Epigenetic Marks as Predictors of Metabolic Response to Bariatric Surgery: Validation from an Epigenome Wide Association Study.

Little is known about the potential role of epigenetic marks as predictors of the resolution of obesity-related comorbidities after bariatric surgery. In this study, 20 patients were classified according to the metabolic improvement observed 6 months after sleeve gastrectomy, based on the diagnosis of metabolic syndrome, into responders if metabolic syndrome reversed after bariatric surgery (n = 10) and non-responders if they had metabolic syndrome bariatric surgery (n = 10). Blood DNA methylation was analyzed at both study points using the Infinium Methylation EPIC Bead Chip array-based platform. Twenty-six CpG sites and their annotated genes, which were previously described to be associated with metabolic status, were evaluated. Cg11445109 and cg19469447 (annotated to Cytochrome P450 2E1 (CYP2E1) gene) were significantly more hypomethylated in the responder group than in the non-responder group at both study points, whilst cg25828445 (annotated to Nucleolar Protein Interacting With The FHA Domain Of MKI67 Pseudogene 3 (NIFKP3) gene) showed to be significantly more hypermethylated in the non-responder group compared to the responder group at both study points. The analysis of the methylation sites annotated to the associated genes showed that CYP2E1 had 40% of the differentially methylated CpG sites, followed by Major Histocompatibility Complex, Class II, DR Beta 1 (HLA-DRB1) (33.33%) and Zinc Finger Protein, FOG Family Member 2 (ZFPM2) (26.83%). Cg11445109, cg19469447 and cg25828445 could have a role in the prediction of metabolic status and potential value as biomarkers of response to bariatric surgery.

Ambient air pollution and thyroid function in Spanish adults. A nationwide population-based study (Di@bet.es study).

BACKGROUND: Recent reports have suggested that air pollution may impact thyroid function, although the evidence is still scarce and inconclusive. In this study we evaluated the association of exposure to air pollutants to thyroid function parameters in a nationwide sample representative of the adult population of Spain. METHODS: The Di@bet.es study is a national, cross-sectional, population-based survey which was conducted in 2008-2010 using a random cluster sampling of the Spanish population. The present analyses included 3859 individuals, without a previous thyroid disease diagnosis, and with negative thyroid peroxidase antibodies (TPO Abs) and thyroid-stimulating hormone (TSH) levels of 0.1-20 mIU/L. Participants were assigned air pollution concentrations for particulate matter <2.5µm (PM2.5) and Nitrogen Dioxide (NO2), corresponding to the health examination year, obtained by means of modeling combined with measurements taken at air quality stations (CHIMERE chemistry-transport model). TSH, free thyroxine (FT4), free triiodothyronine (FT3) and TPO Abs concentrations were analyzed using an electrochemiluminescence immunoassay (Modular Analytics E170 Roche). RESULTS: In multivariate linear regression models, there was a highly significant negative correlation between PM2.5 concentrations and both FT4 (p<0.001), and FT3 levels (p<0.001). In multivariate logistic regression, there was a significant association between PM2.5 concentrations and the odds of presenting high TSH [OR 1.24 (1.01-1.52) p=0.043], lower FT4 [OR 1.25 (1.02-1.54) p=0.032] and low FT3 levels [1.48 (1.19-1.84) p=<0.001] per each IQR increase in PM2.5 (4.86 µg/m3). There was no association between NO2 concentrations and thyroid hormone levels. No significant heterogeneity was seen in the results between groups of men, pre-menopausal and post-menopausal women. CONCLUSIONS: Exposures to PM2.5 in the general population were associated with mild alterations in thyroid function.

Shifts in gut microbiota and their metabolites induced by bariatric surgery. Impact of factors shaping gut microbiota on bariatric surgery outcomes.

Evidence suggests that bariatric surgery alters gut microbiota, although its impact at compositional and functional level is not well described. In this review, the most relevant findings, mainly described in Roux-en-Y gastric bypass and sleeve gastrectomy, are outlined. Although the number of studies has increased in the last years, conclusive assertions cannot be elaborated. An issue to address is to know the influence of these alterations on host metabolism and the contribution of gut microbiota derived metabolites. New lines of research have been focusing on analysing gut microbiota functionality rather than evaluating changes at compositional level, and the functions of gut microbiota metabolites in host metabolism, what will bring more relevant information about the influence of gut microbiota in bariatric surgery outcomes. Personalized medicine, because of the predictive value of gut microbiota, is another promising field. The possibility of a specific gut microbiota pattern that could predict type 2 diabetes remission or weight loss failure after bariatric surgery is a matter of great interest. However, little is known about how gut microbiota manipulation could contribute to the beneficial effects of bariatric surgery. Peri-operative antibiotics prophylaxis or probiotic supplementation early after surgery, are strategies barely studied so far, and could constitute a novel tool in the management of weight loss and metabolic profile improvement after surgery.

GRK2 levels in myeloid cells modulate adipose-liver crosstalk in high fat diet-induced obesity.

Macrophages are key effector cells in obesity-associated inflammation. G protein-coupled receptor kinase 2 (GRK2) is highly expressed in different immune cell types. Using LysM-GRK2+/- mice, we uncover that a reduction of GRK2 levels in myeloid cells prevents the development of glucose intolerance and hyperglycemia after a high fat diet (HFD) through modulation of the macrophage pro-inflammatory profile. Low levels of myeloid GRK2 confer protection against hepatic insulin resistance, steatosis and inflammation. In adipose tissue, pro-inflammatory cytokines are reduced and insulin signaling is preserved. Macrophages from LysM-GRK2+/- mice secrete less pro-inflammatory cytokines when stimulated with lipopolysaccharide (LPS) and their conditioned media has a reduced pathological influence in cultured adipocytes or naïve bone marrow-derived macrophages. Our data indicate that reducing GRK2 levels in myeloid cells, by attenuating pro-inflammatory features of macrophages, has a relevant impact in adipose-liver crosstalk, thus preventing high fat diet-induced metabolic alterations.

Epigenetic Biomarkers of Transition from Metabolically Healthy Obesity to Metabolically Unhealthy Obesity Phenotype: A Prospective Study.

BACKGROUND: Identifying those parameters that could potentially predict the deterioration of metabolically healthy phenotype is a matter of debate. In this field, epigenetics, in particular DNA methylation deserves special attention. RESULTS: The aim of the present study was to analyze the long-term evolution of methylation patterns in a subset of metabolically healthy subjects in order to search for epigenetic markers that could predict the progression to an unhealthy state. Twenty-six CpG sites were significantly differentially methylated, both at baseline and 11-year follow-up. These sites were related to 19 genes or pseudogenes; a more in-depth analysis of the methylation sites of these genes showed that CYP2E1 had 50% of the collected CpG sites differently methylated between stable metabolically healthy obesity (MHO) and unstable MHO, followed by HLA-DRB1 (33%), ZBTB45 (16%), HOOK3 (14%), PLCZ1 (14%), SLC1A1 (12%), MUC2 (12%), ZFPM2 (12.5%) and HLA-DQB2 (8%). Pathway analysis of the selected 26 CpG sites showed enrichment in pathways linked to th1 and th2 activation, antigen presentation, allograft rejection signals and metabolic processes. Higher methylation levels in the cg20707527 (ZFPM2) could have a protective effect against the progression to unstable MHO (OR: 0.21, 95%CI (0.067-0.667), p < 0.0001), whilst higher methylation levels in cg11445109 (CYP2E1) would increase the progression to MUO; OR: 2.72, 95%CI (1.094-6.796), p < 0.0014; respectively). CONCLUSIONS: DNA methylation status is associated with the stability/worsening of MHO phenotype. Two potential biomarkers of the transition to an unhealthy state were identified and deserve further investigation (cg20707527 and cg11445109). Moreover, the described differences in methylation could alter immune system-related pathways, highlighting these pathways as therapeutic targets to prevent metabolic deterioration in MHO patients.

The pro-/anti-inflammatory effects of different fatty acids on visceral adipocytes are partially mediated by GPR120.

PURPOSE: This study examines whether G-protein coupled receptor 120 (GPR120) is involved in the pro-/anti-inflammatory effects of different types of fatty acids (FAs) in human visceral adipocytes, and whether these effects may be altered in obesity, a state with a chronic inflammation. METHODS: Pro-/anti-inflammatory effects of palmitic, oleic, linoleic and docosahexaenoic acids on human visceral adipocytes were tested in mature adipocytes from non-obese and morbidly obese (MO) subjects. Also, the effects of these FAs were tested when the GPR120 gene was silenced. RESULTS: In adipocytes from non-obese subjects, palmitic and linoleic acids increased TNF-α and IL-6 mRNA expression (p < 0.05), and decreased IL-10 and adiponectin expression (p < 0.05). However, oleic and docosahexaenoic acids (DHA) produced the opposite effect (p < 0.05). In adipocytes from MO subjects, all FAs used increased TNF-α and IL-6 expression (p < 0.05). Palmitic and linoleic acids decreased IL-10 and adiponectin expression (p < 0.05), but oleic acid and DHA did not have significant effects. Only oleic acid increased adiponectin expression (p < 0.05). The effects of FAs on TNF-α, IL-6, IL-10 and adiponectin expression in non-obese and MO subjects were significantly annulled when the GPR120 gene was silenced in visceral adipocytes differentiated from human mesenchymal stem cells. CONCLUSIONS: FAs are capable of directly acting on visceral adipocytes to modulate differently TNF-α, IL-6, IL-10 and adiponectin expression, with a different and greater effect in MO subjects. These effects are largely annulled when GPR120 expression was silenced, which suggests that they could be mediated by GPR120.

Bioactive Components in Human Milk Along the First Month of Life: Effects of Iodine Supplementation during Pregnancy.

BACKGROUND/AIMS: Human milk is considered the most suitable food for infants. The potential benefits of breastfeeding can be explained by the presence of different growth and neurotrophic factors in human milk. This study was designed to detect some biomarkers in human milk, which could be involved in the infant neurodevelopment and in the regulation of the maturation of neonatal intestine (brain-derived neurotrophic factor (BDNF), glial cell line-derived neurotrophic factor (GDNF), glial fibrillary acidic protein (GFAP), fibroblast growth factor 21 (FGF21), lysophosphatidic acid (LPA) and autotaxin (ATX)), and compare them on the basis of the consumption of iodine supplements or multivitamins. METHODS: A prospective study included 37 healthy breastfeeding mothers, divided into 3 different groups: (1) 10 mothers who did not take supplements, (2) 17 mothers who took potassium iodine (KI) 200 µg/day and (3) 10 mothers who took a multivitamin supplement. RESULTS: The concentrations of BDNF, GDNF, GFAP, FGF21, LPA and ATX in human milk were not significantly different in women who took a multivitamin or KI supplement compared with those who did not take any supplement. CONCLUSIONS: The presence of neurotrophic factors in human milk is neither modified by the consumption of supplements nor by their type.

The expression of genes involved in jejunal lipogenesis and lipoprotein synthesis is altered in morbidly obese subjects with insulin resistance.

The dyslipidemia associated with type 2 diabetes mellitus (T2DM) is an important risk factor for atherosclerotic cardiovascular disease. However, until now little attention has been paid to the role that the intestine might have. The aim of this research was to determine the relation between insulin resistance and intestinal de novo lipogenesis/lipoprotein synthesis in morbidly obese subjects and to study the effect of insulin on these processes. Jejunal mRNA expression of the different genes involved in the intestinal de novo lipogenesis/lipoprotein synthesis was analyzed in three groups of morbidly obese subjects: Group 1 with low insulin resistance (MO-low-IR), group 2 with high insulin resistance (MO-high-IR), and group 3 with T2DM and treatment with metformin (MO-metf-T2DM). In addition, intestinal epithelial cells (IECs) from MO-low-IR were incubated with different doses of insulin/glucose. In Group 2 (MO-high-IR), the jejunal mRNA expression levels of apo A-IV, ATP-citrate lyase (ACLY), pyruvate dehydrogenase (lipoamide) beta (PDHB), and sterol regulatory element-binding protein-1c (SREBP-1c) were significantly higher and acetyl-CoA carboxylase alpha (ACC1) and fatty-acid synthase lower than in Group 1 (MO-low-IR). In Group 3 (MO-metf-T2DM), only the ACLY and PDHB mRNA expressions were significantly higher than in Group 1 (MO-low-IR). The mRNA expression of most of the genes studied was significantly linked to insulin and glucose levels. The incubation of IEC with different doses of insulin and glucose produced a higher expression of diacylglycerol acyltransferase 2, microsomal triglyceride transfer protein, apo A-IV, SREBP-1c, and ACC1 when both, glucose and insulin, were at a high concentration. However, with only high insulin levels, there were higher apo A-IV, PDHB and SREBP-1c expressions, and a lower ACLY expression. In conclusion, the jejunum of MO-high-IR has a decreased mRNA expression of genes involved in de novo fatty-acid synthesis and an increase of genes involved in acetyl-CoA and lipoprotein synthesis. This effect is attenuated by metformin. In addition, the expression of most of the genes studied was found to be regulated by insulin.

Hypoxia is associated with a lower expression of genes involved in lipogenesis in visceral adipose tissue.

BACKGROUND: A key role for HIF-1α in the promotion and maintenance of dietary obesity has been proposed. We analyzed the association between hypoxia and de novo lipogenesis in human adipose tissue. METHODS: We studied HIF-1α mRNA and protein expression in fasting status in visceral adipose tissue (VAT) from non-obese and morbidly obese subjects, and in VAT from wild-type and ob/ob C57BL6J mice in both fasting and feeding status. We also analyzed the effect of hypoxia on the VAT mRNA expression of genes involved in lipogenesis. RESULTS: HIF-1α was increased in VAT from morbidly obese subjects. In fasting status, C57BL6J ob/ob mice had a higher VAT HIF-1α mRNA expression than C57BL6J wild-type mice. In feeding status, VAT HIF-1α mRNA expression significantly increased in C57BL6J wild-type, but not in C57BL6J ob/ob mice. In humans, HIF-1α mRNA expression correlated positively with body mass index and insulin resistance. VAT HIF-1α mRNA expression correlated negatively with ACC1, PDHB and SIRT3 mRNA expression, and positively with PPAR-γ. VAT explants incubated in hypoxia showed reduced SIRT3 and increased PPAR-γ, SREBP-1c, ACLY, ACC1 and FASN mRNA expression. CONCLUSIONS: Morbidly obese subjects have a higher level of VAT HIF-1α. Postprandial status is associated with an increase in HIF-1α mRNA expression in C57BL6J wild-type mice. Hypoxia alters the mRNA expression of genes involved in de novo lipogenesis in human VAT.

FNDC5 could be regulated by leptin in adipose tissue.

INTRODUCTION: Irisin activates the thermogenic function in adipose tissues. However, little is known on the association between human irisin and different cardiometabolic risk factors. We analyse the influence of morbid obesity on irisin levels and its relation with leptin and different cardiovascular risk factors. MATERIAL AND METHODS: We measured the serum irisin level and the fibronectin type III domain containing 5 (FNDC5) expression in adipose tissue from 33 morbidly obese subjects and 12 nonobese subjects. We also studied the effect of leptin on FNDC5 expression. RESULTS: Serum irisin was higher in the nonobese subjects than in morbidly obese subjects, both before (P = 0·043) and after bariatric surgery (P = 0·042). The variable that best explained the serum irisin levels in a multiple linear regression model was the waist-to-hip ratio (WHR) (R(2) = 0·201) (Beta = -0·357, P = 0·046). Those morbidly obese subjects with android-type obesity had lower serum irisin levels than those with gynecoid-type obesity, both before (P = 0·027) and after bariatric surgery (P = 0·006). Only the percentage change in WHR was associated with serum irisin levels after bariatric surgery (r = -0·529, P = 0·005). FNDC5 expression levels in subcutaneous adipose tissue (SAT) were higher in the nonobese than in the morbidly obese subjects (P = 0·042). In SAT explants from nonobese subjects, leptin (20 and 150 ng/mL) produced a decrease in FNDC5 expression (P = 0·009 and P = 0·037, respectively). CONCLUSIONS: We showed decreased serum irisin levels in morbidly obese subjects, related mainly to WHR. FNDC5 expression could be regulated by leptin.

Variable patterns of obesity and cardiometabolic phenotypes and their association with lifestyle factors in the Di@bet.es study.

BACKGROUND AND AIM: Prevalence rates of "metabolically healthy obese" (MHO) subjects vary depending on the criteria used. This study examined the prevalence and characteristics of MHO subjects and metabolically abnormal normal-weight subjects and compared the findings with the NHANES 1999-2004 study. The aims of the present study were, first, to determine the prevalence rates of MHO and MNHNO subjects using the same criteria as those of the National Health and Nutrition Examination Survey (NHANES) (1999-2004) study, and second to compare the prevalence and correlates of obese subjects who are resistant to the development of adiposity-associated cardiometabolic abnormalities (CA) and normal-weight individuals who display cardiometabolic risk factor clustering between the Spanish and the US populations. METHODS AND RESULTS: Di@bet.es study is a national, cross-sectional population-based survey of 5728 adults conducted in 2009-2010. Clinical, metabolic, sociodemographic, and anthropometric data and information about lifestyle habits, such as physical activity, smoking habit, alcohol intake and food consumption, were collected. Subjects were classified according to their body mass index (BMI) (normal-weight, <25 kg/m(2); overweight, 25-29.9 kg/m(2); and obese, >30 kg/m(2)). CA included elevated blood pressure; elevated levels of triglycerides, fasting glucose, and high-sensitivity C-reactive protein (hs-CRP); and elevated homeostasis model assessment of insulin resistance (HOMA-IR) value and low high-density lipoprotein cholesterol (HDL-c) level. Two phenotypes were defined: metabolically healthy phenotype (0-1 CA) and metabolically abnormal phenotype (≥2 CA). The prevalence of metabolically abnormal normal-weight phenotype was slightly lower in the Spanish population (6.5% vs. 8.1%). The prevalence of metabolically healthy overweight and MHO subjects was 20.9% and 7.0%, respectively, while in NHANES study it was 17.9% and 9.7%, respectively. Cigarette smoking was associated with CA in each phenotype, while moderate physical activity and moderate alcohol intake were associated with being metabolically healthy. Olive oil intake was negatively associated with the prevalence of CA. CONCLUSIONS: Smoking, physical activity level, and alcohol intake contribute to the explanation of the prevalence of CA in the Spanish population, as in the US population. However in Spain, olive oil intake contributes significantly to the explanation of the variance in the prevalence of CA.

Non-alcoholic fatty liver disease in patients with morbid obesity: the gut microbiota axis as a potential pathophysiology mechanism.

BACKGROUND/AIM: Alterations in gut microbiota are associated with the pathogenesis of metabolic diseases, including metabolic-associated fatty liver disease (MAFLD). The aim of this study was to evaluate gut microbiota composition and functionality in patients with morbid obesity with different degrees of MAFLD, as assessed by biopsy. SUBJECTS/METHODS: 110 patients with morbid obesity were evaluated by biopsy obtained during bariatric surgery for MAFLD. Stool samples were collected prior to surgery for microbiota analysis. RESULTS: Gut microbiota from patients with steatosis and non-alcoholic steatohepatitis (NASH) were characterized by an enrichment in Enterobacteriaceae (an ethanol-producing bacteria), Acidaminococcus and Megasphaera and the depletion of Eggerthellaceae and Ruminococcaceae (SCFA-producing bacteria). MAFLD was also associated with enrichment of pathways related to proteinogenic amino acid degradation, succinate production, menaquinol-7 (K2-vitamin) biosynthesis, and saccharolytic and proteolytic fermentation. Basic histological hepatic alterations (steatosis, necroinflammatory activity, or fibrosis) were associated with specific changes in microbiota patterns. Overall, the core microbiome related to basic histological alterations in MAFLD showed an increase in Enterobacteriaceae and a decrease in Ruminococcaceae. Specifically, Escherichia coli was associated with steatosis and necroinflammatory activity, whilst Escherichia-shigella was associated with fibrosis and necroinflammatory activity. CONCLUSIONS: We established a link between gut microbiota alterations and histological injury in liver diagnosis using biopsy. Harmful products such as ethanol or succinate may be involved in the pathogenesis and progression of MAFLD. Thus, these alterations in gut microbiota patterns and their possible metabolic pathways could add information to the classical predictors of MAFLD severity and suggest novel metabolic targets.

Factors determining weight gain in adults and relation with glucose tolerance.

OBJECTIVE: Modifications in lifestyle, diet and certain clinical events are major contributors for the high prevalence of obesity. The aim of this study was to assess factors associated with weight gain in a population of Spanish adults. DESIGN: The study was undertaken in two population-based cohorts from the north and the south of Spain (baseline and after 6 years). The Asturias Study, in the north, included 1034 persons aged 30-75 years, of whom 701 were reassessed. The Pizarra Study, in the south, included 1226 persons aged 18-65 years, of whom 783 were re-evaluated. Both studies involved a nutritional questionnaire, a physical examination and an oral glucose tolerance test (OGTT). RESULTS: During the follow-up, 32.3% of the participants lost weight, 34.5% gained fewer than 4 kg and 33.2% gained more than 4 kg. Weight gain was greater in persons younger than 50 years and in those with an initial body mass index below 30. Weight gain was associated with a greater incidence of type 2 diabetes mellitus (T2DM) and abnormal glucose tolerance, whereas weight loss in persons with these disorders was associated with a normal OGTT 6 years later. Persons who took less exercise and those who reported a higher daily calorie intake experienced greater weight gain. CONCLUSION: The longitudinal changes in weight affect the development of T2DM and abnormal glucose tolerance. The weight is a dynamic phenomenon affected by several social customs.

C-reactive protein and incidence of type 2 diabetes in the Pizarra study.

AIM: To determine the association between serum levels of high-sensitivity C-reactive protein (hs-CRP) and the incidence of type 2 diabetes in a prospective cohort from southern Spain (Pizarra study). MATERIALS AND METHODS: The study formed part of the Pizarra cohort study, a prospective study started in 1995 with a follow-up of 11 years. Anthropometric and metabolic variables were measured at baseline and at 6 years and 11 years of follow-up. All subjects underwent an oral glucose tolerance test. Serum levels of TNFα and its receptors, hs-CRP, IL-6, leptin, adiponectin and FABP4 were measured at 6 years of follow-up. RESULTS: After adjusting for age, sex and obesity, subjects with levels of hs-CRP> 2.9 mg/L in the second study (2003-4) had a higher risk of developing type 2 diabetes by the third study (2008-9) (OR = 7.97; 95% CI = 1.72-36.89; P = 0.008), and subjects with adiponectin levels > 13.2 mg/L had a lower risk of developing type 2 diabetes (OR = 0.23, P = 0.02). High values of hs-CRP and high values of adiponectin were associated positively (OR = 8.26; 95% CI = 1.84-37.19; P = 0.006) and negatively (OR = 0.17; 95% CI = 0.04-0.69; P = 0.01), respectively, with the risk of having HbA1c ≥ 6.5% at 11 years of follow-up. CONCLUSIONS: Subjects with high serum hs-CRP levels and low serum adiponectin levels have a higher risk of developing type 2 diabetes within five years.

Factors affecting levels of urinary albumin excretion in the general population of Spain: the Di@bet.es study.

The present study was undertaken to examine the prevalence of urinary ACR (albumin/creatinine ratio) >30 mg/g and the associated clinical and environmental factors in a representative sample of the population of Spain. Di@bet.es study is a national, cross-sectional population-based survey conducted in 2009-2010. Clinical, metabolic, socio-demographic, anthropometric data and information about lifestyle habit were collected. Those subjects without KDM (known diabetes mellitus) were given an OGTT (oral glucose tolerance test). Albumin and creatinine were measured in a urinary sample and ACR was calculated. The population prevalence of ACR >30 mg/g was 7.65% (adjusted for sex and age). The prevalence of ACR >30 mg/g increased with age (P<0.001). Subjects with carbohydrate metabolism disorders had a greater prevalence of ACR >30 mg/g but after being adjusted for age, sex and hypertension, was significant only in those subjects with UKDM (unknown diabetes mellitus) {OR (odd ratio), 2.07 [95% CI (confidence interval), 1.38-3.09]; P<0.001] and KDM [OR, 3.55 (95% CI, 2.63-4.80); P<0.001]. Prevalence of ACR >30 mg/g was associated with hypertension [OR, 1.48 (95% CI, 1.12-1.95); P=0.001], HOMA-IR (homoeostasis model assessment of insulin resistance) [OR, 1.47 (95% CI, 1.13-1.92); P≤0.01], metabolic syndrome [OR, 2.17 (95% CI, 1.72-2.72); P<0.001], smoking [OR, 1.40 (95% CI, 1.06-1.83); P≤0.05], physical activity [OR, 0.68 (95% CI, 0.54-0.88); P≤0.01] and consumption of fish [OR, 0.38 (95% CI, 0.18-0.78); P≤0.01]. This is the first study that reports the prevalence of ACR >30 mg/g in the Spanish population. The association between clinical variables and other potentially modifiable environmental variables contribute jointly, and sometimes interactively, to the explanation of prevalence of ACR >30 mg/g. Many of these risk factors are susceptible to intervention.

Infant neurocognitive development is independent of the use of iodised salt or iodine supplements given during pregnancy.

The benefits of iodine supplements during pregnancy remain controversial in areas with a mild-to-moderate iodine deficiency. The aim of the present study was to determine the effect of improving iodine intakes, with iodised salt (IS) or iodine supplements, in pregnant Spanish women. A total of 131 pregnant women in their first trimester were randomly assigned to three groups: (1) IS in cooking and at the table, (2) 200 µg potassium iodide (KI)/d or (3) 300 µg KI/d. No differences were found in thyroid-stimulating hormone (TSH), free thyroxine (FT4), free triiodothyronine (FT3) or thyroid volume (TV) between the three groups. Regardless of the group in which women were included, those who had been taking IS for at least 1 year before becoming pregnant had a significantly lower TV in the third trimester (P= 0.01) and a significantly higher urinary iodine in the first (173.7 (sd 81.8) v. 113.8 (sd 79.6) µg/l, P= 0.001) and third trimesters (206.3 (sd 91.2) v. 160.4 (sd 87.7) µg/l, P= 0.03). Also, no differences were seen in TSH, FT4 or FT3. Children's neurological development was not significantly associated with the consumption of IS for at least 1 year before becoming pregnant and no differences were found according to the treatment group. In conclusion, in pregnant women with insufficient iodine intake, the intake of IS before becoming pregnant was associated with a better maternal thyroid function. The form of iodide intake was not associated with maternal thyroid function or children's neurological development.

Epigenetic marks associated with gestational diabetes mellitus across two time points during pregnancy.

An adverse intrauterine or periconceptional environment, such as hyperglycemia during pregnancy, can affect the DNA methylation pattern both in mothers and their offspring. In this study, we explored the epigenetic profile in maternal peripheral blood samples through pregnancy to find potential epigenetic biomarkers for gestational diabetes mellitus (GDM), as well as candidate genes involved in GDM development. We performed an epigenome-wide association study in maternal peripheral blood samples in 32 pregnant women (16 with GDM and 16 non-GDM) at pregnancy week 24-28 and 36-38. Biochemical, anthropometric, and obstetrical variables were collected from all the participants. The main results were validated in an independent cohort with different ethnic origin (European = 307; South Asians = 165). Two hundred and seventy-two CpGs sites remained significantly different between GDM and non-GDM pregnant women across two time points during pregnancy. The significant CpG sites were related to pathways associated with type I diabetes mellitus, insulin resistance and secretion. Cg01459453 (SELP gene) was the most differentiated in the GDM group versus non-GDM (73.6 vs. 60.9, p = 1.06E-11; FDR = 7.87E-06). Three CpG sites (cg01459453, cg15329406, and cg04095097) were able to discriminate between GDM cases and controls (AUC = 1; p = 1.26E-09). Three differentially methylated positions (DMPs) were replicated in an independent cohort. To conclude, epigenetic marks during pregnancy differed between GDM cases and controls suggesting a role for these genes in GDM development. Three CpGs were able to discriminate GDM and non-GDM groups with high specificity and sensitivity, which may be biomarker candidates for diagnosis or prediction of GDM.

Epigenome wide association study in peripheral blood of pregnant women identifies potential metabolic pathways related to gestational diabetes.

Gestational diabetes mellitus (GDM) increases the risk of developing metabolic disorders in both pregnant women and their offspring. Factors such as nutrition or the intrauterine environment may play an important role, through epigenetic mechanisms, in the development of GDM. The aim of this work is to identify epigenetic marks involved in the mechanisms or pathways related to gestational diabetes. A total of 32 pregnant women were selected, 16 of them with GDM and 16 non-GDM. DNA methylation pattern was obtained from Illumina Methylation Epic BeadChip, from peripheral blood samples at the diagnostic visit (26-28 weeks). Differential methylated positions (DMPs) were extracted using ChAMP and limma package in R 2.9.10, with a threshold of FDR <0.05, deltabeta >|5|% and B >0. A total of 1.141 DMPs were found, and 714 were annotated in genes. A functional analysis was performed, and we found 23 genes significantly related to carbohydrate metabolism. Finally, a total of 27 DMPs were correlated with biochemical variables such as glucose levels at different points of oral glucose tolerance test, fasting glucose, cholesterol, HOMAIR and HbA1c, at different visits during pregnancy and postpartum. Our results show that there is a differentiated methylation pattern between GDM and non-GDM. Furthermore, the genes annotated to the DMPs could be implicated in the development of GDM as well as in alterations in related metabolic variables.

Changes in Oxidative Stress and Intestinal Permeability during Pregnancy in Women with Gestational Diabetes Mellitus Treated with Metformin or Insulin and Healthy Controls: A Randomized Controlled Trial.

Both oxidative stress and intestinal permeability are increased in hyperglycemic situations and have been shown to be reduced by metformin in type 2 diabetes mellitus (T2DM) patients. The aim of this study was to elucidate the effect of metformin on oxidative stress and intestinal permeability in women with gestational diabetes mellitus (GDM) treated with metformin compared to those treated with insulin and healthy controls. A total of 120 women were included from August 2016 to February 2022: 41 received metformin (MET group), 38 received insulin (INS group), and 41 were healthy controls. Baseline and antenatal visits were carried out at 25.4 ± 4.8 and 36.1 ± 0.8 weeks of pregnancy, respectively. Advanced oxidation protein products (AOPPs), total antioxidant capacity (TAC), and zonulin levels were measured at every visit. Zonulin levels from baseline to prepartum visit increased significantly in both healthy controls (0.6 ± 0.9 to 1.2 ± 1.7 ng/mL, p = 0.004) and the INS group (0.4 ± 0.3 to 0.6 ± 0.5 ng/mL, p = 0.034) but did not significantly change in the MET group (0.4 ± 0.4 to 0.5 ± 0.4 ng/mL, p = 0.202). However, TAC and AOPP levels significantly increased in women with GDM, both in the INS and MET groups but not in the healthy controls. In conclusion, in our population, metformin has been shown to avoid an increase in intestinal permeability but failed to avoid an increase in oxidative stress related to hyperglycemia.