NECAP2 controls clathrin coat recruitment to early endosomes for fast endocytic recycling.

Endocytic recycling returns receptors to the plasma membrane following internalization and is essential to maintain receptor levels on the cell surface, re-sensitize cells to extracellular ligands and for continued nutrient uptake. Yet, the protein machineries and mechanisms that drive endocytic recycling remain ill-defined. Here, we establish that NECAP2 regulates the endocytic recycling of EGFR and transferrin receptor. Our analysis of the recycling dynamics revealed that NECAP2 functions in the fast recycling pathway that directly returns cargo from early endosomes to the cell surface. In contrast, NECAP2 does not regulate the clathrin-mediated endocytosis of these cargos, the degradation of EGFR or the recycling of transferrin along the slow, Rab11-dependent recycling pathway. We show that protein knockdown of NECAP2 leads to enlarged early endosomes and causes the loss of the clathrin adapter AP-1 from the organelle. Through structure-function analysis, we define the protein-binding interfaces in NECAP2 that are crucial for AP-1 recruitment to early endosomes. Together, our data identify NECAP2 as a pathway-specific regulator of clathrin coat formation on early endosomes for fast endocytic recycling.

Omentin-1 levels are reduced by pharmacologic doses of leptin, but remain unaffected by energy deprivation and display no day-night variation.

OBJECTIVE: To study the day-night variation of omentin-1 levels and assess whether leptin and/or short- and long-term energy deprivation alter circulating omentin-1 levels via cytokines. DESIGN AND METHODS: Omentin-1 levels were measured hourly in serum samples from six healthy men to evaluate for day-night variation. To study effects of acute energy deprivation and of leptin administration, eight healthy subjects were studied in the fasting state for 72 h with administration of either placebo or metreleptin (recombinant human leptin) in physiologic replacement doses. We evaluated the effect of leptin in pharmacologic doses on serum omentin-1 and cytokine levels, as well as on omentin-1 levels in ex vivo omental adipose tissue, in 15 healthy volunteers. To study the effect of chronic energy deprivation and weight loss on omentin-1 levels, we followed 18 obese subjects for 12 months who underwent bariatric surgery. RESULTS: There is no day-night variation in omentin-1 levels. Short-term and chronic energy deprivation, as well as ex vivo leptin administration and physiologic replacement doses of leptin, do not alter omentin-1 levels; pharmacologic doses of metreleptin reduce omentin-1 levels, whereas levels of tumor necrosis factor-α receptor II and interleukin-6 tend to increase. CONCLUSIONS: Omentin-1 levels are reduced by pharmacologic doses of metreleptin independent of effects on cytokine levels.

Circulating fetuin-A in patients with pancreatic cancer: a hospital-based case-control study.

CONTEXT: A proteomic analysis has proposed fetuin-A (alpha-2-HS-glycoprotein) as a new potential marker for pancreatic cancer (PC). OBJECTIVE: Circulating fetuin-A levels in patients with PC. METHODS: Serum fetuin-A was measured in 81 cases with PC and 81 matched controls before the initiation of any treatment. RESULTS: Serum fetuin-A was not independently associated with the presence of PC. Although there was a trend with higher fetuin-A levels across PC stages, comparisons of fetuin-A in patients within different PC prognostic stages revealed no differences. CONCLUSIONS: Circulating fetuin-A was similar between patients and controls and was not associated with the disease severity.

Leptin is an effective treatment for hypothalamic amenorrhea.

Hypothalamic amenorrhea (HA) is associated with dysfunction of the hypothalamic-pituitary-peripheral endocrine axes, leading to infertility and bone loss, and usually is caused by chronic energy deficiency secondary to strenuous exercise and/or decreased food intake. Energy deficiency also leads to hypoleptinemia, which has been proposed, on the basis of observational studies as well as an open-label study, to mediate the neuroendocrine abnormalities associated with this condition. To prove definitively a causal role of leptin in the pathogenesis of HA, we performed a randomized, double-blinded, placebo-controlled trial of human recombinant leptin (metreleptin) in replacement doses over 36 wk in women with HA. We assessed its effects on reproductive outcomes, neuroendocrine function, and bone metabolism. Leptin replacement resulted in recovery of menstruation and corrected the abnormalities in the gonadal, thyroid, growth hormone, and adrenal axes. We also demonstrated changes in markers of bone metabolism suggestive of bone formation, but no changes in bone mineral density were detected over the short duration of this study. If these data are confirmed, metreleptin administration in replacement doses to normalize circulating leptin levels may prove to be a safe and effective therapy for women with HA.

Salutary effects of adiponectin on colon cancer: in vivo and in vitro studies in mice.

BACKGROUND: Obesity and a high-fat diet are associated with the risk and progression of colon cancer. Low adiponectin levels may play an important role in the development of colon and other obesity-related malignancies. No previous studies have directly investigated the mechanistic effects of adiponectin on colon cancer in the settings of obesity, a high-fat diet and/or adiponectin deficiency. OBJECTIVE: To investigate the effects of adiponectin on the growth of colorectal cancer in adiponectin-deficient or wild-type-C57BL/6 mice fed a low-fat or high-fat diet. RESULTS: Mice fed a high-fat-diet gained more weight and had larger tumours than mice fed a low-fat-diet. Adiponectin administration suppressed implanted tumour growth, causing larger central necrotic areas. Adiponectin treatment also suppressed angiogenesis assessed by CD31 staining and VEGFb and VEGFd mRNA expression in tumours obtained from mice fed a high-fat-diet and from adiponectin-deficient mice. Adiponectin treatment decreased serum insulin levels in mice on a high-fat-diet and increased serum-interleukin (IL)-12 levels in adiponectin-deficient mice. In vitro, it was found that adiponectin directly controls malignant potential (cell proliferation, adhesion, invasion and colony formation) and regulates metabolic (AMPK/S6), inflammatory (STAT3/VEGF) and cell cycle (p21/p27/p53/cyclins) signalling pathways in both mouse MCA38 and human HT29, HCT116 and LoVo colon cancer cell lines in a LKB1-dependent way. CONCLUSION: These new mechanistic and pathophysiology studies provide evidence for an important role of adiponectin in colon cancer. The data indicate that adiponectin or analogues might be useful agents in the management or chemoprevention of colon cancer.

A phase 1/2 clinical trial of invariant natural killer T cell therapy in moderate-severe acute respiratory distress syndrome.

Invariant natural killer T (iNKT) cells, a unique T cell population, lend themselves for use as adoptive therapy due to diverse roles in orchestrating immune responses. Originally developed for use in cancer, agenT-797 is a donor-unrestricted allogeneic ex vivo expanded iNKT cell therapy. We conducted an open-label study in virally induced acute respiratory distress syndrome (ARDS) caused by the severe acute respiratory syndrome-2 virus (trial registration NCT04582201). Here we show that agenT-797 rescues exhausted T cells and rapidly activates both innate and adaptive immunity. In 21 ventilated patients including 5 individuals receiving veno-venous extracorporeal membrane oxygenation (VV-ECMO), there are no dose-limiting toxicities. We observe an anti-inflammatory systemic cytokine response and infused iNKT cells are persistent during follow-up, inducing only transient donor-specific antibodies. Clinical signals of associated survival and prevention of secondary infections are evident. Cellular therapy using off-the-shelf iNKT cells is safe, can be rapidly scaled and is associated with an anti-inflammatory response. The safety and therapeutic potential of iNKT cells across diseases including infections and cancer, warrants randomized-controlled trials.

Impacts of fast production of afucosylated antibodies and Fc mutants in ExpiCHO-S™ for enhancing FcγRIIIa binding and NK cell activation.

This study has employed mammalian transient expression systems to generate afucosylated antibodies and antibody Fc mutants for rapid candidate screening in discovery and early development. While chemical treatment with the fucose analogue 2-fluoro-peracetyl-fucose during transient expression only partially produced antibodies with afucosylated N-glycans, the genetic inactivation of the FUT8 gene in ExpiCHO-S™ by CRISPR/Cas9 enabled the transient production of fully afucosylated antibodies. Human IgG1 and murine IgG2a generated by the ExpiCHOfut8KO cell line possessed a 8-to-11-fold enhanced FcγRIIIa binding activity in comparison with those produced by ExpiCHO-S™. The Fc mutant S239D/S298A/I332E produced by ExpiCHO-S™ had an approximate 2-fold higher FcγRIIIa affinity than that of the afucosylated wildtype molecule, although it displayed significantly lower thermal-stability. When the Fc mutant was produced in the ExpiCHOfut8KO cell line, the resulting afucosylated Fc mutant antibody had an additional approximate 6-fold increase in FcγRIIIa binding affinity. This synergistic effect between afucosylation and the Fc mutations was further verified by a natural killer (NK) cell activation assay. Together, these results have not only established an efficient large-scale transient CHO system for rapid production of afucosylated antibodies, but also confirmed a cooperative impact between afucosylation and Fc mutations on FcγRIIIa binding and NK cell activation.

Leptin in human physiology and therapeutics.

Leptin regulates energy homeostasis and reproductive, neuroendocrine, immune, and metabolic functions. In this review, we describe the role of leptin in human physiology and review evidence from recent "proof of concept" clinical trials using recombinant human leptin in subjects with congenital leptin deficiency, hypoleptinemia associated with energy-deficient states, and hyperleptinemia associated with garden-variety obesity. Since most obese individuals are largely leptin-tolerant or -resistant, therapeutic uses of leptin are currently limited to patients with complete or partial leptin deficiency, including hypothalamic amenorrhea and lipoatrophy. Leptin administration in these energy-deficient states may help restore associated neuroendocrine, metabolic, and immune function and bone metabolism. Leptin treatment is currently available for individuals with congenital leptin deficiency and congenital lipoatrophy. The long-term efficacy and safety of leptin treatment in hypothalamic amenorrhea and acquired lipoatrophy are currently under investigation. Whether combination therapy with leptin and potential leptin sensitizers will prove effective in the treatment of garden-variety obesity and whether leptin may have a role in weight loss maintenance is being greatly anticipated.

Caffeinated coffee does not acutely affect energy intake, appetite, or inflammation but prevents serum cortisol concentrations from falling in healthy men.

Our aim in this crossover study was to investigate the acute effects of caffeinated and decaffeinated coffee consumption on appetite feelings, energy intake, and appetite-, inflammation-, stress-, and glucose metabolism-related markers. Sixteen healthy men (age range, 21-39 y; BMI range, 19.7-28.6 kg/m(2)) received in a random order on 3 separate occasions a standard breakfast snack with 200 mL of either caffeinated coffee (3 mg caffeine/kg body weight), decaffeinated coffee, or water (control). Before intervention (-15 min) and at standard time points following breakfast consumption (0, 15, 30, 60, 90, 120, 150, and 180 min), participants recorded their appetite feelings and we collected blood samples for measurements of circulating glucose, insulin, cortisol, and appetite- and inflammation-related markers. At 180 min, participants consumed a meal ad libitum. The appetite-related ratings, the appetite plasma hormonal responses as well as the plasma glucose, serum insulin, and plasma and serum inflammatory marker responses did not show an overall intervention effect or a time x intervention interaction. Ad libitum energy intake did not differ among the 3 interventions. However, a significant intervention effect (P = 0.04) and a time x intervention interaction (P-interaction = 0.02) were found for serum cortisol; cortisol concentrations were significantly higher following the caffeinated coffee intervention, compared to control, at 60 min and thereafter. In conclusion, the usually consumed amount of caffeinated coffee does not have short-term effects on appetite, energy intake, glucose metabolism, and inflammatory markers, but it increases circulating cortisol concentrations in healthy men.

Low circulating adiponectin and resistin, but not leptin, levels are associated with multiple myeloma risk: a case-control study.

Accumulating evidence supports a role for obesity in the etiology of multiple myeloma (MM). The distinct possibility exists that obesity may be linked to MM through altered adipokine secretion and circulating levels, one of which, adiponectin, has a protective role in several malignancies, including leukemia. In this case-control study, we investigated the role of serum adiponectin, resistin, and leptin levels in the etiopathogenesis of MM and we explored their association with several established prognostic factors. Seventy three patients with incident, histologically confirmed MM and 73 controls matched on gender and age were studied between 2001 and 2007, and blood samples were collected. Serum adiponectin, leptin, resistin, as well as MM prognostic parameters were determined. Statistical analysis of the data was performed using univariate and multivariate analyses. Lower serum adiponectin and resistin levels were associated with higher risk of MM by bivariate analysis and after adjusting for age, gender, BMI, and serum levels of leptin (p < 0.0001). Adiponectin may have a protective role in MM, whereas leptin was not associated with risk for MM at a comparable level of significance and resistin levels may be decreased via a compensatory mechanism. Further studies are needed to confirm these associations and to explore the mechanisms underlying adiponectin's role in MM and plasma cell dyscrasias.

Short-term treatment with ezetimibe, simvastatin or their combination does not alter circulating adiponectin, resistin or leptin levels in healthy men.

OBJECTIVE: Statin therapy decreases cardiovascular morbidity and mortality, and ezetimibe, a novel cholesterol absorption inhibitor has both lipid-lowering and anti-atherosclerotic effects in animal models. As several adipokines, that is, adiponectin, high molecular weight (HMW) adiponectin, leptin and/or possibly resistin are involved in the pathogenesis of insulin resistance (IR), dyslipidaemia and atherosclerosis, we investigated whether ezetimibe and/or statin treatment may modulate serum concentrations of these four major adipokines. RESEARCH DESIGN AND METHODS: One-centre, randomized, parallel three-group study in 72 healthy men [mean age 32 +/- 9 years, mean body mass index (BMI) 25.7 +/- 3.2 kg/m(2)]. PATIENTS: Seventy-two healthy men. Each group of 24 subjects received a 14-day treatment with either ezetimibe (10 mg/day), simvastatin (40 mg/day) or their combination. Blood was drawn before and after the 14-day treatment period. MEASUREMENTS: Lipid levels, IR indices, serum leptin, adiponectin, HMW adiponectin and resistin concentrations. Results Neither ezetimibe nor simvastatin or their combination had any effect on serum leptin, adiponectin, HMW adiponectin and resistin concentrations. Baseline leptin levels correlated positively, while adiponectin and HMW adiponectin negatively, with BMI. Leptin concentrations correlated negatively while adiponectin and HMW adiponectin positively with plasma high-density lipoprotein-cholesterol concentrations. Resistin concentrations were not associated with BMI, lipid levels or indicators of IR. CONCLUSIONS: Treatment with ezetimibe, simvastatin or their combination does not alter circulating levels of adiponectin, leptin or resistin in adult healthy men.

Age and dietary form of vitamin K affect menaquinone-4 concentrations in male Fischer 344 rats.

Phylloquinone, the primary dietary form of vitamin K, is converted to menaquinone-4 (MK-4) in certain tissues. MK-4 may have tissue-specific roles independent of those traditionally identified with vitamin K. Fischer 344 male rats of different ages (2, 12, and 24 mo, n = 20 per age group) were used to compare the conversion of phylloquinone to MK-4 with an equivalent dose of another dietary form of vitamin K, 2',3'-dihydrophylloquinone. Rats were age- and diet-group pair-fed phylloquinone (198 +/- 9.0 microg/kg diet) or dihydrophylloquinone (172 +/- 13.0 microg/kg diet) for 28 d. MK-4 was the primary form of vitamin K in serum, spleen, kidney, testes, bone marrow, and brain myelin fractions, regardless of age group. MK-4 concentrations were significantly lower in kidney, heart, testes, cortex (myelin), and striatum (myelin) in the dihydrophylloquinone diet group compared with the phylloquinone diet group (P < 0.05). The MK-4 concentrations in 2-mo-old rats were lower in liver, spleen, kidney, heart, and cortex (myelin) but higher in testes compared with 24-mo-old rats (P < 0.05). However, there were no age-specific differences in MK-4 concentrations among the rats fed the 2 diets. These data suggest that dihydrophylloquinone, which differs from phylloquinone in its side phytyl chain, is absorbed but its intake results in less MK-4 in certain tissues. Dihydrophylloquinone may be used in models for the study of tissue-specific vitamin K deficiency.

Circulating adiponectin and leptin in relation to myelodysplastic syndrome: a case-control study.

OBJECTIVE: Adiponectin plays a protective role in several malignancies, including myeloblastic leukemia, whereas leptin may increase the proliferation of progenitor cells and may stimulate leukemic cell growth in vitro. We investigated the role of adiponectin and leptin levels in the etiopathogenesis of myelodysplastic syndromes (MDS), a preleukemic condition with increasing incidence which has recently been associated with obesity. METHODS: In a case-control study, 101 cases with incident, histologically confirmed primary MDS and 101 controls matched on gender and age were studied between 2004 and 2007, and blood samples were collected. RESULTS: Higher serum adiponectin levels were associated with lower risk of MDS by bivariate analysis and after adjusting for age, gender, body mass index and serum levels of leptin (p < 0.001). Subjects in the third quartile for leptin levels had a lower risk of MDS than controls, and low leptin concentrations were observed in low-risk MDS patients with normal or good prognostic karyotype after adjusting for age, gender and body mass index. CONCLUSIONS: Circulating adiponectin and leptin may play an important role in MDS etiopathogenesis. Future studies are needed to confirm these associations and to explore underlying mechanisms.

Retromer revisited: Evolving roles for retromer in endosomal sorting.

The highly conserved retromer complex has been linked to cargo retrieval from endosomes to the trans-Golgi network. In this issue, Kvainickas et al. (2017. J. Cell Biol. https://doi.org/10.1083/jcb.201702137) and Simonetti et al. (2017. J. Cell Biol. https://doi.org/10.1083/jcb.201703015) fundamentally question the current retromer model and demonstrate that in mammalian cells, the individual retromer subcomplexes have functionally diverged to organize multiple distinct sorting pathways.

Fetuin-A levels and free leptin index are reduced in patients with chronic lymphocytic leukemia: a hospital-based case-control study.

There are limited data on fetuin-A, soluble leptin receptor (sOB-R) and free leptin index (FLI) in patients with chronic lymphocytic leukemia (CLL). The aim of this study was to compare circulating fetuin-A, sOB-R levels and FLI between 95 patients with CLL and 95 matched controls, as well as among different stages of CLL. Circulating fetuin-A was significantly lower in cases than controls (241.9 ± 99.2 vs. 288.8 ± 127.7 µg/mL; p = 0.005). Although circulating sOB-R levels were similar between groups, FLI was lower in cases than controls (0.45 ± 0.42 vs. 0.67 ± 0.57; p = 0.003). Furthermore, lower fetuin-A or FLI, but not sOB-R, were independently associated with CLL (p < 0.05), particularly among overweight/obese individuals. Fetuin-A, s-OB-R and FLI were similar between different stages of CLL severity, or between symptomatic and asymptomatic disease. In conclusion, circulating fetuin-A and FLI, but not sOB-R, were lower in patients with CLL than controls, a finding warranting further investigation.

Adiponectin administration prevents weight gain and glycemic profile changes in diet-induced obese immune deficient Rag1-/- mice lacking mature lymphocytes.

BACKGROUND: Obesity is associated with chronic low-grade inflammation leading to insulin resistance and diabetes. Adiponectin is an adipokine that regulates inflammatory responses. The aim of our study was to investigate whether any effects of adiponectin against obesity and insulin-resistance may depend on the adaptive immune system. METHODS: We treated high-fat-diet fed Rag1-/- mice lacking mature lymphocytes with adiponectin over 7weeks and investigated alterations in their metabolic outcome and inflammatory state. RESULTS: Adiponectin protects from weight gain despite a small compensatory stimulation of energy intake in mice lacking an adaptive immune system. Additionally, adiponectin protects from dysglycemia. Minor alterations in the macrophage phenotype, but not in the circulating cytokine levels, may contribute to the protective role of adiponectin against hyperglycemia and diabetes. CONCLUSION: Adiponectin or agents increasing adiponectin may be a promising therapeutic option against obesity and hyperglycemia in immune-deficient populations.

Down-regulation of malignant potential by alpha linolenic acid in human and mouse colon cancer cells.

Omega-3 fatty acids (also called ω-3 fatty acis or n-3 fatty acid) are polyunsaturated fatty acids (PUFAs) with a double bond (C=C) at the third carbon atom from the end of the carbon chain. Numerous test tube and animal studies have shown that omega-3 fatty acids may prevent or inhibit the growth of cancers, suggesting that omega-3 fatty acids are important in cancer physiology. Alpha-linolenic acid (ALA) is one of an essential omega-3 fatty acid and organic compound found in seeds (chia and flaxseed), nuts (notably walnuts), and many common vegetable oils. ALA has also been shown to down-regulate cell proliferation of prostate, breast, and bladder cancer cells. However, direct evidence that ALA suppresses to the development of colon cancer has not been studied. Also, no previous studies have evaluated whether ALA may regulate malignant potential (adhesion, invasion and colony formation) in colon cancer cells. In order to address the questions above, we conducted in vitro studies and evaluated whether ALA may down-regulate malignant potential in human (HT29 and HCT116) and mouse (MCA38) colon cancer cell lines. We observed that treatment with 1-5 mM of ALA inhibits cell proliferation, adhesion and invasion in both human and mouse colon cancer cell lines. Interestingly, we observed that ALA did not decrease total colony numbers when compared to control. By contrast, we found that size of colony was significantly changed by ALA treatment when compared to control in all colon cancer cell lines. We suggest that our data enhance our current knowledge of ALA's mechanism and provide crucial information to further the development of new therapies for the management or chemoprevention of colon cancer.

Circulating fetuin-A levels are not affected by short and long-term energy deprivation and/or by leptin administration.

OBJECTIVE: Fetuin-A may mediate cross-talk between the liver and adipose tissue. We studied the physiologic regulation of fetuin-A and explored its potential regulation by leptin. DESIGN AND METHODS: Fetuin-A levels were measured in three interventional studies as well as in in vitro experiments. Study 1: 15 lean subjects received placebo or physiologic replacement-dose recombinant human leptin (metreleptin) following short term complete caloric deprivation to induce severe hypoleptinemia; Study 2: 7 women with relative leptin deficiency due to strenuous exercise or low weight received 3 months of metreleptin; Study 3: 17 women with relative leptin deficiency were randomized to receive metreleptin or placebo over 9 months. In study 4 human hepatoma Hep G2 cells were treated with leptin. Fetuin-A mRNA expression and secretion were measured. RESULTS: Complete caloric deprivation significantly decreased leptin but had no effect on fetuin-A levels. Normalizing leptin levels with metreleptin in hypoleptinemic subjects had no effect on circulating fetuin-A levels. Leptin treatment had no effect on fetuin-A mRNA expression and secretion in vitro. CONCLUSIONS: Circulating fetuin-A levels are not affected by short and long-term energy deprivation. Furthermore, both in vivo and in vitro experiments confirm that fetuin-A is not regulated by leptin.

Chemerin levels as predictor of acute coronary events: a case-control study nested within the veterans affairs normative aging study.

OBJECTIVE: Chemerin is a recently identified adipocytokine that has been positively correlated with the presence and severity of coronary artery disease (CAD). However, no studies have examined circulating chemerin levels as a predictor of acute coronary syndrome (ACS). The purpose of this study is to evaluate whether chemerin levels predict the onset of ACS. MATERIALS/METHODS: We studied 90 men whose serum had been collected at least 2 years before the development of ACS, and 162 controls matched with the cases in a 1:2 fashion for age and year of collection. The mean age of the cohort was 66.3±9.6 years (range 34-84 years). Serum chemerin levels were measured with a commercially available enzyme-linked immunosorbent assay. RESULTS: Age was positively associated with chemerin levels (r=0.39, p<0.001). Logistic regression analysis, adjusting for years since blood collection, demonstrated a null association between chemerin levels and the odds ratio for development of ACS (OR: 0.99, 95% CI [0.99-1.001]). This association remained null after adjusting for age (OR: 0.99 95% CI [0.99-1.001]). CONCLUSIONS: Although cross-sectional and case-control studies suggest a positive association between chemerin levels and CAD, we demonstrate that chemerin levels do not predict the development of ACS.

Circulating alanine transaminase (ALT) and γ-glutamyl transferase (GGT), but not fetuin-A, are associated with metabolic risk factors, at baseline and at two-year follow-up: the prospective Cyprus Metabolism Study.

OBJECTIVE: To comparatively evaluate traditional liver tests and fetuin A as predictors of cardiometabolic risk, we studied associations between serum alanine transaminase (ALT), γ-glutamyl transferase (GGT), aspartate aminotransferase (AST) and fetuin-A and anthropometric, metabolic, and cardiovascular parameters cross-sectionally at baseline, and prospectively, after 2-years of follow-up. RESEARCH DESIGN AND METHODS: 616 randomly enrolled young healthy participants in the Cyprus Metabolism Study, including all 93 subjects who participated in the follow-up study 2 years after baseline assessment, were included in this study. RESULTS: In the cross-sectional study, serum ALT and GGT were strongly correlated with anthropometric, cardiovascular, and metabolic variables, while serum AST was only correlated with waist circumference and waist-to-hip ratio. Fetuin-A was correlated with anthropometric variables, systolic blood pressure (SBP), insulin, and homeostasis model of assessment-insulin resistance (HOMA-IR) in the unadjusted model. In the fully adjusted model, both serum ALT and GGT levels remained positively correlated with total and low-density lipoprotein (LDL) cholesterol. GGT levels also remained correlated with triglycerides. ALT levels remained strongly positively correlated with insulin (r=0.17, p<.0001) and HOMA-IR (r=0.16, p=0.0001). Serum fetuin-A levels were no longer significantly correlated with any variables. Prospectively, ALT and GGT were predictors of anthropometric variables and LDL cholesterol, while baseline levels of AST and fetuin-A were not predictors of any variables at 2-year follow-up. CONCLUSIONS: We confirmed associations of ALT and GGT levels but failed to demonstrate an independent association between fetuin-A and cardiometabolic risk factors in young healthy men. Traditional liver tests (LFTs) are thus better than fetuin-A predictors of metabolic risk factors cross-sectionally and prospectively in young healthy adults.