Association of Serum Uric Acid, Urea Nitrogen, and Urine Specific Gravity Levels at 16-18 Weeks of Gestation with the Risk of Gestational Diabetes Mellitus

Impact of body mass index on the association between kidney function and insulin resistance in diabetic and nondiabetic populations

AIMS/INTRODUCTION

The kidneys play a role in regulating insulin metabolism, and kidney function may indicate the progression to insulin resistance (IR) in individuals with obesity and diabetes. We evaluated the relationship between kidney function biomarkers and IR in diabetic and nondiabetic adults categorized by body mass index (BMI).

METHODS

A total of 8,272 adults from the China Health and Nutrition Survey 2009 were categorized into four groups based on BMI (overweight/obesity vs underweight/normal weight) and diabetes status (diabetes vs non-diabetes). Univariable and multivariable linear regression, along with restricted cubic spline regression, were used to determine the relationship between estimated glomerular filtration rate (eGFR), creatinine, urea nitrogen, uric acid (UA), and homeostasis model assessment for insulin resistance (HOMA-IR).

RESULTS

The relationship between kidney function biomarkers and IR only existed in the overweight/obese populations and varied by diabetic status. In diabetic patients, linear associations were observed: eGFR was negatively associated with HOMA-IR, and creatinine was positively associated. In nondiabetic individuals, nonlinear associations were found. The relationship between eGFR and HOMA-IR followed an L-shaped curve: HOMA-IR decreased as eGFR increased up to 100 mL/min/1.73 m2, then slightly increased. The UA-HOMA-IR association showed an inverted L-shape: HOMA-IR increased with higher UA levels, plateauing after UA exceeded 360 μmol/L.

CONCLUSIONS

Kidney function biomarkers are associated with IR in overweight/obese populations, with and without diabetes. eGFR and creatinine can be indicators of IR in overweight/obese subjects with diabetes, while eGFR and UA may be used in those without diabetes.

Elevated serum uric acid to creatinine ratio is associated with adverse pregnancy outcomes: a prospective birth cohort study

Purpose: This study evaluated the association between maternal serum uric acid-to-creatinine ratio (SUA/SCr) in the first trimester and adverse maternal and neonatal outcomes. Methods: A prospective birth cohort study was conducted between 2018 and 2021. Logistic regression models and restricted cubic splines were utilized to estimate the associations between the SUA/SCr ratio and feto-maternal pregnancy outcomes. Women were stratified according to maternal age and pre-pregnancy body mass index. Results: This study included 33,030 pregnant women with live singleton pregnancies. The overall prevalence of gestational diabetes mellitus (GDM), pregnancy-induced hypertension (PIH), cesarean delivery, preterm birth, large-for-gestational age (LGA), small-for-gestational age, and low Apgar scores were 15.18%, 7.96%, 37.62%, 4.93%, 9.39%, 4.79% and 0.28%, respectively. The highest quartile of SUA/SCr was associated with the highest risk of GDM (odds ratio [OR] 2.14, 95% CI 1.93-2.36), PIH (OR 1.79, 95% CI 1.58-2.04), cesarean delivery (OR 1.24, 95% CI 1.16-1.33), and preterm birth (OR 1.30, 95% CI 1.12-1.51). The associations between SUA/SCr with adverse pregnancy outcomes showed linear relationships except for GDM (P < 0.001 for all, P < 0.001 for non-linearity). Subgroup analyses revealed that the associations between the SUA/SCr ratio and the risks of PIH and LGA were significantly stronger in younger pregnant women (P = 0.033 and 0.035, respectively). Conclusion: Maternal SUA/SCr levels were associated positively with the risk of adverse pregnancy outcomes. Timely monitoring of SUA and SCr levels during early pregnancy may help reduce the risk of adverse pregnancy outcomes and provide a basis for interventions.

Establishment of gestational diabetes risk prediction model and clinical verification

OBJECTIVE

The present study aimed to evaluate the risk factors for gestational diabetes mellitus (GDM) and build and validate an early risk prediction model of GDM by comparing the differences in the indicators of the first trimester of pregnancy between pregnant women with GDM and non-gestational diabetes mellitus (NGDM). Thus, this study provided a theoretical basis for early intervention of GDM.

METHODS

A total of 6000 pregnant women who underwent a routine prenatal examination in Qinhuangdao Maternal and Child Health Hospital (Qinhuangdao City, Hebei Province, China) from January 2016-2022 were retrospectively selected and randomly divided into a modeling cohort (4200 cases) and validation cohort (1800 cases) at a ratio of 3:7. According to the results of oral glucose tolerance test (OGTT), they were divided into NGDM and GDM groups. The modeling cohort consisted of 2975 NGDM and 1225 GDM cases, while the validation cohort consisted of 1281 NGDM and 519 GDM cases. The differences in general conditions and laboratory indicators between different groups were compared, and logistic regression analysis was further used to establish a risk prediction model for GDM in the first trimester. The receiver operating characteristic curve (ROC) and Hosmer-Lemeshow (HL) tests were used to evaluate the prediction of the model efficacy.

RESULTS

Age, pre-pregnancy body mass index (BMI), glycosylated hemoglobin (HbA1c), blood uric acid (UA), triglyceride (TG), and high-density lipoprotein cholesterol (HDL-C) in the first trimester were independent risk factors for GDM (P < 0.05). The model equation was Y = 1/{1 + exp[- (- 18.373 + age × 0.065 + BMI × 0.030 + first-trimester HbA1c × 2.519 + UA × 0.014 + TG × 0.224-HDL-C × 0.635)]}. The area under the ROC curve (AUC) of the model cohort was 0.803 (0.788-0.817), the sensitivity was 72.0%, and the specificity was 73.5%. The AUC of the validation cohort was 0.782 (0.759-0.806), the sensitivity was 68.6%, and the specificity was 73.8%. The P values of the HL test in both the training and validation sets were > 0.05, indicating a satisfactory model fit.

CONCLUSION

Age, pre-pregnancy BMI, HbA1C in early pregnancy, blood UA, TG, and HDL-C are independent risk factors for GDM. The risk prediction model established by combining age, pre-pregnancy BMI, and laboratory indicators in the first trimester can provide a theoretical basis for early screening, monitoring, and intervention of GDM high-risk pregnant women.

Is salivary uric acid, a putative biomarker of pre-eclampsia, of maternal, placental, or fetal origin?

OBJECTIVES

Increased salivary uric acid (sUA) represents a potential biomarker predictive of pre-eclampsia (PE), but its origin is unclear. The study explores whether sUA levels reflect maternal or feto-placental physiological stress and whether sUA levels in these cases correlate with amniotic fluid (fetal origin), maternal blood (maternal origin), or cord blood (fetal vs placental origin).

STUDY DESIGN

Pregnant women (n = 39) undergoing amniotomy or caesarean section after 34 gestational weeks were designated into three groups of either maternal, feto-placental, or no signs of physiological stress: women (n = 15) in the established first phase of active labour and without any signs of fetal growth restriction (FGR) or PE were assigned to the maternal stress group, women (n = 6) with an ultrasound-based diagnosis of FGR, with or without PE, were assigned to the feto-placental stress group, and women (n = 18) not yet in active labour and without any signs of FGR or PE, were assigned to the control group. Uric acid levels in corresponding samples of amniotic fluid, saliva, maternal blood, and cord blood were compared between groups and between body compartments within each group.

RESULTS

The feto-placental stress group showed increased UA levels in saliva (median, interquartile range [IQR]: 0.47 [0.38] mmol/L, P = 0.023) and maternal blood (0.42 [0.13] mmol/L, P = 0.032), but no differences in amniotic fluid or cord blood compared with the other groups. Within the control and maternal stress group, sUA levels were lower compared with maternal blood (0.20 [0.08] vs 0.25 [0.08] mmol/L, Pcontrol = 0.018; 0.20 [0.06] vs 0.26 [0.08] mmol/L, Pmaternal = 0.001) and highest in amniotic fluid (control group (0.49 [0.18] mmol/L): Pmaternal,blood = 0.001, Pumbilical,artery = <0.001, Pumbilical,vein = <0.001, Psaliva = <0.001) (maternal stress group (0.56 [0.23] mmol/L): Pmaternal,blood = 0.021, Pumbilical,artery = 0.006, Pumbilical,vein = 0.004, Psaliva = 0.003). Levels did not differ between compartments in the feto-placental stress group.

CONCLUSIONS

Salivary and maternal blood UA levels were increased in the feto-placental stress group with salivary levels increasing more than blood levels compared with the maternal stress and control groups, whilst UA in amniotic fluid were not different between the groups, suggesting a placental origin and potential use of sUA as a biomarker of placental dysfunction, including FGR and severe PE.

Relationship between serum uric acid in early pregnancy and gestational diabetes mellitus: a prospective cohort study

PURPOSE

The association between serum uric acid (UA) and gestational diabetes mellitus (GDM) was still unclear. Serum UA levels in pregnancy differed from that in non-pregnancy. This study aimed to investigate the changes of serum UA in early pregnancy, and to explore the association of serum UA with the risk of GDM.

METHODS

A prospective double-center study including 873 singleton pregnant women was conducted in Beijing, China since 2019 (clinical trial number: NCT03246295). Seventy-eight healthy non-pregnant women were selected to compare the changes of biomarkers in pregnancy. Spearman correlation and logistic regression analysis were performed to measure the relationship between serum UA in early pregnancy and GDM.

RESULTS

The incidence of GDM in our cohort was 20.27%(177/873). Compared with non-pregnant women, serum UA and creatinine decreased significantly during early pregnancy. Serum UA concentration in early pregnancy was significantly higher in GDM women than that in normal glucose tolerance (NGT) women [217.0(192.9, 272.0) μmol/l vs. 201.9(176.0, 232.0) μmol/l, p < 0.001]. After adjusted for confounding factors, elevated serum UA remained as an independent risk factor for GDM. The risk of GDM increased when serum UA was above 240 μmol/l (adjusted OR 1.964, 95% CI 1.296-2.977, p < 0.001), and stronger relationships between serum UA and GDM were observed in pregnant women aged over 35 years old and preBMI ≥ 24 kg/m2.

CONCLUSION

The normal range of serum UA and creatinine in pregnant women were lower than those in non-pregnant women. It is essential to monitor serum UA concentrations since early pregnancy to alert and prevent GDM, especially in older and heavier pregnant women.

CLINICAL TRIAL NUMBER

NCT03246295.

New perspective on first-trimester serum uric acid level in predicting the risk of gestational diabetes mellitus

This study aimed to investigate the correlation between serum uric acid (UA) and gestational diabetes mellitus (GDM) during the first trimester and provide a new perspective for the prevention and treatment of GDM. Based on the diagnostic criteria of gestational diabetes of the International Association of Diabetes and Pregnancy Study Groups, 1744 and 4256 patients were enrolled in the GDM and normal glucose tolerance (NGT) groups. Four groups were constituted based on the quartile of first-trimester serum UA (UA) level, and the differences in each indicator between groups were compared. Logistic regression was used to analyze the effects of UA level on GDM risk. The rate of GDM in the UA quartile changed from low to high. Significant differences were also observed in fasting plasma glucose level, 1 h post glucose and 2 h post glucose levels, in all the groups (P < 0.05), which increased with the UA level. UA level were independent risk factors for GDM. The best threshold of GDM predicted by the first-trimester UA level was 226.55 μmol/L. The first-trimester UA level in patients with GDM was relatively higher and was an independent risk factor for GDM.

Maternal uric acid levels and risk of gestational diabetes mellitus: A systematic review and dose-response meta-analysis of cohort studies including 105,380 participants

AIMS/INTRODUCTION

Although the association between uric acid levels and adverse pregnancy outcomes has been investigated, the effects of higher uric acid levels on the risk of gestational diabetes mellitus (GDM) have yet to be established. Therefore, this systematic review and meta-analysis aimed to investigate the relationship between uric acid levels during pregnancy and the risk of GDM.

MATERIALS AND METHODS

PubMed/Medline, Scopus and Web of Science databases were searched up to April 2022 for relevant observational studies. A random effects model was used to estimate pooled odds ratios (OR) and 95% confidence intervals (95% CI). To assess the heterogeneity of included studies, the I2 index was used.

RESULTS

Among the initial 262 studies that were recognized from the databases search, 23 studies including 105,380 participants were eligible. Pooled analysis showed that higher uric acid levels significantly affected the risk of GDM (OR 2.58, 95% CI 1.89-3.52, I2  = 90.8%, P < 0.001). Subgroup analyses based on the gestational week showed that higher uric acid levels before the 20th week of gestation were significantly associated with the risk of GDM (OR 3.26, 95% CI 2.26-4.71, I2  = 89.3%, P < 0.001). Based on the meta-regression analysis, uric acid levels and odds of GDM were significantly correlated with the participants' age, and it was more significant in younger pregnant women.

CONCLUSIONS

This study showed a positive association between uric acid levels and the risk of GDM. Also, our results indicate that measuring uric acid levels before 20 weeks of gestation can potentially predict GDM, especially in younger women.

Serum uric acid and the risk of gestational diabetes mellitus: a systematic review and meta-analysis

AIMS

Serum uric acid (SUA) is considered as a risk factor for gestational diabetes mellitus (GDM). However, current studies showed inconsistent results. This study aimed to explore the relationship between SUA levels and GDM risk.

METHODS

Eligible studies were retrieved from PubMed, Web of Science, Embase, China National Knowledge Infrastructure, and Wanfang databases up to November 1, 2022. The pooled standardized mean difference (SMD) and 95% confidence interval (CI) were used to represent the difference in SUA levels between GDM women and controls. The combined odds ratios (OR) and 95% CI were applied to assess association between SUA levels and GDM risk. Subgroup analyses were conducted on study continents, design, and quality, detection time of SUA, and GDM diagnostic criteria.

RESULTS

Totally 11 studies including five case-control and six cohort studies, in which 80,387 pregnant women with 9815 GDM were included. The overall meta-analysis showed that the mean SUA level in GDM group was significantly higher than in controls (SMD = 0.423, 95%CI = 0.019-0.826, p = .040, I² = 93%). Notably, pregnant women with elevated levels of SUA had a significantly increased risk of GDM (OR = 1.670, 95%CI = 1.184-2.356, p = .0035, I² = 95%). Furthermore, subgroup analysis performed on the detection time of SUA showed a significant difference in the association between SUA and GDM risk within different trimesters (1st trimester: OR = 3.978, 95%CI = 2.177-7.268; 1st to 2nd trimester: OR = 1.340, 95%CI = 1.078-1.667; p between subgroups <.01).

CONCLUSIONS

Elevated SUA was positively associated with GDM risk, particularly in the 1st trimester of pregnancy. Further studies with high quality are required to validate the findings of this study.

Elevated Serum Uric Acid Is Associated With Gestational Diabetes Mellitus: An Observational Cohort Study

CONTEXT

Elevated serum uric acid may be closely related to the occurrence of gestational diabetes mellitus (GDM).

OBJECTIVE

We aimed to elucidate the relationship between changes in serum uric acid before 24 weeks of gestation and the risk of GDM and associated adverse pregnancy outcomes and provide clinical epidemiological evidence for the involvement of uric acid in the etiology of GDM.

METHODS

We conducted a retrospective cohort study of 23 843 singleton pregnant women between February 2018 and June 2022. The exposure factor was serum uric acid before 24 weeks of gestation, primary outcome was gestational diabetes diagnosed at 24 to 28 weeks of gestation, and secondary outcomes were GDM A2 (GDM requiring pharmacotherapy), GDM combined with pre-eclampsia, preterm delivery, and large for gestational age infants. Adjusted risk ratios (RRs) were calculated using multivariate predictive marginal proportions from logistic regression models.

RESULTS

Among 23 843 singleton pregnant women, 3204 (13.44%) were diagnosed with GDM at 24 to 28 weeks of gestation, and elevated uric acid before 24 weeks of gestation was strongly associated with the risk of GDM. Compared with uric acid <240 µmol/L, the RR for GDM was 1.43 (95% CI 1.29-1.56) when uric acid was between 240 and 300 µmol/L; when uric acid was >300 µmol/L, the RR for GDM was 1.82 (95% CI 1.55-2.15). In secondary outcomes uric acid had a similar relationship with GDM A2, preterm birth, and GDM combined with pre-eclampsia.

CONCLUSION

Elevated uric acid levels before 24 weeks of gestation are associated with subsequent GDM; the best time to test for uric acid is before 18 weeks of gestation. Pregnant women with low and intermediate risk for GDM development may benefit more from serum uric acid measurements before 18 weeks of gestation.

Characterizing and Evaluating Diurnal Salivary Uric Acid Across Pregnancy Among Healthy Women

Uric acid levels during pregnancy have been examined as a potential indicator of risk for gestational diabetes mellites, hypertension, and related adverse birth outcomes. However, evidence supporting the utility of serum uric acid levels in predicting poor maternal and fetal health has been mixed. The lack of consistent findings may be due to limitations inherent in serum-based biomeasure evaluations, such as minimal repeated assessments and variability in the timing of these assessments. To address these gaps, we examined repeated measurements of diurnal salivary uric acid (sUA) levels in a sample of 44 healthy women across early-mid and late pregnancy. We assessed potential covariates and confounds of sUA levels and diurnal trajectories, as well as associations between maternal weight gain and blood pressure during pregnancy and sUA concentrations. Using multilevel linear models, we found sUA increased across pregnancy and displayed a robust diurnal pattern with the highest concentrations at waking, a steep decline in the early morning, and decreasing levels across the day. Maternal pre-pregnancy BMI, age, prior-night sleep duration, and fetal sex were associated with sUA levels and/or diurnal slopes. Maternal blood pressure and gestational weight gain also showed significant associations with sUA levels across pregnancy. Our results expand upon those found with serum UA measurements. Further, they demonstrate the feasibility of using at-home, minimally-invasive saliva sampling procedures to track UA levels across pregnancy with potential applications for the long-term monitoring of maternal cardiometabolic risk.