Investigating Molecular Biomarkers During Gestational Diabetes Mellitus

Introduction: Gestational diabetes mellitus (GDM) is a significant public health concern, due to its association with short- and long-term complications in both mothers and offspring. DNA methylation and single nucleotide polymorphisms (SNPs) offer potential to serve as molecular biomarkers, which may lead to improved detection of GDM with positive effects on health outcomes. Aim: The aim of this study was to investigate whether DNA methylation and SNPs are associated with GDM and may offer potential as molecular biomarkers for GDM in South Africa (SA). Methods: This study followed a two-pronged approach. Firstly, literature searches were conducted to collate and synthesise all published articles reporting on the prevalence of GDM in SA, the screening and diagnostic strategies used, and the current status of DNA methylation and SNPs as biomarkers for GDM. Secondly, we conducted experiments to investigate global (n=201), genome-wide (n=24) and gene-specific DNA methylation (n=286) of the adiponectin gene (ADIPOQ) in whole blood of women with and without GDM, using an Enzyme-Linked Immunosorbent Assay, a methylationEPIC BeadChip Array and pyrosequencing, respectively. In addition, genotype and allele frequencies of ADIPOQ rs266729 and rs17300539, and methylenetetrahydrofolate reductase (MTHFR) rs1801133 were determined, using quantitative real-time PCR (n=449) and DNA sequencing for validation. Results: The literature search showed that the prevalence of GDM in SA has increased over the years. Furthermore, it showed that the lack of uniformity in screening and diagnosis between and within countries hamper the accurate detection of GDM. Lastly, the literature search identified several studies that support the use of DNA methylation and SNPs as potential biomarkers for GDM. Experimentally, we showed no differences in global DNA methylation between GDM and non-GDM groups. Interestingly, global DNA methylation levels were 18% (p=0.012) higher in obese compared to non-obese pregnant women. Genome-wide methylation analysis identified 1046 differentially methylated CpG sites (associated with 939 genes) (Cut-off threshold: M>0.06 and p<0.01). Among the top five CpG sites identified, one CpG mapped to the calmodulin-binding transcription activator 1 (CAMTA1) gene, which has been shown to regulate insulin production and secretion. Two CpG sites (-3410: p=0.048 and -3400: p=0.004) in the ADIPOQ promoter were hypomethylated during GDM in HIV negative, but not in HIV positive women. Lastly, no association between the ADIPOQ and MTHFR polymorphisms and GDM was observed in our population. Conclusion: To our knowledge, this is the first study to investigate the association between DNA methylation or ADIPOQ (rs266729 and rs17300539) and MTHFR (rs1801133) polymorphisms and GDM in SA. Findings suggest that gene-specific, but not global methylation nor SNPs rs266729, rs17300539 and rs1801133, may offer potential as molecular biomarkers of GDM in this population. Future longitudinal studies in larger samples that include both HIV negative and positive pregnant women are warranted to explore the candidacy of DNA methylation as molecular biomarkers for GDM.Thesis (PhD)--University of Pretoria, 2019.National Research Foundation (NRF) of South Africa, Thuthuka Grant (unique grant no. 99391).South African Medical Research Council (SAMRC)Obstetrics and GynaecologyPhDUnrestricte

Does South Africa need a diabetes-in-pregnancy study group?

The prevalence of non-communicable diseases in South Africa (SA) is increasing. Alarmingly, SA is one of the nations with the most obese people in the world. The incidence of gestational diabetes mellitus (GDM) is similarly increasing. However, while healthcare policies focus on communicable and non-communicable diseases, advocacy for screening, immediate and long-term management and follow-up of GDM are lacking.http://www.samj.org.zapm2020Obstetrics and GynaecologyInternal Medicin

No association between ADIPOQ or MTHFR polymorphisms and gestational diabetes mellitus in South African women

PURPOSE : Gestational diabetes mellitus (GDM) is a growing public health concern. GDM affects approximately 14% of pregnancies globally, and without effective treatment, is associated with short- and long-term complications in mother and child. Lower serum adiponectin (ADIPOQ) concentrations and aberrant DNA methylation have been reported during GDM. The aim of this study was to investigate the association between the ADIPOQ −11377C>G and −11391G>A, and methylenetetrahydrofolate reductase (MTHFR) 677C>T polymorphisms and GDM in a population of black South African women. MATERIALS AND METHODS : DNA was isolated from the peripheral blood of 447 pregnant women with (n=116) or without (n=331) GDM, where after ADIPOQ (rs266729 and rs17300539) and MTHFR (rs1801133) polymorphisms were genotyped using TaqMan Quantitative Real-Time PCR analysis. RESULTS : Women with GDM had a higher body mass index (p=0.012), were more insulin resistant (p<0.001) and had lower adiponectin levels (p=0.013) compared to pregnant women with normoglycemia. Genotypic, dominant and recessive genetic models showed no association between ADIPOQ rs266729 and rs17300539 and MTHFR rs1801133 polymorphisms and GDM. Intriguingly, the risk G allele of ADIPOQ rs266729 was associated with higher fasting glucose and insulin concentrations, while the T allele in MTHFR rs1801133 was associated with higher fasting insulin concentrations only. CONCLUSION : ADIPOQ rs266729 and rs17300539 and MTHFR rs1801133 polymorphisms are not associated with GDM in a population of black South African women. These findings suggest that these single nucleotide polymorphisms (SNPs) do not individually increase GDM risk in the African population. However, the role of these SNPs in possible genegene or gene-environment interactions remain to be established.The National Research Foundation, South Africa and the South Africa Medical Research Council (CP).http://www.dovepress.com/diabetes-metabolic-syndrome-and-obesity-targets-and-therapy-journalam2022Internal MedicineObstetrics and Gynaecolog

Association between gestational diabetes and biomarkers : a role in diagnosis

BACKGROUND : We investigated the association between markers of insulin resistance, chronic inflammation, and adipokines and GDM. METHODS : In our case-cohort study in Johannesburg we included women with GDM and controls. We tested the ability of biomarkers to identify women at high risk of GDM. RESULTS : Of the 262 pregnant women, 83 (31.7%) had GDM. Women with GDM were heavier (p = 0.04) and had more clinical risk factors (p = 0.008). We found a significant difference in fasting insulin (p < 0.001), adiponectin (p = 0.046), HOMA (p < 0.001) and QUICKI (p < 0.001). HOMA (AUROC = 0.82) or QUICKI (AUROC = 0.82) improved the ability of risk factors to identify women at high risk of GDM. CONCLUSIONS : Insulin sensitivity markers are promising tools to identify women at high risk of GDM.The Society for Endocrinology, Metabolism and Diabetes of South Africa (SEMDSA), South African Sugar Association (SASA), and Roche Pharmaceuticals.http://www.tandfonline.com/loi/ibmk20hj2019Internal MedicineObstetrics and Gynaecolog

Adiponectin DNA methylation in South African women with gestational diabetes mellitus : effects of HIV infection

DNA methylation is increasingly recognized as a potential biomarker of metabolic disease. However, there is limited information on the impact of human immunodeficiency virus (HIV) infection on the candidacy of DNA methylation to serve as molecular biomarkers. This study investigated the effect of HIV infection on DNA methylation patterns in the peripheral blood of South African women with (n = 95) or without (n = 191) gestational diabetes mellitus (GDM). DNA methylation levels at eight CpG sites in the adiponectin gene (ADIPOQ) promoter were measured using bisulfite conversion and pyrosequencing. Differences between HIV negative ( - ) and positive ( + ) women were observed. In HIVwomen, methylation at CpG -3400 was lower in GDM+ women compared to those with normoglycemia (8.5-fold; p = 0.004), and was associated with higher fasting glucose (β-co-efficient = 0.973; p = 0.006) and lower adiponectin (β-co-efficient = -0.057; p = 0.014) concentrations. These associations were not observed in HIV+ women. In silico analysis showed that Transcription Factor AP2-alpha is able to bind to the altered CpG site, suggesting that CpG -3400 may play a functional role in the regulation of ADIPOQ expression. Our findings show that DNA methylation differs by HIV status, suggesting that HIV infection needs to be taken into consideration in studies exploring DNA methylation as a biomarker of GDM in high HIV prevalence settings.http://www.plosone.orgpm2022Internal MedicineObstetrics and Gynaecolog

Effect of remote ischaemic conditioning on clinical outcomes in patients with acute myocardial infarction (CONDI-2/ERIC-PPCI): a single-blind randomised controlled trial.

BACKGROUND: Remote ischaemic conditioning with transient ischaemia and reperfusion applied to the arm has been shown to reduce myocardial infarct size in patients with ST-elevation myocardial infarction (STEMI) undergoing primary percutaneous coronary intervention (PPCI). We investigated whether remote ischaemic conditioning could reduce the incidence of cardiac death and hospitalisation for heart failure at 12 months. METHODS: We did an international investigator-initiated, prospective, single-blind, randomised controlled trial (CONDI-2/ERIC-PPCI) at 33 centres across the UK, Denmark, Spain, and Serbia. Patients (age >18 years) with suspected STEMI and who were eligible for PPCI were randomly allocated (1:1, stratified by centre with a permuted block method) to receive standard treatment (including a sham simulated remote ischaemic conditioning intervention at UK sites only) or remote ischaemic conditioning treatment (intermittent ischaemia and reperfusion applied to the arm through four cycles of 5-min inflation and 5-min deflation of an automated cuff device) before PPCI. Investigators responsible for data collection and outcome assessment were masked to treatment allocation. The primary combined endpoint was cardiac death or hospitalisation for heart failure at 12 months in the intention-to-treat population. This trial is registered with ClinicalTrials.gov (NCT02342522) and is completed. FINDINGS: Between Nov 6, 2013, and March 31, 2018, 5401 patients were randomly allocated to either the control group (n=2701) or the remote ischaemic conditioning group (n=2700). After exclusion of patients upon hospital arrival or loss to follow-up, 2569 patients in the control group and 2546 in the intervention group were included in the intention-to-treat analysis. At 12 months post-PPCI, the Kaplan-Meier-estimated frequencies of cardiac death or hospitalisation for heart failure (the primary endpoint) were 220 (8·6%) patients in the control group and 239 (9·4%) in the remote ischaemic conditioning group (hazard ratio 1·10 [95% CI 0·91-1·32], p=0·32 for intervention versus control). No important unexpected adverse events or side effects of remote ischaemic conditioning were observed. INTERPRETATION: Remote ischaemic conditioning does not improve clinical outcomes (cardiac death or hospitalisation for heart failure) at 12 months in patients with STEMI undergoing PPCI. FUNDING: British Heart Foundation, University College London Hospitals/University College London Biomedical Research Centre, Danish Innovation Foundation, Novo Nordisk Foundation, TrygFonden

Effect of angiotensin-converting enzyme inhibitor and angiotensin receptor blocker initiation on organ support-free days in patients hospitalized with COVID-19

IMPORTANCE Overactivation of the renin-angiotensin system (RAS) may contribute to poor clinical outcomes in patients with COVID-19. Objective To determine whether angiotensin-converting enzyme (ACE) inhibitor or angiotensin receptor blocker (ARB) initiation improves outcomes in patients hospitalized for COVID-19. DESIGN, SETTING, AND PARTICIPANTS In an ongoing, adaptive platform randomized clinical trial, 721 critically ill and 58 non–critically ill hospitalized adults were randomized to receive an RAS inhibitor or control between March 16, 2021, and February 25, 2022, at 69 sites in 7 countries (final follow-up on June 1, 2022). INTERVENTIONS Patients were randomized to receive open-label initiation of an ACE inhibitor (n = 257), ARB (n = 248), ARB in combination with DMX-200 (a chemokine receptor-2 inhibitor; n = 10), or no RAS inhibitor (control; n = 264) for up to 10 days. MAIN OUTCOMES AND MEASURES The primary outcome was organ support–free days, a composite of hospital survival and days alive without cardiovascular or respiratory organ support through 21 days. The primary analysis was a bayesian cumulative logistic model. Odds ratios (ORs) greater than 1 represent improved outcomes. RESULTS On February 25, 2022, enrollment was discontinued due to safety concerns. Among 679 critically ill patients with available primary outcome data, the median age was 56 years and 239 participants (35.2%) were women. Median (IQR) organ support–free days among critically ill patients was 10 (–1 to 16) in the ACE inhibitor group (n = 231), 8 (–1 to 17) in the ARB group (n = 217), and 12 (0 to 17) in the control group (n = 231) (median adjusted odds ratios of 0.77 [95% bayesian credible interval, 0.58-1.06] for improvement for ACE inhibitor and 0.76 [95% credible interval, 0.56-1.05] for ARB compared with control). The posterior probabilities that ACE inhibitors and ARBs worsened organ support–free days compared with control were 94.9% and 95.4%, respectively. Hospital survival occurred in 166 of 231 critically ill participants (71.9%) in the ACE inhibitor group, 152 of 217 (70.0%) in the ARB group, and 182 of 231 (78.8%) in the control group (posterior probabilities that ACE inhibitor and ARB worsened hospital survival compared with control were 95.3% and 98.1%, respectively). CONCLUSIONS AND RELEVANCE In this trial, among critically ill adults with COVID-19, initiation of an ACE inhibitor or ARB did not improve, and likely worsened, clinical outcomes. TRIAL REGISTRATION ClinicalTrials.gov Identifier: NCT0273570

Intimate partner violence : a risk factor for gestational diabetes

The early detection and management of gestational diabetes mellitus (GDM) is an important public health goal. GDM, which is defined as a glucose intolerance that develops during pregnancy, affects about 14% of pregnancies globally, and without effective treatment, it is associated with adverse short- and long-term maternal and neonatal outcomes. Risk-factor screening is an acceptable and affordable strategy to enable risk stratification and intervention. However, common biological risk factors such as overweight or obesity, excessive gestational weight gain, and family history of diabetes often have poor predictive ability, failing to identify a large proportion of women at risk of developing GDM. Accumulating evidence implicate psychosocial factors in contributing to GDM risk. As such, intimate partner violence (IPV), through its contributing effects on maternal stress and depression, presents a plausible risk factor for GDM. Experiencing IPV during pregnancy may dysregulate the hypothalamus–pituitary–adrenal (HPA) axis, leading to increased cortisol secretion and insulin resistance. These effects may exacerbate the insulin-resistant environment characteristic of pregnancy, thus increasing GDM risk. This review explores the relationship between IPV and GDM. We highlight studies that have linked IPV with GDM and propose a biological mechanism that connects IPV and GDM. Recommendations for IPV screening strategies to prevent GDM are discussed.This research was funded by South African Medical Research Council.http://www.mdpi.com/journal/ijerphpm2021Obstetrics and Gynaecolog

MicroRNA profiling in HIV-infected South African women with gestational diabetes mellitus

BACKGROUND : Recently, we reported that the microRNAs (miRNAs) miR-20a-5p and—to a lesser extent—miR-222-3p hold potential as biomarkers for gestational diabetes mellitus (GDM) in human immunodeficiency virus (HIV)-negative South African women. METHODS : In this preliminary study, we measured the expression of these miRNAs in HIV-positive women (GDM 15, non-GDM 52; median 26.0 weeks; range 16–30). RESULTS : Although the same trend of decreased expression of miR-20a-5p (1.5-fold decrease) and miR-222-3p (1.4-fold decrease) was observed in sera of women with and without GDM, these differences were not statistically significant. Stratification according to antiretroviral treatment (ART) confirmed decreased expression of miR-20a-5p and miR-222-3p in ART-naïve and ART-treated women with GDM, although again this was not statistically significant. CONCLUSION : Our results demonstrate that HIV infection modifies the expression of miR-20a-5p and miR-222-3p in women with GDM. Importantly, this study highlights the complexities of miRNA profiling and the need for GDM biomarker discovery in both HIV-infected and uninfected individuals, particularly in South Africa, where approximately 30% of pregnancies are complicated by HIV. Further studies to elucidate the mechanisms that underlie these miRNA differences are needed.The South African Medical Research Council (C. Pheiffer) and the Society for Endocrinology, Metabolism and Diabetes in South Africa and the University of Pretoria (S. Adam).https://link.springer.com/journal/402912020-08-01hj2019Internal MedicineObstetrics and Gynaecolog

Altered genome-wide DNA methylation in peripheral blood of South African women with gestational diabetes mellitus

Increasing evidence implicate altered DNA methylation in the pathophysiology of gestational diabetes mellitus (GDM). This exploratory study probed the association between GDM and peripheral blood DNA methylation patterns in South African women. Genome-wide DNA methylation profiling was conducted in women with (n = 12) or without (n = 12) GDM using the Illumina Infinium HumanMethylationEPIC BeadChip array. Functional analysis of di erentially methylated genes was conducted using Gene Ontology (GO) and Kyoto Encyclopedia of Genes and Genomes (KEGG) pathway analyses. A total of 1046 CpG sites (associated with 939 genes) were di erentially methylated between GDM and non-GDM groups. Enriched pathways included GDM-related pathways such as insulin resistance, glucose metabolism and inflammation. DNA methylation of the top five CpG loci showed distinct methylation patterns in GDM and non-GDM groups and was correlated with glucose concentrations. Of these, one CpG site mapped to the calmodulin-binding transcription activator 1 (CAMTA1) gene, which have been shown to regulate insulin production and secretion and may o er potential as an epigenetic biomarker in our population. Further validation using pyrosequencing and conducting longitudinal studies in large sample sizes and in di erent populations are required to investigate their candidacy as biomarkers of GDM.Supplementary Material : Table S1. Genome-wide DNA methylation profiling identified 1098 differentially methylated CpG loci. Table S2. Differentially methylated CpG sites annotated to 942 unique genes. Table S3. Functional enrichment analysis identified 247 KEGG pathways. Table S4. Statistically significant KEGG pathways associated with GDM. Table S5. GO terms enriched by differentially methylated genes, categorized into 1181 biological processes, 161 molecular functions and 99 cellular components.This research was funded by the National Research Foundation, South Africa (Unique Grant no. 99391), and the South African Medical Research Council.The National Research Foundation, South Africa (Unique Grant no. 99391), and the South African Medical Research Council.http://www.mdpi.com/journal/ijmsam2020Internal MedicineObstetrics and Gynaecolog