Circulating levels of resistin and risk of type 2 diabetes in men and women: results from two prospective cohorts

Genetic variation in the RETN promoter, accompanied by latent sarcopenic obesity, led to insulin resistance in a Japanese cohort: the Toon Genome Study

AIMS/HYPOTHESIS

Resistin, inducing insulin resistance, is elevated in the sera of individuals with the G-A haplotype at c.-420 C>G (rs1862513) and c.-358 G>A (rs3219175). This haplotype is associated with visceral obesity and low grip strength. To elucidate the hidden relationship between the G-A haplotype and insulin resistance, integration of specific phenotypes defined by body composition and 75 g OGTT would be a promising strategy.

METHODS

The 803 Japanese participants (average age: 62 years), attending annual medical checkups, were evaluated every 5 years. Participants were categorised by skeletal muscle mass, visceral fat score and OGTT results. Hierarchical clustering was performed using body composition and glucose metabolism parameters. Whole blood cells from participants homozygous for the G-A or C-G haplotype (n=25 and 33, respectively), matched for age, sex and BMI, using propensity score matching, were used for RNA-seq, pathway analysis and RT-PCR.

RESULTS

Multivariate analysis showed that individuals with the G-A haplotype, when accompanied by latent skeletal muscle loss and visceral obesity (latent sarcopenic obesity), presented a pronounced deterioration in insulin resistance over a 5 year period. Cluster 2, identified using hierarchical clustering, was characterised by low skeletal muscle mass, visceral obesity and insulin resistance. This cluster, with the G-A haplotype, demonstrated deterioration in insulin resistance. RNA-seq and RT-PCR revealed altered expression of mitophagy-related genes in whole blood cells of the G-A homozygotes.

CONCLUSIONS/INTERPRETATION

The G-A haplotype, accompanied by latent low skeletal muscle mass and visceral obesity, led to the deterioration of insulin resistance over a 5 year period in this cohort, possibly through the altered expression of mitophagy-related genes.

Evaluation of Selected Pro- and Anti-Inflammatory Adipokines in Colostrum from Mothers with Gestational Diabetes Mellitus

Adipokines related to gestational diabetes mellitus (GDM) are an emerging area of interest. The aim of this study was to evaluate the associations between GDM and adipokine levels in human milk. This was an observational cohort study targeting mothers with gestational diabetes, which evaluated the association of maternal hyperglycemia severity, classified as GDM-G1 (diet treatment) and GDM-G2 (insulin treatment), with colostral adipokines involved in pro- and anti-inflammatory processes. Colostrum was collected from hyperglycemic (N = 34) and normoglycemic (N = 26) mothers, and adipokine levels were determined by immunoenzymatic assay. Among anti-inflammatory adipokines, only for irisin and vaspin, but not for obestatin and adropin, were significantly different levels noted between the GDM-G1, GDM-G2 and non-GDM cohorts. Colostrum of the GDM-G2 subgroup contained more vaspin (4.77 ng/mL) than that of normoglycemic mothers (3.12 ng/mL) and more irisin (26.95 μg/mL) than in the GDM-G1 subgroup (17.59 μg/mL). The levels of pro-inflammatory adipokines, namely, dermcidin, chemerin and visfatin, were at similar levels irrespective of maternal glycemia. Moreover, irisin showed a negative correlation with dermcidin in GDM-G2 and non-GDM cohorts. Associations were observed between colostral irisin and maternal preconception BMI, dermcidin and gestational age, and vaspin and maternal age. This study provides evidence that the way of restoring glucose homeostasis in pregnant women has an impact on the anti-inflammatory adipokines irisin and vaspin, but not on obestatin and adropin. GDM, regardless of severity, did not influence the colostral pro-inflammatory adipokines visfatin, chemerin and dermcidin.

Relationship between physical activity and abdominal obesity and metabolic markers in postmenopausal women

This study aimed to investigate the impact of physical activity indicators monitored by the POLAR accelerometer on body obesity indicators, metabolic syndrome parameters, and energy metabolism hormones in postmenopausal women. Was included 71 participants from this study program (68.8 ± 4.3 years). We divided participants into LPA and MVPA groups based on their level of moderate to vigorous physical activity per week; Physical activity levels over 7 days were assessed using a POLAR accelerometer, with daily step counts and sedentary time recorded. Measurements included waist circumference, visceral fat volume, body fat percentage, blood pressure, fasting blood glucose, triglyceride levels, HDL cholesterol, and energy metabolism hormone levels (leptin, resistin, adiponectin). The MVPA group displayed lower waist circumference, body fat percentage, abdominal fat, and BMI compared to the LPA group (p < 0.05). A significant negative correlation was observed between daily step count and obesity indicators, including waist circumference (r = -0.301), body fat percentage (r = -0.295), abdominal fat (r = -0.318), and BMI (r = -0.238). Conversely, sedentary time showed a positive correlation with obesity indicators such as waist circumference (r = 0.258), body fat percentage (r = 0.239), and abdominal fat (r = 0.244). Moreover, daily step count exhibited a significant negative correlation with leptin levels (r = -0.245), while sedentary time was positively correlated with the energy metabolic factor leptin (r = 0.279). Waist circumference demonstrated significant positive correlations with triglycerides, blood glucose, adiponectin, resistin, and leptin levels. Postmenopausal women who engage in at least 150 min of MVPA weekly show lower obesity indices. There is a significant correlation between physical activity levels and obesity indicators, which relate to metabolic syndrome and energy metabolism factors. Thus, increased physical activity may help prevent metabolic syndrome and cardiovascular diseases in this population.

The Trend of Changes in Adiponectin, Resistin, and Adiponectin-Resistin Index Values in Type 2 Diabetic Patients with the Development of Metabolic Syndrome

Background and Objectives: This study aimed to investigate the novel adiponectin-resistin (AR) index as a predictor of the development of metabolic syndrome (MetS) in individuals with type 2 diabetes mellitus (T2DM). MetS is common in T2DM and increases cardiovascular risk. Adiponectin and resistin, adipokines with opposing effects on insulin sensitivity and inflammation, make the AR index a potential marker for metabolic risk. Materials and Methods: This prospective observational study included 80 T2DM participants (ages 30-60) from Sarajevo, Bosnia and Herzegovina, over 24 months. The participants were divided into two groups: T2DM with MetS (n = 48) and T2DM without MetS (n = 32). Anthropometric data, biochemical analyses, and serum levels of adiponectin and resistin were measured at baseline and every six months. The AR index was calculated using the formula AR = 1 + log10(R) - 1 + log10(A), where R and A represent resistin and adiponectin concentrations. Logistic regression identified predictors of MetS. Results: T2DM patients who developed MetS showed a significant decline in adiponectin levels (40.19 to 32.49 ng/mL, p = 0.02) and a rise in resistin levels (284.50 to 315.21 pg/mL, p = 0.001). The AR index increased from 2.85 to 2.98 (p = 0.001). The AR index and resistin were independent predictors of MetS after 18 months, with the AR index showing a stronger predictive value (p = 0.007; EXP(B) = 1.265). Conclusions: The AR index is a practical marker for predicting MetS development in T2DM participants, improving metabolic risk stratification. Incorporating it into clinical assessments may enhance early detection and treatment strategies.

Biomarkers of insulin sensitivity/resistance

In recent years, remarkable advancements in elucidating the intricate molecular underpinnings of type 2 diabetes mellitus (T2D) have been achieved. Insulin resistance (IR) has been unequivocally acknowledged as the driving pathogenetic mechanism of T2D, preceding disease onset by several years. Nonetheless, diagnostic tools for ascertaining IR are lacking in current clinical practice, representing a critical unmet need; use of the hyperinsulinemic-euglycemic glucose clamp, widely accepted as the gold standard method for evaluating IR at present, is cumbersome in a clinical setting. Thus, the development of well-validated, reliable, and affordable biomarkers of IR has attracted considerable attention from the research community. The biomarkers under investigation can be divided into two major categories: (1) indices or ratios, comprising parameters obtained from a basic or comprehensive metabolic panel and/or derived from anthropometric measurements, and (2) circulating molecules implicated in pathophysiological processes associated with IR. Furthermore, numerous novel biomarkers, including markers of β-cell dysfunction, radiographic quantification of excess visceral adipose tissue, T2D prediction models, certain microRNAs and metabolomic biomarkers, have also provided promising preliminary results. This narrative review aims to present current evidence pertaining to the most notable and exciting biomarkers of IR that are under rigorous evaluation.

The Role of Adipokines between Genders in the Pathogenesis of Osteoarthritis

Osteoarthritis (OA) is a chronic, progressive, degenerative joint disease characterized by joint pain, stiffness, and limited movement. It presents significant intra- and inter-individual variability-in particular, between genders. Recent research has increasingly focused on the role of adipokines-especially leptin, adiponectin, and resistin-in the development of OA. Adipokines, peptide hormones primarily secreted by adipose tissue, are involved in crucial physiological processes related to metabolism and immunity. They can also impact bone and cartilage turnover by interacting with joint cells such as osteoblasts, osteoclasts, chondrocytes, and mesenchymal stem cells, thereby linking inflammation with bone cartilage homeostasis. This review aims to elucidate the structure and functions of various adipokines, their serum and synovial levels, and their association with clinical presentation and radiographic progression in OA patients, with a focus on differences between sexes. A narrative literature review was conducted using three databases specifically analyzing sex differences. OA patients generally show elevated serum and synovial levels of leptin, chemerin, and visfatin, as well as high plasma levels of resistin and visfatin. In contrast, synovial levels of adiponectin and omentin are reduced in OA patients compared to healthy individuals, with an inverse relationship to disease severity, suggesting a potential protective role. Resistin and leptin were positively correlated with pain severity and radiographic progression, while adiponectin's role in OA remains controversial. Regarding sex differences, male OA patients exhibited higher serum levels of leptin, chemerin, and omentin compared to healthy controls, with a positive correlation to the BMI and estrogen levels, potentially explaining the sexual dimorphism observed in this condition. Studies on visfatin and lipocalin did not reveal significant differences in synovial or serum levels between the sexes. The role of resistin remains controversial. Adipokines influence the joint microenvironment and contribute to the progression of osteoarthritis (OA). However, the precise biological mechanisms are not yet fully understood due to the complex interactions between the metabolic, mechanical, and immune systems. Further research is needed to clarify their roles in OA and to identify targeted therapies for managing this degenerative disease.

Influence of Type 2 Diabetes and Adipose Tissue Dysfunction on Breast Cancer and Potential Benefits from Nutraceuticals Inducible in Microalgae

Breast cancer (BC) represents the most prevalent cancer in women at any age after puberty. From a pathogenetic prospective, despite a wide array of risk factors being identified thus far, poor metabolic health is emerging as a putative risk factor for BC. In particular, type 2 diabetes mellitus (T2DM) provides a perfect example bridging the gap between poor metabolic health and BC risk. Indeed, T2DM is preceded by a status of hyperinsulinemia and is characterised by hyperglycaemia, with both factors representing potential contributors to BC onset and progression. Additionally, the aberrant secretome of the dysfunctional, hypertrophic adipocytes, typical of obesity, characterised by pro-inflammatory mediators, is a shared pathogenetic factor between T2DM and BC. In this review, we provide an overview on the effects of hyperglycaemia and hyperinsulinemia, hallmarks of type 2 diabetes mellitus, on breast cancer risk, progression, treatment and prognosis. Furthermore, we dissect the role of the adipose-tissue-secreted adipokines as additional players in the pathogenesis of BC. Finally, we focus on microalgae as a novel superfood and a source of nutraceuticals able to mitigate BC risk by improving metabolic health and targeting cellular pathways, which are disrupted in the context of T2DM and obesity.

Aging adipose tissue, insulin resistance, and type 2 diabetes

With the increase of population aging, the prevalence of type 2 diabetes (T2D) is also rising. Aging affects the tissues and organs of the whole body, which is the result of various physiological and pathological processes. Adipose tissue has a high degree of plasticity and changes with aging. Aging changes the distribution of adipose tissue, affects adipogenesis, browning characteristics, inflammatory status and adipokine secretion, and increases lipotoxicity. These age-dependent changes in adipose tissue are an important cause of insulin resistance and T2D. Understanding adipose tissue changes can help promote healthy aging process. This review summarizes changes in adipose tissue ascribable to aging, with a focus on the role of aging adipose tissue in insulin resistance and T2D.

Intermittent fasting favorably modulates adipokines and potentially attenuates atherosclerosis

Adipose tissue is now recognized as an endocrine organ that secretes bioactive molecules called adipokines. These biomolecules regulate key physiological functions, including insulin sensitivity, energy metabolism, appetite regulation, endothelial function and immunity. Dysregulated secretion of adipokines is intimately associated with obesity, and translates into increased risk of obesity-related cardiovasculo-metabolic diseases. In particular, emerging evidence suggests that adipokine imbalance contributes to the pathogenesis of atherosclerosis. One of the promising diet regimens that is beneficial in the fight against obesity and cardiometabolic disorders is intermittent fasting (IF). Indeed, IF robustly suppresses inflammation, meditates weight loss and mitigates many aspects of the cardiometabolic syndrome. In this paper, we review the main adipokines and their role in atherosclerosis, which remains a major contributor to cardiovascular-associated morbidity and mortality. We further discuss how IF can be employed as an effective management modality for obesity-associated atherosclerosis. By exploring a plethora of the beneficial effects of IF, particularly on inflammatory markers, we present IF as a possible intervention to help prevent atherosclerosis.

Increases in BMI contribute to worsening inflammatory biomarkers related to breast cancer risk in women: a longitudinal study

BACKGROUND

Inflammatory adipokines and cytokines play a pivotal role in linking obesity and breast cancer (BC) risk in women. We investigated the longitudinal associations between BMI change and trajectories of inflammatory biomarkers related to BC risk.

METHODS

A longitudinal study was conducted among 442 Chinese women with 3-year repeated measures from 2019 to 2021. Plasma circulating inflammatory biomarkers related to BC risk, including adiponectin (ADP), resistin (RETN), soluble leptin receptor (sOB-R), insulin-like growth factor-binding protein-3 (IGFBP-3), and C-reactive protein (CRP), were examined annually. Linear mixed-effect models (LMM) were applied to investigate associations of time-varying BMI with trajectories of biomarkers. We additionally examined the modification effect of baseline BMI groups, menopausal status, and metabolic syndrome.

RESULTS

BMI was associated with increased levels of RETN, CRP, sOB-R, and decreased levels of ADP at baseline. An increasing BMI rate was significantly associated with an average 3-year increase in RETN (β = 0.019, 95% CI 0.004 to 0.034) and sOB-R (β = 0.022, 95% CI 0.009 to 0.035), as well as a decrease in ADP (β =  - 0.006, 95% CI  - 0.012 to 0.001). These associations persisted across different baseline BMI groups. An increasing BMI rate was significantly associated with an average 3-year increase in CRP levels among normal weight (β = 0.045, 95% CI 0.001 to 0.088) and overweight (β = 0.060, 95% CI 0.014 to 0.107) women. As BMI increased over time, a more remarkable decrease in ADP was observed among women with metabolic syndrome (β =  - 0.016, 95% CI - 0.029 to - 0.004) than those without metabolic syndrome at baseline.

CONCLUSIONS

A higher increase rate of BMI was associated with poorer trajectories of inflammatory biomarkers related to BC risk. Recommendations for BMI reduction may benefit BC prevention in women, particularly for those with metabolic syndrome.

The influence of whole-body cryotherapy or winter swimming on the lipid profile and selected adipokines

PURPOSE

The aim of this study was to investigate the effect of a series of 20 whole-body cryotherapy (WBC) sessions and 20 winter swimming sessions on the lipid profile and selected adipokines.

MATERIALS/METHODS

The experimental group consisted of 30 people who underwent a series of WBC treatments and 30 people who underwent a winter swimming. The control group consisted of 30 people - without intervention. Study 1: on the day of the commencement of whole-body cryotherapy / at the beginning of the winter swimming season; and Study 2: after a series of 20 cryotherapy sessions / at the end of the winter swimming season. The control group was also tested twice (4-week break). There were 20 WBC treatments - 5 times a week (4 weeks) and 20 cold water baths - once a week (20 weeks).

RESULTS

A statistically significant increase in the concentration of adiponectin, resistin and leptin in women and resistin and leptin in men was observed after the winter swimming season. Differences were also found in the second study between the groups of women using WBC and the control group, as well as the groups of women swimming and the control group. In men, however, these differences were observed in WBC and the control group. The significance level of α = 0.05 was adopted in the analyzes.

CONCLUSIONS

The use of WBC may changes in the lipid profile and selected adipokines in men. Regular winter swimming may changes of selected adipokines in both women and men.

Association of adipokines with insulin resistance and metabolic syndrome including obesity and diabetes

Adipose tissue (AT) acts as a highly active endocrine organ, which secretes a wide range of adipokine hormones. In the past few years, several adipokines (leptin, adiponectin, resistin etc.) have been discovered showing metabolic consequences in relation to insulin resistance (IR), obesity and diabetes. These adipokines are considered to be an important component playing an important role in the regulation of energy metabolism. They have been shown to be involved in the pathogenesis of metabolic syndrome (MetS) and cardiac diseases. The current article provides a holistic summary of recent knowledge on adipokines and emphasizes their importance in association with IR, obesity, diabetes and MetS. Adipokines such as leptin, adiponectin, resistin and tumor necrosis factor-alpha (TNF-α) have been involved in the regulation of an array of metabolic functions and disease associated with it, e.g. appetite and energy balance of the body, suppression of atherosclerosis and liver fibrosis, obesity with type 2 diabetes (T2D) and IR. An important adipokine, Interleukin-6 (IL-6), also correlates positively with human obesity and IR and also the elevated level of IL-6 predicts development of T2D. All of these hormones have important correlation with energy homeostasis, glucose and lipid metabolism, cardiovascular function and immunity. All the possible connections have extended the biological emphasis of AT secreted adipokines as an investigator in the development of MetS, and are now no longer considered as only an energy storage site.

Anti-Diabesity Middle Eastern Medicinal Plants and Their Action Mechanisms

Over the last four decades, the escalation in diabetes and obesity rates has become epidemic all over the world. Diabesity describes the strong link between T2D and obesity. It correlates deeper with the elevated risks of developing cardiovascular disease hypertension, stroke, and several malignancies. Therapeutic usage of medicinal plants and natural products in the treatment of diabetes and obesity has long been known to physicians of Greco-Arab and Islamic medicine. Improved versions of their abundant medicinal plant-based formulations are at present some of the most popular herbal treatments used. Preclinical and clinical data about medicinal plants along with their bioactive constituents are now available, justifying the traditionally known therapeutic uses of products derived from them for the prevention and cure of obesity-related T2D and other health problems. The aim of this review is to systematize published scientific data dealing with the efficiency of active ingredients or extracts from Middle Eastern medicinal plants and diet in the management of diabesity and its complications. Google Scholar, MEDLINE, and PubMed were searched for publications describing the medicinal plants and diet used in the management of T2D, obesity, and their complications. The used keywords were "medicinal plants" or "herbals" in combination with "obesity," "diabetes," "diabetes," or nephropathy. More than 130 medicinal plants were identified to target diabesity and its complications. The antidiabetic and anti-obesity effects and action mechanisms of these plants are discussed here. These include the regulation of appetite, thermogenesis, lipid absorption, and lipolysis; pancreatic lipase activity and adipogenesis; glucose absorption in the intestine, insulin secretion, glucose transporters, gluconeogenesis, and epigenetic mechanisms.

Influence of BMI on Serum Adiponectin, Resistine, and FBG among Overweight and Obese Females Diabetic Patient Type2

Abstract: Background and aim: Obesity is a frequent comorbidity in patients with T2DM and it has been estimated that at least 90% of these patients are overweight or obese.[4] The risks of many complications and comorbidities (e.g., cardiovascular disease and chronic kidney disease) are considerably increased in patients with T2DM who have concomitant obesity. In this study evaluation the level of Resistine, Fasting Blood Glucose and Adiponectin in overweight, obese versus normal weight, females. Compare with the BMI. Methods: A descriptive cross-sectional - case-control study, the target population is a total 204 Sudanese females were recruited to participate in this study (102 overweight, obese versus 102 non-overweight, non-obese), aged 20-50 years. and venous blood samples were collected. Plasma levels of blood glucose were measured using the particle-enhanced immunoturbidimetric assay method Cobas C-311®.While Adiponectin and Resistine estimated by ELISA Kits. Anthropometric measurements, including height and weight, were taken using standard protocols. BMI was calculated as weight (in kilograms) divided by height (in meters squared). Results: According to these results observed significant difference between the means of fasting blood glucose (FBG), adiponectin, Resistine and BMI compare with normal weight, overweight and obese respectively. FBG (mean + SD), normal weight (127 ± 16.7), over weight (153 ± 19.2), obese (189 ± 22.7), P = 0.037, adiponectin, (11.2 ± 1.9), (9.7 ± 1.6), (6.1 ± 1.5), P = 0.043, Resistine, (12.8 ± 1.1) ,(14.2 ± 2.7), (18.2 ± 2.9), P = 0.021, BMI, (18.3 ± 1.7) ,(26.1 ± 2.2), (30.4 ± 3.7), P = 0.006.  In this study, the results show strong negative Correlation between the levels of serum Adiponectin and Fasting Blood Glucose, Adiponectin and Resistine. (P.value = 0.013, r = -7.9). (P.value = 0.019, r = -6.6). While showing in the other side strong positive Correlation between the levels of serum Resistine and Fasting Blood Glucose. (P.value = 0.015, r = 6.0). Conclusion: Increase of Resistine and Fasting Blood Glucose and reduced of Adiponectin in overweight, obese versus non-overweight, non-obese females. Compare with the BMI. Keywords: Obese, Overweight, BMI, FBG, Adiponectin and Resistine

Assessment of Adiponectin and Resistin Indexes Compared to FBG and Useful as Diagnostic Biomarkers in Insulin Resistance and Type 2 Diabetes

Abstract: Background and aim: The world prevalence of diabetes among adults will be 6.4%, affecting 285 million adults, in year 2010, and will increase to 7.7% and 439 million adults by year 2030. Insulin resistance is a prerequisite root factor for development of type 2 diabetes (T2DM). Adiponectin and resistin are adipokines which modulate insulin action, energy, glucose and lipid homeostasis. Meta-analyses showed that hypoadiponectinemia and hyperresistinemia are strongly associated with increased risk of insulin resistance, type 2 diabetes (T2DM), Methods: In this case control study, A total 204 Sudanese males and females were recruited to participate in this study (102 diabetic and 102 non-diabetic) and venous blood samples were collected. Serum levels of blood glucose were measured using the particle-enhanced immunoturbidimetric assay method Cobas C-311®.While Adiponectin and Resistine estimated by ELISA Kits. Results: In this results shows significant difference between the means fasting blood glucose (FBG), adiponectin, resistine of diabetic patient and non-diabetic patient. FBG (mean + SD) (164.5 ± 16.7) versus (95.7 ± 13.6), P = 0.041, adiponectin (mean + SD) (5.9 ± 1.6) versus (10.1 ± 1.3), P = 0.037, resistine (mean + SD) (18.2 ± 2.7) versus (12.2 ± 1.1), P = 0.023.  In this study, observed from this results strong negative Correlation between the levels of serum Adiponectin and Fasting Blood Glucose, Adiponectin and Resistine. (P.value = 0.013, r = -7.9). (P.value = 0.019, r = -6.6). While showing in the other side moderate positive Correlation between the levels of serum Resistine and Fasting Blood Glucose. (P.value = 0.015, r = 6.0). Conclusion: Iccrease of Resistine and Fasting Blood Glucose and reduced of Adiponectin in diabetic patient compare to non-diabetic patient can be useful as diagnostic biomarkers. Keywords: Adiponectin and Resistin, insulin resistance, type 2 diabetes

Analysis of an Indian diabetes prevention programme on association of adipokines and a hepatokine with incident diabetes

To study the association and possible predictive role of visfatin, resistin, fetuin-A and chemerin with incident type 2 diabetes (T2DM) among Asian Indians with prediabetes. Their association with insulin resistance, β-cell function, glycaemia and anthropometry were also studied. This is a nested case-control study of a large 2-year prospective prevention trial in persons at high risk of developing T2DM. Baseline HbA1c values between 6.0% (42 mmol/mol) and 6.2% (44 mmol/mol) were chosen for this analysis (n = 144). At follow-up, persons with incident T2DM (HbA1c ≥ 6.5%, 48 mmol/mol) were grouped as cases (n = 72) and those reverted to normoglycaemia, (HbA1c < 5.7% (39 mmol/mol) as controls (n = 72). Insulin resistance showed the strongest association with incident T2DM ((Odds Ratio (OR): 23.22 [95%CI 6.36-84.77]; p < 0.0001). Baseline visfatin (OR: 6.56 [95%CI 2.21-19.5]; p < 0.001) and fetuin-A (OR: 1.01 [95%CI (1.01-1.04)]; p < 0.0001) independently contributed to the conversion of prediabetes to T2DM. The contribution was significantly higher when their elevated levels coexisted (OR: 12.63 [95%CI 3.57-44.63]; p < 0.0001). The area under the curve was 0.77 ± SE 0.4 (95%CI 0.69-0.85) and 0.80 ± SE 0.04 (95%CI 0.73-0.88) for visfatin (median 17.7 ng/ml, sensitivity and specificity: 75%, p < 0.0001) and fetuin-A (mean 236.2 µg/ml, sensitivity: 71%, specificity: 75%, p < 0.0001) respectively. Higher baseline visfatin and fetuin-A concentrations are strongly associated with incident T2DM and are predictive of future diabetes.

Resistin is Associated with Inflammation and Renal Function, but not with Insulin Resistance in Type 2 Diabetes

The aim of the study was to investigate the association of adipokines (resistin, leptin and adiponectin) with obesity, insulin resistance (IR) and inflammation in type 2 diabetes mellitus (T2DM). A total of 284 patients with T2DM were included. Concentrations of resistin, leptin, adiponectin, and inflammatory markers [high sensitivity C-reactive protein (hsCRP), tumor necrosis factor α (TNF-α), and interleukin 6 (IL-6)] were measured and homeostatic model assessment for IR (HOMA-IR) index was calculated. Resistin correlated negatively with estimated glomerular filtration rate (eGFR) and positively with hsCRP, TNF-α, IL-6, and white blood cell count (WBC). Leptin correlated positively with HOMA-IR, whereas adiponectin correlated negatively. Leptin also correlated positively with body mass index (BMI), waist circumference, IL-6, WBC and negatively with eGFR. Adiponectin correlated negatively with waist circumference, WBC, and eGFR. Multivariate logistic regression indicated lower eGFR and higher WBC and IL-6 as independent predictive factors of resistin concentration above the upper quartile (CAQ3), whereas female sex and higher BMI and HOMA-IR of leptin CAQ3, and lower HOMA-IR and older age of adiponectin CAQ3. In conclusion, in contrast to leptin and adiponectin, in T2DM patients, resistin is not associated with BMI and IR, but with inflammation and worse kidney function.

High Plasma Resistin Levels Portend the Insulin Resistance-Associated Susceptibility to Early Cognitive Decline in Patients with Type 2 Diabetes Mellitus

BACKGROUND

Metabolic disorders, including insulin resistance, obesity, and hyperlipidemia occur frequently prior to hyperglycemia in patients with type 2 diabetes mellitus (T2DM) and cause mild cognitive impairment (MCI).

OBJECTIVE

We investigated the involvement of resistin in these metabolic abnormalities contributes to MCI in patients with T2DM.

METHODS

A total of 138 hospitalized patients with T2DM were enrolled and categorized into MCI and non-MCI groups according to the Montreal Cognitive Assessment (MoCA) score. Metabolic indicators and cognitive state were assessed, and plasma resistin levels were determined by ELISA.

RESULTS

The resistin levels and homeostasis model assessment of insulin resistance (HOMA-IR) scores of MCI and gender-stratified subgroups were significantly higher than those of controls without MCI (all p < 0.01). Correlation analysis showed that the resistin level was negatively associated with majority of cognitive domains, e.g., MoCA (r = -0.693, p < 0.001) and Mini-Mental State Examination (r = -0.571, p < 0.001), and was related to HOMA-IR (r = 0.667, p < 0.001) but not to obesity and lipid indices. Multivariable regression analysis indicated that resistin (β= -0.675, p < 0.001) and educational level (β= 0.177, p = 0.003) were independent risk factors of MoCA in patients with T2DM.

CONCLUSIONS

High plasma resistin levels portend the insulin resistance-related susceptibility to early cognitive decline in Chinese patients with T2DM. The involvement of this adipokine in other metabolic disorders leading to diabetic MCI and its clinical value for early disease screening must be further studied.

Factors Affecting Metabolic Outcomes Post Bariatric Surgery: Role of Adipose Tissue

Obesity is an ever-growing public health crisis, and bariatric surgery (BS) has become a valuable tool in ameliorating obesity, along with comorbid conditions such as diabetes, dyslipidemia and hypertension. BS techniques have come a long way, leading to impressive improvements in the health of the majority of patients. Unfortunately, not every patient responds optimally to BS and there is no method that is sufficient to pre-operatively predict who will receive maximum benefit from this surgical intervention. This review focuses on the adipose tissue characteristics and related parameters that may affect outcomes, as well as the potential influences of insulin resistance, BMI, age, psychologic and genetic factors. Understanding the role of these factors may help predict who will benefit the most from BS.

The β3-adrenergic receptor agonist mirabegron improves glucose homeostasis in obese humans

BACKGROUNDBeige adipose tissue is associated with improved glucose homeostasis in mice. Adipose tissue contains β3-adrenergic receptors (β3-ARs), and this study was intended to determine whether the treatment of obese, insulin-resistant humans with the β3-AR agonist mirabegron, which stimulates beige adipose formation in subcutaneous white adipose tissue (SC WAT), would induce other beneficial changes in fat and muscle and improve metabolic homeostasis.METHODSBefore and after β3-AR agonist treatment, oral glucose tolerance tests and euglycemic clamps were performed, and histochemical analysis and gene expression profiling were performed on fat and muscle biopsies. PET-CT scans quantified brown adipose tissue volume and activity, and we conducted in vitro studies with primary cultures of differentiated human adipocytes and muscle.RESULTSThe clinical effects of mirabegron treatment included improved oral glucose tolerance (P < 0.01), reduced hemoglobin A1c levels (P = 0.01), and improved insulin sensitivity (P = 0.03) and β cell function (P = 0.01). In SC WAT, mirabegron treatment stimulated lipolysis, reduced fibrotic gene expression, and increased alternatively activated macrophages. Subjects with the most SC WAT beiging showed the greatest improvement in β cell function. In skeletal muscle, mirabegron reduced triglycerides, increased the expression of PPARγ coactivator 1 α (PGC1A) (P < 0.05), and increased type I fibers (P < 0.01). Conditioned media from adipocytes treated with mirabegron stimulated muscle fiber PGC1A expression in vitro (P < 0.001).CONCLUSIONMirabegron treatment substantially improved multiple measures of glucose homeostasis in obese, insulin-resistant humans. Since β cells and skeletal muscle do not express β3-ARs, these data suggest that the beiging of SC WAT by mirabegron reduces adipose tissue dysfunction, which enhances muscle oxidative capacity and improves β cell function.TRIAL REGISTRATIONClinicaltrials.gov NCT02919176.FUNDINGNIH: DK112282, P30GM127211, DK 71349, and Clinical and Translational science Awards (CTSA) grant UL1TR001998.

Ratios of serum eicosapentaenoic acid to arachidonic acid and docosahexaenoic acid to arachidonic acid were inversely associated with serum resistin levels: The Hisayama Study

AIMS/INTRODUCTION

Resistin is an adipocyte-derived polypeptide that leads to the progression of insulin resistance and subsequent atherosclerosis. Some studies have reported an association between self-reported intake of n-3 polyunsaturated fatty acids (PUFAs) and serum resistin levels. However, no studies have investigated the association between the ratio of serum levels of n-3 to serum n-6 PUFAs and the serum resistin concentration in the general population.

MATERIALS AND METHODS

We carried out a cross-sectional study of 3,200 community-dwelling Japanese individuals aged ≥40 years in 2002-2003. The ratios of serum eicosapentaenoic acid or docosahexaenoic acid to arachidonic acid (AA) were categorized into quartiles. The associations of serum eicosapentaenoic acid/AA and docosahexaenoic acid/AA with the serum resistin concentration were assessed using linear regression models with adjustment for potential confounding factors.

RESULTS

The geometric mean of serum resistin was 10.3 ng/mL. The age- and sex-adjusted geometric mean of serum resistin decreased significantly with increased levels of serum eicosapentaenoic acid/AA (quartile 1: 11.3 ng/mL; quartile 2: 10.6 ng/mL; quartile 3: 10.3 ng/mL; quartile 4: 9.3 ng/mL; P for trend <0.001). A similar association was observed for serum docosahexaenoic acid/AA (quartile 1: 11.1 ng/mL; quartile 2: 10.6 ng/mL; quartile 3: 10.1 ng/mL; quartile 4: 9.7 ng/mL; P for trend <0.001). An adjustment for potential confounding factors did not change these associations.

CONCLUSIONS

Higher ratios of serum n-3 to n-6 PUFAs were associated with lower serum resistin levels. Consumption of a large amount of n-3 PUFAs might have desirable effects on resistin-mediated diseases.

Salivary Amylase Gene Copy Number Is Associated with the Obesity and Inflammatory Markers in Children

BACKGROUND

We have recently shown that the copy number of salivary amylase (AMY1) gene was significantly decreased, and the obesity-related salivary biomarkers resistin, MCP-1, TNF-α, IL-6, and CRP were significantly increased in overweight/obese children compared to normal weight. This study aimed to evaluate the association of AMY1 copy number variant (CNV) with obesity and inflammatory markers. Seventy-six participants aged between 6 and 10 years have participated, and the saliva samples were collected along with the anthropometric measurements.

METHODS

AMY1 copy number was analyzed by 3D digital PCR, and obesity-related biomarkers were performed with a Bioplex multiplex analyzer.

RESULTS

The mean AMY1 copy number was higher in normal weight (7.90 ± 0.38) compared to the overweight/obese group (6.20 ± 0.29). The association of AMY1 CNV with obesity and inflammatory markers showed significant negative correlation [CRP, β = -0.238 (p < 0.05); resistin, β = -0.25 (p < 0.05); MCP-1, β = -0.304 (p < 0.01)] except for complement factor D, TNF α and IL-6. The anti-inflammatory cytokine, IL-10 reported a positive correlation with AMY1 copy number with a β = 0.268 (p < 0.05). The multivariable model adjusted with age and gender depicted a similar correlation with obesity markers.

CONCLUSION

Our results report that AMY1 CNV is associated with obesity and inflammatory biomarkers in children's saliva sample.

Relationship Between Intermittent Hypoxia and Type 2 Diabetes in Sleep Apnea Syndrome

Sleep apnea syndrome (SAS) is a very common disease involving intermittent hypoxia (IH), recurrent symptoms of deoxygenation during sleep, strong daytime sleepiness, and significant loss of quality of life. A number of epidemiological researches have shown that SAS is an important risk factor for insulin resistance and type 2 diabetes mellitus (DM), which is associated with SAS regardless of age, gender, or body habitus. IH, hallmark of SAS, plays an important role in the pathogenesis of SAS and experimental studies with animal and cellular models indicate that IH leads to attenuation of glucose-induced insulin secretion from pancreatic β cells and to enhancement of insulin resistance in peripheral tissues and cells, such as liver (hepatocytes), adipose tissue (adipocytes), and skeletal muscles (myocytes). In this review, we focus on IH-induced dysfunction in glucose metabolism and its underlying molecular mechanisms in several cells and tissues related to glucose homeostasis.

Relationship Between Resistin Levels and Sepsis Among Children Under 12 Years of Age: A Case Control Study

Objective: The aim of this study was to investigate the level of resistin in children with and without sepsis hospitalized in the pediatric intensive care unit (PICU) and compare them to levels in healthy subjects in order to determine the trend of resistin levels in children in PICUs and also to identify the cut-off values for positive sepsis. Methods: This was a case-control study conducted in 2014 at a children's hospital in Tabriz, Iran. Three groups were investigated, a case group comprised of patients with sepsis admitted to PICU and two control groups; one made up of patients admitted to PICU without sepsis and the other of healthy children. Variables included demographic, anthropometric (growth metric percentile), and clinical factors. Results: Patients were randomized into control group A (n = 12, 48%), control group B (n = 11, 44%), and the sepsis group (n = 24, 47.1%). The difference in the means of resistin levels was significant on the first, fourth, and seventh days (P < 0.0001) in the case and control group A. Means comparisons in the case and control group B revealed significant differences on the fourth and seventh day (P = 0.005 and P < 0.0001, respectively) but not on the first day (P = 0.246). The trend of resistin levels increased in the septic group (F Huynh-Feldt = 37.83, P < 0.0001). The diagnostic accuracy of resistin level was high for discriminating sepsis (area under the receiver operating characteristic curve [AUC] 0.864 [SE = 0.41]). The sensitivity was 0.824 and specificity 0.72 with a cut-off point of 5.2 ng/ml on the first day. Conclusion: In the present study, resistin level can be used as an indicator of sepsis in children admitted to PICU. However, the cut-off point based upon when a prediction could be made is different and is dependent on a variety of factors, such as control group and number of days since the first signs of sepsis.

Association of salivary C-reactive protein with the obesity measures and markers in children

OBJECTIVE

Overweight and obesity is a pro-inflammatory state. This study aimed to examine the level of the salivary obesity markers in normal weight (NW) and overweight/obese (OW/OB) children, association with the obesity measures and the interrelations between the biomarkers.

SUBJECTS AND METHODS

Seventy-six children (40 normal weight and 36 overweight/obese) were recruited for this study. Body weight, height, and waist circumference measurement were obtained. The saliva sample was collected from all the participants. According to the Center for Disease Control and Prevention (CDC), the participants were classified into the normal weight or overweight/obese depending upon the body mass index (BMI) percentile ranking. The obesity panel of salivary markers resistin, C-C Motif Chemokine Ligand 2 (CCL2)/monocyte chemotactic protein-1 (MCP-1), tumor necrosis factor-alpha (TNF-α), interleukin-6 (IL-6), C-reactive protein (CRP), complement factor D, and interleukin-10 (IL-10) were determined using human magnetic Luminex performance assay. The receiver operating characteristics (ROC) analysis was used to determine the area under the curve (AUC) to identify the best salivary biomarker in children. Linear regression and Pearson's correlation analyses to determine the association between the parameters.

RESULTS

The obesity biomarkers resistin, MCP-1, TNF-α, IL-6 and CRP were significantly high in overweight/obese compared to normal weight. Salivary CRP (AUC: 0.866, 95% CI: 0.780-0.952; p<0.0001) showed superiority area under ROC curves with good discriminatory power than resistin, MCP-1, TNF-α, and IL-6. BMI z-score, WC z-score, and WHtR z-score showed a significant association (p<0.0001) with CRP. The CRP significantly (p<0.0001) correlated with resistin, CCL2/MCP-1, TNF-α, IL-6, and IL-10 by linear regression and Pearson's correlation analysis.

CONCLUSION

Increased level of salivary CRP in children may be considered as a non-invasive marker for childhood obesity for detection of the risk factors for the development of metabolic dysregulation.

Intermittent Hypoxia Up-Regulates CCL2, RETN, and TNFα mRNAs in Adipocytes via Down-regulation of miR-452

Sleep apnea syndrome (SAS), characterized by recurrent episodes of oxygen desaturation and reoxygenation (intermittent hypoxia [IH]), is a risk factor for insulin resistance. Recently, IH is considered to independently cause adipose tissue inflammation/dysfunction, leading to worsening insulin resistance; however, the detailed mechanism remains unknown. We exposed mouse 3T3-L1 and human SW872 adipocytes to experimental IH or normoxia for 24 h, and analyzed mRNA expression of several adipokines. We found that the mRNA levels of RETN, TNFα, and CCL2 in SW872 and 3T3-L1 adipocytes were significantly increased by IH, whereas the promoter activities of these genes were not increased. A target mRNA search of microRNA (miR)s revealed that all human mRNAs have a potential target sequence for miR-452. The miR-452 level of IH-treated cells was significantly decreased compared to normoxia-treated cells. MiR-452 mimic and non-specific control RNA (miR-452 mimic NC) were introduced into SW872 cells, and the IH-induced up-regulation of the genes was abolished by introduction of the miR-452 mimic but not by the miR-452 mimic NC. These results indicate that IH stress down-regulates the miR-452 in adipocytes, resulting in increased levels of RETN, TNFα, and CCL2 mRNAs, leading to insulin resistance in SAS patients.

Relationship between Resistin, Endothelin-1, and Flow-Mediated Dilation in Patient with and without Metabolic Syndrome

Background:

Resistin is peptides that signal the functional status of adipose tissue to the brain and other target organs. It causes insulin resistance and affects the vascular endothelial dysfunction. However, the function and relation between resistin in endothelin-1 (ET-1), which leads to the endothelial dysfunction in humans are enigmatic.

Materials and Methods:

In a cross-sectional study of 76 participants (38 metabolic syndrome patients and 38 healthy participants), biochemical and clinical parameters, including lipid profile, fasting glucose, resistin, ET-1, C-reactive protein (CRP), flow-mediated dilation (FMD), and hypertension were determined and compared between the two groups.

Results:

Multiple linear regression analysis was performed with age- and sex-adjusted plasma resistin levels, FMD, and ET-1 as the dependent variables. Analysis showed that weight, body mass index, triglycerides (TGs), and ET-1 were statistically significant correlated with serum resistin. FMD has negative significantly correlated with weight (r = −0.491, P = 0.001), waist circumference (r = −0.491, P = 0.001), waist-to-hip ratio (r = −0.0444, P = 0.001), and ET-1 (r = −0.075, P = 0.050), but it has significantly correlated with systolic blood pressure (SBP) (r = 0.290, P = 0.016), diastolic blood pressure (DBP) (r = 0.275, P = 0.023), and high-density lipoprotein cholesterol (HDL-C) (r = −0.266, P = 0.050), and ET-1, but it has significantly correlated with SBP, DBP, and HDL-C. ET-1 is significantly correlated with TGs (r = −0.436, P = 0.006), total cholesterol (r = 0.452, P = 0.004), low-density lipoprotein cholesterol (r = 0.454, r = 0.004), and resistin (r = 0.282, P = 0.050), whereas it has negative significantly correlated with HDL-C (r = 0.346, P = 0.034), FMD (r = −0.075, P = 0.050.

Conclusion:

In this study, results shown plasma ET-1 and resistin are suggested as risk factors for the development of endothelial dysfunction and with further study, it is possible that can diagnose the risk of diabetes and cardiovascular disease in the early stages.

Association between serum resistin, adiposity measures and inflammatory makers in women without cardiovascular diseases

AIMS

The convergence of obesity and inflammation in the pathogenesis of cardiovascular diseases (CVD) has been recognized over the past decade. Resistin has emerged as a novel secreted protein with links to both insulin resistance and inflammation. We aimed to investigate the relationship between changes in serum resistin levels with metabolic parameters, including obesity and inflammatory markers in women free of CVD.

METHODS AND RESULTS

A total of 200 apparently healthy women were consecutively recruited from the Out-patients Clinics at King Abdulaziz university Hospital in Jeddah, Saudi Arabia. They were classified into 4 groups based on quartile for serum resistin. Anthropometric variables were measured in all study subjects. Fasting blood samples were collected for measurement of lipid profile, blood glucose and inflammatory markers. Study subjects within the upper quartile (Q4) had significantly higher body height (p < 0.0001), waist and hip circumferences (p < 0.05) and inflammatory markers (p < 0.0001) values than those in the lower quartile (Q1). Significant correlations were found between circulating resistin levels and systolic blood pressure, some anthropometric measures as well as inflammatory markers.

CONCLUSION

Serum resistin levels were found to be increased in overweight and obese women. Resistin was also independently associated with hs-CRP in women free of CVD, suggesting that resistin may be related to low-grade inflammation among obese subjects in the absence of overt CVD.

Telmisartan reverses antiretroviral-induced adipocyte toxicity and insulin resistance in vitro

BACKGROUND

Antiretroviral therapy in HIV-positive patients leads to insulin resistance which is central to the pathogenesis of various metabolic abnormalities and cardiovascular disease seen in this patient group. We have investigated the dose-response relationship of telmisartan, an antihypertensive, on adipocytes in vitro in order to determine whether it may have metabolic beneficial effects.

METHODS

Using in vitro chronic toxicity models (3T3-F442A murine and primary human adipocytes), we evaluated the effects of different concentrations of telmisartan on adipocyte differentiation and adipogenic gene expression using lipid accumulation assays and real-time polymerase chain reaction, respectively. Adipokine secretion and expression of insulin signalling mediators were evaluated using enzyme-linked immunosorbent assays.

RESULTS

Telmisartan partially reversed the deleterious effects of antiretrovirals on adipocyte lipid accumulation, expression of adipogenic regulators (peroxisome proliferator receptor-gamma and lipin 1), adipokine secretion and expression of the insulin signalling mediator pAkt_Ser473. The metabolic effects of telmisartan followed a non-monotonic response with the maximal effect observed at 5 µM in the primary human adipocyte model.

CONCLUSION

Telmisartan has beneficial metabolic effects in adipocytes in vitro, but its potential to reduce antiretroviral-induced cardiometabolic disease in HIV-infected individuals needs to be evaluated in a well-designed adequately powered clinical trial.

An inverse association between serum resistin levels and n-3 polyunsaturated fatty acids intake was strongest in the SNP-420 G/G genotype in the Japanese cohort: The Toon Genome Study

OBJECTIVE

Resistin is secreted by monocytes/macrophages and is associated with insulin resistance, inflammation and cardiovascular diseases. In the Japanese cohort, serum resistin is tightly associated with a single-nucleotide polymorphism (SNP) at -420 (rs1862513) in the promoter region of the human resistin gene. However, interactions between SNP-420 and environmental factors remain to be elucidated. The aim of this study was to investigate the association between serum resistin levels and nutrient intake, and the effect of SNP-420 on this association.

DESIGN, PARTICIPANTS AND MEASUREMENTS

The Toon Genome Study is a cohort study of Japanese community-dwelling subjects. A total of 1981 participants were cross-sectionally analysed. Each nutrient intake was assessed using the semiquantitative food frequency questionnaire and categorized into the quartiles (Q1-Q4). Serum resistin was measured by ELISA.

RESULTS

Serum resistin tended to be inversely associated with fish intake and positively associated with meat intake after adjustment for age, sex, BMI and energy intake. Serum resistin was inversely associated with n-3 polyunsaturated fatty acids (PUFA) intake after adjustment for age, sex, BMI and energy intake (Q1 12.5, Q2 12.5, Q3 12.2, Q4 11.5 ng/mL; P for trend = .007). This inverse association was strongest in the G/G genotype of SNP-420, followed by C/G and C/C (G/G, Q1 18.9, Q2 19.5, Q3 18.4, Q4 14.5 ng/mL, P = .001; C/G, 14.4, 13.3, 13.1, 12.9, P = .015; C/C, 9.5, 9.5, 9.2, 8.8, P = .020; P for interaction = .004).

CONCLUSIONS

The inverse association between serum resistin and n-3 PUFA intake was strongest in SNP-420 G/G genotype in the Japanese cohort.

The levels of adipokines in relation to hormonal changes during the menstrual cycle in young, normal-weight women

CONTEXT

The aim of this study was to assess the plasma leptin, adiponectin, resistin, visfatin/NAMPT, omentin-1, vaspin, apelin, TNF-α, IL-6 and RBP4 levels in relation to hormonal changes during the menstrual cycle in young, healthy, normal-weight women.

METHODS

The study involved 52 young, healthy, normal-weight women. Anthropometric parameters, body composition and levels of plasma leptin, adiponectin, resistin, visfatin/NAMPT, omentin-1, vaspin, apelin, TNF-α, IL-6 and RBP4 in addition to serum FSH, LH, estradiol, progesterone, 17-OH progesterone, androgens, SHBG and insulin concentrations were measured during a morning in fasting state three times: between days 2-4, days 12-14 and days 24-26 of the menstrual cycle.

RESULTS

Plasma adiponectin, omentin-1, resistin and visfatin/NAMPT, apelin, TNF-α, IL-6 and RBP4 concentrations were stable during the menstrual cycle, while leptin and vaspin levels were significantly higher in both the midcycle and the luteal phases than those in the follicular phase. Multivariate regression analyses revealed that changes in leptin and vaspin levels between the follicular and the luteal phase are strongly related to changes in total testosterone levels.

CONCLUSIONS

Our results revealed stable levels of adipokines during the phases of the physiological menstrual cycle, except for leptin and vaspin, which showed increased levels in both the midcycle and the luteal phases. This effect was significantly associated with changes in the secretion of testosterone, 17-OH progesterone and insulin in the luteal phase.

Adipokines in Liver Cirrhosis

Liver fibrosis can progress to cirrhosis, which is considered a serious disease. The Child-Pugh score and the model of end-stage liver disease score have been established to assess residual liver function in patients with liver cirrhosis. The development of portal hypertension contributes to ascites, variceal bleeding and further complications in these patients. A transjugular intrahepatic portosystemic shunt (TIPS) is used to lower portal pressure, which represents a major improvement in the treatment of patients. Adipokines are proteins released from adipose tissue and modulate hepatic fibrogenesis. These proteins affect various biological processes that are involved in liver function, including angiogenesis, vasodilation, inflammation and deposition of extracellular matrix proteins. The best studied adipokines are adiponectin and leptin. Adiponectin protects against hepatic inflammation and fibrogenesis, and leptin functions as a profibrogenic factor. These and other adipokines are supposed to modulate disease severity in patients with liver cirrhosis. Consequently, circulating levels of these proteins have been analyzed to identify associations with parameters of hepatic function, portal hypertension and its associated complications in patients with liver cirrhosis. This review article briefly addresses the role of adipokines in hepatitis and liver fibrosis. Here, studies having analyzed these proteins in systemic blood in cirrhotic patients are listed to identify adipokines that are comparably changed in the different cohorts of patients with liver cirrhosis. Some studies measured these proteins in systemic, hepatic and portal vein blood or after TIPS to specify the tissues contributing to circulating levels of these proteins and the effect of portal hypertension, respectively.

Even- and odd-chain saturated fatty acids in serum phospholipids are differentially associated with adipokines

Background

Saturated fatty acids are generally thought to have detrimental effects on health. However, a recent study showed that even- and odd-chain saturated fatty acids had opposite associations with type 2 diabetes. Limited studies of Western populations examined the associations of circulating saturated fatty acids with adipokines, an important role in glucose metabolism.

Objective

We examined the associations of saturated fatty acids in serum phospholipids with circulating levels of adipokines among a Japanese population.

Design

A cross-sectional study was conducted among 484 Japanese employees (284 men and 200 women) aged 20–65 years. The serum fatty acid composition in the phospholipid fraction was measured by gas-chromatography. Serum leptin, adiponectin, plasminogen activator inhibitor-1 (PAI-1), resistin, and visfatin were measured using a Luminex suspension bead-based multiplexed array. Multiple linear regression analysis was performed to assess the association between saturated fatty acids and adipokines, with adjustment for potential confounding variables.

Results

Even- and odd-chain saturated fatty acids were differentially associated with adipokines. Higher levels of even-chain saturated fatty acids (14:0 myristic, 16:0 palmitic, and 18:0 stearic acids) were associated with higher levels of resistin (P for trend = 0.048) and lower levels of adiponectin (P for trend = 0.003). By contrast, odd-chain saturated fatty acids (15:0 pentadecanoic and 17:0 heptadecanoic acids) showed inverse associations with leptin and PAI-1 (P for trend = 0.048 and 0.02, respectively). Visfatin was positively associated with both even- and odd-chain saturated fatty acids.

Conclusions

The results suggest that even- and odd-chain saturated fatty acids are differentially associated with adipokine profile.

Obesity-Induced Changes in Adipose Tissue Microenvironment and Their Impact on Cardiovascular Disease

Obesity is causally linked with the development of cardiovascular disorders. Accumulating evidence indicates that cardiovascular disease is the collateral damage of obesity-driven adipose tissue dysfunction that promotes a chronic inflammatory state within the organism. Adipose tissues secrete bioactive substances, referred to as adipokines, which largely function as modulators of inflammation. The microenvironment of adipose tissue will affect the adipokine secretome, having actions on remote tissues. Obesity typically leads to the upregulation of proinflammatory adipokines and the downregulation of anti-inflammatory adipokines, thereby contributing to the pathogenesis of cardiovascular diseases. In this review, we focus on the microenvironment of adipose tissue and how it influences cardiovascular disorders, including atherosclerosis and ischemic heart diseases, through the systemic actions of adipokines.

Adipokine Contribution to the Pathogenesis of Osteoarthritis

Recent studies have shown that overweight and obesity play an important role in the development of osteoarthritis (OA). However, joint overload is not the only risk factor in this disease. For instance, the presence of OA in non-weight-bearing joints such as the hand suggests that metabolic factors may also contribute to its pathogenesis. Recently, white adipose tissue (WAT) has been recognized not only as an energy reservoir but also as an important secretory organ of adipokines. In this regard, adipokines have been closely associated with obesity and also play an important role in bone and cartilage homeostasis. Furthermore, drugs such as rosuvastatin or rosiglitazone have demonstrated chondroprotective and anti-inflammatory effects in cartilage explants from patients with OA. Thus, it seems that adipokines are important factors linking obesity, adiposity, and inflammation in OA. In this review, we are focused on establishing the physiological mechanisms of adipokines on cartilage homeostasis and evaluating their role in the pathophysiology of OA based on evidence derived from experimental research as well as from clinical-epidemiological studies.

Dual Effects of a RETN Single Nucleotide Polymorphism (SNP) at -420 on Plasma Resistin: Genotype and DNA Methylation

CONTEXT

We previously reported that single nucleotide polymorphism (SNP)-420 C>G (rs1862513) in the promoter region of RETN was associated with type 2 diabetes. Plasma resistin was tightly correlated with SNP-420 genotypes. SNP-420 is a CpG-SNP affecting the sequence of cytosine-phosphate-guanine dinucleotides.

OBJECTIVE

To examine whether methylation at SNP-420 affects plasma resistin, we analyzed plasma resistin and methylation at RETN SNP-420.

DESIGN AND METHODS

Genomic DNA was extracted from peripheral white blood cells in 2078 Japanese subjects. Quantification of the methylation was performed by pyrosequencing after DNA bisulfite conversion.

RESULTS

Methylation at SNP-420 was highest in the C/C genotype (36.9 ± 5.7%), followed by C/G (21.4 ± 3.5%) and G/G (2.9 ± 1.4%; P < 0.001). When assessed in each genotype, methylation at SNP-420 was inversely associated with plasma resistin in the C/C (β = -0.134, P < 0.001) or C/G (β = -0.227, P < 0.001) genotype. In THP-1 human monocytes intrinsically having the C/C genotype, a demethylating reagent, 5-aza-dC, decreased the methylation at SNP-420 and increased RETN messenger RNA. SNP+1263 (rs3745369), located in the 3' untranslated region of RETN, was also associated with methylation at SNP-420. In addition, highly sensitive C-reactive protein was inversely associated with methylation at SNP-420 in the C/C genotype, whereas body mass index was positively associated.

CONCLUSIONS

Plasma resistin was inversely associated with the extent of methylation at SNP-420 mainly dependent on the SNP-420 genotype. The association can also be explained partially independent of SNP-420 genotypes. SNP-420 could have dual, genetic and epigenetic effects on plasma resistin.

Linking resistin, inflammation, and cardiometabolic diseases

Adipose tissue secretes a variety of bioactive substances that are associated with chronic inflammation, insulin resistance, and an increased risk of type 2 diabetes mellitus. While resistin was first known as an adipocyte-secreted hormone (adipokine) linked to obesity and insulin resistance in rodents, it is predominantly expressed and secreted by macrophages in humans. Epidemiological and genetic studies indicate that increased resistin levels are associated with the development of insulin resistance, diabetes, and cardiovascular disease. Resistin also appears to mediate the pathogenesis of atherosclerosis by promoting endothelial dysfunction, vascular smooth muscle cell proliferation, arterial inflammation, and the formation of foam cells. Thus, resistin is predictive of atherosclerosis and poor clinical outcomes in patients with cardiovascular disease and heart failure. Furthermore, recent evidence suggests that resistin is associated with atherogenic dyslipidemia and hypertension. The present review will focus on the role of human resistin in the pathogeneses of inflammation and obesity-related diseases.

Resistin as an inflammatory marker in patients with schizophrenia treated with clozapine

BACKGROUND

Schizophrenia is associated with excess cardiovascular comorbidity and mortality related to lifestyle factors, such as lack of physical activity, poor diet, and smoking. The prevalence of metabolic syndrome is increased among patients with schizophrenia, with the highest rates among patients on clozapine treatment. Smoking, obesity, physical inactivity, airway inflammation and obstruction, and adipose tissue and inflammatory marker activation are related in systemic inflammation. Low-grade inflammation is also associated with schizophrenia. Adipokine resistin is a biomarker involving several acute and chronic inflammatory states. However, the inflammatory role of resistin is so far inconclusive and studies in schizophrenia are scanty.

AIMS

The aim of the present study was to explore the role of serum resistin as an inflammatory marker in patients with schizophrenia on clozapine treatment.

METHODS

Associations between serum levels of resistin and some other selected cytokines/adipokines (adiponectin, leptin, adipsin, IL-6, IL-1Ra, TNF-α, hs-CRP) and metabolic markers in 190 patients with schizophrenia on clozapine treatment were studied using a cross-sectional study design.

RESULTS

Among male patients especially, smokers had higher levels of resistin than non-smokers, and among smokers resistin levels were associated with IL-1Ra and hs-CRP levels. In the whole patient group levels of resistin associated with levels of IL-1Ra, and among male patients with low HDL-cholesterol.

CONCLUSIONS

Resistin is a biomarker of systemic inflammation associated with smoking among patients with schizophrenia on clozapine treatment. Resistin might have a role as a marker of cardiovascular comorbidity.

Increased circulating resistin is associated with insulin resistance, oxidative stress and platelet activation in type 2 diabetes mellitus

Resistin is an adipokine that promotes inflammation and insulin resistance by targeting several cells including platelets. We hypothesised that in type 2 diabetes (T2DM), resistin may foster in vivo oxidative stress, thromboxane-dependent platelet activation and platelet-derived inflammatory proteins release, key determinants of atherothrombosis. A cross-sectional comparison of circulating resistin, sCD40L, as a marker of platelet-mediated inflammation, asymmetric dimethylarginine (ADMA), endothelial dysfunction marker, Dickkopf (DKK)-1, reflecting the inflammatory interaction between platelets and endothelial cells, and urinary 8-iso-PGF_2α and 11-dehydro-TxB₂, reflecting in vivo lipid peroxidation and platelet activation, respectively, was performed between 79 T2DM patients and 30 healthy subjects. Furthermore, we investigated the effects of the α-glucosidase inhibitor acarbose and the PPARγ agonist rosiglitazone, targeting hyperglycaemia or insulin resistance, versus placebo, in 28 and 18 T2DM subjects, respectively. Age- and gender-adjusted serum resistin levels were significantly higher in patients than in controls. HOMA (β=0.266, p=0.017) and 11-dehydro-TXB₂ (β=0.354, p=0.002) independently predicted resistin levels. A 20-week treatment with acarbose was associated with significant reductions (p=0.001) in serum resistin, DKK-1, urinary 11-dehydro-TXB₂ and 8-iso-PGF_2α with direct correlations between the change in serum resistin and in other variables. A 24-week rosiglitazone treatment on top of metformin was associated with significant decreases in resistin, DKK-1, 11-dehydro-TXB₂ and 8-iso-PGF_2α, in parallel with HOMA decrease. In conclusion, resistin, antagonising insulin action in part through PPARγ activation, may favour insulin resistance and enhance oxidative stress, endothelial dysfunction and platelet activation. The adipokine-platelet interactions may be involved in platelet insulin resistance and their consequent pro-aggregatory phenotype in this setting.

Therapeutic applications of conditioned medium from adipose tissue

For the past number of decades, adipose tissue has attracted significant interest due to its complicated composition and versatile functions. Adipose tissue is no longer considered to be just an energy-storing fat pad, but is also a key ring player in interaction networks between various organs and tissues. A wide range of factors released by adipose tissue are responsible for regulation of adipose tissue and other distant target tissues and cells, such as kidneys, skeletal muscle, the cardiovascular system and the immune system, in an auto-/paracrine manner. A mixture of bioactive molecules makes up the conditioned medium of adipose tissue. The beneficial role played by these bioactive molecules in angiogenesis, wound healing, tissue regeneration and immunomodulation has been demonstrated by various studies. Study of this conditioned medium helps deepen our understanding of underlying mechanisms and broadens the potential for therapeutic applications. In this review, we have aimed to improve fundamental understanding of conditioned medium from adipose tissue and to summarize recent efforts to study its therapeutic applications.

Executive functioning and diabetes: The role of anxious arousal and inflammation

Individuals who perform poorly on measures of the executive function of inhibition have higher anxious arousal in comparison to those with better performance. High anxious arousal is associated with a pro-inflammatory response. Chronically high anxious arousal and inflammation increase one's risk of developing type 2 diabetes. We sought to evaluate anxious arousal and inflammation as underlying mechanisms linking inhibition with diabetes incidence. Participants (N=835) completed measures of cognitive abilities, a self-report measure of anxious arousal, and donated blood to assess interleukin-6 (IL-6) and glycated hemoglobin (HbA1c). Individuals with low inhibition were more likely to have diabetes than those with high inhibition due to the serial pathway from high anxious arousal to IL-6. Findings remained when entering other indicators of cognitive abilities as covariates, suggesting that inhibition is a unique cognitive ability associated with diabetes incidence. On the basis of our results, we propose several avenues to explore for improved prevention and treatment efforts for type 2 diabetes.

Circulating ferritin concentrations are differentially associated with serum adipokine concentrations in Japanese men and premenopausal women

PURPOSE

Increased iron storage, as measured by circulating ferritin, has been linked to an increased risk of various diseases including diabetes. We examined the association of circulating ferritin with serum adiponectin, leptin, resistin, plasminogen activator inhibitor-1 (PAI-1), and visfatin levels.

METHODS

We conducted a cross-sectional study among 429 Japanese employees (284 men and 145 premenopausal women, mean age: 42.5 ± 10.5 years). Serum adipokines were measured using Luminex suspension bead-based multiplexed array, and serum ferritin was determined using a chemiluminescence immunoassay. Multivariable regression analysis was performed to calculate mean concentrations of adipokine according to the tertile of ferritin concentrations with adjustment for potential confounders.

RESULTS

Leptin and visfatin concentrations increased with increasing ferritin concentrations in men after multivariable adjustment of physical activity, smoking, alcohol use, and body mass index (P for trend = 0.02 and 0.01 for leptin and visfatin, respectively). Serum ferritin concentrations were inversely and significantly associated with adiponectin in women (P for trend = 0.01). Resistin and PAI-1 were not appreciably associated with ferritin concentration.

CONCLUSIONS

Increased iron storage may be associated with higher circulating concentrations of leptin and visfatin in men and with lower concentrations of adiponectin in women.

Ghrelin, insulin-like growth factor I and adipocytokines concentrations in born small for gestational age prepubertal children after the catch-up growth

BACKGROUND

In children born small for gestational age (SGA) with catch-up growth, a higher risk of insulin resistance (IR) and cardiovascular diseases is noted. Ghrelin stimulates a growth hormone (GH) secretion and regulates lipid and carbohydrate metabolism. We assessed gherlin's influence on achieving normal height and the occurrence of metabolic complications in SGA children.

METHODS

Ghrelin, insulin-like growth factor type I (IGF-I), leptin, adiponectin, resistin, glucose, insulin and lipid concentrations were analysed in 134 prepubertal children in four groups: normal-height SGA, short SGA, normal-height born appropriate for gestational age (AGA) and short AGA.

RESULTS

Ghrelin and IGF-I concentrations were significantly higher while adiponectin - lower in normal-height SGA comparing to others.

CONCLUSIONS

The increased production of ghrelin and IGF-I seems to be an adaptive mechanism to achieve normal growth in SGA children. The significance of high ghrelin and low adiponectin concentrations, observed in normal-height prepubertal SGA children, requires elucidation, with reference to the development of metabolic complications.

Expression of miR-199a-3p in human adipocytes is regulated by free fatty acids and adipokines

Obesity is associated with a notable risk for disease, including risk of cardiovascular disorders, type 2 diabetes mellitus (T2DM) and hypertension. Adipose tissue modulates the metabolism by releasing free fatty acids (FFAs) and adipokines, including leptin, resistin, tumor necrosis factor-α (TNF-α) and interleukin 6 (IL-6). Altered secretion patterns of FFAs and adipokines have been demonstrated to result in obesity-associated insulin resistance (IR) and inflammatory responses. MicroRNA-199a-3p (miR)-199a-3p expression is significantly induced in differentiated human adipose-derived mesenchymal stem cells and indicates the association with T2DM. However, the association between miR-199a-3p levels in adipocytes and obesity-associated IR, as well as inflammatory responses remains to be elucidated. The present study observed an elevation of miR-199a-3p expression level in mature human adipocytes (visceral) compared with pre-adipocytes. In addition, miR-199a-3p expression was higher in visceral adipose deposits from obese subjects. FFA, TNF-α, IL-6 and leptin significantly induced miR-199a-3p expression in mature human adipocytes, while resistin had the opposite effect. miR-199a-3p may represent a factor in the modulation of obesity-associated IR and inflammatory responses.

The triad psoriasis-obesity-adipokine profile

Psoriasis is a chronic inflammatory skin disease, often associated with overweight/obesity. The adipose tissue is a complex organ that secretes several adipokines, involved in the regulation of some metabolic processes, such as lipid metabolism, glucose homeostasis, angiogenesis, blood pressure and inflammation. In obesity, the distribution and function of adipose tissue, and the adipokine profile are altered. The unbalanced production of pro- and anti-inflammatory adipokines in obesity, contributes to the development of a chronic low-grade inflammation state, which seems to favour worsening of psoriasis lesion and a poorer response to treatment. In this review, we will debate published data concerning the current knowledge about the triad psoriasis-obesity-adipokine profile.

Biomarkers of Metabolic Syndrome: Biochemical Background and Clinical Significance

Biomarkers of the metabolic syndrome are divided into four subgroups. Although dividing them in groups has some limitations, it can be used to draw some conclusions. In a first part, the dyslipidemias and markers of oxidative stress are discussed, while inflammatory markers and cardiometabolic biomarkers are reviewed in a second part. For most of them, the biochemical background and clinical significance are discussed, although here also a well-cut separation cannot always be made. Altered levels cannot always be claimed as the cause, risk, or consequence of the syndrome. Several factors are interrelated to each other and act in a concerted, antagonistic, synergistic, or modulating way. Most important conclusions are summarized at the end of every reviewed subgroup. Genetic biomarkers or influences of various food components on concentration levels are not included in this review article.