Serum Fatty Acid-binding Protein 4 Levels Research Articles

Correlation between the serum FABP4, ANGPTL3, and ANGPTL4 levels and coronary artery disease.

Lipid metabolism related factors, such as angiopoietin-like protein 3 (ANGPTL3), angiopoietin-like 4 (ANGPTL4), fatty acid-binding protein 4 (FABP4) are newly discovered factors that can affect coronary artery disease (CAD). In this study, we aimed to investigate the relationship between CAD and these lipid metabolism factors. ANGPTL3, ANGPTL4, and FABP4 may provide a new method for the control of CAD risk factors and the prevention and treatment of CAD. We enrolled 284 consecutive inpatients with suspected CAD and divided them into CAD and non-CAD groups based on the coronary angiography results. Serum ANGPTL3, ANGPTL4, FABP4, and tumor necrosis factor-α (TNF-α) levels were estimated using the enzyme-linked immunosorbent assay. Multivariate logistic regression was used to assess the risk factors for CAD. The receiver operating characteristic curve was used to determine the cutoff and diagnostic values. The serum TNF-α, FABP4, ANGPTL3, and ANGPTL4 values showed a significant difference between the CAD and non-CAD groups (p < .05). After adjusting for confounding factors, the FABP4, ANGPTL3, and ANGPTL4 levels were independently associated with CAD (p < .05). The ANGPTL3 expression level was an independent risk factor for CAD in patients with hypertension, but not in those without hypertension. The ANGPTL3 > 67.53 ng/mL, ANGPTL4 > 29.95 ng/mL, and FABP4 > 1421.25 ng/L combination had the highest diagnostic value for CAD. ANGPTL3, ANGPTL4, and FABP4 were identified as independent risk factors for CAD and have valuable clinical implications for the diagnosis and treatment of CAD.

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.

Maternal serum fatty acid binding protein-4 level is upregulated in fetal growth restriction with abnormal Doppler flow patterns.

This study aimed to determine fatty acid binding protein-4 (FABP-4) concentrations in maternal serum of fetal growth restriction (FGR) pregnancies and controls of normal pregnancies. Furthermore, we hypothesized that the alterations in FABP-4 levels might correlate with FGR severity. We performed this prospective case-control study with 83 pregnant women. The study groups included 26 FGR pregnancies without abnormal fetal Doppler flow patterns and 25 pregnancies complicated with FGR accompanied by abnormal fetal Doppler flow patterns. The median serum FABP-4 concentrations were significantly higher in the FGR cases with abnormal Doppler flow pattern group (2.09 ng/mL) than in the FGR cases without abnormal Doppler flow pattern group (1.62 ng/mL) and the control group (1.20 ng/mL, p < 0.001). A significant negative correlation was observed between maternal serum FABP-4 levels and time to birth from blood sample collection (r = -0.356 and p = 0.001), gestational week at birth (r = -0.386 and p < 0.001), and birth weight (r = -0.394 and p < 0.001). A 1.35 ng/mL cut-off value of serum FABP-4 level could be used to discriminate FGR cases with a 78.4% sensitivity and 60.6% specificity. The optimal cut-off value of FABP-4 levels as an indicator for the diagnosis of FGR with abnormal Doppler flow pattern was estimated to be 1.76 ng/mL, which yielded a sensitivity of 84.0% and a specificity of 75.8%. FABP-4 is a crucial biomarker in the diagnosis and determining the severity of pregnancies with restricted fetal growth. We consider that FABP-4 is a powerful, reliable, and unique biomarker to diagnose FGR pregnancies.

Elevated serum fatty acid-binding protein 4 level predicts all-cause and cardiovascular mortality in peritoneal dialysis patients: a five-year study

Background To explore the prospective role of serum fatty acid-binding protein 4 (FABP4) in the outcomes of peritoneal dialysis (PD) patients. Methods A prospective observational study was conducted with 159 patients on PD. Demographic and clinical data at baseline were collected from medical records. Biochemical data were recorded based on blood samples measured in a central laboratory. Serum FABP4 concentrations were determined using enzyme-linked immunosorbent assay. Body composition was measured using a Body Composition Monitor. Abdominal lateral plain radiography was used to evaluate vascular calcification. The primary endpoints were all-cause and cardiovascular death. Results The median of serum FABP4 concentration was 154.6 ng/mL (interquartile range, 132.8–269.7 ng/mL). Increased serum FABP4 was associated with increased vascular calcification proportion, time on dialysis, body mass index, high-sensitivity C-reactive protein (hs-CRP), intact parathyroid hormone (iPTH), triglycerides, body fat mass, and body fat percentage (p < 0.05). Increased serum FABP4 was associated with decreased residual kidney Kt/V urea (p < 0.05). Patients with hs-CRP≥ 3 mg/L had significantly higher serum FABP4 than those with hs-CRP< 3 mg/L (p < 0.05). Patients with vascular calcification had significantly higher serum FABP4 than those without vascular calcification (p < 0.05). During a median follow-up of 58.0 months, 58 all-cause deaths and 26 cardiovascular deaths occurred. High serum FABP4 levels were independently predictive for all-cause [hazard ratio (HR), 1.003; 95% confidence interval (CI), 1.001–1.005; p = 0.016] and cardiovascular death (HR, 1.005; 95% CI, 1.001–1.008; p = 0.006) in PD patients. Conclusions Increased serum FABP4 levels can independently predict all-cause and cardiovascular death in patients on PD.

Assessment of serum fatty acid-binding protein 4 and adiponectin levels in psoriasis patients and their correlation with disease severity

Background Psoriasis is a chronic multifactorial autoimmune disease that has significant impacts on the quality of life. Adiponectin exhibits important anti-inflammatory, antioxidants, and antidiabetic effects. The role of fatty acid-binding protein 4 (FABP4) in psoriasis may be linked to tumor necrosis factor-α, which is one of the main cytokines contributing to the etiopathogenesis of this disease. Aim To understand the role of serum levels of FABP4 and adiponectin in disease pathogenesis and their correlation to disease severity. Patients and methods A case–control study was conducted on two groups. The first group included 35 psoriatic patients; the second group included 35 healthy volunteers matched for age, sex, and weight. Serum FABP4 and adiponectin levels were evaluated. Results The mean level of adiponectin among the patients was 4.3±1.4 ng/dl. The mean level of FABP4 among controls was 2.1±1.5 ng/dl. The difference between both groups was statistically significant (P&lt;0.05). Conclusion In this study, serum FABP4 level and adiponectin levels were decreased in patients with psoriasis with no relation to disease severity. So, they cannot be used as clinical biomarkers of inflammation and disease activity in psoriasis

Fatty Acid-Binding Protein 4 in Patients with and without Diabetic Retinopathy.

BackgroundFatty acid-binding protein 4 (FABP4) has been demonstrated to be a predictor of early diabetic nephropathy. However, little is known about the relationship between FABP4 and diabetic retinopathy (DR). This study explored the value of FABP4 as a biomarker of DR in patients with type 2 diabetes mellitus (T2DM).MethodsA total of 238 subjects were enrolled, including 20 healthy controls and 218 T2DM patients. Serum FABP4 levels were measured using a sandwich enzyme-linked immunosorbent assay. The grade of DR was determined using fundus fluorescence angiography. Based on the international classification of DR, all T2DM patients were classified into the following three subgroups: non-DR group, non-proliferative diabetic retinopathy (NPDR) group, and proliferative diabetic retinopathy (PDR) group. Multivariate logistic regression analyses were employed to assess the correlation between FABP4 levels and DR severity.ResultsFABP4 correlated positively with DR severity (r=0.225, P=0.001). Receiver operating characteristic curve analysis was used to assess the diagnostic potential of FABP4 in identifying DR, with an area under the curve of 0.624 (37% sensitivity, 83.6% specificity) and an optimum cut-off value of 76.4 μg/L. Multivariate logistic regression model including FABP4 as a categorized binary variable using the cut-off value of 76.4 μg/L showed that the concentration of FABP4 above the cut-off value increased the risk of NPDR (odds ratio [OR], 3.231; 95% confidence interval [CI], 1.574 to 6.632; P=0.001) and PDR (OR, 3.689; 95% CI, 1.306 to 10.424; P=0.014).ConclusionFABP4 may be used as a serum biomarker for the diagnosis of DR.

Correlation between Serum Fatty Acid Binding Protein 4 (FABP4) Levels and Cardiac Function in Patients with Thalassemia Major.

Background Patients with thalassemia major may suffer from complications due to iron overload. It has been suggested that several adipokines may play a potential role in the development of complications in thalassemia. Fatty acid-binding protein 4 (FABP4) is one of the adipokines, bridging several aspects of metabolic and inflammatory pathways. Little is known about the relationship between this adipokine and cardiac and liver function, especially in patients with thalassemia major. Aims This study is aimed at determining serum FABP4 levels in patients with thalassemia major and whether its concentration correlated with serum ferritin levels, as well as cardiac and liver function. Methods Thalassemia major outpatients (n = 48) completed laboratory examination, echocardiography, and electrocardiography. Results The mean age was 21.9 ± 8.0 years. A negative and weak correlation between serum ferritin and FABP4 was observed (r = −0.291, p < 0.05). In addition, there was moderate and positive correlation between left atrial volume index (LAVI) and FABP4 (r = 0.316, p < 0.05). Conclusions Serum FABP4 correlated with serum ferritin and cardiac function in patients with thalassemia major. FABP4 may be a potential clinical biomarker for cardiac dysfunction via metabolic and inflammatory pathways due to iron accumulation and toxicity in patients with thalassemia major.

Relationship Between Fatty Acid Binding Protein 4 and Liver Fat in Individuals at Increased Cardiometabolic Risk.

Background: Liver steatosis is considered the onset of the non-alcoholic fatty liver disease (NAFLD), a major public health challenge. Nevertheless, NAFLD detection and diagnosis remain a difficult task. Fatty acid binding protein 4 (FABP4) has been proposed as potential biomarker for the ectopic fat accumulation in non-adipose tissues, although its role reflecting liver steatosis in metabolic patients is not fully explored. The aim of this study was to assess the relationship between FABP4 and the fatty liver index (FLI) in metabolic patients and to evaluate its potential role in the fatty liver disease.Methods: A cross-sectional study involving 389 participants at increased cardiometabolic risk was performed. FLI was calculated in order to assess liver fatty disease and a FLI ≥ 60 was considered to define liver steatosis. The serum FABP4 levels were assessed by using a sandwich enzyme-linked immunosorbent assay. Multivariable regression models were used to examine the associations of FABP4 with fatty liver after adjusting for demographic and clinical characteristics.Results: Both, FLI and serum FABP4 levels were upregulated in diabetic, obese, and metabolic syndrome patients. Serum FABP4 levels were higher in individuals with liver steatosis. Serum FABP4 were robustly associated with FLI in metabolic patients in both linear and logistic regression analyses.Conclusion: Our findings show that the serum FABP4 is associated to liver steatosis in metabolic patients.

Fatty acid-binding protein 4 circulating levels in non-segmental vitiligo

BackgroundVitiligo is an acquired and progressive mucocutaneous disease resulting from the loss of active epidermal melanocytes. Metabolic syndrome (MetS) affects about 25% of the world’s population and is linked to inflammatory skin diseases including vitiligo. Fatty Acid-Binding Protein 4 (FABP4) is an intracellular lipid chaperone. FABP4 is closely associated with MetS. ObjectivesTo evaluate the serum level of FABP4 in vitiligo patients and its relation to MetS in the investigated cases. MethodsThis case control study was conducted on 45 patients having non segmental vitiligo and 45 matched controls. Their lipid profile, blood glucose and serum FABP4 levels were measured. ResultsThere were significant elevations in FABP4 (p < 0.001), cholesterol (p < 0.001), triglycerides (p = 0.005), and glucose (fasting [p = 0.001] and 2 hours post prandial [p < 0.001]) levels in patients in comparison with controls. MetS was significantly more prevalent among vitiligo patients (p < 0.001) and associated with high FABP4 serum levels (p = 0.037). In vitiligo patients, there were significant positive correlations between FABP4 serum levels and triglycerides (p = 0.047), cholesterol (p = 0.001) and LDL (p = 0.001) levels and negative correlation regarding HDL level (p = 0.009). FABP4 level was a significantly good diagnostic test for early detection of vitiligo (p < 0.001). Study limitationsThe small number of studied subjects. ConclusionsFABP4 may play an active role in the disease process of vitiligo that could be mediated through associated dyslipidemia and hyperglycemia. FABP4 may be a marker of vitiligo helping in its early diagnosis, but it does not appear to be useful for determining vitiligo severity, activity or associated MetS.

Development of FABP4/5 inhibitors with potential therapeutic effect on type 2 Diabetes Mellitus.

Fatty acid-binding protein 4 (FABP4) and fatty acid-binding protein 5 (FABP5) are promising therapeutic targets for the treatment of various metabolic diseases. However, the weak potency, low selectivity over FABP3, or poor pharmacokinetic profiles of currently reported dual FABP4/5 inhibitors impeded further research. Here, we described the characterization of a series of dual FABP4/5 inhibitors with improved metabolic stabilities and physicochemical properties based on our previous studies. Among the compounds, D9 and E1 exhibited good inhibitory activities against FABP4/5 and favorable selectivity over FABP3 invitro. In cell-based assays, D9 and E1 exerted a decrease of FABP4 secretion, a strong anti-lipolytic effect in mature adipocytes, and suppression of MCP-1 expression in THP-1 macrophages. Moreover, D9 and E1 possessed good metabolic stabilities in mouse hepatic microsomes and acceptable pharmacokinetics profiles in ICR mice. Further invivo experiments showed that D9 and E1 could potently decrease serum FABP4 levels and ameliorate glucose metabolism disorders in obese diabetic db/db mice. These results demonstrated that D9 and E1 could serve as lead compounds for the development of novel anti-diabetic drugs.

P–389 The relationship between serum hormone profiles and missed abortion in humans

Abstract Study question Are circulating profiles of metabolic-related hormones also associated with the missed abortion (MA) in humans? Summary answer Serum levels of fatty acid-binding protein–4 (FABP4) and fibroblast growth factor 21 (FGF21) are positively associated with MA. What is known already A cluster of endocrine hormones, including FABP4, FGF21, adiponectin, lipocalin–2 (LCN2), exhibit pleiotropic effects on regulating systematic metabolism. Serum levels of them are associated with gestational obesity and diabetes and affect pregnancy outcomes, however, the relationship between their circulating profiles and MA is under-investigated. Study design, size, duration 78 patients with MA and 86 healthy pregnant subjects matching on maternal age and body mass index (BMI) were nested from a prospective cohort in the Chinese population. Participants/materials, setting, methods Fasting serum samples from all participants were collected to test their serum levels of FGF21, FABP4, adiponectin, and LCN2 by enzyme-linked immunosorbent assay method (ELISA). Main results and the role of chance There were no significant differences in circulating profiles of adiponectin and LCN2 between MA patients and healthy pregnant subjects. By contrast, circulating levels of FGF21 and FABP4 were significantly and independently elevated in patients with MA relative to control cases even after adjusting confounding factors (for FGF21: MA: 28.96 ± 2.17 ng/ml; HP: 19.18 ± 1.12 ng/ml, P &amp;lt; 0.001, for FABP4: MA: 152.50 ± 9.31 pg/ml; HP: 90.86 ± 4.14 pg/ml, P &amp;lt; 0.001). Linear regression analysis showed, FGF21 raised every 10 pg/ml contributed to a 24% (95% CI: 15% - 34%) increase in the risk of MA, whereas the OR of FABP4 for the risk of MA was 1.052 (95% CI: 1.022 –1.088). Furthermore, using serum FGF21 level or FABP4 levels discriminated MA from healthy controls with an area under the operating characteristic’s curve (AUROC) of 0.81 (95% CI 0.76–0.92) and 0.70 (95% CI 0.62 - 0.78), respectively. Limitations, reasons for caution The study is limited by the sample size. In addition, our results were based-on Chinese population, whether it could be observed in other ethics group remain to be investigated. Meanwhile, the cause-effect relationship between increased serum FGF21 level and MA remains to be explored. Wider implications of the findings: Our data would suggest that serum levels of FGF21 and FABP4 are associated with MA. Moreover, circulating FGF21 levels may serve as a potential diagnostic biomarker for the recognition of M. Trial registration number IRB Ref. No.: KY201913

Serum fatty acid-binding protein 4 levels and responses of pancreatic islet \u03b2-cells and \u03b1-cells in patients with type 2 diabetes

BackgroundSerum fatty acid-binding protein 4 (FABP4), as an intracellular lipid chaperone and adipokine, was reported to be related to the incidence of type 2 diabetes (T2D) and diabetic complications, but its association with pancreatic islet β-cell and α-cell functions has not been fully elucidated. So the present study was to investigate the serum FABP4 levels and responses of islet β-cells and α-cells in patients with T2D.Methods115 patients with T2D and 89 healthy controls (HC), who received serum FABP4 levels test, were recruited to participate in this study. Moreover, 75-g oral glucose tolerance test (OGTT) was performed in T2D patients to evaluate islet β-cell and α-cell functions. Systemic insulin sensitivity and overall insulin secretion of islet β-cell function were assessed by Matsuda index using C peptide (ISIM-cp) and ratio of the area under the C peptide curve to the glucose curve (AUCcp/glu) during OGTT, respectively. Fasting glucagon (Gluca0min) and postchallenge glucagon assessed by the area under the glucagon curve (AUCgluca) were determined during OGTT to evaluate islet α-cell function. And other various clinical variables were also measured in all participants. Skewed variables were natural log-transformed (ln), such as lnFABP4.ResultsThe serum FABP4 levels in T2D patients were significantly higher than those in HC (p < 0.05). And after partially adjusting for fasting plasma glucose, serum lnFABP4 levels were negatively correlated with lnISIM-cp (r = − 0.332, p < 0.001) and positively correlated with lnAUCcp/glu (r = 0.324, p < 0.001), lnGluca0min (r = 0.200, p = 0.040) and lnAUCgluca (r = 0.311, p < 0.001), respectively, in patients with T2D. Furthermore, when multiple linear regression analyses were applied to adjust for other various clinical variables, serum lnFABP4 levels were found to remain associated with lnISIM-cp (β = − 0.296, t = − 2.900, p = 0.005), lnAUCcp/glu (β = 0.223, t = 2.038, p = 0.046), lnGluca0min (β = 0.272, t = 2.330, p = 0.024) and lnAUCgluca (β = 0.341, t = 3.065, p = 0.004), respectively.ConclusionIncreased serum FABP4 levels were closely associated with blunted insulin sensitivity, increased insulin secretion, and elevated fasting and postchallenge glucagon levels in patients with T2D.

Circulating fatty-acid binding-protein 4 levels predict CV events in patients after coronary interventions

Fatty-acid binding protein-4 (FABP4) has been associated with the metabolic syndrome, diabetes mellitus, atherosclerosis, incident heart failure, and the prognosis of coronary heart disease (CHD). However, recent studies have not reported a significant correlation between FABP4 and cardiovascular (CV) mortality in high-risk patients or those with documented CHD. The present study aimed to evaluate the association between FABP4 and the prognosis in a cohort of patients with CHD who received coronary interventions. Serum FABP4 levels were measured in 973 patients after a successful intervention for CHD, who were then prospectively followed for 30 months. During this period, 223 patients experienced composite CV outcomes (22.92%), defined as cardiovascular/cerebrovascular death, nonfatal myocardial infarction (MI), nonfatal stroke, hospitalization for refractory or unstable angina, hospitalization for heart failure, and peripheral artery occlusive disease. Kaplan-Meier curves showed a significant association between FABP4 levels at baseline (categorized in tertiles) and composite CV outcomes during follow-up (log-rank test, p<0.003). The patients with the highest tertile of baseline FABP4 had an increased risk of composite CV outcomes (hazard ratio (HR) 1.662; 95% confidence interval (CI), 1.2-2.302; p=0.0022), which remained significant after multivariate adjustments for traditional risk factors and hs-CRP (HR 1.596; 95% CI, 1.088-2.342; p=0.0168). In contrast, FABP4 failed to show a significant association with cardiovascular/cerebrovascular death, nonfatal MI, or nonfatal stroke after multivariate adjustments (HR, 1.594; 95% CI, 0.651-3.904, p=0.3073). In conclusion, circulating FABP4 is an independent prognostic predictor for the composite cardiovascular events in the patients with stable CHD after coronary interventions.

Correlation of serum fatty acid binding protein-4 and interleukin-6 with airflow limitation and quality of life in stable and acute exacerbation of COPD

Background/aim The serum fatty acid binding protein 4 (FABP-4) level increases in chronic inflammatory diseases. The present study aimed to examine serum FABP-4 and interleukin (IL)-6 levels in patients with stable and acute exacerbation of chronic obstructive pulmonary disease (COPD) and the correlation of these markers with airflow limitation.Materials and methods We measured serum FABP-4 and IL-6 levels in 60 COPD patients [30 stable COPD (SCOPD), and 30 acute exacerbation of COPD (AECOPD)], and 30 healthy subjects and compared them with airflow limitation according to the COPD stage in the Global Initiative for Chronic Obstructive Pulmonary Disease (GOLD) criteria, peripheral O2 saturation (SpO2), and COPD Assessment Test (CAT) score. We also tested the association between serum FABP-4 levels and some characteristics of study parameters. Results Both serum FABP-4 and IL-6 levels increased with increasing severity of GOLD grades in SCOPD (P < 0.01 for both) and AECOPD groups (P < 0.001 and P < 0.01, respectively). It also increased in patients with AECOPD group compared with SCOPD group in GOLD grades I-II (P < 0.01) and GOLD grades III-IV (P < 0.05). In addition, there was a significant positive correlation between serum FABP-4 level with IL-6, CAT score, and smoking history and inversely with FEV1 and SpO2. Conclusion The study revealed that serum FABP-4 level was elevated with increasing GOLD grades in COPD patients, markedly in acute exacerbation phase. The increase was associated with elevated serum levels of IL-6 and severity of hypoxia. Thus, it seems that FABP-4 may be involved in the pathogenesis of COPD.

FABP4 levels in hypothyroidism and its relationship with subclinical atherosclerosis

Background/aimThe aim of this study is to evaluate the relationship between serum fatty acid binding protein 4 (FABP4) levels and carotid intima media thickness (CIMT) in patients with hypothyroidism.Materials and methodsForty subclinical hypothyroidism patients, 40 overt hypothyroidism patients, and 40 healthy controls were enrolled in the study. Blood pressure, body mass index, CIMT, fasting blood sugar, creatine, alanine aminotransferase, lipid parameters, insulin, free thyroxine, triiodothyronine, thyroid-stimulating hormone (TSH), thyroid peroxidase antibody (anti-TPO), thyroglobulin antibody (anti-TG), high-sensitivity C-reactive protein (Hs-CRP), and FABP4 levels of all participants were measured.ResultsSerum FABP4 levels were significantly higher in patients with subclinical and overt hypothyroidism than healthy controls (HCs) (P = 0.044 and P = 0.014, respectively). There was no significant difference in terms of FABP4 levels between patients with subclinical and overt hypothyroidism (P = 0.641). Serum TSH levels and serum FABP4 levels were positively correlated (r = 0.201, P = 0.039). CIMT was found to be higher in patients with subclinical and overt hypothyroidism than in HCs (P = 0.042 and P < 0.001, respectively). No correlation was found between CIMT and FABP4 levels (r = 0.038, P = 0.702). There was a positive correlation between CIMT and TSH, anti-TPO, anti-TG, triglycerides (TG), and total cholesterol levels. It was found that high TG levels were an independent factor that increased CIMT (r = 0.382, r2 = 0.146).ConclusionIn patients with subclinical and overt hypothyroidism, the level of FABP4 increases and this increase is correlated with the increase in TSH level. It is thought that FABP4 does not play a role in atherosclerosis development in patients with hypothyroidism without metabolic disorder.

Periodontal Pathogens Modulate Lipid Flux via Fatty Acid Binding Protein 4

A strong correlation between chronic periodontitis and systemic diseases (e.g., cardiovascular disease, metabolic disorders) has been suggested for several decades. However, the evidence supporting this correlation is restricted primarily to epidemiologic studies, with only a few experimental outcomes confirming such a correlation and providing information about the underlying molecular mechanisms. To reveal a correlation between periodontitis and systemic diseases as well as a relevant molecular pathway, we investigated the effects of Porphyromonas gingivalis and Fusobacterium nucleatum, which play roles in chronic periodontitis progression, on Raw264.7 and THP-1 macrophages. Infection with P. gingivalis or F. nucleatum significantly induced the expression of fatty acid binding protein 4 (FABP4), one of the most important adipokines that play a role in the progression of systemic diseases such as atherosclerosis and type 2 diabetes. Periodontal pathogen–induced FABP4 expression in macrophages promoted lipid uptake by these cells, as demonstrated by the diminished lipid accumulation in cells treated with an FABP4 inhibitor, BMS309403, or with knockdown of FABP4 expression. This periodontal pathogen–induced FABP4 expression was dependent on the JNK pathway, and JNK inhibition reduced lipid uptake by reducing FABP4 expression. Serum levels of antibodies against P. gingivalis correlated with serum FABP4 levels in humans, whereas no association occurred between F. nucleatum antibody titers and FABP4 levels. To our knowledge, this report is the first to experimentally demonstrate that periodontal pathogens stimulate lipid uptake in macrophages by modulating FABP4 expression. These findings strongly support the hypothesis that periodontitis may affect the progression of various systemic diseases.

Unconventional Secretion of Adipocyte Fatty Acid Binding Protein 4 Is Mediated By Autophagic Proteins in a Sirtuin-1-Dependent Manner.

Fatty acid binding protein 4 (FABP4) is a leaderless lipid carrier protein primarily expressed by adipocytes and macrophages that not only functions intracellularly but is also secreted. The secretion is mediated via unconventional mechanism(s), and in a variety of species, metabolic dysfunction is correlated with elevated circulating FABP4 levels. In diabetic animals, neutralizing antibodies targeting serum FABP4 increase insulin sensitivity and attenuate hepatic glucose output, suggesting the functional importance of circulating FABP4. Using animal and cell-based models, we show that FABP4 is secreted from white, but not brown, adipose tissue in response to lipolytic stimulation in a sirtuin-1 (SIRT1)-dependent manner via a mechanism that requires some, but not all, autophagic components. Silencing of early autophagic genes such as Ulk1/2, Fip200, or Beclin-1 or chemical inhibition of ULK1/2 or VPS34 attenuated secretion, while Atg5 knockdown potentiated FABP4 release. Genetic knockout of Sirt1 diminished secretion, and serum FABP4 levels were undetectable in Sirt1 knockout mice. In addition, blocking SIRT1 by EX527 attenuated secretion while activating SIRT1 by resveratrol-potentiated secretion. These studies suggest that FABP4 secretion from adipocytes is regulated by SIRT1 and requires early autophagic components.

Cord blood fatty acid-binding protein-4 levels are upregulated at both ends of the birthweight spectrum.

Fatty acid-binding protein-4 (FABP4) is an adipokine associated with obesity and signs of the metabolic syndrome. We aimed to investigate at birth in term neonates with normal and abnormal intrauterine growth concentrations of FABP4 and associate them with various perinatal parameters. Serum cord blood FABP4 levels were prospectively determined by ELISA in 80 singleton term appropriate-for-gestational-age (AGA), intrauterine growth-restricted (IUGR) and large-for-gestational-age (LGA) neonates. Compared to the AGA group, cord blood FABP4 levels were increased in the IUGR and LGA groups. Additionally, they were higher in early-term than full-term neonates. A significant U-shaped correlation was recorded between serum FABP4 levels and birthweight. A significant negative correlation between cord blood FABP4 and gestational age in the whole study population was noted. Cord blood FABP4 levels were significantly higher at the extremes of foetal growth at term and negatively correlated with gestational age, being increased in early-term versus full-term neonates. Further longitudinal studies with larger sample sizes are required to elucidate FABP4 implication in foetal growth and its association with future adverse cardiometabolic outcomes in the offspring.

Vaspin in Serum and Urine of Post-Partum Women with Excessive Gestational Weight Gain.

Background and objectives: Data concerning vaspin in obstetric aspects are limited and conflicting. The aim of the study was to evaluate vaspin concentrations in the serum and urine of women with excessive gestational weight gain (EGWG) in the early post-partum period (i.e., 48 h after delivery), when placental function no longer influences the results. Materials and Methods: The study subjects were divided into two groups of 28 healthy controls and 38 mothers with EGWG. Maternal body composition and hydration status were evaluated by the bioelectrical impedance analysis (BIA) method. Concentrations of vaspin, fatty acid-binding protein 4 (FABP4), leptin, and ghrelin were determined via enzyme-linked immunosorbent assay (ELISA). Results: Serum vaspin levels were lower in the EGWG group, whereas no significant differences were noted between the groups, with regard to the urine vaspin concentrations. In both studied groups, the serum vaspin concentrations correlated positively with the urine FABP4 levels and negatively with gestational weight gain, body mass index gain in the period from pre-pregnancy to 48 h after delivery (ΔBMI), and fat tissue index (FTI). In the multiple linear regression models, the serum vaspin concentrations were positively dependent on the serum FABP4 levels, as well as negatively dependent on triglycerides, FTI, and ΔBMI. Conclusions: Our study revealed that the EGWG mothers were characterized by significantly lower serum vaspin concentrations in the early post-partum period compared with the subjects that had appropriate gestational weight gain. Our observation supports previous hypotheses that vaspin might be used as a marker of lipid metabolism in pregnancy and maternal adipose tissue. Considering the fact that FABP4 is widely referred to as a pro-inflammatory adipokine, further research on the protective role of vaspin seems crucial, especially in the context of its relationship to FABP4.

FABP4 in Gestational Diabetes-Association between Mothers and Offspring.

Fetuses exposed to gestational diabetes mellitus (GDM) have a higher risk of abnormal glucose homeostasis in later life. The molecular mechanisms of this phenomenon are still not fully understood. Fatty acid binding protein 4 (FABP4) appears to be one of the most probable candidates involved in the pathophysiology of GDM. The main aim of the study was to investigate whether umbilical cord serum FABP4 concentrations are altered in term neonates born to GDM mothers. Two groups of subjects were selected—28 healthy controls and 26 patients with GDM. FABP4, leptin, and ghrelin concentrations in the umbilical cord serum, maternal serum, and maternal urine were determined via an enzyme-linked immunosorbent assay. The umbilical cord serum FABP4 levels were higher in the GDM offspring and were directly associated with the maternal serum FABP4 and leptin levels, as well as the prepregnancy body mass index (BMI) and the BMI at and after delivery; however, they correlated negatively with birth weight and lipid parameters. In the multiple linear regression models, the umbilical cord serum FABP4 concentrations depended positively on the maternal serum FABP4 and negatively on the umbilical cord serum ghrelin levels and the high-density lipoprotein cholesterol. There are many maternal variables that can affect the level of FABP4 in the umbilical cord serum, thus, their evaluation requires further investigation.