, KCNQ1 rs163182, MC4R rs12970134, and PROX1 rs340841 may be markers for susceptibility to GDM in a Chinese population.

The rs10229583 polymorphism near paired box gene 4 is associated with gestational diabetes mellitus in Chinese women

Objective

The rs10229583 polymorphism near paired box gene 4 (PAX4) is associated with insulin resistance and type 2 diabetes. Mutations in the PAX4 gene may be associated with impaired differentiation/development of pancreatic islet beta cells during fetal development and, consequently, a compromised insulin response to high blood glucose. To ascertain whether this polymorphism plays a role in gestational diabetes mellitus (GDM), we investigated the genotypic and allele frequency differences between GDM and normal pregnancies.

Methods

A total of 310 GDM and 440 normal pregnancies were evaluated. Allele and genotype frequencies of rs10229583 were determined for all participants with Sanger sequencing and SNaPshot. Association of the allele and genotypes of the single nucleotide polymorphism with the disease was analyzed using Pearson’s χ² test and OR (odds ratio).

Results

The G allele was more frequent in patients with GDM compared with controls (OR = 1.47, 95% confidence interval (CI): 1.12–1.939). The GG genotype frequency of rs10229583 was significantly different between subjects with GDM and normal controls (OR = 1.411, 95% CI: 1.032–1.928). The OR of the GA + GG genotype was 3.182 (95% CI: 1.294–7.826) for patients with GDM compared with controls.

Conclusion

The present study suggests that rs10229583 is associated with GDM.

Nutritional Intervention Preconception and During Pregnancy to Maintain Healthy Glucose Metabolism and Offspring Health ("NiPPeR"): study protocol for a randomised controlled trial

Background

Improved maternal nutrition and glycaemic control before and during pregnancy are thought to benefit the health of the mother, with consequent benefits for infant body composition and later obesity risk. Maternal insulin resistance and glycaemia around conception and in early pregnancy may be key determinants of maternal physiology and placental function, affecting fetal nutrient supply and maternal-feto-placental communications throughout gestation, with implications for later postnatal health.

Methods/design

This double-blind randomised controlled trial will recruit up to 1800 women, aged 18–38 years, who are planning a pregnancy in the United Kingdom (UK), Singapore and New Zealand, with a view to studying 600 pregnancies. The primary outcome is maternal glucose tolerance at 28 weeks’ gestation following an oral glucose tolerance test. Secondary outcomes include metabolic, molecular and health-related outcomes in the mother and offspring, notably infant body composition. Participants will be randomly allocated to receive a twice-daily control nutritional drink, enriched with standard micronutrients, or a twice-daily intervention nutritional drink enriched with additional micronutrients, myo-inositol and probiotics, both demonstrated previously to assist in maintaining healthy glucose metabolism during pregnancy. Myo-inositol is a nutrient that enhances cellular glucose uptake. The additional micronutrients seek to address deficiencies of some B-group vitamins and vitamin D that are both common during pregnancy and that have been associated with maternal dysglycaemia, epigenetic changes and greater offspring adiposity. Women who conceive within a year of starting the nutritional drinks will be followed through pregnancy and studied with their infants at six time points during the first year of life. Blood, urine/stool, hair and cheek swabs will be collected from the mothers for genetic, epigenetic, hormone, nutrient and metabolite measurements, and assessments of the mother’s body composition, anthropometry, health, diet and lifestyle will be made. Infants will also undergo hair, cheek swab, urine and stool sampling for similar biological measurements; infant body composition will be assessed and feeding recorded.

Discussion

There is an increasing focus on the need to optimise maternal nutrition starting prior to conception. This trial will provide evidence on the potential for nutritional interventions beginning prior to conception to promote healthy maternal and offspring outcomes.

Trial registration

ClinicalTrials.gov, identifier: NCT02509988, Universal Trial Number U1111-1171-8056. Registered on 16 July 2015. This is an academic-led study by the EpiGen Global Research Consortium.

Electronic supplementary material

The online version of this article (doi:10.1186/s13063-017-1875-x) contains supplementary material, which is available to authorized users.

Resistin - 420 C/G polymorphism and serum resistin level in Iranian patients with gestational diabetes mellitus

Background

Resistin is a circulating adipokine with insulin-antagonizing effects. The aim of this study was to investigate the relationship between the single nucleotide polymorphism (SNP) -420C > G in the resistin gene with serum resistin levels, insulin resistance, and risk of gestational diabetes (GDM) in Iranian population.

Method

75 GDM patients and 70 healthy pregnant women were enrolled in this study. Genotyping for SNP- 420C > G in the resistin gene was performed by the polymerase chain reaction- restriction fragment length polymorphism (PCR-RFLP) method. Serum resistin and insulin were measured by immunoassay. Blood glucose levels and lipid profile were measured by enzymatic methods. Homeostasis model of assessment for insulin resistance (HOMA-IR) were calculated.

Result

GG genotype and G allele of SNP-420C > G were more frequent in GDM patients compared to non-GDM subjects. Serum resistin level was similar in GDM and non-GDM patients. The serum levels of resistin in GDM and non-GDM women with GG genotype were similar to those with GC + CC genotype. Multivariate logistic regression analysis after adjusting for confounding factors showed a higher susceptibility to GDM in patients with GG genotype compared to subjects with GG + GT genotype (odds ratio = 4.59, 95% CI; 1.96-10.71, p = 0.00). Serum resistin level was correlated with serum triglyceride, total and low density lipoprotein (LDL) cholesterol (p < 0.05) in GDM patients. No significant association was found between serum resistin, insulin resistance, and SNP-420C > G.

Conclusion

The SNP-420C/G of resistin gene is associated with genetic susceptibility to GDM in our population. Further studies are necessary to confirm the role of this polymorphism in pathogenesis of GDM and to explore potential mechanisms by which it modulates susceptibility to GDM.

The association of circulating adiponectin and + 45 T/G polymorphism of adiponectin gene with gestational diabetes mellitus in Iranian population

Background

Adiponectin is an adipokine with insulin-sensitizing effects. We investigated the relationship between the single nucleotide polymorphism (SNP) +45 T > G ( rs 2241766 ;Gly15Gly) in the adiponectin gene, serum adiponectin levels, insulin resistance and risk of gestational diabetes (GDM) in Iranian population.

Methods

65 GDM patients and 70 healthy pregnant women were enrolled in this study. Genotyping for SNP +45 T > G in the adiponectin gene ( rs 2241766 ) was performed by the polymerase chain reaction-restriction fragment length polymorphism method. The level of fasting serum adiponectin, insulin, glucose, and lipid levels were measured. Insulin resistance was estimated using homeostasis model of assessment for insulin resistance (HOMA-IR).

Results

The G allele and TG/GG genotype of rs 2241766 were more frequent than the T allele and TT genotype in GDM patients compared to the controls (p < 0.05). Multiple logistic regression analysis revealed that the risk of GDM was significantly higher in subjects with the TG/GG genotype to those with TT genotype [odds ratio = 2.38, 95% CI 1.09-5.22, p = 0.030]. No significant association was observed between genotypes of rs 2241766 and circulating concentrations of adiponectin. Multiple regression analysis showed that serum adiponectin levels was negatively associated with HOMA-IR in GDM patients (β = −0.385, p <0.01).

Conclusion

The findings demonstrated that TG/GG genotype of rs 2241766 was an independent risk factor of GDM in our population. Furthermore, circulating adiponectin level was negatively correlated with insulin resistance in GDM patients.

Enabling nutrient security and sustainability through systems research

Human and companion animal health depends upon nutritional quality of foods. Seed varieties, seasonal and local growing conditions, transportation, food processing, and storage, and local food customs can influence the nutrient content of food. A new and intensive area of investigation is emerging that recognizes many factors in these agri-food systems that influence the maintenance of nutrient quality which is fundamental to ensure nutrient security for world populations. Modeling how these systems function requires data from different sectors including agricultural, environmental, social, and economic, but also must incorporate basic nutrition and other biomedical sciences. Improving the agri-food system through advances in pre- and post-harvest processing methods, biofortification, or fortifying processed foods will aid in targeting nutrition for populations and individuals. The challenge to maintain and improve nutrient quality is magnified by the need to produce food locally and globally in a sustainable and consumer-acceptable manner for current and future populations. An unmet requirement for assessing how to improve nutrient quality, however, is the basic knowledge of how to define health. That is, health cannot be maintained or improved by altering nutrient quality without an adequate definition of what health means for individuals and populations. Defining and measuring health therefore becomes a critical objective for basic nutritional and other biomedical sciences.

Early developmental conditioning of later health and disease: physiology or pathophysiology?

Extensive experimental animal studies and epidemiological observations have shown that environmental influences during early development affect the risk of later pathophysiological processes associated with chronic, especially noncommunicable, disease (NCD). This field is recognized as the developmental origins of health and disease (DOHaD). We discuss the extent to which DOHaD represents the result of the physiological processes of developmental plasticity, which may have potential adverse consequences in terms of NCD risk later, or whether it is the manifestation of pathophysiological processes acting in early life but only becoming apparent as disease later. We argue that the evidence suggests the former, through the operation of conditioning processes induced across the normal range of developmental environments, and we summarize current knowledge of the physiological processes involved. The adaptive pathway to later risk accords with current concepts in evolutionary developmental biology, especially those concerning parental effects. Outside the normal range, effects on development can result in nonadaptive processes, and we review their underlying mechanisms and consequences. New concepts concerning the underlying epigenetic and other mechanisms involved in both disruptive and nondisruptive pathways to disease are reviewed, including the evidence for transgenerational passage of risk from both maternal and paternal lines. These concepts have wider implications for understanding the causes and possible prevention of NCDs such as type 2 diabetes and cardiovascular disease, for broader social policy and for the increasing attention paid in public health to the lifecourse approach to NCD prevention.

Gestational diabetes mellitus among Nordic Caucasian women: prevalence and risk factors according to WHO and simplified IADPSG criteria

BACKGROUND

Gestational diabetes mellitus (GDM) is associated with both maternal and offspring adverse effects. The World Health Organization (WHO) has recently adopted novel GDM criteria. The aim of this study was to evaluate the former WHO and a simplified version of the new International Association for Diabetes in Pregnancy Study Group (IADPSG) criteria as to prevalence of and risk factors for GDM in a Nordic Caucasian population.

METHODS

A 75 g oral glucose tolerance test was performed in 687 women at 18-22 and 32-36 pregnancy weeks. GDM was defined according to the WHO criteria as fasting plasma glucose ≥ 7.0 mmol/L and/or 2-hour plasma glucose ≥ 7.8 mmol/L and by a simplified version of the IADPSG criteria as either fasting glucose ≥ 5.1 mmol/L and/or 2-h plasma glucose ≥ 8.5 mmol/L. One-hour glucose values were not available and were thus not included in the diagnosis of GDM by IADPSG. Prevalence of GDM during pregnancy and risk factors for GDM at 18-22 weeks were studied in retrospect according to each of the two criteria.

RESULTS

The total prevalence of GDM during pregnancy was 6.1% (42/687) for the WHO criteria and 7.4% (51/687) for the simplified IADPSG criteria. High maternal age and short stature were independently associated with WHO GDM. Maternal age, fasting insulin and no regular exercise at 18-22 pregnancy weeks associated with simplified IADPSG GDM.

CONCLUSIONS

Simplified IADPSG criteria moderately increase GDM prevalence compared with the WHO criteria. Risk factors for GDM differ with the diagnostic criteria used.

Gestational diabetes mellitus among Norwegian women with polycystic ovary syndrome: prevalence and risk factors according to the WHO and the modified IADPSG criteria

OBJECTIVE

The consequences of the recently proposed International Association of Diabetes in Pregnancy Study Group (IADPSG) criteria for gestational diabetes mellitus (GDM) in women with polycystic ovary syndrome (PCOS) are not known. We compared the prevalence rates and risk factors for GDM in PCOS women according to both the WHO and the modified IADPSG criteria.

DESIGN

Post hoc analyses from a randomized, multicenter study were used.

METHODS

Fasting and 2-h plasma glucose levels were measured using a 75 g oral glucose tolerance test. GDM was diagnosed according to both the WHO and the modified IADPSG criteria.

RESULTS

The prevalence rates of GDM according to the WHO and the modified IADPSG criteria were 9.2 and 15.0% at week 12, 18.7 and 18.7% at week 19, and 25.6 and 24.2% at week 32. Shorter stature and increased insulin levels were correlated with WHO-GDM, but not with modified IADPSG-GDM at weeks 12 and 19. Less weight gain in pregnancy predicted GDM according to both sets of criteria. GDM diagnosis was correlated with less maternal weight loss the first year post-partum.

CONCLUSIONS

No difference was found in the prevalence of GDM between the two sets of criteria used. Less weight gain in pregnancy was associated with GDM, independent of the diagnostic criteria used. Reduced weight loss the first year post-partum in women with GDM raises the question of whether GDM diagnosis per se or the fact that these women lose less weight after pregnancy predicts later diabetes mellitus.

Genetic variants and the risk of gestational diabetes mellitus: a systematic review

BACKGROUND

Several studies have examined associations between genetic variants and the risk of gestational diabetes mellitus (GDM). However, inferences from these studies were often hindered by limited statistical power and conflicting results. We aimed to systematically review and quantitatively summarize the association of commonly studied single nucleotide polymorphisms (SNPs) with GDM risk and to identify important gaps that remain for consideration in future studies.

METHODS

Genetic association studies of GDM published through 1 October 2012 were searched using the HuGE Navigator and PubMed databases. A SNP was included if the SNP-GDM associations were assessed in three or more independent studies. Two reviewers independently evaluated the eligibility for inclusion and extracted the data. The allele-specific odds ratios (ORs) and 95% confidence intervals (CIs) were pooled using random effects models accounting for heterogeneity.

RESULTS

Overall, 29 eligible articles capturing associations of 12 SNPs from 10 genes were included for the systematic review. The minor alleles of rs7903146 (TCF7L2), rs12255372 (TCF7L2), rs1799884 (-30G/A, GCK), rs5219 (E23K, KCNJ11), rs7754840 (CDKAL1), rs4402960 (IGF2BP2), rs10830963 (MTNR1B), rs1387153 (MTNR1B) and rs1801278 (Gly972Arg, IRS1) were significantly associated with a higher risk of GDM. Among them, genetic variants in TCF7L2 showed the strongest association with GDM risk, with ORs (95% CIs) of 1.44 (1.29-1.60, P < 0.001) per T allele of rs7903146 and 1.46 (1.15-1.84, P = 0.002) per T allele of rs12255372.

CONCLUSIONS

In this systematic review, we found significant associations of GDM risk with nine SNPs in seven genes, most of which have been related to the regulation of insulin secretion.

The major circadian pacemaker ARNT-like protein-1 (BMAL1) is associated with susceptibility to gestational diabetes mellitus

AIMS

Recently a relationship between circadian clock function and the risk for type 2 diabetes (T2D) has been shown. BMAL1 is a key component of the mammalian molecular clock. Two SNPs in the BMAL1 gene have been identified to confer T2D susceptibility. In the present study we investigated for the first time the association between the BMAL1 gene and the risk for GDM, in a Greek population.

METHODS

We studied 185 women with GDM and 161 non-diabetic controls for BMAL1 polymorphisms. For BMAL1 mRNA expression, peripheral leukocytes were harvested from 20 GDM and 20 control women, harboring different genotypes for the tested polymorphisms, using real-time quantitative PCR.

RESULTS

The minor allele (A) of the BMAL1 rs7950226 (G>A) polymorphism was found to be significantly associated with an increased risk of GDM (P=0.025). Analysis of the second BMAL1 rs11022775 (T>C) polymorphism, showed that the C-allele frequency was strongly increased in women with GDM (P=4.455e-06). The CC genotype was also significantly overrepresented in GDM vs. controls (P=0.00001). Additionally, the rs7950226G/rs11022775C and rs7950226A/rs11022775C haplotypes were also found to be associated with increased susceptibility to GDM. Furthermore, the expression levels of BMAL1 mRNA were significantly lower in GDM patients than in controls.

CONCLUSION

These data suggest that the impairment of the BMAL1 clock gene expression is closely associated with GDM susceptibility.

Early life opportunities for prevention of diabetes in low and middle income countries

BACKGROUND

The global burden of diabetes and other non-communicable diseases is rising dramatically worldwide and is causing a double poor health burden in low- and middle-income countries. Early life influences play an important part in this scenario because maternal lifestyle and conditions such as gestational diabetes and obesity affect the risk of diabetes in the next generation. This indicates important periods during the lifecourse when interventions could have powerful affects in reducing incidence of non-communicable diseases. However, interventions to promote diet and lifestyle in prospective parents before conception have not received sufficient attention, especially in low- and middle-income countries undergoing socio-economic transition.

DISCUSSION

Interventions to produce weight loss in adults or to reduce weight gain in pregnancy have had limited success and might be too late to produce the largest effects on the health of the child and his/her later risk of non-communicable diseases. A very important factor in the prevention of the developmental component of diabetes risk is the physiological state in which the parents enter pregnancy. We argue that the most promising strategy to improve prospective parents' body composition and lifestyle is the promotion of health literacy in adolescents. Multiple but integrated forms of community-based interventions that focus on nutrition, physical activity, family planning, breastfeeding and infant feeding practices are needed. They need to address the wider social economic context in which adolescents live and to be linked with existing public health programmes in sexual and reproductive health and maternal and child health initiatives.

SUMMARY

Interventions aimed at ensuring a healthy body composition, diet and lifestyle before pregnancy offer a most effective solution in many settings, especially in low- and middle-income countries undergoing socio-economic transition. Preparing a mother, her partner and her future child for "the 1000 days", whether from planned or unplanned conception would break the cycle of risk and demonstrate benefit in the shortest possible time. Such interventions will be particularly important in adolescents and young women in disadvantaged groups and can improve the physiological status of the fetus as well as reduce the prevalence of pregnancy conditions such as gestational diabetes mellitus which both predispose to non-communicables diseases in both the mother and her child. Pre-conception interventions require equipping prospective parents with the necessary knowledge and skills to make healthy lifestyle choices for themselves and their children. Addressing the promotion of such health literacy in parents-to-be in low- and middle-income countries requires a wider social perspective. It requires a range of multisectoral agencies to work together and could be linked to the issues of women's empowerment, to reproductive health, to communicable disease prevention and to the Millennium Development Goals 4 and 5.