Decreased Adiponectin Levels in Early Pregnancy Are Associated with High Risk of Prematurity for African American Women

The relationship of low maternal serum adiponectin levels with preterm delivery among a multi-ethnic group has not been extensively investigated. We examined ethnic differences in cytokine/adipokine profiles and whether they contribute to several adverse pregnancy outcomes, particularly preterm delivery. Data and samples were from a large prospective observational cohort (n = 1776) of young, generally healthy pregnant women (African American 36.4%, Hispanic 48.0%, Caucasian 15.6%). Serum cytokine/adipokine concentrations were measured at entry (mean gestational age of 16.83 weeks) using the Liminex xMap Technology. Multivariable analyses were performed. A significant difference in adiponectin level was observed among ethnic groups. African Americans had a decreased adiponectin and increased resistin levels compared to Hispanics and Caucasians (p < 0.05 to p < 0.0001 for each). Decreased adiponectin (lowest quartile) was positively associated with preterm delivery independent of usual risk factors (adjusted odds ratio (AOR) 1.46, 95% confidence interval (CI) 1.05, 2.04 for all preterm and AOR 1.84, 95% CI 1.07, 3.17 for early preterm births). The results were unchanged when women with preeclampsia were excluded. Similar results were observed in African Americans. Decreased adiponectin levels were not related to preterm birth in either Hispanics or Caucasians. Lower adiponectin levels were also significantly associated with an increased risk of developing gestational diabetes (AOR 1.72, 95% CI 1.05, 2.84) and preeclampsia (AOR 1.45, 95% CI 1.00, 2.14) in the whole cohort and in Caucasians. We did not find any consistent relationships between the other markers with outcome variables. Dysregulation in maternal adiponectin at early gestation is associated with an increased risk of preterm delivery. An ethnic difference in adiponectin levels may contribute to a higher preterm delivery rate in African American women.

Individual free fatty acids have unique associations with inflammatory biomarkers, insulin resistance and insulin secretion in healthy and gestational diabetic pregnant women

OBJECTIVE

We investigated the relationships of maternal circulating individual free fatty acids (FFA) with insulin resistance, insulin secretion and inflammatory biomarkers during mid-pregnancy.

RESEARCH DESIGN AND METHODS

The data were drawn from a prospective cohort of generally healthy pregnant women (n=1368, African-American 36%, Hispanic 48%, Caucasian 16%) in Camden, NJ. We quantitatively determined 11 FFAs, seven cytokine/adipokine, homeostatic model assessment of insulin resistance (HOMA-IR) and C-peptide levels from the fasting blood samples that were collected at 16 weeks of gestation. Multivariate analyses were performed along with separate analyses for each individual FFA.

RESULTS

High HOMA-IR (p<0.001) and C-peptide (p<0.0001) levels were positively associated with a twofold to fourfold increased risk for developing gestational diabetes mellitus (GDM). Negative relationships were found with specific FFAs (molecular percentage, palmitoleic, oleic, linolenic, myristic acids) and HOMA-IR and C-peptide levels (p<0.01 to p<0.0001). In contrast, palmitic, stearic, arachidonic, dihomo-γ-linolenic (DGLA) and docosahexaenoic acids were positively associated with HOMA-IR and C-peptide (p<0.01 to p<0.0001). The individual FFAs also predicted cytokine/adipokine levels. For example, women who had elevated DGLA (highest quartile) were twice as (adjusted OR 2.06, 95% CI 1.42 to 2.98) likely to have higher interleukin (IL)-8 (p<0.0001) levels. Conversely, women with high palmitoleic, oleic, and linolenic acid levels had reduced odds (≥2-fold, p<0.01 to p<0.001) for having higher IL-8, IL-6 or tumor necrosis factor-alpha levels.

CONCLUSION

Our results suggest that maternal individual FFAs uniquely affect insulin resistance and secretion. The effects are either direct or indirect via modulation of the inflammatory response. Modifying the composition of FFAs may help in reducing the risk of GDM.

Ethnic Differences in Maternal Adipokines during Normal Pregnancy

Two adipokines (adiponectin and resistin) have opposite relations with insulin resistance and inflammation. Our major focus was to determine whether there were detectable ethnic differences in maternal adipokines during pregnancy. We also explored the correlation of the adipokines with maternal glucose homeostasis, blood pressure and anthropometric parameters. Pregnant women (n = 1634) were from a large prospective cohort study in Camden NJ (African-American 36.8%; Hispanic 47.6%; Caucasian 15.6%). Serum adiponectin and resistin were measured at entry (week 16.8) and the 3rd trimester (week 30.7) using the Luminex xMapTechnology. Significant differences were observed among ethnic groups, controlling for confounding variables. African American women were exceptional in that they had decreased adiponectin and increased resistin throughout the course of pregnancy (p < 0.05 to p < 0.0001) and a greater than two fold risk of simultaneously exhibiting low adiponectin (lowest tertile) and high resistin (highest tertile) compared to Caucasians and/or Hispanics. The cohort as a whole and each ethnic group showed similar negative correlations between adiponectin, and glucose homeostasis, blood pressure and anthropometric parameters but there was lesser correspondence with resistin. Our data underscore the need for further research on ethnic variation in adipokines and other physiologic biomarkers during complicated and uncomplicated pregnancy.