Pathophysiological Insight into Fatty Acid-Binding Protein-4: Multifaced Roles in Reproduction, Pregnancy, and Offspring Health

Serum fatty acid binding protein 4 and Doppler of uterine artery ultrasound in the first trimester for the prediction of preeclampsia

The objective of this study was to determine the predictive value of serum fatty acid binding protein 4 (FABP4) combined with Doppler of the uterine artery in singleton pregnancy at gestational age (GA) 11-13+6 weeks for prediction of preeclampsia. A prospective observational study included singleton pregnant women at GA 11-13+6 weeks and was conducted at the Department of Obstetrics and Gynecology, Faculty of Medicine, Chulalongkorn University, Bangkok, Thailand, between December 2020 and April 2022. Serum FABP4 levels and Doppler of the uterine artery were performed. Pregnancy outcomes were recorded. The predictive values of these combined tests at the optimal cut-off values were determined to predict preeclampsia. A total of 330 participants with 15 cases of preeclampsia (4.5%) and 6 cases of them had preterm preeclampsia (GA < 37 weeks) (1.8%) were analyzed. Women with preeclampsia had significantly higher serum FABP4 levels than normal pregnant women (12.9 ± 6.5 ng/ml vs 10.1 ± 4.8 ng/ml, p = 0.034) but no difference in the mean pulsatility index (PI) of the uterine artery and the presence of an early diastolic notch. When using serum FABP4 levels greater than 1.0 multiple of the median of GA as a cut-off value to predict preeclampsia, combined with abnormal Doppler PI of the uterine artery, the sensitivity, specificity, positive predictive value, and negative predictive value were 73.3%, 47.3%, 6.2%, and 97.4%, respectively. This study demonstrated that serum FABP4 levels combined with Doppler of the uterine artery at GA 11-13+6 weeks were effective in predicting preeclampsia.

Investigating the Role of FABP4 in Diabetes and Obesity and the Influence of Age and Ethnicity: A Comprehensive Analysis of a Cohort from the KEDP-Study

Adipocyte P2 (aP2), also known as FABP4, is an adipokine that adipose tissue produces and expresses in macrophages. Its primary role is to facilitate the transportation of fatty acids across cell membranes. Numerous studies have reported associations between FABP4 and the development of metabolic disorders. However, there is limited knowledge regarding FABP4 expression in diabetes and obesity, especially about different age groups, genders, and ethnicities. This study aims to investigate the association between FABP4 levels, diabetes mellitus, and obesity within various ethnic groups. We measured plasma FABP4 concentrations in a cohort of 2083 patients from the KDEP study and gathered anthropometric data. Additionally, we collected and analyzed clinical, biochemical, and glycemic markers using multivariate regression analysis. The average FABP4 concentration was significantly higher in female participants than in males (18.8 ng/mL vs. 14.4 ng/mL, p < 0.001, respectively), and in those over 50 years old compared to those under 50 years of age (19.3 ng/mL vs. 16.2 ng/mL, p < 0.001, respectively). In this study, significant positive associations were found between the plasma level of FABP4 and obesity markers: BMI (r = 0.496, p < 0.001), hip circumference (r = 0.463, p < 0.001), and waist circumference (WC) (r = 0.436, p < 0.001). Similar observations were also seen with glycemic markers, which included HbA1c (r = 0.126, p < 0.001), fasting blood glucose (FBG) (r = 0.184, p < 0.001), fasting insulin (r = 0.326, p < 0.001), and HOMA-IR (r = 0.333, p < 0.001). Importantly, these associations remained significant even after adjusting for age, gender, and ethnicity. Furthermore, FABP4 levels were negatively associated with male gender (β: -3.85, 95% CI: -4.92, -2.77, p < 0.001), and positively associated with age (β: 0.14, 95% CI: 0.096, 0.183, p < 0.001), BMI (β: 0.74, 95% CI: 0.644, 0.836, p < 0.001), and fasting insulin (β: 0.115, 95% CI: 0.091, 0.138, p < 0.001). In this study, plasma FABP4 levels were significantly higher in diabetic and obese participants, and they were strongly influenced by age, gender, and ethnicity. These findings suggest that FABP4 may serve as a valuable prognostic and diagnostic marker for obesity and diabetes, particularly among female patients, individuals over 50 years old, and specific ethnic groups.