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Abstract Background Cancer cachexia is a life‐threatening, inflammation‐driven wasting syndrome that remains untreatable. Adiponectin, the most abundant adipokine, plays an important role in several metabolic processes as well as in inflammation modulation. Our aim was to test whether administration of AdipoRon (AR), a synthetic agonist of the adiponectin receptors, prevents the development of cancer cachexia and its related muscle atrophy. Methods The effect of AR on cancer cachexia was investigated in two distinct murine models of colorectal cancer. First, 7‐week‐old CD2F1 male mice were subcutaneously injected with colon‐26 carcinoma cells (C26) or vehicle (CT). Six days after injection, mice were treated for 5 days with AdipoRon (50 mg/kg/day; C26 + AR) or the corresponding vehicle (CT and C26). Additionally, a genetic model, the ApcMin/+ mouse, that develops spontaneously numerous intestinal polyps, was used. Eight‐week‐old male ApcMin/+ mice were treated with AdipoRon (50 mg/kg/day; Apc + AR) or the corresponding vehicle (Apc) over a period of 12 weeks, with C57BL/6J wild‐type mice used as controls. In both models, several parameters were assessed in vivo: body weight, grip strength and serum parameters, as well as ex vivo: molecular changes in muscle, fat and liver. Results The protective effect of AR on cachexia development was observed in both cachectic C26 and ApcMin/+ mice. In these mice, AR administration led to a significant alleviation of body weight loss and muscle wasting, together with rescued muscle strength (P

Abstract Objective To investigate the influence of adiponectin (APN) rs2241766 and rs1501299 polymorphisms on adiponectin levels and their association with metabolic syndrome (MetS). Methods Analyzed two polymorphisms (rs2241766 and rs1501299) of the adiponectin gene (ADIPOQ) in 210 MetS patients and 102 control patients using the polymerase chain reaction‐restriction fragment length polymorphism method and DNA sequencing technology. Results The genotypes of the rs2241766 T/G and rs1501299 G/T polymorphism were significantly associated with serum APN levels in MetS patients. The ADIPOQ polymorphisms were associated with a risk of MetS when compared with that in healthy controls. TG and GG genotypes of rs2241766 were associated with a significantly elevated risk of MetS as compared with the TT genotype (OR = 1.32 and OR = 2.53). Subjects with the G allele appeared to have higher susceptibility to MetS than those with the T allele (OR = 2.21). In common with the findings for rs2241766, the rs1501299 GT and TT genotypes were associated with a significantly increased risk of MetS as compared with the GG genotype (OR = 1.51 and OR = 2.24). The susceptibility to MetS appeared to be higher in subjects with the T allele than in those with the G allele (OR = 1.88). Conclusions The occurrence of MetS may be associated with genetic variations at the rs2241766 and rs1501299 loci, especially in individuals with T to G mutations (rs2241766) and G to T mutations (rs1501299). These mutations may lead to decreased APN levels and a higher risk of developing MetS.

Abstract Background In our previous study, we identified a population of adiponectin expressing regulatory T cells (Tregs) residing within thymic nurse cell complexes, which were capable of inhibiting the development of breast cancer in vitro. Triple‐negative breast cancer (TNBC) with no proper treatment at present is characterized by the absence of estrogen receptor, progesterone receptor, and human epidermal growth factor receptor‐2. In this study, we aimed to investigate the potential of a cultured T cell fraction comprising adiponectin‐expressing Tregs, referred to as A‐TregTF (adiponectin‐expressing Treg‐containing T cell fraction), in inhibiting the progression of TNBC in vivo. Methods The efficacy of a spontaneously expanding T cell fraction comprising adiponectin‐expressing Treg in inhibiting tumor growth was analyzed in a murine orthotopic 4 T1‐Luc TNBC model. Results The treatment with T cell fraction containing adiponectin‐expressing Tregs significantly inhibited the growth and metastasis of orthotopically transplanted 4 T1‐Luc tumor cells. Histopathological examination further revealed that the adiponectin‐expressing Tregs infiltrated the tumor tissue via a cell‐in‐cell mechanism and were found to be specifically localized around the necrotic areas. Conclusions Based on our findings, the T cell fraction comprising adiponectin‐expressing Tregs, represents a potential candidate for adoptive cell therapy against TNBC.

Abstract Background A population of regulatory T cells (Treg), which reside within thymic nurse cell complexes, express adiponectin and abrogate breast cancer development in transgenic mice. In this study, we examined whether adiponectin‐expressing Treg could impair triple‐negative breast cancer, which is defined by a lack of estrogen receptors, progesterone receptors, and human epidermal growth factor receptor‐2. Methods CD4‐ and CD25‐positive cells were sorted from cultured T lymphocytes of a previously characterized experimental thymic tumor model composed of thymic nurse cells and abundant lymphoid stroma. These sorted cells were examined for FOXP3 and adiponectin immunoreactivity and subsequently exposed to triple‐negative breast cancer MDA‐MB‐157 and ‐231 cells. Results Adiponectin‐expressing Treg were obtained by CD4‐ and CD25‐positive sorting and cell death was induced in triple‐negative breast cancer cells through the cell‐in‐cell phenomenon. Conclusions Adiponectin‐expressing Treg may be candidates for adoptive cell therapy against triple‐negative breast cancer.

Abstract Background Obesity among older adults has increased tremendously. Obesity accelerates ageing and predisposes to age‐related conditions and diseases, such as loss of endurance capacity, insulin resistance and features of the metabolic syndrome. Namely, ectopic lipids play a key role in the development of nonalcoholic fatty liver disease (NAFLD) and myosteatosis, two severe burdens of ageing and metabolic diseases. Adiponectin (ApN) is a hormone, mainly secreted by adipocytes, which exerts insulin‐sensitizing and fat‐burning properties in several tissues including the liver and the muscle. Its overexpression also increases lifespan in mice. In this study, we investigated whether an ApN receptor agonist, AdipoRon (AR), could slow muscle dysfunction, myosteatosis and degenerative muscle markers in middle‐aged obese mice. The effects on myosteatosis were compared with those on NAFLD. Methods Three groups of mice were studied up to 62 weeks of age: One group received normal diet (ND), another, high‐fat diet (HFD); and the last, HFD combined with AR given orally for almost 1 year. An additional group of young mice under an ND was used. Treadmill tests and micro‐computed tomography (CT) were carried out in vivo. Histological, biochemical and molecular analyses were performed on tissues ex vivo. Bodipy staining was used to assess intramyocellular lipid (IMCL) and lipid droplet morphology. Results AR did not markedly alter diet‐induced obesity. Yet, this treatment rescued exercise endurance in obese mice (up to 2.4‐fold, P

Abstract Aims/Introduction The increase in the number of patients with type 2 diabetes mellitus is an important concern worldwide. The goal of this study was to investigate factors involved in the onset of type 2 diabetes mellitus, and sex differences in long‐term follow up of people with normal glucose tolerance. Materials and Methods Of 1,309 individuals who underwent screening at our facility in 2004, 748 individuals without diabetes were enrolled. Correlations of metabolic markers including serum adiponectin (APN) with onset of type 2 diabetes mellitus were examined over 15 years in these individuals. Results The Kaplan–Meier curve for onset of type 2 diabetes mellitus for 15 years in the decreased APN group was examined. Hazard ratios for the APN concentration for onset of diabetes were 1.78 (95% confidence interval [CI] 1.20–2.63, P = 0.004) in all participants, 1.48 (95% CI 0.96–2.29, P = 0.078) for men and 3.01 (95% CI 1.37–6.59, P = 0.006) for women. During the follow‐up period of 15 years, body mass index, estimated glomerular filtration rate, fatty liver, C‐reactive protein and alanine aminotransferase in men were significant in univariate analysis, but only estimated glomerular filtration rate and fatty liver were significantly related to onset of type 2 diabetes mellitus in multivariate analysis. In women, body mass index, systolic blood pressure, triglyceride, fatty liver and APN were significant in univariate analysis, and APN was the only significant risk factor in multivariate analysis (P

Abstract Background Adiponectin is an important adipocytokine and has been associated with the risks of gastrointestinal cancers (GICs). Mendelian randomization (MR) analysis is needed to assess the causal relationships between adiponectin and GICs. Methods We retrieved the summary data of genome‐wide association studies for adiponectin and six types of GICs in East Asians. A series of quality control steps were performed to select the eligible genetic instrumental tools. Horizontal pleiotropy and between‐SNP heterogeneity were tested to choose the primary MR method. We also conducted sensitivity analyses to test the robustness of the main findings. Results We detected neither heterogeneity nor horizontal pleiotropy for the eligible SNPs in all of the MR analyses. Inverse variance weighted (IVW) was therefore used as the primary method, and suggested that per 10% increase in log‐transformed adiponectin level was significantly associated with a decreased risk of gastric cancer (odds ratio [OR] = 0.88, 95% CI 0.81, 0.96), whereas with an increased risk of hepatocellular carcinoma (OR = 1.26, 95% CI 1.09, 1.44) and of biliary tract cancer (OR = 1.54, 95% CI 1.12, 2.12). However, only the association between adiponectin and HCC risk was statistically significant after correction for multiple testing. No statistically significant association was detected between adiponectin and esophageal (OR = 1.05, 95% CI 0.89, 1.23), pancreatic (OR = 1.04, 95% CI 0.78, 1.37), and colorectal cancers (OR = 1.00, 95% CI 0.93, 1.07). Sensitivity analyses did not find contradictory results. Conclusion High level of adiponectin may have a causal effect on and can serve as a biomarker for the carcinogenesis of gastric cancer, hepatocellular carcinoma, and biliary tract cancer.

Abstract Introduction Adiponectin is a potent vascular protective molecule. Recent findings have suggested adiponectin resistance during early diabetes. However, the molecular mechanisms responsible remain unidentified. Here, we took an unbiased approach to identify whether hyperlipidemic plasma molecules exist that bind and inhibit adiponectin function, contributing to adiponectin resistance and diabetic vascular injury. Methods Adult rats were randomly assigned to receive either a normal or a high‐fat diet for 8 weeks. Plasma was co‐immunoprecipitated with anti‐APN antibody and analyzed by mass spectrometry. The APN binding molecules and their effect upon APN biological activity were determined. Results As expected, the high‐fat‐diet increased plasma triglyceride, total cholesterol, and low‐density lipoprotein. Importantly, the circulating APN level was significantly increased at this time point. Mass spectrometry identified 18 proteins with increased APN binding in hyperlipidemic plasma, among which four proteins critical in lipid metabolism, including apolipoprotein A1 (APOA1), APOA4, APOC1, and paraoxonase 1, were further investigated. Incubating recombinant APN with APOA1 markedly (P

Abstract Introduction Adipose tissue is the source of a broad array of signalling molecules (adipokines), which mediate interorgan communication and regulate metabolic homeostasis. Alterations in adipokine levels have been causally implicated in various metabolic disorders, including changes in bone mass. Osteoporosis is the commonest progressive metabolic bone disease, characterized by elevated risk of fragility fractures as a result of a reduced bone mass and microarchitectural deterioration. The effects of different adipokines on bone mass have been studied in an attempt to identify novel modulators of bone mass or diagnostic biomarkers of osteoporosis. Methods In this review, we sought to aggregate and assess evidence from independent studies that quantify specific adipokines and their effect on bone mineral density (BMD). Results A literature search identified 57 articles that explored associations between different adipokines and BMD. Adiponectin and leptin were the most frequently studied adipokines, with most studies demonstrating that adiponectin levels are associated with decreased BMD at the lumbar spine and femoral neck. Conversely, leptin levels are associated with increased BMD at these sites. However, extensive heterogeneity with regards to sample size, characteristics of study subjects, ethnicity, as well as direction and magnitude of effect at specific skeletal anatomical sites was identified. The broad degree of conflicting findings reported in this study can be attributed several factors. These include differences in study design and ascertainment criteria, the analytic challenges of quantifying specific adipokines and their isoforms, pre‐analytical variables (in particular patient preparation) and confounding effects of co‐existing disease. Conclusions This review highlights the biological relevance of adipokines in bone metabolism and reinforces the need for longitudinal research to elucidate the causal relationship of adipokines on bone mass.

ABSTRACT Leptin replacement therapy (LRT) has drastically improved the prognosis of patients with lipodystrophy, but pro‐inflammatory properties of leptin could become evident in the long term. Here, we report a 30‐year‐old Japanese woman with generalized lipodystrophy‐associated progeroid syndrome due to a heterozygous LMNA variant (c.29C > T; p.T10I), who was diagnosed with severe aortic stenosis (AS) after more than a decade of LRT, which required transcatheter aortic valve implantation. Given her marked hypoadiponectinemia and the LMNA variant, our patient might have been susceptible to progeria‐associated disorders, including aortic stenosis, which could have been exaggerated by the prolonged ‘imbalanced adipokines’ caused by LRT between pro‐inflammatory leptin and anti‐inflammatory adiponectin. Thus, long‐term LRT could be associated with AS in patients with the LMNA variant to cause generalized lipodystrophy‐associated progeroid syndrome and hypoadiponectinemia.

Abstract To explore the relationship between the severity of hypertension and the imbalanced intestinal flora, inflammatory factors, adiponectin (ADPN) and vascular endothelial function in primary hypertension patients. According to the grading criteria for hypertension, in total of 60 patients with primary hypertension in our hospital from April to July, 2020 were divided into Grade 1 group (n = 20), Grade 2 group (n = 20), and Grade 3 group (n = 20). The feces of the research subjects were collected to extract the deoxyribonucleic acid (DNA) and detect its composition of intestinal flora. Subsequently, the peripheral blood was collected to determine the changes in inflammatory factors interleukin‐2 (IL‐2), IL‐4, tumor necrosis factor‐α (TNF‐α) and IL‐1β, serum immunoglobulin G (IgG) and IgM, ADPN and vascular endothelial function‐related endothelin‐1 (ET‐1), nitric oxide (NO), vascular endothelial growth factor (VEGF), and intercellular adhesion molecule‐1 (ICAM‐1). There were no significant differences in the gender, age, and body mass index (BMI), the proportion of smokers, diet habit, probiotics and antihypertensive medication use, and number of diabetic cases among groups (p > 0.05). We found an inverse association between blood pressure measures and microbial diversity, in particular microbial richness (p < 0.05). Among the four major kinds of intestinal flora, the composition of firmicutes (p < 0.05) and bacteroidetes (p < 0.05) showed obvious differences among the three groups, and they had consistent trends with the changes in the abundance of firmicutes and bacteroidetes. Intestinal flora imbalance is closely related to the severity of hypertension, inflammatory factors, ADPN, and vascular endothelial function.

Introduction: Adiponectin, a key adipokine, shows promise as a non-invasive biomarker for liver cirrhosis by reflecting inflammation and metabolic changes, but conflicting findings highlight the need for a systematic review and meta-analysis to clarify its role. Our study aimed to evaluate adiponectin levels across various stages of liver cirrhosis, compare them with other chronic liver diseases (CLD) and hepatocellular carcinoma (HCC), and assess its potential as a diagnostic and prognostic biomarker., Methods: Our systematic search was conducted on September 2023 using PubMed, EMBASE and Scopus, searching for observational studies evaluating serum and plasma adiponectin levels in liver cirrhosis. Inclusion and exclusion criteria were applied, and study quality was assessed using the Newcastle-Ottawa Scale. To evaluate the overall effect size, we utilized a random-effects model along with a mean difference (MD) analysis. The principal summary outcome was the MD in adiponectin levels., Results: We included 16 articles involving 2617 subjects in our qualitative and quantitative synthesis. We found significantly higher adiponectin levels in liver cirrhosis patients (8.181 [95% CI 3.676, 12.686]), especially in Child-Pugh B individuals (13.294 [95% CI 4.955, 21.634]), compared to controls. Child-Pugh A patients did not show significant differences compared to controls. In addition, adiponectin levels were significantly elevated in primary biliary cholangitis (PBC) patients compared to controls (8.669 [95% CI .291, 17.047]), as well as in liver cirrhosis compared to other CLD patients (4.805 [95% CI 1.247, 8.363]), including non-alcoholic fatty liver disease (NAFLD) (8.532 [95% CI 3.422, 13.641]), but not viral hepatitis. No significant MD was observed between liver cirrhosis and HCC patients., Conclusion: Adiponectin levels are significantly elevated in liver cirrhosis, especially in advanced stages, potentially serving as a biomarker for advanced cirrhosis. Adiponectin also differentiates cirrhosis from other CLD, including NAFLD. However, its role in distinguishing cirrhosis from viral hepatitis and HCC is limited., (© 2024 The Author(s). European Journal of Clinical Investigation published by John Wiley & Sons Ltd on behalf of Stichting European Society for Clinical Investigation Journal Foundation.)

AdipoRon is an adiponectin receptor 1, 2 (ADIPOR1 and ADIPOR2) agonist with potential antifibrotic effects. Whether AdipoRon can mitigate joint stiffness in a rabbit model of arthrofibrosis is unknown. We examined the efficacy of intravenous (IV) AdipoRon at mitigating contracture in a rabbit model of knee arthrofibrosis. Fifty-six female New Zealand White rabbits were divided into three dosing groups: vehicle (dimethyl sulfoxide, DMSO), 2.5 mg/kg AdipoRon, and 5 mg/kg AdipoRon. AdipoRon, in DMSO, was administered IV preoperatively and for 5 days postoperatively (30 rabbits, Aim 1). AdipoRon was again dosed similarly after Kirschner wire (K-wire) removal at 8 weeks (26 rabbits; Aim 2). The primary outcome of joint passive extension angle (PEA,°) was measured at 8, 10, 12, 16, and 24 weeks following index surgery. At 24 weeks, rabbits were euthanized and limbs were harvested to measure posterior capsular stiffness (N cm/°). In Aim 1, the 5 mg/kg treated rabbits had a significant increase in PEA when compared to controls at 16-week (p < 0.05). In Aim 2, the 5 mg/kg treated rabbits had a significant increase in PEA when compared to controls at 10-week (p < 0.05). In both aims, no significant differences were observed at later time points. Capsular stiffness was no different in any group. We are the first to report the efficacy of IV AdipoRon in a rabbit model of arthrofibrosis. We identified a significant dose-dependent decrease in joint PEA at early time points; however, no differences were observed between groups at later time points. Clinical Significance: The present investigation provided the first assessment of AdipoRon's efficacy in mitigating knee stiffness in the current gold standard rabbit model of arthrofibrosis. Results of this investigation provided further evidence as to the potential role of AdipoRon as a preventative for arthrofibrosis in large mammals., (© 2024 Orthopaedic Research Society.)

Abstract This study aimed to analyze the association between elevated gamma‐glutamyl transpeptidase (GGT) and metabolic syndrome (MetS), hepatic steatosis, and fibrosis in patients with nonalcoholic fatty liver disease (NAFLD). From August 2013 to August 2018, a community‐based study was conducted in the northeastern part of Taiwan. Patients who underwent abdominal ultrasonography (US) and had no history of alcoholic liver disease were included. According to a US examination showing fatty liver degree, 1566 patients with NAFLD were divided into four groups: normal GGT, isolated GGT elevation, isolated alanine aminotransferase (ALT) elevation, and both GGT and ALT elevation groups. Further 1147 participants with normal serum ALT, GGT, and the abdominal US were included as the control group. GGT levels were associated with high sensitivity C‐reactive protein, lower adiponectin, diabetes mellitus, and chronic kidney disease. A stepwise increase in odds ratio (OR) for MetS was found in the normal GGT group (OR = 1.71), isolated GGT elevation group (OR = 3.06), isolated ALT elevation (OR = 4.00), and both GGT + ALT elevation group (OR = 4.17) than the control group. Linear regression analysis revealed a positive association between GGT/ALT value and hepatic steatosis degree, GGT value, and degree of hepatic fibrosis. Hence, GGT elevation is associated with MetS, hepatic steatosis, and fibrosis in patients with NAFLD.

Abstract Aims/Introduction Obesity is characterized by disturbed adipocytokine expression and insulin resistance in adipocytes. Growth arrest‐specific 6 (GAS6) is a gene encoding the Gas6 protein, which is expressed in fibroblasts, and its related signaling might be associated with adipose tissue inflammation, glucose intolerance and insulin resistance. The aim of this study was to investigate the associations among Gas6, adipocytokines and insulin resistance in adipocytes. Materials and Methods Mature Simpson Golabi Behmel Syndrome adipocytes were treated with high levels of insulin to mimic insulin resistance, and were examined for the expressions of Gas6, cytokines and adipocytokines from preadipocytes in differentiation. In an animal study, high‐fat diet‐induced obese mice were used to verify the Gas6 expression in vitro. Results During the differentiation of adipocytes, the expression of Gas6 gradually decreased, and was obviously downregulated with adipocyte inflammation and insulin resistance. Gas6 levels were found to be in proportion to the expression of adiponectin, which has been regarded as closely relevant to improved insulin sensitivity after metformin treatment. Similar results were also confirmed in the animal study. Conclusions Our results suggest that Gas6 might modulate the expression of adiponectin, and might therefore be associated with insulin resistance in adipose tissues.

Abstract Background The adiponectin‐to‐leptin (A/L) ratio has been identified as a potential surrogate biomarker for metabolic disorders. However, it remains unknown whether the serum A/L ratio is associated with heart rate variability in paroxysmal atrial fibrillation (AF). Methods For this retrospective study, we included consecutive patients who underwent 24‐h long‐range electrocardiogram examination in our center for paroxysmal AF. The results of echocardiography, heart rate variability tests, and blood tests were also retrieved. Multivariate line regression analysis was performed to evaluate identify factors independently associated with heart rate variability. Results Among the 85 included patients with paroxysmal AF, the median A/L ratio was 1.71. Univariate analysis indicated that patients with a low A/L ratio (

Abstract Objective Cardiovascular diseases and vascular aging are common in patients with diabetes. High glucose is a major cause of vascular aging and cardiovascular diseases. Premature senescence of vascular smooth muscle cells (VSMCs) is one of the main contributors to vascular aging. Adiponectin has been demonstrated to have an anti‐aging effect. The present study explored the mechanisms by which adiponectin protects VSMCs against high‐glucose‐induced senescence. Methods Senescence‐associated β‐galactosidase (SA‐β‐gal) staining was used to detect senescence cells. Western blot was used for measuring protein levels. Flow cytometry was carried out to detect the cell cycle and telomeric repeat amplification protocol (TRAP)–polymerase chain reaction (PCR) silver staining was selected to measure the telomerase activity. Results Premature senescence of VSMCs was induced by high glucose (30 mM) in a time‐dependent manner, which was verified by an increased number of senescence cells, p21 and p53 expression, as well as the decreased proliferation index. High glucose reduced telomerase activity of VSMCs via inhibition of the AMPK/TSC2/mTOR/S6K1 pathway and activation of the PI3K/Akt/mTOR/S6K1 pathway, while adiponectin treatment significantly increased telomerase activity of VSMCs through activation of AMPK/TSC2/mTOR/S6K1 signaling and inhibition of PI3K/Akt/mTOR/S6K1 signaling. Conclusion Adiponectin attenuated the high‐glucose‐induced premature senescence of VSMCs via increasing telomerase activity of VSMCs, which was achieved by activation of AMPK/TSC2/mTOR/S6K1 signaling and inhibition of PI3K/Akt/mTOR/S6K1 signaling.

Abstract Aims/Introduction The incidence of severe hypoglycemia and its risk factors including an insulin‐sensitizing adipokine, adiponectin, were prospectively investigated in Japanese patients with type 1 or insulin‐treated type 2 diabetes. Materials and Methods A total of 207 participants with type 1 diabetes (mean age 55 years) and 1,396 with insulin‐treated type 2 diabetes (mean age 65 years) from the local diabetes registry were followed for 5 years (follow‐up rate 99%). Severe hypoglycemia was defined as events requiring the assistance of others for recovery from hypoglycemia. Results The incidence of severe hypoglycemia was 9.2 per 100 person‐years in those with type 1 diabetes, and 2.3 per 100 person‐years in those with insulin‐treated type 2 diabetes, respectively. For type 1 diabetes, the risk was significant in those with a history of severe hypoglycemia within the previous year, slow eating and higher serum adiponectin (the highest vs the lowest in quartile hazard ratio 2.36, 95% confidence interval 1.22–4.69). For insulin‐treated type 2 diabetes, the risk included age ≥65 years, history of severe hypoglycemia within the previous year, alcohol consumption ≥60 g/day, larger insulin dose and higher serum adiponectin (the highest vs the lowest in quartile, hazard ratio 2.95, 95% confidence interval 1.22–4.69). For all participants, the incidence of severe hypoglycemia increased along with serum adiponectin (age‐ and sex‐adjusted hazard ratio 1.65 per 1 standard deviation increase of log serum adiponectin, 95% confidence interval 1.45–1.87). Conclusions The incidence of severe hypoglycemia was prospectively determined, and the association between severe hypoglycemia and higher serum adiponectin was observed in Japanese patients with type 1 and insulin‐treated type 2 diabetes.

Abstract Obesity has been identified as a risk factor for developing breast cancer in post‐menopausal period in humans and has been suspected to be associated with a worse prognosis also in the bitch. The aims of this study were to investigate the association between body condition score (BCS) and the prognosis of canine mammary carcinomas (CMCs) and the relationships between adiponectin expression and tumour behaviour. Seventy‐three bitches with tubular, tubulopapillary, solid or complex carcinomas were included in the present study. For each dog, evaluation of BCS was conducted using a nine‐point BCS system and the study population was divided into normal weight (4–5/9 points; n = 42), overweight (6–7/9 points; n = 19) and obese (8–9/9 points; n = 12). Type of diet (commercial, homemade or mixed) was recorded. After surgical excision, histological type, tumour size and nodal status were assessed and adiponectin expression was determined and quantified by immunohistochemistry and morphometric analysis. CMC histotype was not correlated with BCS, while a positive correlation between BCS and histological grade (p

Summary Objective Low testosterone and hyperuricemia are associated with metabolic syndrome (MetS). However, little is known about the nature of the relationships between serum testosterone and sex hormone‐binding globulin (SHBG) concentrations, and hyperuricemia. Methods We evaluated the relationships between serum testosterone (calculated bioavailable testosterone [cbT], calculated free testosterone [cFT], SHBG, and total testosterone [TT]) and metabolic indices, including serum uric acid, in 363 Japanese males (mean age 51.1 ± 8.7 years) at routine health examinations. Results Participants with hyperuricemia (≥7.0 mg/dL) demonstrated lower adiponectin, cbT, cFT, SHBG, and TT, but a higher MetS prevalence and higher values of various MetS‐related parameters than those without hyperuricemia (

Abstract Objective Adipokines, such as adiponectin and chemerin, regulate fat metabolism and are critical for the development of atherosclerosis. Investigating the correlations of adiponectin and chemerin with atherosclerosis in older adults with type 2 diabetes mellitus (T2DM) will shed light on the search for new markers for early diagnosis of diabetic atherosclerosis. Methods A total of 120 older T2DM patients and nine healthy controls were enrolled in this study. The clinical parameters, such as brachial‐ankle pulse wave velocity (ba‐PWV), adiponectin, and chemerin, were examined and recorded. T2DM subjects were divided into three groups according to ba‐PWV level (high, medium, or low). The data were processed and analyzed by identical methods. Results Significantly higher chemerin and lower adiponectin levels were detected in the plasma of T2DM patients than in healthy controls. The plasma levels of chemerin and adiponectin were negatively correlated in T2DM patients. Moreover, chemerin and adiponectin were significantly correlated with body mass index, ankle‐brachial index, insulin, and ba‐PWV. Multiple linear regression analysis revealed that chemerin and adiponectin were independently affecting ba‐PWV. Conclusion Adiponectin and chemerin are potential markers for diagnosis and monitoring of early stage of atherosclerosis in older adults with T2DM. Further clinical investigations are required to confirm these markers.

Adiponectin exhibits potent antitumor activities. Herein, we examined the molecular mechanisms underlying suppression of tumor growth by globular adiponectin (gAcrp). We demonstrated that gAcrp suppressed B‐cell lymphoma 2 (Bcl‐2) expression, an anti‐apoptotic gene, by inducing its mRNA destabilization, which was accompanied with a decrease in cell viability and increased caspase‐3 activity in hepatic cancer cells. In addition, gAcrp increased expression of tristetraprolin (TTP) and AU‐rich element RNA‐binding protein 1 (AUF1), which are mRNA stability regulatory proteins. Moreover, gAcrp‐induced suppression of Bcl‐2 expression was abrogated by knockdown of TTP or AUF1. These data indicate that gAcrp induces apoptosis of hepatic cancer cells by TTP‐ and AUF1‐mediated Bcl‐2 mRNA destabilization, and further suggest that TTP and AUF1 are novel targets mediating the antitumor activity of adiponectin.

Abstract Hypoadiponectinemia is speculated to play a key role in the relationship between obesity and COVID‐19 respiratory failure. However, only one study has examined adiponectin levels in COVID‐19 patients, and none have investigated adiponectin levels strictly in patients with acute respiratory failure. In this study, we performed a retrospective case‐control study of adipokine levels in patients with acute respiratory failure caused by either COVID‐19 or other viral/bacterial source. All patients with COVID‐19 respiratory failure in the University of Virginia Biorepository and Tissue Research database were included. We also selected patients with non‐COVID‐19 infectious respiratory failure from the same biorepository to serve as a comparison cohort. Plasma adipokine levels were measured on three occasions during the first 72 hours of hospitalization. Twelve patients with COVID‐19 respiratory failure and 17 patients with other infectious respiratory failure were studied. Adiponectin levels were significantly lower in patients with COVID‐19 respiratory failure, even after adjustment for age, sex, BMI, and other covariates. In conclusion, adiponectin levels appear to be reduced in COVID‐19 respiratory failure. Larger studies are needed to confirm this report.

Background The menopausal transition is characterized by increased cardiovascular risk, weight gain, and increased adiposity for many women. The adipose‐derived secretory proteins adiponectin and leptin are associated with insulin resistance, metabolic syndrome, and cardiovascular disease but their role in subclinical atherosclerotic disease is unclear. This cross‐sectional study evaluated the associations of adiponectin and leptin with carotid artery intima‐media thickness, adventitial diameter, presence of carotid plaques, and brachial‐ankle pulse wave velocity (baPWV) in women aged 54 to 65 years. Methods and Results Participants were 1399 women from SWAN (Study of Women's Health Across the Nation), a community‐based study of women transitioning through menopause. Carotid ultrasound and baPWV measures were obtained at SWAN follow‐up visits 12 or 13, when 97% of participants were post‐menopausal. Adipokines were assayed from serum specimens obtained concurrently at these visits. Linear and logistic regression models were used to evaluate adiponectin or leptin, both log‐transformed attributable to skewness, in relationship to carotid artery intima‐media thickness, adventitial diameter, baPWV, and presence of carotid plaque. Covariates included age, race, study site, smoking, alcohol use, obesity, cardiovascular disease risk factors, and menopausal status. Lower levels of adiponectin were related to greater carotid artery intima‐media thickness, wider adventitial diameter, and faster baPWV; associations were attenuated after adjusting for cardiovascular disease risk factors. Higher levels of leptin were associated with greater carotid artery intima‐media thickness and wider adventitial diameter in minimally and fully adjusted models, and contrary to expectation, with slower baPWV, particularly among women with diabetes mellitus or obesity. Conclusions Adiponectin and leptin are 2 important inflammatory pathways that may contribute to adverse subclinical cardiovascular disease risk profiles in women at midlife.

Abstract Aims/Introduction An association between the pathogenesis of type 2 diabetes mellitus (T2D) and that of metabolic syndrome (MS) in obese children has been suggested. We clarified the critical markers for the development of T2D in obese Japanese children. Methods One hundred and seven obese children who visited our outpatient clinic were enrolled in this study. The obese subjects were divided into 3 groups: Group A, T2D (n = 19); Group B, MS but not T2D (n = 19); and Group C: non‐T2D, non‐MS (n = 69). In all the subjects, a biochemical examination was performed and the serum adiponectin and leptin levels were measured. Visceral adipose tissue (VAT) and subcutaneous adipose tissue (SAT) were measured using computed tomography images. Results Group A tended to have higher VAT values and VAT/SAT ratios and lower leptin and adiponectin levels, compared with Groups B and C. In Group A, the alanine aminotransferase (ALT) level was significantly higher and the aspartate aminotransferase (AST)/ALT ratio was significantly lower than in Group C. A receiver operating characteristic (ROC) analysis showed that the optimal cut‐off point for adiponectin was 6.4 μg/mL (AUC = 0.859). The cut‐off points for ALT, the AST/ALT ratio and VAT were 35 IU/L (AUC = 0.821), 0.85 (AUC = 0.794) and 78 cm2 (AUC = 0.713), respectively. Group A had a significantly higher frequency of a family history of T2D than Group B. Conclusions Our study revealed that the adiponectin level, ALT level, AST/ALT ratio, VAT value and a family history of T2D may be critical characteristic markers for T2D among obese Japanese children.

Abstract The purpose of this research was to identify if Sirt3 plays a role in marrow adipogenesis and adipokines secretion, especially adiponectin using bone marrow‐derived stroma (ST2) cell model. Sirt3 overexpression leads to a significant increase in adipogenesis compared to controls. The induction of adipogenesis by Sirt3 is associated with increased gene expression of adipocyte markers as well as adiponectin/adipokines. In sharp contrast, the inhibition of Sirt3 exhibited significantly decreased adipogenesis, adipocyte markers, and adiponectin/adipokines compared to the controls. Interestingly, perilipin 1 (Plin 1) expression was decreased in Sirt3 induction but increased in Sirt3 inhibition. One hundred and fifteen mitochondrial acetylated peptides from 67 mitochondrial proteins had lower levels of acetylation in adipocytes induced by Sirt3 overexpression (Sirt3OE) compared to the control. Of the 67 proteins less enriched in acetylation, 22 acetylated proteins were decreased by more than twofold. These proteins are considered potential Sirt3 substrates in adipogenesis. In conclusion, Sirt3 has a novel, important role in modulating adipogenesis and adiponectin/adipokine expression. The connection axis among Sirt3‐adipogenesis‐adipokines was linked to its substrates by mass spectrometry analysis. These findings contribute to the efforts of revealing Sirt3 functions and Sirt3 usage as a potential target for treatment of metabolic homeostasis and diseases including type 2 diabetes.

Background: Hypoadiponectinaemia is a risk factor for endocrinopathic laminitis, but the directionality and nature of its association with insulin dysregulation is unclear., Objectives: To investigate the effects of short-term induced hyperinsulinaemia and dexamethasone challenge on circulating [total adiponectin] and whole blood expression of adiponectin (AdipoR1 and AdipoR2), insulin, and insulin-like growth factor 1 (IGF-1) receptors in insulin-sensitive ponies., Study Design: In vivo experiment., Methods: Six never-laminitic, insulin-sensitive, native-breed UK ponies first underwent a dexamethasone challenge (0.08 mg/kg i.v.) with blood samples collected every 15 min over 3 h. After a 14-day washout period, hyperinsulinaemia was induced for 9 h via a euglycaemic-hyperinsulinaemic clamp (EHC), with blood samples collected every 30 min. Serum [insulin], plasma [total adiponectin], and plasma [IGF-1] were measured using validated assays and receptor gene expression was assessed via quantitative polymerase chain reaction (qPCR). Finally, whole blood was incubated with 10-1000 ng/mL dexamethasone for 3 h at 37°C to investigate its direct effects on gene expression., Results: There were no adverse effects observed during either protocol. Dexamethasone challenge did not alter circulating [insulin] or [total adiponectin] at any time-point, but significantly upregulated AdipoR1 and IGF-1R expression at 150 and 180 min. Ex vivo incubation of whole blood with dexamethasone did not alter expression of the genes examined. There was no change in [total adiponectin] or expression of the genes examined associated with EHC-induced hyperinsulinemia., Main Limitations: This was a small sample size that included only native-breed ponies; total adiponectin was measured rather than high-molecular-weight adiponectin., Conclusions: Short-term induced hyperinsulinaemia and dexamethasone challenge did not affect circulating [total adiponectin] in insulin-sensitive ponies. However, dexamethasone administration was associated with upregulation of two receptors linked to adiponectin signalling, suggesting that a physiological response occurred possibly to counteract dexamethasone-associated changes in tissue insulin sensitivity., (© 2023 MARS Horsecare and The Authors. Equine Veterinary Journal published by John Wiley & Sons Ltd on behalf of EVJ Ltd.)

Background: The hormones insulin and adiponectin are commonly measured in equids because of their involvement in endocrinopathic laminitis. These are currently measured in serum/plasma, although jugular venipuncture can cause stress in some animals and may be impossible in needle-shy individuals. However, both hormones can be measured in saliva in other species., Objectives: To determine whether [insulin] and [total adiponectin] are detectable in equine saliva using automated assays and whether saliva collection is associated with changes in stress indicators. Additionally, the correlation between serum and salivary [insulin] was investigated., Study Design: In vivo experiment., Methods: Paired blood and saliva samples were collected from eight adult ponies at multiple time-points (n = 45 paired samples). [Insulin] and [total adiponectin] were measured using automated assays validated for equine serum/plasma. Blink rates and heart rates were determined, using video recordings and a wearable heart rate monitor respectively, to assess the effects of sample collection on stress indicators compared with a control situation without a stressful stimulus., Results: [Total adiponectin] was undetectable in saliva. However, salivary [insulin] was measurable with acceptable inter-assay (1.3 ± 0.9%) and intra-assay (1.1 ± 0.6%) variability. Blink and heart rates during saliva collection did not differ significantly from those in the control setting. Serum and salivary [insulin] were not significantly correlated., Main Limitations: Small sample size comprising native UK ponies; potential sampling bias as animals were recruited to the study partly based on their behaviour during blood sampling; saliva collected from unfasted animals., Conclusions: Insulin is measurable in equine saliva using an automated assay currently available in the UK, but further validation and the determination of specific diagnostic thresholds are required. Saliva collection was not associated with changes in stress indicators. Further research is therefore needed to determine the potential of equine saliva as a non-invasive alternative to blood for insulin determination., (© 2023 MARS Horsecare and The Authors. Equine Veterinary Journal published by John Wiley & Sons Ltd on behalf of EVJ Ltd.)

Background: Equine metabolic syndrome is a collection of risk factors associated with an increased risk of endocrinopathic laminitis. All affected animals display insulin dysregulation and some may show adiponectin dysregulation and/or excessive adiposity. However, the relationship between obesity and hypoadiponectinaemia in equids remains unclear., Objectives: To investigate the relationship between obesity and circulating plasma total adiponectin (TA) concentrations in native-breed ponies in England., Study Design: Secondary data analysis., Methods: Data collected for three previous studies were retrospectively analysed and cohorts were pooled where possible (maximum sample size: n = 734 ponies). Correlations between [TA], age, and morphometric measures were assessed using Spearman's correlation coefficient. [TA] was compared between animals of different body condition score (BCS) classification (ideal-weight, overweight, and obese), breed, and body shape using Kruskal-Wallis with Dunn's post hoc tests, and sex using Mann-Whitney U test. The proportions of obese and ideal-weight ponies with basal hyperinsulinaemia and/or hypoadiponectinaemia were compared using a Chi-square test of homogeneity and post hoc z-test. Logistic regression was used to identify factors that may discriminate ponies with hypoadiponectinaemia., Results: [TA] was weakly positively correlated with BCS, height, weight, and weight:height ratio (Spearman's ρ = 0.14-0.29, p < 0.05). There were significant differences in [TA] in ponies with different BCS group classification, body shape, and breed. A greater percentage of obese (54.6%) than ideal-weight ponies (33.1%, p < 0.001) had both normal [TA] and [basal insulin], and a greater percentage of ideal-weight (38.6%) than obese ponies (16.5%, p < 0.001) showed hypoadiponectinaemia. Weight:height and BCS group were significant variables in a logistic regression of hypoadiponectinaemia but model fit and predictive accuracy were poor., Main Limitations: Retrospective study design, only native-breed ponies included., Conclusions: Morphometric measures such as BCS do not closely reflect [TA]. Circulating [TA] and [basal insulin] should be determined in all animals with predisposing factors, regardless of obesity status., (© 2023 MARS Horsecare and The Authors. Equine Veterinary Journal published by John Wiley & Sons Ltd on behalf of EVJ Ltd.)

Background: Serum insulin concentration at 60 min (InsulinT60) during an oral sugar test (OST) indicates future laminitis risk and insulin dysregulation (ID). Associations between InsulinT60 and physical and owner-reported variables may help clinicians select individuals for ID testing. Associations between InsulinT60 and other metabolic markers may help elucidate ID pathophysiology., Objectives: To describe associations between (A) season, physically-apparent and owner-reported factors and binary InsulinT60 interpretation (initial models) and (B) variables included in the initial models, other metabolic markers and continuous InsulinT60 (full models)., Study Design: Prospective longitudinal., Methods: Non-laminitic ponies were examined and OSTs (0.3 mL/kg Karo syrup) performed every 6 months (autumn and spring) for ≤4 years. Factors associated with InsulinT60 were determined using mixed-effects models with physical, owner-reported, season and serum/plasma markers as fixed effects and pony and premises identifiers as random effects. Autumn and spring data were analysed separately for full models., Results: One thousand seven hundred and sixty-three OSTs from 367 ponies were included. High-risk InsulinT60 (>153 μIU/mL) was independently associated with (odds ratio, 95% confidence interval [CI]): age (1.36, 1.16-1.60), body condition score (BCS) (2.38, 1.21-4.69), and bulging supraorbital fatpads (7.25, 2.1-24.98). However, the initial models provided little explanatory power (Nakagawa R 2  = 0.1-0.27). LoginsulinT60 was independently associated with (effect estimate, 95% CI): age (0.02, 0.01-0.04), Welsh/Welsh X breed (0.22, 0.05, 0.39), sex (gelding = -0.2, -0.34 to 0.06), BCS (0.16, 0.08-0.23), plasma adiponectin (-0.02, -0.02 to 0.01) and basal insulin (0.01, 0.01-0.01) in spring, and: age (0.03, 0.02-0.04), BCS (0.17, 0.08-0.26), bulging supraorbital fatpads (0.37, 0.2-0.54), turnout score (0.05, 0.02-0.09), plasma adiponectin (-0.01, -0.02 to 0.01), ACTH (per 10 pg/mL) (0.01, 0.00-0.01), triglycerides (0.28, 0.07-0.49) and InsulinT0 (0.01, 0.01-0.01) in autumn., Main Limitations: Only non-laminitic ponies in one region were included., Conclusions: Owner-reported and physically-apparent data were limited InsulinT60 predictors. InsulinT60 is a complex trait, independently associated with numerous variables, some with seasonal interactions., (© 2023 Mars Horsecare and The Authors. Equine Veterinary Journal published by John Wiley & Sons Ltd on behalf of EVJ Ltd.)

Abstract Preterm infants are at high risk for developing bronchopulmonary dysplasia and pulmonary hypertension from inflammatory lung injury. In adult models, adiponectin (APN)—an adipocyte‐derived hormone—protects the lung from inflammatory injury and pulmonary vascular remodeling. Cord blood APN levels in premature infants born

Abstract C1q/TNF‐related protein 3 (CTRP3) is a relatively novel adipose tissue‐derived cytokine (adipokine) which has been linked to improved glucose regulation and insulin sensitivity. However, the relationship between circulating CTRP3 levels and diabetes is controversial. CTRP3 can circulate in different oligomeric complexes: trimeric, hexameric, and high molecular weight (HMW) oligomeric complexes. However, the concentration of the different oligomeric complexes in human disease states has not been previously investigated. Therefore, the purpose of this study was to compare the levels of different oligomeric complexes of CTRP3 between type 2 diabetic and nondiabetic individuals. Additionally, the association between the oligomeric complexes and other serum factors was examined. CTRP3 primarily circulates in the HMW complex (>50%) and the hexametric multimer, with no CTRP3 detected in the trimeric complex or as a monomer. Further, no differences were observed in total, hexameric, or HMW CTRP3 levels regardless of diabetic status. Surprisingly, HMW CTRP3 was found to be positively correlated with circulating triglyceride levels. Combined, these data suggest that CTRP3 is associated with triglyceride regulation, not diabetic status. These data may explain some of the discrepancies in the literature as elevated triglyceride levels are often detected in patients with obesity and type 2 diabetes.

Recent studies showed that rapamycin improved diabetic complications. Here, we investigated the metabolic effects of rapamycin in type 2 diabetes model (T2DM) mice. Mice were treated with a daily intraperitoneal injection of rapamycin at 2 mg/kg or vehicle only for 3 weeks and were maintained on a high-fat diet. The treated diabetic mice exhibited decreased body weight, blood glucose levels, and fat mass. FGF21 expression was suppressed in C57B/L6 mice, but adiponectin expression increased both in FGF21 KO and C57B/L6 mice. These results suggest that rapamycin may alleviate FGF21 resistance in mice on a high-fat diet. The reduction of adipose tissue mass of the diabetic mice may be due to the increased adiponectin.

Background Elevated levels of ceramide, a sphingolipid known to cause a transition from nitric oxide (NO)– to hydrogen peroxide–dependent flow‐induced dilation (FID) in human arterioles, correlate with adverse cardiac events. However, elevations of ceramide are associated with changed concentrations of other sphingolipid metabolites. The effects of sphingolipid metabolites generated through manipulation of this lipid pathway on microvascular function are unknown. We examined the hypothesis that inhibition or activation of the ceramide pathway would determine the mediator of FID. Methods and Results Using videomicroscopy, internal diameter changes were measured in human arterioles collected from discarded adipose tissue during surgery. Inhibition of neutral ceramidase, an enzyme responsible for the hydrolysis of ceramide, favored hydrogen peroxide–dependent FID in arterioles from healthy patients. Using adenoviral technology, overexpression of neutral ceramidase in microvessels from diseased patients resulted in restoration of NO‐dependent FID. Exogenous sphingosine‐1‐phosphate, a sphingolipid with opposing effects of ceramide, also restored NO as the mediator of FID in diseased arterioles. Likewise, exogenous adiponectin, a known activator of neutral ceramidase, or, activation of adiponectin receptors, favored NO‐dependent dilation in arterioles collected from patients with coronary artery disease. Conclusions Sphingolipid metabolites play a critical role in determining the mediator of FID in human resistance arterioles. Manipulating the sphingolipid balance towards ceramide versus sphingosine‐1‐phosphate favors microvascular dysfunction versus restoration of NO‐mediated FID, respectively. Multiple targets exist within this biolipid pathway to treat microvascular dysfunction and potentially improve patient outcomes.

Background: Evidence has linked low-grade systemic inflammation and visceral adipose tissue (VAT) with development of chronic conditions. Cytokines and select proteins released by VAT may promote a low-grade inflammatory response. A number of equations have been developed to estimate VAT levels. In this study, we compared predicted VAT equation relationships with biomarkers of inflammation., Methods: This was a cross-sectional study of 2038 men and women aged 46-73 years. Correlation and linear regression analyses were performed to examine inflammatory biomarker relationships with four commonly assessed anthropometric measures and 10 predicted VAT equations., Results: Compared with anthropometric measures, predicted VAT equations were found to explain a greater proportion of variance in CRP (R 2  = .075, p = .001), IL-6 (R 2  = .060, p = .001), TNF-α (R 2  = .017, p = .005), resistin (R 2  = .011, p = .012), monocyte (R 2  = .027, p = .001), eosinophil (R 2  = .012, p = .01) and basophil (R 2  = .015, p = .002) levels in males, and a greater variance in concentrations of C3 (R 2  = .175, p = .001), IL-6 (R 2  = .090, p = .001), TNF-α (R 2  = .036, p = .001), adiponectin (R 2  = .121, p = .001), the adiponectin-to-leptin ratio (R 2  = .444, p = .001), resistin (R 2  = .025, p = .001), white blood cell count (R 2  = .057, p = .001), neutrophils (R 2  = .061, p = .001) and lymphocytes (R 2  = .020, p = .001) in females., Conclusion: Equations for assessing VAT levels might be useful to characterise metabolic health. Further studies that examine predicted VAT relationships with disease and mortality outcomes are warranted., (© 2023 The Authors. European Journal of Clinical Investigation published by John Wiley & Sons Ltd on behalf of Stichting European Society for Clinical Investigation Journal Foundation.)