Higher direct bilirubin levels during mid-pregnancy are associated with lower risk of gestational diabetes mellitus

Interaction between Dietary Magnesium Intake and Genetic Risk Score on the Risk of Gestational Diabetes

SCOPE

We aim to assess the interaction between genetic risk and magnesium (Mg) intake during pregnancy on the development of gestational diabetes mellitus (GDM).

METHODS AND RESULTS

Three thousand ninety-six pregnant women from Tongji Maternal and Child Health Cohort are involved in our study. One hundred twelve susceptibility genetic variants of diabetes are selected and genotyped through Asian Screening Array bead chip. Mg intake were assessed by a validated food frequency questionnaire conducted at gestational weeks 25.1 ± 2.7 before GDM diagnosis. The study identifies 22 variants associated with GDM. Weighted genetic risk score (GRS) based on these 22 SNPs is associated with higher occurrence of GDM. There is an interaction between GRS and Mg intake on GDM risk (p-interaction = 0.019). Pregnant women with high GRS (≥23.48) and insufficient Mg intake (<370.0 mg d-1) have a 1.74 (95% confidence interval [CI]: 1.02, 2.98) fold risk of GDM after adjusting for potential confounders. No such relationship exists among pregnant women with low GRS (<23.48) (adjusted relative risk [RR] = 1.18; 95% CI: 0.73, 1.92).

CONCLUSION

Genetic predisposition to GDM is modified by Mg intake. This suggests that clinical nutrition guidance may benefit from being tailored by screening women with high diabetic genetic risk.

High serum total bilirubin as a potential protective factor for gestational diabetes mellitus: A retrospective cohort study of 92,885 Chinese pregnant women

AIMS

Identifying physiological factors that could reduce pregnant women's risk for developing gestational diabetes mellitus (GDM) is crucial for early prevention and intervention. We aimed to examine whether higher serum levels of total bilirubin (TBIL) were associated with a decreased risk of GDM.

METHODS

We conducted a retrospective cohort study in a tertiary care hospital in Shanghai, China. A total of 92,885 pregnant women were included. Serum TBIL levels were determined during the first antenatal visit before 24 weeks of gestation and GDM was diagnosed with a 75-g oral glucose tolerance test (OGTT) at 24-28 weeks of gestation.

RESULTS

A total of 13,037 GDM cases were identified, a prevalence of 14.0 % (13,037/92,885). These women had a higher median TBIL concentration 7.9 versus 7.6 mmol/l (P < 0.001). For the 91,051 women with TBIL within the physiologically normal range (≤ 17.1 μmol/l), a one interquartile range increase in TBIL (3.4 μmol/l) was associated with a decreased risk of GDM: adjusted odds ratio (OR)=0.89 [95 % CI 0.87;0.92]. For these women, the adjusted ORs for GDM across TBIL quartiles were: 0.92 [0.88;0.97] for the second, 0.85 [0.81;0.90] for the third, and 0.78 [0.74;0.83] for the fourth quartile in comparison with the first quartile.

CONCLUSION

Our study demonstrated that elevated serum TBIL levels were associated with decreased risk of GDM and supported its potential role in the prevention and early intervention of GDM.

The association between bilirubin levels, and the incidence of metabolic syndrome and diabetes mellitus: a systematic review and meta-analysis of cohort studies

OBJECTIVES

The objective of this meta-analysis was to investigate the association between plasma bilirubin levels and the incidence of metabolic syndrome and diabetes mellitus across all populations.

METHODS

Several databases were searched, including PubMed (Medline), Scopus, Web of Science, and Embase (Elsevier), to identify relevant cohort studies. All cohort studies that reported the risk ratio along with a 95% confidence interval were included. The association between bilirubin levels and metabolic syndrome or diabetes was reported as a pooled RR with a 95% CI in the forest plot. All analyses were conducted using STATA version 17, with a significance level of 0.05.

RESULTS

Out of the 10 studies included in the analysis, four investigated the effect of hyperbilirubinemia on the incidence of type 2 diabetes. When these four studies were combined, the pooled RR was 0.78 (95% CI: 0.73, 0.83; I2: 88.61%; P heterogeneity <  0.001), indicating a significant association between hyperbilirubinemia and decreased risk of type 2 diabetes. Five of the 10 studies evaluated the effect of hyperbilirubinemia on the incidence of metabolic syndrome, and the pooled RR was 0.70 (95% CI: 0.67, 0.73; I2: 78.13%; P heterogeneity <  0.001), indicating a significant association between hyperbilirubinemia and decreased risk of metabolic syndrome.

CONCLUSION

The findings suggest that elevated levels of bilirubin may have a significant protective effect against the development of diabetes mellitus and metabolic syndrome.

Evaluating the relationship between hepatitis B viral activity and gestational diabetes mellitus: A prospective cohort study

BACKGROUND

Hepatitis B infection has been associated with the development of gestational diabetes but the underlying mechanism is not known.

OBJECTIVE

To examine associations between viral activity, gestational diabetes mellitus (GDM), and insulin resistance in pregnant people with chronic hepatitis B infection (HBV).

DESIGN

Prospective cohort study across three tertiary maternity centres in Melbourne, Australia, between May 2021 and April 2023.

METHODS

Participants were followed prospectively through pregnancy to evaluate subsequent GDM diagnosis. Demographics, pregnancy outcomes, and markers of viral activity were compared between those with GDM versus those without. Logistic regression analysis was performed pre- and post-adjustment for known confounders. Sub-group analysis of participants from South East Asia (SEA) was performed. Outcome measures included GDM diagnosis, insulin resistance (Homeostatic Model Assessment Insulin Resistance score (HOMA-IR) score), HBV activity as measured by liver function tests, HBV viral load, hepatitis B e antigen, and quantitative hepatitis B surface antigen (quantHBsAg).

RESULTS

A total of 113 women were recruited. One third (38/112, 33.9%) developed GDM, mostly diagnosed on isolated postprandial hyperglycaemia (25/38, 65.8%). Over half were born in SEA (66/113, 58.4%). Mean quantHBsAg was significantly lower in those with GDM (p = 0.044). No other associations were identified between GDM or HOMA-IR and markers of hepatic activity on multivariate logistic regression analysis and on sub-group analysis of those born in SEA.

CONCLUSIONS

QuantHBsAg was significantly lower in those with GDM; otherwise, no association between GDM and measures of HBV viral activity was found. QuantHBsAg may be useful as an early pregnancy marker for GDM risk and warrants further research.

Association between Arsenic Methylation in Early Pregnancy and Gestational Diabetes Mellitus: A Prospective Cohort Study

The metabolism of arsenic (As) plays a crucial role in its health effects. However, the impact of arsenic methylation during early pregnancy on gestational diabetes mellitus (GDM) remains unclear. This study aimed to investigate the associations between As methylation in the first and second trimesters and the incidence of GDM by conducting a prospective cohort study in Chongqing, China. Urine samples from first (n = 131) and second (n = 53) trimester pregnant women were analyzed for arsenite (AsIII), arsenate (AsV), monomethylarsonic acid (MMA), and dimethylarsinic acid (DMA) concentrations. Logistic regressions assessed associations between the concentrations of As species, methylation indices, and GDM risk. As species concentrations showed no significant differences between GDM and non-GDM groups. Higher MMA% (OR = 1.11; 95% CI = 1.02, 1.22) and lower secondary methylation index (SMI) (OR = 0.81; 95% CI = 0.71, 0.93) correlated with GDM risk, primarily in the first trimester. MMA% decreased and DMA% and SMI increased from the first to the second trimester. Results of stratified analyses revealed these associations in women under 28 or with normal BMIs (18-24 kg/m2). The study underscores inefficient arsenic methylation as a GDM risk, modified by age and BMI, with the first trimester as a critical period.

Longitudinal plasma magnesium status during pregnancy and the risk of gestational diabetes mellitus: a prospective cohort study

Emerging evidence has shown that magnesium (Mg) was associated with type 2 diabetes while few focused on abnormal glucose metabolism during pregnancy. The study is aimed at investigating the association between longitudinal changes in plasma Mg during pregnancy and subsequent risk of gestational diabetes (GDM) and exploring the possible influence of iron supplementation on the changes of plasma Mg levels. One thousand seven hundred fifty-six pregnant women from Tongji Maternal and Child Health Cohort (TMCHC) were involved. Blood samples were collected at gestational weeks 17.0 ± 0.9 and later 26.2 ± 1.4. Plasma Mg was measured by inductively coupled plasma mass spectrometry (ICP-MS) with decline rates calculated. Information on general characteristics and iron supplementation was collected by questionnaires. Oral glucose tolerance test (OGTT) was conducted at 24-28 gestational weeks to diagnose GDM. Poisson regression with robust error variance was used to estimate relative risks (RR) of GDM. Median concentrations of plasma Mg were 0.69 mmol/L and 0.63 mmol/L respectively at two collections. The prevalence of hypomagnesemia at the first collection was 73% and associated with a 1.59 (95%CI: 1.07, 2.37) fold risk of GDM. Adjusted RRs were 1.74 (95%CI: 1.06, 2.83) and 2.44 (95%CI: 1.54, 3.85) for women with hypomagnesemia and followed more tertile (T2 and T3 vs. T1) of Mg decrement. Iron supplementation above 30 mg/day was found associated with more Mg decrement (25.5% and 27.5% in T2 and T3 vs. 19.5% in T1). In conclusion, hypomagnesemia during pregnancy is prevalent and associated with increased GDM risk, especially in women followed by more plasma Mg decrement during pregnancy. High-dose iron supplementation may involve more plasma Mg decrement.

Role of liver parameters in diabetes mellitus - a narrative review

Diabetes mellitus is characterized by hyperglycemia and abnormalities in insulin secretion and function. This review article focuses on various liver parameters, including albumin, alanine aminotransferase (ALT), aspartate aminotransferase (AST), alkaline phosphatase (ALP), alpha fetoprotein (AFP), alpha 1 antitrypsin (AAT), ammonia, bilirubin, bile acid, gamma-glutamyl transferase (GGT), immunoglobulin, lactate dehydrogenase (LDH), and total protein. These parameters play significant roles in the development of different types of diabetes such as type 1 diabetes (T1DM), type 2 diabetes (T2DM) and gestational diabetes (GDM). The article highlights that low albumin levels may indicate inflammation, while increased ALT and AST levels are associated with liver inflammation or injury, particularly in non-alcoholic fatty liver disease (NAFLD). Elevated ALP levels can be influenced by liver inflammation, biliary dysfunction, or bone metabolism changes. High bilirubin levels are independently linked to albuminuria in T1DM and an increased risk of T2DM. Elevated GGT levels are proposed as markers of oxidative stress and liver dysfunction in T2DM. In GDM, decreased serum AFP levels may indicate impaired embryo growth. Decreased AFP levels in T2DM can hinder the detection of hepatocellular carcinoma. Hyperammonemia can cause encephalopathy in diabetic ketoacidosis, and children with T1DM and attention deficit hyperactivity disorder often exhibit higher ammonia levels. T2DM disrupts the regulation of nitrogen-related metabolites, leading to increased blood ammonia levels. Bile acids affect glucose regulation by activating receptors on cell surfaces and nuclei, and changes in bile acid metabolism are observed in T2DM. Increased LDH activity reflects metabolic disturbances in glucose utilization and lactate production, contributing to diabetic complications. Poor glycemic management may be associated with elevated levels of IgA and IgG serum antibodies, and increased immunoglobulin levels are also associated with T2DM.

Higher Serum Bilirubin Levels in Response to Higher Carbohydrate Intake During Early Pregnancy and Lower Gestational Diabetes Mellitus Occurrence in Overweight and Obese Gravidae

Background and Aim: Serum bilirubin levels are recently shown to be a novel protector of gestational diabetes mellitus (GDM), yet whether they could be affected by carbohydrate quality is unclear. We aimed to examine the associations between dietary carbohydrate parameters and serum bilirubin levels during early pregnancy, with further exploration on a potential mediating role of serum bilirubin levels on carbohydrate parameters-GDM pathways. Methods: 260 healthy but overweight or obese gravidae (BMI ≥24 kg/m2) derived from a historical cohort in two hospitals in China were included. The associations between carbohydrate parameters (total carbohydrate intake, glycemic index GI, fiber intake, glycemic load GL) and serum bilirubin levels (total bilirubin, TB and direct bilirubin, DB) and GDM were evaluated by multivariable regression analysis. Generalized structural equation modeling was then applied to perform adjusted mediation analysis. Results: Increased serum bilirubin levels (mmol/L) and decreased GDM occurrence were observed following dietary carbohydrate intake (%E) and GL (g/1,000 kcal) in highest tertile compared to the lowest tertile [carbohydrate: TB: β = 0.926 (95%CI: 0.069, 1.782), DB: β = 0.554 (95%CI: 0.192, 0.916);GL:TB: β = 1.170 (95%CI: 0.339, 2.001); DB: β = 0.369 (95%CI: 0.016, 0.700); carbohydrate: adjusted OR = 0.43 (95%CI:0.19-0.99); GL: adjusted OR = 0.36 (95%CI:0.16, 0.84)]. The mediating effect of carbohydrate intake and GL on GDM through bilirubin levels was evaluated as modest (carbohydrate: 6.2% for TB, 1.3% for DB; GL: 8.7% for TB, 2.3% for DB). No association was observed regarding GI and fiber. Conclusions: Mildly elevated serum bilirubin levels appeared to be in response to higher energies consumed from carbohydrate during early pregnancy in healthy overweight or obese gravidae. However, the mediating effect of bilirubin levels on carbohydrate-GDM pathways is not evident. Larger investigation is further needed for solid evidence.

Delayed Lactogenesis Is Associated with Suboptimal Breastfeeding Practices: A Prospective Cohort Study

BACKGROUND

Breastfeeding has many established health benefits to both babies and mothers. There is limited evidence on the association between delayed lactogenesis and breastfeeding practices.

OBJECTIVE

We assessed the association between delayed lactogenesis and breastfeeding practices in women initiating breastfeeding.

DESIGN

We used data from a prospective cohort study in Wuhan, China, which enrolled pregnant women at 8-16 weeks of gestation and followed up to postpartum. Women were included who had a singleton live birth, initiated breastfeeding, and provided information on infant feeding. Maternal lactogenesis status was assessed by face-to-face interview at day 4 postpartum. Breastfeeding practices (full breastfeeding and/or any breastfeeding) were queried by telephone interview at 3, 6, and 12 mo postpartum. Poisson regression and Cox regression were used to identify the association between delayed lactogenesis and breastfeeding practices.

RESULTS

Delayed lactogenesis was reported by 17.9% of the 2877 participants. After adjusting for potential confounders, when compared with timely lactogenesis, delayed lactogenesis was significantly associated with higher risk of inability to sustain full breastfeeding at 3 mo postpartum (RR: 1.24, 95% CI: 1.10, 1.39) and 6 mo postpartum (RR: 1.14, 95% CI: 1.04, 1.24). Delayed lactogenesis was also significantly associated with early termination of any breastfeeding (HR: 1.15, 95% CI: 1.01, 1.30) in the adjusted model. In a combined analysis, women with higher gestational weight gain (GWG, ≥16 kg for underweight and normal weight, 15 kg for overweight/obesity) and who subsequently experienced delayed lactogenesis had the highest risk of ending any breastfeeding earlier (adjusted HR: 1.32, 95% CI: 1.11, 1.55) compared with those who gained less GWG and experienced timely lactogenesis.

CONCLUSIONS

This study shows that delayed lactogenesis was associated with low rate of full breastfeeding and shorter duration of any breastfeeding. Greater efforts to promote breastfeeding should be targeted towards women with delayed lactogenesis.

Exposure to multiple metals in early pregnancy and gestational diabetes mellitus: A prospective cohort study

BACKGROUND

A growing number of epidemiologic studies have estimated associations between type 2 diabetes mellitus and exposure to metals. However, studies on the associations of internal assessments of metal exposure and gestational diabetes mellitus (GDM) are limited in scope and have inconsistent outcomes.

OBJECTIVES

This investigation aimed to explore the associations between urinary nickel (Ni), arsenic (As), cadmium (Cd), antimony (Sb), cobalt (Co), or vanadium (V) in early pregnancy and the subsequent risk of GDM in Chinese pregnant women.

METHODS

The study population included 2090 women with singleton pregnancy from the Tongji Maternal and Child Health Cohort (TMCHC). Urine samples were collected before 20 gestational weeks, and an oral glucose tolerance test (OGTT) was conducted at 24-28 gestational weeks to diagnose GDM. The concentrations of urinary metals were measured using inductively coupled plasma mass spectrometry (ICP-MS) and were corrected for urinary creatinine. The associations between the risk of GDM and urinary metals were assessed using Poisson regression with a robust error variance with generalized estimating equations (GEE) models and Bayesian kernel machine regression (BKMR).

RESULTS

A total of 241 participants (11.53%) were diagnosed with GDM. Five metals (Ni, As, Sb, Co, and V) were found significantly and positively associated with GDM based on single-metal models. In multiple-metal models, for each unit increase of ln-transformed urinary Ni or Sb, the risk of GDM increased 18% [relative risk (RR):1.18, 95%confidence interval (CI): 1.00, 1.38 or RR: 1.18, 95%CI: 1.00, 1.39, respectively]. The BKMR analysis revealed a statistically significant and positive joint effect of the six metals on the risk of GDM, when the urinary levels of the six metals were all above the 55th percentile, compared to the median levels. The effect of metal Ni was significant when the concentrations of the other metals were all fixed at their 25th percentile, and metal Sb displayed a significant and positive effect when all the other metals were fixed at 25th, 50th, and 75th percentiles.

CONCLUSIONS

To the best of our knowledge, this study is the first to demonstrate that increased concentrations of urinary Ni in early pregnancy are associated with an elevated risk of GDM, either evaluated individually or as a metal mixture. All six metals mixed exposure was positively associated with the risk of GDM, while Sb and Ni were demonstrated more important effects than the other four metals in the mixture.

Glucuronidated bilirubin: Significantly increased in hepatic encephalopathy

Bilirubin is produced by the breakdown of hemoglobin in senescent erythrocytes by macrophages and carried by albumin from blood circulation to the liver for removal in normal physiology. Glucuronic acid modification of bilirubin by UDP-glucuronyltransferase in the liver is the key event for its subsequent elimination from human body. Conditions that accelerate the breakdown of erythrocytes may cause an elevated blood level of unconjugated bilirubin whereas the factors affect the glucuronidated bilirubin formation and subsequent elimination may cause decreased or increased blood level of glucuronidated bilirubin, the water soluble "direct bilirubin" measured by clinical blood test. Studies showed that increased total serum bilirubin has a protective effect on cardiovascular and other related diseases, but it is unknown how direct bilirubin levels were related to different diseases. By taking advantage of the data collected in the clinical laboratory of our hospital, the direct bilirubin data from 192,535 patients with 72 clinically defined diseases were compared to that of healthy controls (10,497). Based on the mean, median, and p values, we found that patients with hepatic encephalopathy had the highest serum direct bilirubin level, which resembled acute hepatic encephalopathy caused by increased serum direct bilirubin level in neonates. In contrast, patients with uremia, nephrotic syndrome, and preeclampsia had significantly lower levels of serum direct bilirubin. Taken together, our data revealed that serum direct bilirubin levels were either increased or decreased in a disease-dependent manner. The possible molecular mechanisms of increased direct bilirubin levels in patients suffering hepatic encephalopathy are discussed.

Lower serum total bilirubin concentration is associated with higher prevalence of gestational diabetes mellitus in Japanese pregnant women

We aimed to clarify the pathophysiological significance of total bilirubin (TB) in gestational diabetes mellitus (GDM). This was a cross-sectional study that included 616 pregnant Japanese women (368 normal glucose tolerance [NGT] and 248 GDM). Serum TB concentration, homeostasis model assessment of insulin resistance (HOMA-IR), and other clinical parameters were compared in NGT and GDM women. TB concentration was also compared according to the number of abnormal OGTT values. Logistic regression analysis was used to evaluate the association between TB and GDM prevalence. A multiple linear regression model was used to evaluate the association between TB and HOMA-IR. TB concentrations were significantly lower in GDM women than in NGT women. This result did not change after adjustments for TB sampling timing were made. Out of 248 GDM women, the prevalences of 1- and 2/3- abnormal OGTT values (1- and 2/3-AV) GDM were 72.2% (n = 179) and 27.8% (n = 69), respectively. In the multiple comparisons, TB concentrations were significantly lower in women with 2/3-AV GDM than in women with NGT and 1-AV GDM. Multiple logistic regression analysis showed that TB was a significantly associated factor for 2/3-AV, but not for total GDM. HOMA-IR was significantly higher in GDM women than in NGT women. The univariate, but not multivariate, analysis showed that TB was a significantly associated factor for HOMA-IR. Our findings suggest that hypobilirubinemia may be involved in the pathogenesis of GDM.

Direct bilirubin is associated with low-density lipoprotein subfractions and particle size in overweight and centrally obese women

BACKGROUND AND AIMS

Bilirubin has antioxidant and anti-inflammatory properties; serum bilirubin levels have been known to be inversely associated with cardiovascular disease. However, the effects of different bilirubin subtypes on cardiometabolic traits are unknown. In this study, we aimed to determine whether direct bilirubin is more strongly correlated with small, dense low-density lipoprotein (sdLDL) compared to other bilirubin subtypes. We also investigated which LDL subfractions exhibited the highest correlation with direct bilirubin.

METHODS AND RESULTS

A total of 288 overweight and centrally obese women were included in this study. The Pearson correlation and Steiger's Z test were used to compare the correlation coefficients between bilirubin subtypes and lipoproteins. Multiple linear regression analyses were used to evaluate the independent association between direct bilirubin and mean LDL particle size. Only direct bilirubin levels were significantly associated with the sdLDL subfraction and mean LDL particle size. Mean LDL particle size exhibited a significantly stronger correlation with direct bilirubin than sdLDL, percent sdLDL, and the sdLDL:large LDL ratio. Regression analysis showed that direct bilirubin was significantly associated with mean LDL particle size, according to both the stepwise method (β = 11.445, P value = 0.002) and the enter method (β = 11.655, P value = 0.002).

CONCLUSIONS

Direct bilirubin is more strongly correlated with the sdLDL subfraction compared with total and indirect bilirubin, and is independently associated with mean LDL particle size in overweight and centrally obese women.

Plasma concentration of trimethylamine-N-oxide and risk of gestational diabetes mellitus

Background

The microbiota-dependent metabolite trimethylamine-N-oxide (TMAO) has been reported as a novel and independent risk factor for the development of cardiovascular and metabolic diseases, but the association with gestational diabetes mellitus (GDM) remains unclear.

Objective

The aim of this study was to investigate the association between plasma TMAO concentration and GDM in a 2-phase study.

Design

A 2-phase design was used in the current study. An initial phase included 866 participants (433 GDM cases and 433 matched controls) with fasting blood samples collected at the time of GDM screening (24-32 wk of gestation). An independent-phase study, with 276 GDM cases and 552 matched controls who provided fasting blood samples before 20 wk of gestation and who had GDM screened during 24-32 wk of gestation, was nested within a prospective cohort study. These 2 studies were both conducted in Wuhan, China, and the incidence of GDM in the cohort study was 10.8%. Plasma TMAO concentrations were determined by stable isotope dilution liquid chromatography-tandem mass spectrometry. GDM was diagnosed according to the American Diabetes Association criteria by using an oral-glucose-tolerance test.

Results

In the initial case-control study, the adjusted OR of GDM comparing the highest TMAO quartile with the lowest quartile was 1.94 (95% CI: 1.28, 2.93). Each SD increment of ln-transformed plasma TMAO was associated with 22% (95% CI: 5%, 41%) higher odds of GDM. In the nested case-control study, women in the highest quartile also had increased odds of GDM (adjusted OR: 2.06; 95% CI: 1.28, 3.31) compared with women in the lowest quartile, and the adjusted OR for GDM per SD increment of ln-transformed plasma TMAO was 1.26 (95% CI: 1.08, 1.47).

Conclusions

Consistent findings from this 2-phase study indicate a positive association between plasma TMAO concentrations and GDM. Future studies are warranted to elucidate the underlying mechanisms. This trial was registered at www.clinicaltrials.gov as NCT03415295.