First-trimester adiponectin and subsequent development of preeclampsia or fetal growth restriction

Adiponectin as a Potential Biomarker for Pregnancy Disorders

Adiponectin is an adipocyte-derived hormone that plays a critical role in energy homeostasis, mainly attributed to its insulin-sensitizing properties. Accumulating studies have reported that adiponectin concentrations are decreased during metabolic diseases, such as obesity and type 2 diabetes, with an emerging body of evidence providing support for its use as a biomarker for pregnancy complications. The identification of maternal factors that could predict the outcome of compromised pregnancies could act as valuable tools that allow the early recognition of high-risk pregnancies, facilitating close follow-up and prevention of pregnancy complications in mother and child. In this review we consider the role of adiponectin as a potential biomarker of disorders associated with pregnancy. We discuss common disorders associated with pregnancy (gestational diabetes mellitus, preeclampsia, preterm birth and abnormal intrauterine growth) and highlight studies that have investigated the potential of adiponectin to serve as biomarkers for these disorders. We conclude the review by recommending strategies to consider for future research.

The role of serum adipokine levels in preeclampsia: A systematic review

BACKGROUND

Preeclampsia represents a major pregnancy complication, associated with high rates of perinatal morbidity. The aim of this systematic review is to accumulate current literature evidence in order to examine the pattern of serum adipokine levels among preeclamptic women and asses their potential efficacy in the prediction of the disease.

METHODS

Medline, Scopus, CENTRAL, Clinicaltrials.gov and Google Scholar databases were systematically searched from inception. All observational studies reporting serum adipokine values among preeclamptic and healthy pregnant women were held eligible.

RESULTS

A total of 163 studies were included, comprising 23,482 women. Leptin was evaluated in 91 studies and its values were found to be significantly elevated in preeclamptic women during all pregnancy trimester, independently of disease onset and severity. Preeclampsia was also associated with increased serum fatty acid binding protein-4 and chemerin levels, when measured both during the 1st and 3rd trimester. Data concerning the rest adipokines were either conflicting or limited to reach firm conclusions. Quality of evidence was evaluated to be high for leptin, moderate for serum fatty acid binding protein-4 and chemerin and low for the other adipokines.

CONCLUSIONS

The existing evidence suggests that preeclampsia is linked to increased levels of leptin, chemerin and fatty acid binding protein-4 in all pregnancy trimesters and forms of the disease. Inconsistent data currently exists concerning the role of the other adipokines. Large-scale prospective studies should longitudinally evaluate the serum concentration of novel adipokines and define the optimal threshold and timing of measurement to be widely applied in clinical practice.

Maternal adipokines longitudinally measured across pregnancy and their associations with neonatal size, length, and adiposity

BACKGROUND/OBJECTIVES

Maternal obesity impacts fetal growth as early as second trimester of pregnancy, yet little is known about the molecular mechanisms involved. We aimed to examine associations between maternal adipokines throughout pregnancy and neonatal size by prepregnancy obesity status.

METHODS

In a prospective cohort of 2802 U.S. pregnant women from the NICHD Fetal Growth Studies-Singleton Cohort (2009-2013), biospecimens were analyzed in a matched case-control subset of 321 women. Blood was collected at 10-14, 15-26 (fasting), 23-31, and 33-39 gestational weeks. Plasma leptin and soluble leptin receptor (sOB-R) and total and high-molecular-weight (HMW)-adiponectin were measured. Free leptin was calculated as leptin/sOB-R. Birthweight was abstracted from medical records. Neonatal length and skinfolds were measured.

RESULTS

Leptin and sOB-R in late pregnancy tended to be positively and negatively associated with neonatal length, respectively, while free leptin throughout pregnancy tended to be positively associated with length. Free leptin associations with neonatal length were differential by obesity (i.e., inversely among women without obesity and positively among women with obesity). A per unit increase in free leptin at 33-39 weeks was associated with a shorter neonatal length by -0.55 cm (95%CI, -0.83, -0.28) in women without obesity and longer length by 0.49 cm (95%CI, 0.34, 0.65) in women with obesity. HMW-adiponectin at 33-39 weeks was inversely associated with neonatal length (β = -1.29 cm; 95%CI, -1.74, -0.85) and skinfold thickness (β = -1.46 mm; 95%CI, -1.58, -0.56) among women with obesity. Free leptin across pregnancy tended to be negatively associated with neonatal skinfold thickness among women without obesity, while free leptin in early pregnancy was positively associated with skinfold thickness.

CONCLUSIONS

Maternal adipokines were associated with multiple pathways that influence neonatal size including length and adiposity, which differed in timing across pregnancy and by prepregnancy obesity. These findings provide new potential insights into mechanisms and timing by which maternal obesity may impact fetal growth.

Serum adipokine levels and insulin resistance in the first trimester of pregnancy in adolescents and their relationship with neonatal weight

Introduction: The approach to the physiology of pregnancy based on adipokine behavior and the homeostasis-insulin resistance (HOMA-IR) model, along with their relationship to neonatal weight, has been poorly studied in adolescent pregnant women. Objective: To determine possible correlations between adipokines –leptin and adiponectin– and HOMA-IR in pregnant women aged 14 to 17 years, and first-trimester body mass index (BMI) and neonatal weight. Materials and methods: In the weeks 11 to 14 of gestation, the biochemical variables leptin, adiponectin, glycemia and insulin were measured and HOMA-IR was calculated. Maternal and neonatal anthropometric variables were obtained. Statistical analysis was performed with Pearson correlation and the p value. Results: We noticed a positive correlation of serum leptin levels with HOMA-IR in the first trimester of gestation (r=0.5, p≤0.000) and a negative correlation between adiponectin and HOMA-IR (r=-0.4; p=0.017), along with positive correlations between BMI and leptin, insulin and HOMA-IR (r=0.83 and p <0.000, r=0.56 and p≤0.000; r=0.54 and p≤0.000, respectively). In adolescent non-obese mothers with no history of dyslipidemia, there was a positive correlation between HOMA-IR and neonatal weight (r=0.43, p=0.012). Conclusions: Leptin and HOMA-IR showed a positive correlation, while adiponectin and HOMA-IR showed a negative correlation. Leptin and HOMA-IR were positively correlated with BMI. HOMA-IR correlated with the weight of neonates of non-obese adolescents without dyslipidemia.

Maternal and Cord Blood Adiponectin Concentrations in Small for Gestational Age: A Meta-Analysis

Background: Adiponectin, which may have a growth-promoting effect through its insulin-sensitizing action, is thought to play a key role in fetal growth. This study was performed to determine whether maternal and/or cord blood adiponectin concentrations differ between small for gestational age (SGA) and healthy controls. Methods: Databases were searched to identify good quality English language studies providing the number of SGA and healthy controls, and the means and standard deviations of maternal or cord blood adiponectin concentration in both groups. A meta-analysis was performed to summarize the standardized mean differences (SMDs) in maternal and cord blood adiponectin concentrations between SGA and healthy controls. Results: There was no statistically significant difference in maternal blood adiponectin concentration between SGA and healthy controls (n = 8, p = 0.951). However, cord blood adiponectin concentration was significantly lower in SGA than in healthy controls (n = 6, p = 0.028), and the effect was large (i.e., SMD >0.7). Conclusions: Maternal blood adiponectin concentration is not low in SGA compared with healthy controls. However, SGA shows lower cord blood adiponectin concentration than healthy controls.

Metformin as a prophylactic treatment of gestational diabetes in pregnant patients with pregestational insulin resistance: A randomized study

AIM

We aimed to assess the use of metformin (MTF) in the prevention of gestational diabetes mellitus (GDM) in patients with pregestational insulin resistance (PIR).

METHODS

A double blind, multicenter, randomized trial was carried out in patients with a history of PIR and pregestational MTF treatment. Groups were allocated either to MTF 1700 mg/day or placebo. Patients were recruited between 12⁺⁰ and 15⁺⁶  gestational weeks, and treatment was extended until week 36. A multiple logistic regression analysis was applied to determine the relation between the use of metformin and the development of GDM.

RESULTS

One hundred and forty one patients were randomized (68 patients in the MTF group and 73 in the placebo group). A total of 30 patients withdrew from the study during follow-up. Administration of MTF was not associated with a decrease in the incidence of GDM as compared to placebo (37.5% vs 25.4%, respectively; P = 0.2). Moreover, MTF administration was associated with a significant increase in drug intolerance as compared to placebo (14.3% vs 1.8%, respectively; P = 0.02).

CONCLUSION

The use of MTF is not effective in prevention of GDM in populations with PIR. The use of MTF shows a significantly higher frequency of drug intolerance than placebo.

Comparison of serum maternal adiponectin concentrations in women with isolated intrauterine growth retardation and intrauterine growth retardation concomitant with pre-eclampsia

OBJECTIVE

The aim of this study was to compare serum maternal adiponectin concentrations in pregnant women with isolated intrauterine growth retardation (IUGR) and in pregnant women with IUGR concomitant with pre-eclampsia (IUGRcwPE).

MATERIAL AND METHODS

Thirty patients with isolated IUGR (group 1), 20 patients with IUGRcwPE (group 2), and 30 healthy controls (group 3) between age 18-40 were included into the study. Venous blood samples of those patients were obtained in the starving state. Adiponectin concentrations were measured by enzyme-linked immunosorbent assay in serum obtained after centrifugation. To find the differences between the groups, student t-test and one-way ANOVA statistical methods were used.

RESULTS

There were no differences between the groups in terms of age, body mass index, gestational age, and parity (p>0.05). The values of amniotic fluid index (p<0.001) and weight gained during pregnancy (p=0.017) were significantly different when compared among the three groups. The mean concentrations of adiponectin were 94.041 pg/mL in the IUGR group, 55.717 pg/mL in the IUGRcwPE group, and 51.831 pg/mL in the control group. Both of the differences between the IUGR and IUGRcwPE groups (p value; <0.05) and IUGR and control groups were statistically significant (p value; <0.001). However, there were no significant differences between the IUGRcwPE group and control group (p>0.05).

CONCLUSION

We found that IUGR increased maternal serum adiponectin concentrations; however, this rise does not occur in pregnant women with IUGRcwPE.