Afamin serum concentrations are associated with insulin resistance and metabolic syndrome in polycystic ovary syndrome

Comparison of Afamin Values in Umbilical Cord Blood After Delivery in Pregnancies With and Without Gestational Diabetes Mellitus

OBJECTIVE

Afamin is a protein that increases in gestational diabetes but its concentration in neonates hasn't been investigated. Our objective is to compare cord blood afamin levels in neonates born to mothers with and without diabetes, and to explore its relationship with maternal and neonatal variables.

METHODS

In this case control study, umbilical cord blood was collected for afamin measurement in pregestational/gestational diabetic pregnancies (n = 40) and healthy pregnancies (n = 45) after delivery. Correlation analysis was conducted to examine the relationship between afamin levels and maternal BMI, age, HbA1c, fasting and postprandial blood glucose, gestational age, birth weight.

RESULTS

The diabetic group had a higher median afamin level (p < 0.001). Afamin concentrations did not differ significantly between diabetic subgroups. The concentration of afamin in cord blood was independent of maternal BMI, age, HbA1c, blood glucose, gestational age, birth weight.

CONCLUSION

The concentration of afamin in cord blood of diabetic pregnancies is significantly higher, irrespective of other clinical factors.

Serum afamin and its implications in adult growth hormone deficiency: a prospective GH-withdrawal study

Introduction

Adult growth hormone deficiency (AGHD) is associated with a high prevalence of metabolic syndrome (MS), which contributes to the unfavorable cardiovascular risk profile in these patients. Insulin like growth factor-1 (IGF-1) is a widely used biomarker, however it does not always reflect the cardiometabolic risk and has a poor relationship with clinical efficacy endpoints. Consequently, there is an unmet need for biomarkers to monitor responses to GH-replacement. Afamin is a hormone-like glycoprotein, expressed in the liver. Higher afamin levels are strongly associated with MS and insulin resistance (IR). Although both MS and IR are very common in AGHD, afamin has not been investigated in these patients.

Purpose

To investigate afamin as a potential biomarker in patients with AGHD.

Materials and methods

Participants included 20 AGHD patients (11 GH-substituted and 9 GH-unsubstituted) and 37 healthy controls. Subjects underwent routine laboratory examinations, anthropometric measurements, body composition analysis using multi-frequency bioelectrical impedance analysis (InBody720) and measurement of serum afamin concentrations. In GH-substituted subjects, GH-substitution was withdrawn for 2 months. Measurements were carried out right before GH-withdrawal, at the end of the 2-month withdrawal period, and 1 month after reinstituting GH-replacement therapy (GHRT).

Results

GH-unsubstituted patients demonstrated higher afamin levels compared to controls (p=0.03). Afamin positively correlated with skeletal muscle mass, bone mineral content, total body water, extracellular- and intracellular water content, insulin (all, p<0.01), HOMA-IR (p=0.01) and C-peptide (p=0.03) levels in AGHD but not in healthy controls. In GH-substituted patients 2-month of GH-withdrawal caused significant changes in body composition, including decreased fat-free mass, skeletal muscle mass, total body water, and intracellular water content (all, p<0.01); but these changes almost fully recovered 1 month after reinstituting GHRT. Unexpectedly, afamin levels decreased after GH-withdrawal (p=0.03) and increased with reinstitution (p<0.01). Changes of afamin levels during GH-withdrawal positively correlated with changes of HOMA-IR (r=0.80; p<0.01) and changes of insulin (r=0.71; p=0.02).

Conclusion

Higher afamin levels in unsubstituted AGHD patients might indicate severe metabolic dysregulation. Significant changes accompanying GH-withdrawal and reinstitution, along with strong correlations with measures of IR, suggest that afamin could be a promising biomarker to monitor GHRT-associated changes of insulin sensitivity.

Association of insulin resistance with polycystic ovary syndrome phenotypes and patients' characteristics: a cross-sectional study in Iran

BACKGROUND

Polycystic ovary syndrome (PCOS) is the most common endocrine disorder in women. This disorder affects 6-15% of women of childbearing age worldwide. It is diagnosed with hyperandrogenism, polycystic ovaries, and chronic anovulation with insulin resistance. This study aimed to assess the prevalence of insulin resistance (IR) in 4 phenotypes of PCOS, and its relationship with demographic, clinical, and paraclinical individual characteristics in a sample of Iranian PCOS patients.

METHODS

This particular cross-sectional investigation involved 160 female participants, aged between 18 and 45 years, who were receiving care at gynecology clinics in Urmia, northwestern Iran. All the participants had been diagnosed with PCOS and were categorized into one of four phenotypes. All the participants underwent clinical evaluations, paraclinical assessments, and ultrasound scans. IR was defined as HOMA-IR > 2.5. The statistical significance level was 0.05.

RESULTS

Among the 160 participants, the prevalences of the 4 phenotypes were: A: 83 (51.9%), B: 37 (23.1%), C: 21 (13.1%), and D: 19 (11.9%). IR was detected in 119 participants (74.4%); its rate was significantly different between the 4 phenotypes (p-value: 0.008) as A: 62 (74.7%), B: 34 (91.9%), C: 12 (57.1%), D: 11 (57.9%). Linear and logistic regression analyses were performed to control confounding factors. In linear regression, PCOS phenotype, classic phenotype (A&B), economic status, and Hb levels were significantly related to HOMA-IR; in logistic regression Hb levels, exercise, economic status, and PCOS phenotypes were significantly associated with insulin resistance.

CONCLUSIONS

The most prevalent PCOS phenotype in this study was A. PCOS phenotypes were significantly related to insulin resistance and HOMA-IR, with the highest levels of insulin resistance and HOMA-IR observed in phenotype B. Determining the phenotype of PCOS may be helpful for better management of PCOS and its associated complications. However, further investigations are recommended in this regard.

Serum afamin levels in predicting gestational diabetes mellitus and preeclampsia: A systematic review and meta-analysis

OBJECTIVES

The association between biomarkers and the risk of gestational diabetes mellitus (GDM) or preeclampsia (PE) has been extensively studied. However, there is still a lack of convenient, specific, and sensitive indicators for early identification of GMD and PE. Therefore, we conducted a meta-analysis of published articles to investigate the value of afamin circulating levels in the early diagnosis of GDM and PE.

METHODS

We searched the PubMed, Embase, Cochrane Library, and Web of Science databases for English studies published before November 16, 2022, that examined the association between afamin and GDM or PE. In addition, we searched Clinicaltrials.gov for the relevant completed and ongoing clinical trials. Pooled standard mean differences (SMDs) and weighted mean differences (WMDs) with 95% confidence intervals (CIs) were used to compare the levels of afamin in different groups.

RESULTS

Eleven studies were included in our analysis (N = 3047 participants: 1195 GDM, 1407 non-GDM, 195 PE, and 250 non-PE). Subgroup analysis based on different blood collection periods found that the plasma afamin levels in pregnant women with GDM in the first trimester were significantly higher than those in healthy pregnant women (SMD = 0.481, 95% CI: 0.280-0.682), but the analysis showed the opposite results in the second and late stages (SMD = 0.292, 95% CI: -0.092-0.676). The plasma afamin levels of pregnant women with PE in the first trimester (SMD = 0.808, 95% CI: 0.558-1.059) and second/third trimesters (SMD = 0.904, 95% CI: 0.570-1.239) were significantly higher than those in healthy pregnant women.

CONCLUSION

The plasma afamin levels in pregnant women with GDM in the first trimester were significantly higher than those in healthy pregnant women, but the analysis showed the opposite results in the second and third trimesters. The plasma afamin levels in pregnant women with PE in the first, second, and third trimesters were significantly higher than those in healthy pregnant women. Additional large-scale prospective studies are desired to verify these findings, and it is recommended that afamin should be included as a routine diagnostic test for women with GDM and PE.

SYSTEMATIC REVIEW REGISTRATION

https://www.crd.york.ac.uk/PROSPERO/display_record.php?RecordID=339171, identifier CRD42022339171.

Association Between Serum Afamin Levels with Nonalcoholic Associated Fatty Liver Disease

Afamin is a member of the hepatokine that are strongly associated with various metabolic diseases. The relationship between afamin and nonalcoholic fatty liver disease (NAFLD) remains unclear. This study aimed to explore the correlation between serum afamin levels and NAFLD. We analyzed 88 NAFLD patients and 88 age- and sex-matched healthy controls who took their health examinations at the First Affiliated Hospital, Zhejiang University School of Medicine. The association was further confirmed in 22 biopsy-confirmed NAFLD patients and 36 healthy controls. Serum afamin levels were evaluated using an enzyme-linked immunosorbent assay (ELISA). NAFLD patients had significantly higher serum afamin levels than the healthy controls (14.79 ± 5.04 mg/L versus 10.83 ± 3.24 mg/L; P < 0.001). Serum afamin levels were positively correlated with metabolic parameters including the body mass index, waist circumference, systolic blood pressure, liver enzymes, and lipid profiles. A multiple regression analysis showed that serum afamin levels were independently related to the risk of NAFLD (OR: 1.289, 95% CI, 1.141-1.456; P < 0.001). The receiver operating characteristic (ROC) analysis showed that the area under curve (AUC) of serum afamin plus the BMI for detecting NAFLD was 0.878. In participants with liver biopsies, the serum afamin plus the BMI detected NAFLD with an AUC of 0.758. In conclusion, serum afamin levels were positively associated with prevalence and risk of NAFLD, and serum afamin plus the BMI had a high diagnostic performance for NAFLD. This study provides epidemiological evidence of afamin in NAFLD.

Afamin predicts the prevalence and incidence of nonalcoholic fatty liver disease

OBJECTIVES

In the general population, increased afamin concentrations are associated with the prevalence and incidence of metabolic syndrome as well as type 2 diabetes. Although metabolic syndrome is commonly associated with nonalcoholic fatty liver disease (NAFLD), there exist no information on afamin and NAFLD.

METHODS

Afamin concentrations were cross-sectionally measured in 146 Austrian patients with NAFLD, in 45 patients without NAFLD, and in 292 age- and sex-matched healthy controls. Furthermore, the feasibility of afamin to predict incident NAFLD was evaluated in 1,434 adult participants in the population-based Cardiovascular Risk in Young Finns Study during a 10-year follow-up.

RESULTS

Median afamin concentrations were significantly higher in NAFLD patients (83.6 mg/L) than in patients without NAFLD (61.6 mg/L, p<0.0001) or in healthy controls (63.9 mg/L, p<0.0001). In age- and sex-adjusted logistic regression analyses a 10 mg/L increase of afamin was associated with a 1.5-fold increase of having NAFLD as compared with patients without NAFLD and the risk was even two-fold when compared with healthy controls. In the population-based cohort, afamin concentrations at baseline were significantly lower in participants without NAFLD (n=1,195) than in 239 participants who developed NAFLD (56.5 vs. 66.9 mg/L, p<0.0001) during the 10-year follow up, with highest afamin values observed in individuals developing severe forms of NAFLD. After adjustment for several potentially confounding parameters, afamin remained an independent predictor for the development of NAFLD (OR=1.37 [95% CI 1.23-1.54] per 10 mg/L increase, p<0.0001).

CONCLUSIONS

Afamin concentrations are increased in patients with NAFLD and independently predict the development of NAFLD in a population-based cohort.

The Clinical Values of Afamin, Triglyceride and PLR in Predicting Risk of Gestational Diabetes During Early Pregnancy

Objective

To establish a model to predict gestational diabetes mellitus (GDM) based on the clinical characteristics, early pregnancy (10-12 weeks gestation) peripheral blood routine, and biochemical indicators, and to explore its predictive efficiencies.

Methods

Data from 607 pregnant women with GDM were compared to the data from 833 pregnant women without GDM admitted to the Obstetrics Department of Fujian Maternity and Child Health Hospital (affiliated to Fujian Medical University) from May 2018 to December 2018 were retrospectively included. The ages of the pregnant women, paternal ages, number of pregnancies, number of deliveries, pre-pregnancy heights/weights, and the calculated body mass indexes (BMI) were recorded. In all participants, 10-12 weeks of pregnancy, afamin concentration, routine blood work, prenatal aneuploidy screening, and biochemical testing were performed. At weeks 24-28 of gestation, patients underwent oral glucose tolerance test (OGTT) for GDM screening.

Results

Multivariate logistic regression analysis showed that maternal age, early pregnancy afamin level, triglycerides, and platelet/lymphocyte ratio (PLR) were independent risk factors for gestational diabetes. The formula for predicting GDM probability was as follows: P = 1/1 + exp( - 6.054 + 0.774 × triglycerides + 0.002 × afamin + 0.155 × age - 0.012 × PLR)]. From the established ROC curve, the area under the curve (AUC) was 0.748, indicating that the model has a good degree of discrimination. When the predictive probability cut-off value was set on 0.358, sensitivity, specificity, positive predictive value, and negative predictive value were 69.2%, 68.3%, 42.5%, and 86.2%, respectively, and the accuracy rate was 70.2%. The Hosmer-Lemeshow test results showed that the goodness of the model fit has a good calibration ability (χ2 = 12.269, df=8, P=0.140).

Conclusions

Maternal age, early pregnancy afamin level, triglycerides, and PLR are independent risk factors for gestational diabetes. When combined, the above indicators are helpful for prediction, early diagnosis, and intervention of gestational diabetes.

Comparison of serum human Klotho levels and thiol/disulfide homeostasis in women with polycystic ovary syndrome and in healthy women

OBJECTIVES

Women with polycystic ovary syndrome (PCOS) have an increased cardiometabolic risk. Similarly, it was previously shown that atherosclerotic and cardiovascular risk is increased in the general population with lower serum Klotho levels. The aim of this study was to investigate the lotho and thiol/disulfide levels in women with non-obese PCOS compared to healthy controls and also to investigate the relationship of serum Klotho and thiol/disulfide homeostasis with cardiometabolic risk factors.

MATERIALS AND METHODS

In this prospective case control study, human serum alpha Klotho levels and thiol/disulfide homeostasis of women with PCOS aged between 19-33 were compared to their age and BMI matched non - PCOS healthy controls. In addition, the correlation of these molecules with other metabolic markers/measurements were also investigated.

RESULTS

Metabolic parameters such as mean waist circumference, lipid accumulation product, visceral adiposity index, fasting insulin, homeostasis model assessment of insulin resistance and triglyceride values were higher in the PCOS group (p = 0.038, p = 0.008, p = 0.001, p = 0.001, p = 0.002 and p = 0.002, respectively) compared to controls. However, mean serum Klotho and native thiol levels (respectively p < 0.0001 and p = 0.038) were lower compared to controls. Correlation analysis revealed that serum Klotho levels were negatively correlated with BMI, waist circumference, disulphide/total thiol, disulphide/native thiol, HOMA-IR and LAP-index.

CONCLUSIONS

Findings of decreased serum Klotho and native thiol values of the PCOS group compared to controls and the negative correlation of serum Klotho levels with metabolic markers supports the idea that decreased Klotho may be another mechanism by which cardiovascular risk is increased in women with PCOS.

The Physiological Roles of Vitamin E and Hypovitaminosis E in the Transition Period of High-Yielding Dairy Cows

Simple Summary

In high-yield cows, most production diseases occur during transition periods. Alpha-tocopherol, the most biologically active form of vitamin E, declines in blood and reaches the lowest levels (hypovitaminosis E) around calving. Hypovitaminosis E is associated with the incidence of peripartum diseases. Therefore, many studies which have been published for more than 30 years have investigated the effects of α-tocopherol supplementation. This α-tocopherol deficiency was thought to be caused by complex factors. However, until recently, the physiological factors or pathways underlying hypovitaminosis E in the transition period have been poorly understood. In the last 10 years, the α-tocopherol-related genes expression, which regulate the metabolism, transportation, and tissue distribution of α-tocopherol in humans and rodents, has been reported in ruminant tissues. In this paper, we discuss at least six physiological phenomena that occur during the transition period and may be candidate factors predisposing to a decreased blood α-tocopherol level and hypovitaminosis E with changes in α-tocopherol-related genes expression.

Abstract

Levels of alpha-tocopherol (α-Toc) decline gradually in blood throughout prepartum, reaching lowest levels (hypovitaminosis E) around calving. Despite numerous reports about the disease risk in hypovitaminosis E and the effect of α-Toc supplementation on the health of transition dairy cows, its risk and supplemental effects are controversial. Here, we present some novel data about the disease risk of hypovitaminosis E and the effects of α-Toc supplementation in transition dairy cows. These data strongly demonstrate that hypovitaminosis E is a risk factor for the occurrence of peripartum disease. Furthermore, a study on the effectiveness of using serum vitamin levels as biomarkers to predict disease in dairy cows was reported, and a rapid field test for measuring vitamin levels was developed. By contrast, evidence for how hypovitaminosis E occurred during the transition period was scarce until the 2010s. Pioneering studies conducted with humans and rodents have identified and characterised some α-Toc-related proteins, molecular players involved in α-Toc regulation followed by a study in ruminants from the 2010s. Based on recent literature, the six physiological factors: (1) the decline in α-Toc intake from the close-up period; (2) changes in the digestive and absorptive functions of α-Toc; (3) the decline in plasma high-density lipoprotein as an α-Toc carrier; (4) increasing oxidative stress and consumption of α-Toc; (5) decreasing hepatic α-Toc transfer to circulation; and (6) increasing mammary α-Toc transfer from blood to colostrum, may be involved in α-Toc deficiency during the transition period. However, the mechanisms and pathways are poorly understood, and further studies are needed to understand the physiological role of α-Toc-related molecules in cattle. Understanding the molecular mechanisms underlying hypovitaminosis E will contribute to the prevention of peripartum disease and high performance in dairy cows.

Emerging Protein Biomarkers for the Diagnosis or Prediction of Gestational Diabetes-A Scoping Review

Introduction: Gestational diabetes (GDM), defined as hyperglycemia with onset or initial recognition during pregnancy, has a rising prevalence paralleling the rise in type 2 diabetes (T2DM) and obesity. GDM is associated with short-term and long-term consequences for both mother and child. Therefore, it is crucial we efficiently identify all cases and initiate early treatment, reducing fetal exposure to hyperglycemia and reducing GDM-related adverse pregnancy outcomes. For this reason, GDM screening is recommended as part of routine pregnancy care. The current screening method, the oral glucose tolerance test (OGTT), is a lengthy, cumbersome and inconvenient test with poor reproducibility. Newer biomarkers that do not necessitate a fasting sample are needed for the prompt diagnosis of GDM. The aim of this scoping review is to highlight and describe emerging protein biomarkers that fulfill these requirements for the diagnosis of GDM. Materials and Methods: This scoping review was conducted according to preferred reporting items for systematic reviews and meta-analyses (PRISMA) guidelines for scoping reviews using Cochrane Central Register of Controlled Trials (CENTRAL), the Cumulative Index to Nursing & Allied Health Literature (CINAHL), PubMed, Embase and Web of Science with a double screening and extraction process. The search included all articles published in the literature to July 2020. Results: Of the 3519 original database citations identified, 385 were eligible for full-text review. Of these, 332 (86.2%) were included in the scoping review providing a total of 589 biomarkers studied in relation to GDM diagnosis. Given the high number of biomarkers identified, three post hoc criteria were introduced to reduce the items set for discussion: we chose only protein biomarkers with at least five citations in the articles identified by our search and published in the years 2017-2020. When applied, these criteria identified a total of 15 biomarkers, which went forward for review and discussion. Conclusions: This review details protein biomarkers that have been studied to find a suitable test for GDM diagnosis with the potential to replace the OGTT used in current GDM screening protocols. Ongoing research efforts will continue to identify more accurate and practical biomarkers to take GDM screening and diagnosis into the 21st century.

Protein signatures from blood plasma and urine suggest changes in vascular function and IL-12 signaling in elderly with a history of chronic diseases compared with an age-matched healthy cohort

Key processes characterizing human aging are immunosenescence and inflammaging. The capacity of the immune system to adequately respond to external perturbations (e.g., pathogens, injuries, and biochemical irritants) and to repair somatic mutations that may cause cancers or cellular senescence declines. An important goal remains to identify genetic or biochemical, predictive biomarkers for healthy aging. We recruited two cohorts in the age range 70 to 82, one afflicted by chronic illnesses (non-healthy aging, NHA) and the other in good health (healthy aging, HA). NHA criteria included major cardiovascular, neurodegenerative, and chronic pulmonary diseases, diabetes, and cancers. Quantitative analysis of forty proinflammatory cytokines in blood plasma and more than 500 proteins in urine was performed to identify candidate biomarkers for and biological pathway implications of healthy aging. Nine cytokines revealed lower quantities in blood plasma for the NHA compared with the HA groups (fold change > 1.5; p value < 0.025) including IL-12p40 and IL-12p70. We note that, sampling at two timepoints, intra-individual cytokine abundance patterns clustered in 86% of all 60 cases, indicative of person-specific, highly controlled multi-cytokine signatures in blood plasma. Twenty-three urinary proteins were differentially abundant (HA versus NHA; fold change > 1.5; p value < 0.01). Among the proteins increased in abundance in the HA cohort were glycoprotein MUC18, ephrin type-B receptor 4, matrix remodeling-associated protein 8, angiopoietin-related protein 2, K-cadherin, and plasma protease C1 inhibitor. These proteins have been linked to the extracellular matrix, cell adhesion, and vascular remodeling and repair processes. In silico network analysis identified the regulation of coagulation, antimicrobial humoral immune responses, and the IL-12 signaling pathway as enriched GO terms. To validate links of these preliminary biomarkers and IL-12 signaling with healthy aging, clinical studies using larger cohorts and functional characterization of the genes/proteins in cellular models of aging need to be conducted.

The positive effect of short-term nano-curcumin therapy on insulin resistance and serum levels of afamin in patients with metabolic syndrome

OBJECTIVE

Metabolic syndrome (MS) is a cluster of cardio-metabolic risk factors. MS is known as a highly prevalent disease worldwide. According to the existing evidence, consuming curcumin has positive effects on lipids profile, glucose, and body weight. This study aimed to evaluate the effects of nano-curcumin therapy on insulin resistance and serum level of afamin in patients with MS.

MATERIALS AND METHODS

Thirty MS patients (15 males and 15 females) received 80 mg/daily nano-curcumin for two months. The samples of fasting blood were collected from the participants at the beginning and 60 days after initiation of the intervention to measure biomarkers.

RESULTS

Comparing pre- and post-treatment with nano-curcumin values revealed a significant decrease in fasting plasma glucose (FPG) (p=0.017), insulin, homeostatic model assessment of insulin resistance (HOMA-IR) (p=0.006), and afamin (p=0.047). Moreover, there was a significantly negative relationship between afamin and high-density lipoprotein cholesterol (HDL-C) (p=0.044), as well as a significantly positive relationship between afamin and systolic (SBP) (p<0.001) and diastolic (DBP) (p<0.001) blood pressures.

CONCLUSION

Results suggest that taking nano-curcumin for 60 days may have positive effects on afamin, FPG, insulin, and HOMA-IR in patients with MS, but would not significantly affect other metabolic profiles. More studies with larger sample sizes are required to confirm these findings.

Serum Afamin a Novel Marker of Increased Hepatic Lipid Content

AIM

Afamin is a liver-produced glycoprotein, a potential early marker of metabolic syndrome. Here we investigated regulation of afamin in a course of the metabolic disease development and in response to 3-month exercise intervention.

METHODS

We measured whole-body insulin sensitivity (euglycemic hyperinsulinemic clamp), glucose tolerance, abdominal adiposity, hepatic lipid content (magnetic resonance imaging/spectroscopy), habitual physical activity (accelerometers) and serum afamin (enzyme-linked immunosorbent assay) in 71 middle-aged men with obesity, prediabetes and newly diagnosed type 2 diabetes. Effects of 3-month exercise were investigated in 22 overweight-to-obese middle-aged individuals (16M/6F).

RESULTS

Prediabetes and type 2 diabetes, but not obesity, were associated with increased serum afamin (p<0.001). Afamin correlated positively with hepatic lipids, fatty liver index and liver damage markers; with parameters of adiposity (waist circumference, %body fat, adipocyte diameter) and insulin resistance (fasting insulin, C-peptide, HOMA-IR; p<0.001 all). Moreover, afamin negatively correlated with whole-body insulin sensitivity (M-value/Insulin, p<0.001). Hepatic lipids and fasting insulinemia were the most important predictors of serum afamin, explaining >63% of its variability. Exercise-related changes in afamin were paralleled by reciprocal changes in insulinemia, insulin resistance and visceral adiposity. No significant change in hepatic lipid content was observed.

CONCLUSIONS

Subjects with prediabetes and type 2 diabetes had the highest serum afamin levels. Afamin was more tightly related to hepatic lipid accumulation, liver damage and insulin resistance than to obesity.

Protein signatures from blood plasma and urine suggest changes in vascular function and IL-12 signaling in elderly with a history of chronic diseases compared with an age-matched healthy cohort

Key processes characterizing human aging are immunosenescence and inflammaging. The capacity of the immune system to adequately respond to external perturbations (e.g., pathogens, injuries, and biochemical irritants) and to repair somatic mutations that may cause cancers or cellular senescence declines. An important goal remains to identify genetic or biochemical, predictive biomarkers for healthy aging. We recruited two cohorts in the age range 70 to 82, one afflicted by chronic illnesses (non-healthy aging, NHA) and the other in good health (healthy aging, HA). NHA criteria included major cardiovascular, neurodegenerative, and chronic pulmonary diseases, diabetes, and cancers. Quantitative analysis of forty proinflammatory cytokines in blood plasma and more than 500 proteins in urine was performed to identify candidate biomarkers for and biological pathway implications of healthy aging. Nine cytokines revealed lower quantities in blood plasma for the NHA compared with the HA groups (fold change > 1.5; p value < 0.025) including IL-12p40 and IL-12p70. We note that, sampling at two timepoints, intra-individual cytokine abundance patterns clustered in 86% of all 60 cases, indicative of person-specific, highly controlled multi-cytokine signatures in blood plasma. Twenty-three urinary proteins were differentially abundant (HA versus NHA; fold change > 1.5; p value < 0.01). Among the proteins increased in abundance in the HA cohort were glycoprotein MUC18, ephrin type-B receptor 4, matrix remodeling-associated protein 8, angiopoietin-related protein 2, K-cadherin, and plasma protease C1 inhibitor. These proteins have been linked to the extracellular matrix, cell adhesion, and vascular remodeling and repair processes. In silico network analysis identified the regulation of coagulation, antimicrobial humoral immune responses, and the IL-12 signaling pathway as enriched GO terms. To validate links of these preliminary biomarkers and IL-12 signaling with healthy aging, clinical studies using larger cohorts and functional characterization of the genes/proteins in cellular models of aging need to be conducted.

A multi-omics investigation of the molecular characteristics and classification of six metabolic syndrome relevant diseases

Metabolic syndrome (MTS) is a cluster of concurrent metabolic abnormal conditions. MTS and its component metabolic diseases are heterogeneous and closely related, making their relationships complicated, thus hindering precision treatment. Methods: We collected seven groups of samples (group a: healthy individuals; group b: obesity; group c: MTS; group d: hyperglycemia, group e: hypertension, group f: hyperlipidemia; group g: type II diabetes, n=7 for each group). We examined the molecular characteristics of each sample by metabolomic, proteomic and peptidomic profiling analysis. The differential molecules (including metabolites, proteins and peptides) between each disease group and the healthy group were recognized by statistical analyses. Furthermore, a two-step clustering workflow which combines multi-omics and clinical information was used to redefine molecularly and clinically differential groups. Meanwhile, molecular, clinical, network and pathway based analyses were used to identify the group-specific biological features. Results: Both shared and disease-specific molecular profiles among the six types of diseases were identified. Meanwhile, the patients were stratified into three distinct groups which were different from original disease definitions but presented significant differences in glucose and lipid metabolism (Group 1: relatively favorable metabolic conditions; Group 2: severe dyslipidemia; Group 3: dysregulated insulin and glucose). Group specific biological signatures were also systematically described. The dyslipidemia group showed higher levels in multiple lipid metabolites like phosphatidylserine and phosphatidylcholine, and showed significant up-regulations in lipid and amino acid metabolism pathways. The glucose dysregulated group showed higher levels in many polypeptides from proteins contributing to immune response. The another group, with better glucose/lipid metabolism ability, showed higher levels in lipid regulating enzymes like the lecithin cholesterol acyltransferase and proteins involved in complement and coagulation cascades. Conclusions: This multi-omics based study provides a general view of the complex relationships and an alternative classification for various metabolic diseases where the cross-talk or compensatory mechanism between the immune and metabolism systems plays a critical role.

Omics-based biomarkers in the diagnosis of diabetes

Diabetes mellitus (DM) is a group of metabolic diseases related to the dysfunction of insulin, causing hyperglycaemia and life-threatening complications. Current early screening and diagnostic tests for DM are based on changes in glucose levels and autoantibody detection. This review evaluates recent studies on biomarker candidates in diagnosing type 1, type 2 and gestational DM based on omics classification, whilst highlighting the relationship of these biomarkers with the development of diabetes, diagnostic accuracy, challenges and future prospects. In addition, it also focuses on possible non-invasive biomarker candidates besides common blood biomarkers.

Assessment of Serum Concentrations of Adropin, Afamin, and Neudesin in Children with Type 1 Diabetes

Introduction

The increasing knowledge of adropin, afamin, and neudesin and the regulation of glucose metabolism and insulin resistance allows for the assessment of the differences in their concentrations between the groups with varied duration of diabetes mellitus (DM).

Aim of the Study

Assessment of serum levels of adropin, afamin, and neudesin in children with type 1 diabetes, with respect to the disease duration.

Materials and Methods

The study consisted of 138 patients aged 5–18 years (M 40.58%). Children with type 1 diabetes (n = 68) were compared to the control group (n = 70). The diabetic group was divided into 4 subgroups: (I) newly diagnosed patients, after an episode of ketoacidosis (n = 14), (II) duration no longer than 5 years (n = 18), (III) 5 to 10 years (n = 27), and (IV) longer than 10 years (n = 9). Serum concentrations of adropin, afamin, and neudesin were assessed and compared between the groups of patients. The criterion for statistical significance was p < 0.05.

Results

The concentrations of adropin and afamin across all subgroups were lower than that in the control group, while neudesin levels were higher in diabetic patients compared to the control group. The differences were statistically significant.

Conclusions

Adropin, afamin, and neudesin may play a major role in the regulation of glucose metabolism and have a significant potential as novel biomarkers to predict future metabolic disorders. However, further multicentre studies on a larger cohort of patients are necessary to specify the role of these substances in the course and treatment of type 1 diabetes.

Urinary afamin levels are associated with the progression of diabetic nephropathy

AIMS

In this study, we applied quantitative proteomic analysis to identify urinary proteins associated with diabetic nephropathy (DN).

METHODS

Two-dimensional image-converted analysis of liquid chromatography and mass spectrometry detected the proteins differentially excreted between normoalbuminuric and macroalbuminuric patients with type 2 diabetes mellitus (T2DM) (n = 6 each). Urinary levels of excreted proteins were measured by multiple reaction monitoring (MRM) analysis using an independent sample set (n = 77). Urinary afamin levels were measured by ELISA in T2DM and DN patients enrolled in this cohort study (n = 203).

RESULTS

One-hundred-four proteins displayed significant alterations in excretion. Nine of these candidates were validated by MRM analysis. Among them, the levels of afamin, CD44 antigen, and lysosome-associated membrane glycoprotein 2, which have not previously been implicated in DN, were significantly associated with both the urinary albumin to creatinine ratio (ACR) and eGFR. We further measured afamin levels in urine collected from T2DM patients who did not yet have significant kidney disease (ACR < 300 mg/g or eGFR change rate ≤ 3.3%/year). The urinary afamin to creatinine ratio (Afa/Cre) was significantly higher in patients who progressed to a more severe DN stage or had early renal decline than in patients who did not.

CONCLUSIONS

Afa/Cre was significantly increased in T2DM patients who subsequently developed DN. Afa/Cre may be useful to predict patients with T2DM at high risk of nephropathy before the development of macroalbuminuria or reduced kidney function, although further validation studies in a larger population are needed.

TWEAK and monocyte to HDL ratio as a predictor of metabolic syndrome in patients with polycystic ovary syndrome

We aimed at analyzing serum TWEAK levels and monocyte/HDL ratio in polycystic ovary syndrome (PCOS) and their predictivity for metabolic syndrome (MS) in PCOS. We included 71 women with PCOS and 40 healthy controls without any cardiovascular risk factors in this cross-sectional study. Patient group was classified as MS positive (n = 34) and negative (n = 37). Study group had higher monocyte/HDL ratio and TWEAK levels (9.59 ± 2.82 vs 8.2 ± 2.46, p = .007 and 1085.54 ± 780.95 vs 694.88 ± 369.67 ng/ml, p = .009). Monocyte/HDL ratio and TWEAK levels were higher in MS positive group (10.47 ± 2.81 vs 8.77 ± 2.61, p = .01 and 1417.59 ± 921.52 vs 780.41 ± 455.67, p = .009). In multivariate regression analysis, monocyte/HDL ratio (>9.9, OR 3.42, 95%CI 1.41-5.78, p = .008) and TWEAK (>846.5 ng/ml, OR 5.49, 95%CI 3.14-7.59, p = .002) were found to be independent predictors of MS in study group. Discriminative value of monocyte/HDL ratio for MS in study group was evaluated by receiver operating curve. Area under curve for monocyte/HDL ratio was 0.669 with a sensitivity of 70.3% and specifity of 67.7%, cutoff value was >9.9. Receiver operating curve for TWEAK at >846.5 pg/ml threshold to diagnose MS in study group was performed and area under the curve was 0.769 with a sensitivity of 73% and specifity of 72%. TWEAK and monocyte/HDL ratio may be promising in predicting MS at early stages in PCOS to prevent future cardiovascular diseases by modifying life-style or giving pharmacotheraphy.

Afamin: an early predictor of preeclampsia

Purpose

Oxidative stress is involved in the pathogenesis of hypertensive disorders such as preeclampsia (PE) and associated with the human vitamin E-binding protein afamin. The aim of this study was, therefore, to analyse afamin in the first trimester of patients developing PE later in pregnancy and in control subjects without pregnancy complications.

Methods

In this retrospective study, 137 serum samples from the first trimester of pregnancy were analysed in a case–control study design. 39 patients developed PE (10 patients with early-onset and 29 patients with late onset disease) and 98 women had an uncomplicated pregnancy. Mann–Whitney U test, t test, logistic regression and ROC analyses were performed for statistical evaluation.

Results

Pregnant women developing PE presented with higher afamin concentrations in the first trimester [median 101.81 mg/L; interquartile range (IQR) 88.94–113.26] compared to subjects with uncomplicated pregnancy (median 86.40; IQR 75.26–96.92; p < 0.001). After adjusting for confounders, the odds ratio per afamin standard deviation was 1.60 (95% CI: 1.04–2.58; p = 0.04). An afamin threshold concentration of 87.8 mg/L exhibited the best sensitivity (79.5%) and specificity (57.1%) in predicting PE. Subgroup analysis of early- and late-onset disease resulted in substantially higher afamin concentrations in women with developing late-onset PE compared to controls (p < 0.001) with an odds ratio per afamin standard deviation of 1.62 (95% CI: 0.98–2.70; p = 0.06).

Conclusions

Serum afamin concentrations are elevated in the first trimester among patients developing PE compared to controls. Substantial differences were observed mainly among patients with late-onset PE.

Expression, Purification, and Biochemical Characterization of Human Afamin

Afamin is an 87 kDa glycoprotein with five predicted N-glycosylation sites. Afamin's glycan abundance contributes to conformational and chemical inhomogeneity presenting great challenges for molecular structure determination. For the purpose of studying the structure of afamin, various forms of recombinantly expressed human afamin (rhAFM) with different glycosylation patterns were thus created. Wild-type rhAFM and various hypoglycosylated forms were expressed in CHO, CHO-Lec1, and HEK293T cells. Fully nonglycosylated rhAFM was obtained by transfection of point-mutated cDNA to delete all N-glycosylation sites of afamin. Wild-type and hypo/nonglycosylated rhAFM were purified from cell culture supernatants by immobilized metal ion affinity and size exclusion chromatography. Glycan analysis of purified proteins demonstrated differences in micro- and macro-heterogeneity of glycosylation enabling the comparison between hypoglycosylated, wild-type rhAFM, and native plasma afamin. Because antibody fragments can work as artificial chaperones by stabilizing the structure of proteins and consequently enhance the chance for successful crystallization, we incubated a Fab fragment of the monoclonal anti-afamin antibody N14 with human afamin and obtained a stoichiometric complex. Subsequent results showed sufficient expression of various partially or nonglycosylated forms of rhAFM in HEK293T and CHO cells and revealed that glycosylation is not necessary for expression and secretion.

Plasma Concentrations of Afamin Are Associated With Prevalent and Incident Type 2 Diabetes: A Pooled Analysis in More Than 20,000 Individuals

OBJECTIVE

The human vitamin E-binding glycoprotein afamin is primarily expressed in the liver and has been associated with prevalent and incident metabolic syndrome. These data were in line with observations in transgenic mice. We thus investigated whether afamin concentrations are associated with prediabetes, type 2 diabetes, and insulin resistance (IR).

RESEARCH DESIGN AND METHODS

Individual-level baseline (n = 20,136) and follow-up data (n = 14,017) of eight prospective cohort studies were investigated. Study-level data were combined using random-effects meta-analyses. Main outcomes were prevalent and incident type 2 diabetes, prediabetes, and IR. Discrimination and reclassification of participants was analyzed for incident type 2 diabetes.

RESULTS

Mean afamin concentrations between studies ranged from 61 to 73 mg/L. The eight studies included 1,398 prevalent and 585 incident cases of type 2 diabetes. Each increase of afamin by 10 mg/L was associated with prevalent type 2 diabetes (odds ratio [OR] 1.19 [95% CI 1.12-1.26], P = 5.96 × 10^-8). Afamin was positively associated with IR assessed by HOMA-IR (β 0.110 [95% CI 0.089-0.132], P = 1.37 × 10^-23). Most importantly, afamin measured at baseline was an independent predictor for 585 incident cases of type 2 diabetes (OR 1.30 [95% CI 1.23-1.38], P = 3.53 × 10^-19) and showed a significant and valuable gain in risk classification accuracy when added to this extended adjustment model.

CONCLUSIONS

This pooled analysis in >20,000 individuals showed that afamin is strongly associated with IR, prevalence, and incidence of type 2 diabetes independent of major metabolic risk factors or parameters. Afamin might be a promising novel marker for the identification of individuals at high risk for the development of type 2 diabetes.

Modifications in acute phase and complement systems predict shifts in cognitive status of HIV-infected patients

BACKGROUND

The prevalence of HIV-associated neurocognitive disorders (HAND) has not changed considerably in the last two decades. Potent antiretroviral therapy has shifted the severity of HAND to milder phenotypes, but excess morbidity and mortality continue to be associated with HAND. Changes in numerous markers of immune function, inflammation, and cellular stress have been repeatedly associated with HAND, but the underlying systems that drive these changes have not been identified.

METHOD

In this study, we used systems informatics to interrogate the cerebrospinal fluid proteomic content of longitudinal samples obtained from HIV-infected adults with stably unimpaired, stably impaired, worsening, or improving neurocognitive performance.

RESULTS AND CONCLUSION

The patterns of change in cerebrospinal fluid protein content implicated the induction of acute phase and complement systems as important regulators of neurocognitive status. Worsening neurocognitive performance was preceded by induction of acute phase and complement systems, whereas improving neurocognitive performance was preceded by a downregulation of these systems.

The N14 anti-afamin antibody Fab: a rare VL1 CDR glycosylation, crystallographic re-sequencing, molecular plasticity and conservative versus enthusiastic modelling

The monoclonal antibody N14 is used as a detection antibody in ELISA kits for the human glycoprotein afamin, a member of the albumin family, which has recently gained interest in the capture and stabilization of Wnt signalling proteins, and for its role in metabolic syndrome and papillary thyroid carcinoma. As a rare occurrence, the N14 Fab is N-glycosylated at Asn26L at the onset of the VL1 antigen-binding loop, with the α-1-6 core fucosylated complex glycan facing out of the L1 complementarity-determining region. The crystal structures of two non-apparent (pseudo) isomorphous crystals of the N14 Fab were analyzed, which differ significantly in the elbow angles, thereby cautioning against the overinterpretation of domain movements upon antigen binding. In addition, the map quality at 1.9 Å resolution was sufficient to crystallographically re-sequence the variable VL and VH domains and to detect discrepancies in the hybridoma-derived sequence. Finally, a conservatively refined parsimonious model is presented and its statistics are compared with those from a less conservatively built model that has been modelled more enthusiastically. Improvements to the PDB validation reports affecting ligands, clashscore and buried surface calculations are suggested.

Afamin--A pleiotropic glycoprotein involved in various disease states

The human glycoprotein afamin was discovered as the fourth member of the albumin gene family. Despite intense research over the last 20 years, our knowledge of afamin's physiological or pathophysiological functions is still very limited. Circulating afamin is primarily of hepatic origin and abundant concentrations are found in plasma, cerebrospinal, ovarian follicular and seminal fluids. In vitro binding studies revealed specific binding properties for vitamin E. A previously performed analytical characterization and clinical evaluation study of an enzyme-linked immunosorbent assay for quantitative measurement of afamin in human plasma demonstrated that the afamin assay meets the quality specifications for laboratory medicine. Comparative proteomics has identified afamin as a potential biomarker for ovarian cancer and these findings were confirmed by quantitative immunoassay of afamin and validated in independent cohorts of patients with ovarian cancer. Afamin has also been investigated in other types of carcinoma. Most of these studies await further evaluation with validated quantitative afamin assays and require validation in larger patient cohorts. Transgenic mice overexpressing the human afamin gene revealed increased body weight and increased blood concentrations of lipids and glucose. These transgenic mouse data were in line with three large human population-based studies showing that afamin is strongly associated with the prevalence and development of the metabolic syndrome. This review summarizes and discusses the molecular, biochemical and analytical characterization of afamin as well as possible clinical applications of afamin measurement.