Emerging Role of Adipocytokines in Type 2 Diabetes as Mediators of Insulin Resistance and Cardiovascular Disease

Naringin reduces body weight, plasma lipids and increases adiponectin levels in patients with dyslipidemia

Abstract. Naringin is a citrus-flavonoid which has been shown to have positive metabolic and anti-inflammatory effects. For this reason, we believe it would be interesting to study the effects of Naringin administration on body weight, BMI, lipid profile and adiponectin levels in patients with dyslipidemia, especially considering that dyslipidemias along with obesity and subsequent cardiometabolic complications are some of the most important public health issues plaguing our society today. A double-blind, randomized clinical trial was conducted in a group of 28 adult patients previously diagnosed with dyslipidemia who attended the Institute of Experimental and Clinical Therapeutics. Patients were divided into two groups; the first group (n = 14) received 450 mg of naringin every 24 hours, in the mornings, while the second group (n = 14) was given a homologated placebo over the course of a 90-day period. Significant differences were observed in naringin group compared to the placebo group in terms of decreased BMI (30.6 ± 3.19 vs 33.3 ± 3.23 kg/m2; p = 0.03), total cholesterol (182 ± 20.2 vs 245 ± 24.1 mg/dl; p < 0.01), LDL cholesterol (100 ± 17.5 vs 125 ± 38.3 mg/dl; p = 0.03) and an increase in adiponectin levels (0.82 ± 0.25 vs 0.59 ± 0.19 μg/ml; p = 0.01). Our results support the use of Naringin as a potential therapeutic agent which could play an important role in the management of metabolic disorders.

Relationship between adipocytokines and angiotensin converting enzyme gene insertion/deletion polymorphism in lean women with and without polycystic ovary syndrome

This study was designed to investigate the relationship between the levels of select adipocytokines (adiponectin, visfatin and apelin) and angiotensin in converting enzyme (ACE) gene insertion/deletion (ID) polymorphism in lean women with and without polycystic ovary syndrome (PCOS). The PCOS group (N = 94) was identified according to the Rotterdam criteria. The Control group (N = 68) included age- and body mass index (BMI)-matched healthy volunteers. Serum levels of adipocytokines were measured using enzyme immunoassays (EIA) and ACE genes were evaluated by polymerase chain reaction (PCR). The PCOS group, when compared to the Control group had lower adiponectin (p < .001) but higher visfatin (p < .001) and apelin (p = .003). There was no significant correlation of the levels of these adipocytokines with BMI, fasting glucose, fasting insulin or Homeostasis Model Assessment-Insulin Resistance (HOMA-IR). The PCOS and the Control groups also differed with regard to the ACE ID genotype distribution (p < .001). The ID, DD, and II genotype frequencies were, respectively, 34, 57 and 9% in the PCOS group and 49, 22 and 29% in the Control group. When stratified according to individual ID genotypes, the levels of adipocytokines in the PCOS and the Control groups remained significantly different. There was no statistically significant relationship between the levels of adipocytokines and ACE ID genotypes.

Association between inflammatory obesity phenotypes, FTO-rs9939609, and cardiovascular risk factors in patients with type 2 diabetes

Background

The role of inflammatory states in cardiometabolic risks among patients with type 2 diabetes mellitus (T2DM) with similar degrees of obesity is unknown. The study aimed to compare cardiometabolic risk factors in inflammatory obesity phenotypes with regard to the role of the FTO rs9939609 gene polymorphism.

Materials and Methods

This study was performed on 155 patients with T2DM (77 men and 78 women) in Ahvaz, Iran. Participants were grouped into four groups based on the presence of obesity and inflammation (high-sensitivity C-reactive protein ≥3.9 mg/L): low inflammatory normal weight (LINW), high inflammatory normal weight (HINW), low inflammatory obese (LIO), and high inflammatory obese (HIO). The genotypes of FTO rs9939609, including homozygous carriers of the FTO risk allele (AA), heterozygous carriers (AT), and carrying no risk allele (TT), were studied. The cardiometabolic risk factors, including anthropometric status, hypertension, lipid and glycemic profile, and inflammatory markers, were evaluated. The waist-hip ratio (WHR), mean arterial pressure (MAP), and atherogenic index of plasma (AIP) were calculated.

Results

The patients in inflammatory groups (HINW and HIO) have significantly higher levels in AIP when compared to inflammatory healthy groups (LINW and LIO). No significant differences between any of the four group means were detected in WHR, blood pressure, MAP, glycemic status (fasting blood sugar and insulin), homeostatic model assessment, lipid profile (triglyceride, very low-density lipoprotein, high-density lipoprotein, low-density lipoprotein, and cholesterol), interleukin-6, and total antioxidant capacity. The most frequent of high-risk genotype (AA) of FTO rs9939609 was in HIO, LIO, HINW, and LINW.

Conclusion

T2DM patients with inflammatory condition have similar degree of increased atherogenic risk irrespective of obesity. The obesity-risk genotype AA of FTO gene was associated with an increased risk for inflammatory obesity in T2DM patients.

Anti-Inflammatory Strategies Targeting Metaflammation in Type 2 Diabetes

One of the concepts explaining the coincidence of obesity and type 2 diabetes (T2D) is the metaflammation theory. This chronic, low-grade inflammatory state originating from metabolic cells in response to excess nutrients, contributes to the development of T2D by increasing insulin resistance in peripheral tissues (mainly in the liver, muscles, and adipose tissue) and by targeting pancreatic islets and in this way impairing insulin secretion. Given the role of this not related to infection inflammation in the development of both: insulin resistance and insulitis, anti-inflammatory strategies could be helpful not only to control T2D symptoms but also to treat its causes. This review presents current concepts regarding the role of metaflammation in the development of T2D in obese individuals as well as data concerning possible application of different anti-inflammatory strategies (including lifestyle interventions, the extra-glycemic potential of classical antidiabetic compounds, nonsteroidal anti-inflammatory drugs, immunomodulatory therapies, and bariatric surgery) in the management of T2D.

Adiponectin levels decrease independently of body mass index and diabetes type after the normalization of hyperglycemia

Background/aim

Acute hyperglycemia is generally a frequently encountered condition in the emergency department (ED), because it is seen as a complication of diabetes mellitus (DM). In this study, we aimed to detect the change in adiponectin levels during acute hyperglycemic states and after normalization of blood glucose with insulin treatment.

Materials and methods

Forty-eight patients over the age of 18 years who were admitted to the ED with acute hyperglycemia were included in the study. Serum samples were taken from patients on admission and 6 h after the normalization of blood glucose with insulin treatment, and adiponectin levels were measured in both samples.

Results

There were 21 female and 27 male patients with a median age of 58.7 ± 18 years. All patients’ blood glucose levels were normalized with insulin treatment according to international recommendations. Serum adiponectin levels decreased significantly after the normalization of blood glucose in the whole group. Adiponectin levels decreased from 28.9 ± 16.5 to 12.1 ± 10.9 μg/mL (P < 0.0001) in the whole group. This decrease was independent of diabetes type and body mass index. 

Conclusion

Normalization of blood glucose in patients with hyperglycemia caused a decrease in adiponectin levels, independent of diabetes type and/or body weight in an acute emergency setting. Inhibited upregulation of adiponectin secretion and/or blunted suppressive effect of insulin due to hyperglycemia or exogenous insulin administration may have caused the decrease in adiponectin levels.

Aging Fits the Disease Criteria of the International Classification of Diseases

The disease criteria used by the World Health Organization (WHO) were applied to human biological aging in order to assess whether aging can be classified as a disease. These criteria were developed for the 11th revision of the International Classification of Diseases (ICD) and included disease diagnostics, mechanisms, course and outcomes, known interventions, and linkage to genetic and environmental factors. RESULTS: Biological aging can be diagnosed with frailty indices, functional, blood-based biomarkers. A number of major causal mechanisms of human aging involved in various organs have been described, such as inflammation, replicative cellular senescence, immune senescence, proteostasis failures, mitochondrial dysfunctions, fibrotic propensity, hormonal aging, body composition changes, etc. We identified a number of clinically proven interventions, as well as genetic and environmental factors of aging. Therefore, aging fits the ICD-11 criteria and can be considered a disease. Our proposal was submitted to the ICD-11 Joint Task force, and this led to the inclusion of the extension code for "Ageing-related" (XT9T) into the "Causality" section of the ICD-11. This might lead to greater focus on biological aging in global health policy and might provide for more opportunities for the new therapy developers.

Leptin levels are not affected by enalapril treatment after an uncomplicated myocardial infarction, but associate strongly with changes in fibrinolytic variables in men

Leptin, an adipocyte-derived hormone, is involved in the regulation of body weight and is associated with obesity-related complications, notably cardiovascular disease (CVD). A putative link between obesity and CVD could be induction of plasminogen activator inhibitor-1 (PAI-1) synthesis by leptin. In this study, we hypothesized that the beneficial effect of the angiotensin-converting enzyme inhibitor (ACE_i) enalapril on PAI-1 levels is mediated by effects on leptin levels. The association between leptin and components of the fibrinolytic system was evaluated in a non-prespecified post hoc analysis of a placebo-controlled randomized, double-blind trial where the effect of the ACE_i enalapril on fibrinolysis was tested. A total of 46 men and 37 women were randomized to treatment with enalapril or placebo after (median 12 months) an uncomplicated myocardial infarction. At baseline, the participants were stable and had no signs of congestive heart failure. Leptin and fibrinolytic variables (mass concentrations of PAI-1, tissue plasminogen activator (tPA) and tPA-PAI complex) were measured at baseline, and after 10 days, 6 months and 12 months. Enalapril treatment did not change leptin levels, which increased significantly during 1 year of follow-up (p = .007). Changes in leptin levels were strongly associated with changes of tPA mass (p = .001), tPA-PAI complex (p = .003) and of PAI-1 (p = .006) in men, but not in women. Leptin levels are not influenced by treatment with an ACE_i. In contrast, leptin associates strongly with changes in fibrinolytic variables notably with a sex difference, which could be of importance for obesity-related CVD.

Ghrelin, resistin and insulin in obese diabetic women in Wad-Madani, Sudan

BACKGROUND

Obesity in the Sudan is increasing at alarming rate with the tendency of reaching an epidemic proportion in women. It is commonly associated with type 2 diabetes (T2D). Some adipokine hormones such as resistin are associated with obesity.

OBJECTIVES

To study how the levels of resistin, ghrelin and insulin are associated with obesity,fat distribution and (T2D) and to ascertain any interrelationships between them.

SUBJECTS AND METHODS

150 women, age ≥18 years old, resident in Wad-Madani town, Sudan were participated in the study. They were divided into 3 groups according to body mass index (BMI) value: I (normal weight), II (overweight) and III (obese diabetic). Fasting serum resistin and ghrelin concentrations were measured using ELISA method. Insulin levels were determined by radioimmunoassay(RIA).

RESULTS

The mean±SD levels of resistin 5.80±4.91ng/mL,Ghrelin107.60±26.67pg/M and Insulin 11.92±8.54mLU/ml in obese diabetic were found to be greater than in normal or overweight women. In normal weight values were 3.07±2.15 ng/mL 83.30±13.38pg/mL, and 6.62±6.77mLU/ml for resistini, ghrelin and Insulin, respectively. Values for overweight women 3.64±2.63 pg/mL 90±17.35 pg/mL and 8.13±7.54 mLU/ml for resistin, ghrelin and insulin respectively.

CONCLUSIONS AND RECOMMENDATIONS

Increased BMI, waist circumference (WC) and hormones (ghrelin and resistin) were associated with insulin resistance. Further studies are needed to accept or refute these findings.

Elevated Serum TNF-α Is Related to Obesity in Type 2 Diabetes Mellitus and Is Associated with Glycemic Control and Insulin Resistance

BACKGROUND

Diabetes and obesity are very common associated metabolic disorders that are linked to chronic inflammation. Leptin is one of the important adipokines released from adipocytes, and its level increases with increasing body mass index (BMI). Tumor necrosis factor alpha (TNF-α) is a cytokine that is released by adipocytes and inflammatory cells in response to chronic inflammation. Type 2 diabetes mellitus (T2DM) is believed to be associated with low-grade chronic inflammation. The current study aims to investigate the involvement of leptin and TNF-α) is a cytokine that is released by adipocytes and inflammatory cells in response to chronic inflammation. Type 2 diabetes mellitus (T2DM) is believed to be associated with low-grade chronic inflammation. The current study aims to investigate the involvement of leptin and TNF-Methodology. This is a cross-sectional study involving 63 healthy volunteers and 65 patients with T2DM. Body composition was measured, and fasting venous blood samples were analyzed for blood glucose, glycosylated hemoglobin (HbA1c), basal insulin, leptin, and TNF-α) is a cytokine that is released by adipocytes and inflammatory cells in response to chronic inflammation. Type 2 diabetes mellitus (T2DM) is believed to be associated with low-grade chronic inflammation. The current study aims to investigate the involvement of leptin and TNF-α) is a cytokine that is released by adipocytes and inflammatory cells in response to chronic inflammation. Type 2 diabetes mellitus (T2DM) is believed to be associated with low-grade chronic inflammation. The current study aims to investigate the involvement of leptin and TNF.

RESULTS

Our study showed a significantly higher level of TNF-α) is a cytokine that is released by adipocytes and inflammatory cells in response to chronic inflammation. Type 2 diabetes mellitus (T2DM) is believed to be associated with low-grade chronic inflammation. The current study aims to investigate the involvement of leptin and TNF-p=0.008). In obese diabetic patients, the serum level of TNF-α) is a cytokine that is released by adipocytes and inflammatory cells in response to chronic inflammation. Type 2 diabetes mellitus (T2DM) is believed to be associated with low-grade chronic inflammation. The current study aims to investigate the involvement of leptin and TNF-p=0.008). In obese diabetic patients, the serum level of TNF-p=0.008). In obese diabetic patients, the serum level of TNF-α) is a cytokine that is released by adipocytes and inflammatory cells in response to chronic inflammation. Type 2 diabetes mellitus (T2DM) is believed to be associated with low-grade chronic inflammation. The current study aims to investigate the involvement of leptin and TNF-r = 0.361, p=0.008). In obese diabetic patients, the serum level of TNF-r = 0.361, p=0.008). In obese diabetic patients, the serum level of TNF.

CONCLUSION

TNF-α is associated with concurrent obesity and T2DM and correlates with HbA1c. This suggests that TNF-α needs further investigation to explore if it has a role in monitoring the effectiveness of management in individuals with obesity and T2DM.α) is a cytokine that is released by adipocytes and inflammatory cells in response to chronic inflammation. Type 2 diabetes mellitus (T2DM) is believed to be associated with low-grade chronic inflammation. The current study aims to investigate the involvement of leptin and TNF-α) is a cytokine that is released by adipocytes and inflammatory cells in response to chronic inflammation. Type 2 diabetes mellitus (T2DM) is believed to be associated with low-grade chronic inflammation. The current study aims to investigate the involvement of leptin and TNF.

Diagnostic Significance of Plasma Levels of Novel Adipokines in Patients With Symptomatic Intra- and Extracranial Atherosclerotic Stenosis

Background: Adipokines have been proven to be associated with atherosclerotic diseases such as ischemic stroke and coronary heart disease. The role of novel adipokines in the development of symptomatic intracranial atherosclerotic stenosis (sICAS) and extracranial atherosclerotic stenosis (sECAS) has not yet been investigated. This study aimed to evaluate the plasma levels of novel adipokines in patients with sICAS and sECAS and their associations with the prognosis of sICAS groups.

Methods: A total of 134 patients with acute ischemic stroke attribute to large-artery atherosclerosis (LAA) and 66 age- and sex-matched controls without atherosclerotic stenosis (NCAS) were included in this study. The LAA group was further sub-classified as sICAS (n = 102) and sECAS (n = 32) according to the location of atherosclerosis. Demographics, clinical parameters, angiographical features and plasma levels of novel adipokines (apelin, visfatin, omentin, RBP-4) were assayed and compared among groups.

Results: LAA patients had significantly lower levels of omentin [39.92 (30.74–52.61) ng/ml vs. 54.42 (34.73–79.91) ng/ml, P < 0.001] and visfatin [11.32 (7.62–16.44) ng/ml vs. 13.01 (9.46–27.54) ng/ml, P < 0.001] than those in the NCAS group. Multiple logistic regression analysis identified that the lowest tertile of omentin was independently associated with LAA (OR, 3.423; 95% CI, 1.267–9.244, when referenced to the third tertile). Levels of omentin, visfatin and RBP-4 showed no significant difference between sICAS and sECAS groups. However, median concentrations of apelin were lower in sECAS [84.94 (46.88–130.41) ng/mL) than in sICAS [118.64 (93.22–145.08) ng/mL, P = 0.002] and NCAS [114.38 (80.56–162.93) ng/mL, P = 0.004]. Logistic regression analysis showed that the lowermost tertile of apelin was independently associated with sECAS (OR, 5.121; 95% CI, 1.597–16.426) when adjusted for risk factors. As for sICAS patients, spearman coefficient analysis showed no significant correlation between these four adipokines and the severity of sICAS or the number of vessels with intracranial stenoses. Patients with severe stroke had lower levels of apelin (P = 0.005), while the other three adipokines showed no such difference. During follow up, no difference was found between these four novel adipokines and short- and long-term outcome of sICAS.

Conclusions: Lower levels of omentin are independent biomarkers of LAA while low apelin plasma levels seem to be risk factors of sECAS.

Serum adipokine concentrations in patients with type 2 diabetes: the relationships with distribution, hypertrophy and vascularization of subcutaneous adipose tissue

Academy of Sciences, Novosibirsk, Russia 2Novosibirsk State Medical University, Novosibirsk, Russia BACKGROUND: Adipose tissue (AT) dysfunction plays an important role in metabolic disorders in obesity and type 2 diabetes. The role of distribution, hypertrophy and vascularization of AT in adipokine secretion disturbances remain to be clarified. AIMS: To determine the relationships between serum concentrations of adipokines and the mass and distribution of AT, diameter of adipocytes and vascularization of subcutaneous AT in patients with type 2 diabetes. MATERIALS AND METHODS: A total of 125 patients were examined, including 82 subjects with obesity. Thirty persons without diabetes and obesity, matched by sex and age, were acted as control. Concentrations of leptin, resistin, visfatin, adipsin and adiponectin in fasting serum were determined using multiplex analysis. Mass and distribution of AT was assessed by dual-energy X-ray absorptiometry. Samples of SAT were obtained from umbilical region using a knife biopsy in 25 patients and in 15 individuals who died in accidents. Blood and lymphatic vessels in SAT were revealed with immunohistochemistry, using antibody to CD-34 and podoplanin respectively. The volume and numerical density, ultrastructure of blood and lymphatic vessels, and mean diameter of subcutaneous adipocytes were evaluated. RESULTS: Patients with diabetes, as compared to control, had significantly higher levels of leptin, resistin, adipsin and visfatin (all p0.001). Adiponectin showed no differences. Concentrations of leptin, resistin, visfatin, adipsin and adiponectin correlated positively with gynoid fat mass. Additionally, leptin and adipsinshowed positive correlations with truncal and central abdominal fat mass. Concentration of leptin, but not other adipokines, was associated with hypertrophy of subcutaneous adipocytes. A decrease in volumetric density of microvessels(р=0.01) and increase in volume and numerical density of lymphatic vessels (both р=0.02) was observed in subcutaneous AT from diabetic subjects. The swelling of cytoplasm, mitochondria, cisterns of granular endoplasmic reticulum and reduced content of micropinocytotic vesicles was revealed in lymphatic capillaries. Resistin and visfatin showed inverse associations with density of microvessels. CONCLUSION: Endocrine dysfunction of AT in patients with type 2 diabetes, manifested by elevation of serum concentrations of leptin, resistin, visfatin and adipsin, is associated with mass and distribution of AT, hypertrophy of subcutaneous adipocytes and vascularization abnormalities of subcutaneous AT.

Glucose and lipid lowering effects of Enhydra fluctuans extract in cadmium treated normal and type-2 diabetic model rats

BACKGROUND

Recent epidemiological and experimental studies suggest that cadmium and diabetes-related hyperglycemia may act synergistically to worsen metabolic regulation. The present study aims to evaluate the potential effects of Enhydra fluctuans extract in diabetes and dyslipidemia in cadmium (CdCl₂) induced- normal and type 2 diabetic model rats.

METHOD

Forty-eight Long-Evans rats were divided equally into the following six groups: Normal Control (N-C), Normal treated with CdCl₂ (N-Cd), Normal treated with plant extract (N-P), Normal treated with both plant extract and CdCl₂ (N-PCd), Diabetic treated with plant extract (DM-P) and Diabetic treated with both plant extract and CdCl2 (DM-PCd). Blood glucose and other biochemical parameters were estimated by the enzymatic colorimetric method. Histological analysis of liver and heart was done by the hematoxylin-eosin (H & E) method.

RESULTS

Twenty-one days treatment of E. fluctuans extracts at a dose of 200 mg/kg significantly reduced blood glucose level in N-PCd and DM-PCd (p < 0.05), and DM-P (p < 0.01) group. The plant extract had no direct effects on total blood lipids but, it had beneficial effects on TG/HDL-C ratio in N-P and DM-PCd groups (p < 0.05). Cd induction significantly reduced body weight [(N-Cd, N-PCd, DM-PCd) (p < 0.01)], and induced liver [N-Cd (p < 0.05), N-PCd, p < 0.001] and renal impairment [N-Cd (p < 0.05)]. In bi-variate association, a significant positive correlation between serum glucose and SGPT (p < 0.05) as well as SGPT and TG/HDL ratio (p = 0.019) was found in DM-P and in the merged group. The histology of liver and heart showed severe damages including inflammation, nuclear pyknosis, loss of myocardial fibers, necrosis and fibrosis in the Cd treated groups compared to plant treated groups.

CONCLUSION

E. fluctuans seems to have potent antihyperglycemic effects in diabetes and Cd toxicity along with partial antidyslipidemic properties in euglycemic and diabetic rats. Our study suggests a novel oral antihyperglycemic agent in the present environmental context.

Evaluation of visceral fat mass in dogs by computed tomography

In human medicine, computed tomography (CT) is the gold standard for visceral fat measurement. Research shows that the visceral fat area (VFA) of the umbilical slice is significantly correlated with the visceral fat volume (VFV). In veterinary medicine, however, few studies have evaluated visceral fat using CT. This study aimed to evaluate the visceral fat in dogs using CT images, and determine if the slice significantly correlated with VFV to simplify visceral fat measurements. This retrospective study includes data on 90 dogs that underwent whole-body CT scans for diagnostic purposes. VFV was calculated as the product of VFA and thickness in each CT slice; the correlation between VFV and VFA was analyzed at the level of each lumbar vertebra. Visceral fat percentage (VF%) was calculated as the ratio of the product of VFV and fat density to the body weight. Visceral fat area percentage (VFA%) was calculated as the ratio of VFA to the body area, and its correlation with the VF% and the body condition score (BCS) was analyzed. VFA was highly correlated with VFV at the level of each lumbar vertebra, with the highest correlation (r=0.964) at the L3 level. VFA% was significantly correlated with VF% (r=0.930) and weakly correlated with BCS (r=0.523). This study demonstrates that it is sufficient to use only the L3 slice for visceral fat evaluation and that the evaluation can be based on VFA% of the L3 level.

Role of Complement and Complement-Related Adipokines in Regulation of Energy Metabolism and Fat Storage

Adipose tissue releases many cytokines and inflammatory factors described as adipokines. In obesity, adipokines released from expanding adipose tissue are implicated in disease progression and metabolic dysfunction. However, mechanisms controlling the progression of adiposity and metabolic complications are not fully understood. It has been suggested that expanding fat mass and sustained release of inflammatory adipokines in adipose tissue lead to hypoxia, oxidative stress, apoptosis, and cellular damage. These changes trigger an immune response involving infiltration of adipose tissue with immune cells, complement activation and generation of factors involved in opsonization and clearance of damaged cells. Abundant evidence now indicates that adipose tissue is an active secretory source of complement and complement-related adipokines that, in addition to their inflammatory role, contribute to the regulation of metabolic function. This article highlights advances in knowledge regarding the role of these adipokines in energy regulation of adipose tissue through modulating lipogenic and lipolytic pathways. Several adipokines will be discussed including adipsin, Factor H, properdin, C3a, Acylation-Stimulating Protein, C1q/TNF-related proteins, and response gene to complement-32 (RGC-32). Interactions between these factors will be described considering their immune-metabolic roles in the adipose tissue microenvironment and their potential contribution to progression of adiposity and metabolic dysfunction. The differential expression and the role of complement factors in gender-related fat partitioning will also be addressed. Identifying lipogenic adipokines and their specific autocrine/paracrine roles may provide means for adipose-tissue-targeted therapeutic interventions that may disrupt the vicious circle of adiposity and disease progression. © 2019 American Physiological Society. Compr Physiol 9:1411-1429, 2019.

Association of circulating adipokine concentrations with indices of adiposity and sex in healthy, adult client owned cats

Background

Both diabetes mellitus (DM) and obesity are common in cats. The adipokines leptin, adiponectin, resistin and omentin are thought to have important roles in human obesity and glucose homeostasis; however, their functions in the pathophysiology of feline diabetes mellitus and obesity are poorly understood. We determined whether sexual dimorphism exists for circulating concentrations of these adipokines, whether they are associated with adiposity, and whether they correlate with basic indices of insulin sensitivity in cats. Healthy, client-owned male and female cats that were either ideal weight or obese were recruited into the study. Fasting blood glucose, fructosamine, cholesterol, triglycerides, insulin and plasma concentrations of adipokines were evaluated.

Results

Obese cats had greater serum concentrations of glucose and triglycerides than ideal weight cats, but fructosamine and cholesterol concentrations did not differ between groups. Body weight and body mass index were greater in male than female cats, but circulating metabolite cocentrations were similar between sexes of both the ideal weight and obese groups. Plasma concentrations of insulin and leptin were greater in obese than ideal weight cats, with reciprocal reduction in adiponectin concentrations in obese cats; there were no sex differences in these hormones. Interestingly, plasma omentin concentrations were greater in male than female cats but with no differences between obese and ideal weight states.

Conclusion

Together our findings suggest that rather than gender, body weight and adiposity are more important determinants of circulating concentrations of the adipokines leptin and adiponectin. On the contrary, the adipokine omentin is not affected by body weight or adiposity but instead exhibits sexual dimorphism in cats.

Altered expression of glucose metabolism associated genes in a tacrolimus‑induced post‑transplantation diabetes mellitus in rat model

Post‑transplantation diabetes mellitus (PTDM) is a known side effect in transplant recipients administered with immunosuppressant drugs, such as tacrolimus (Tac). Although injury of islet cells is considered a major reason for Tac‑induced PTDM, the involvement of insulin resistance in PTDM remains unknown. In the present study, expression levels of adipocytokines, glucose metabolism associated genes and peroxisome proliferator‑activated receptor (PPAR)‑γ in adipose, muscular and liver tissues from a rat model induced with Tac (1 mg/kg/day) were examined. Rats developed hyperglycemia and glucose intolerance after 10 days of Tac administration. A subgroup of diabetic rats was further treated with rosiglitazone (4 mg/kg), a PPAR‑γ activator. Adipose, muscle and liver tissues were obtained on day 15 after induction and the results demonstrated that expression levels of adipocytokines, PPAR‑γ and proteins in the insulin associated signaling pathway varied in the different groups. Rosiglitazone administration significantly improved hyperglycemia, glucose intolerance and expression levels of proteins associated with insulin signaling, as well as adipocytokines expression. The results of this study demonstrated that adipocytokines and PPAR‑γ signaling may serve important roles in the pathogenesis of Tac‑induced PTDM, which may provide a promising application in the treatment of PTDM in the future.

Molecular Insight into the Interaction between Epigenetics and Leptin in Metabolic Disorders

Nowadays, it is well-known that the deregulation of epigenetic machinery is a common biological event leading to the development and progression of metabolic disorders. Moreover, the expression level and actions of leptin, a vast adipocytokine regulating energy metabolism, appear to be strongly associated with epigenetics. Therefore, the aim of this review was to summarize the current knowledge of the epigenetic regulation of leptin as well as the leptin-induced epigenetic modifications in metabolic disorders and associated phenomena. The collected data indicated that the deregulation of leptin expression and secretion that occurs during the course of metabolic diseases is underlain by a variation in the level of promoter methylation, the occurrence of histone modifications, along with miRNA interference. Furthermore, leptin was proven to epigenetically regulate several miRNAs and affect the activity of the histone deacetylases. These epigenetic modifications were observed in obesity, gestational diabetes, metabolic syndrome and concerned various molecular processes like glucose metabolism, insulin sensitivity, liver fibrosis, obesity-related carcinogenesis, adipogenesis or fetal/early postnatal programming. Moreover, the circulating miRNA profiles were associated with the plasma leptin level in metabolic syndrome, and miRNAs were found to be involved in hypothalamic leptin sensitivity. In summary, the evidence suggests that leptin is both a target and a mediator of epigenetic changes that develop in numerous tissues during metabolic disorders.

Lactobacillus reuteri V3401 Reduces Inflammatory Biomarkers and Modifies the Gastrointestinal Microbiome in Adults with Metabolic Syndrome: The PROSIR Study

Previous studies have reported that probiotics may improve clinical and inflammatory parameters in patients with obesity and metabolic syndrome (MetS). Lactobacillus (L.) reuteri V3401 has shown promising results on the components of MetS in animal studies. We aimed to evaluate the effects of L. reuteri V3401 together with healthy lifestyle recommendations on adult patients with MetS.

METHODS

We carried out a randomized, crossover, placebo-controlled, single-center trial in which we included 53 adult patients newly diagnosed with MetS. Patients were block randomly allocated by body mass index (BMI) and sex to receive a capsule containing either the probiotic L. reuteri V3401 (5 × 109 colony-forming units) or a placebo once daily for 12 weeks. Anthropometric variables, biochemical and inflammatory biomarkers, as well as the gastrointestinal microbiome composition were determined.

RESULTS

There were no differences between groups in the clinical characteristics of MetS. However, we found that interleukin-6 (IL-6) and soluble vascular cell adhesion molecule 1 (sVCAM-1) diminished by effect of the treatment with L. reuteri V3401. Analysis of the gastrointestinal microbiome revealed a rise in the proportion of Verrucomicrobia.

CONCLUSIONS

Consumption of L. reuteri V3401 improved selected inflammatory parameters and modified the gastrointestinal microbiome. Further studies are needed to ascertain additional beneficial effects of other probiotic strains in MetS as well as the mechanisms by which such effects are exerted.

Association between plasma phospholipid omega-3 polyunsaturated fatty acids and type 2 diabetes is sex dependent: The Hunter Community Study

BACKGROUND & AIMS

Chronic inflammation drives the development of insulin resistance and type 2 diabetes. Long-chain omega-3 polyunsaturated fatty acids (LCn-3PUFA) eicosapentaenoic acid (EPA, c20:5n-3) and docosahexaenoic acid (DHA, c22:6n-3) may protect against type 2 diabetes development. The aim of this current study is to determine whether LCn-3PUFA status is associated with type 2 diabetes in the Hunter Community Study.

METHODS

Men and women aged 55-85 years were randomly selected from the electoral roll and invited to participate. Participants were included in the current study if they had plasma phospholipid fatty acid composition data available and diabetes status could be determined. LCn-3PUFA status was determined by fatty acid composition of plasma phospholipids (EPA + DHA, %,w/w). Diabetes was determined according to World Health Organisation criteria. Insulin was measured in n = 251 participants and HOMA-IR calculated.

RESULTS

In total, n = 2092 (diabetes: n = 249) participants were included. After adjusting for confounders of diabetes, LCn-3PUFA status was inversely associated with diabetes in overweight/obese females (OR [95%CI]: 0.90 [0.80, 1.00], p = 0.045) but not males (p-interaction_sex = 0.041). Overweight/obese females with diabetes had significantly lower levels of DHA than those without diabetes (mean difference [95%CI]: -0.53 [-0.87, -0.20], p = 0.002), with no difference in EPA. LCn-3PUFA was inversely associated with HOMA-IR (r = -0.175, p = 0.005).

CONCLUSIONS

This study provides further evidence of a sex-dependent association between LCn-3PUFA and type 2 diabetes. Causal pathways between LCn-3PUFA and type 2 diabetes merits delineation.

Physiological roles and molecular mechanisms of K+ -Cl- cotransport in the mammalian kidney and cardiovascular system: where are we?

In the early 80s, renal microperfusion studies led to the identification of a basolateral K⁺ -Cl^- cotransport mechanism in the proximal tubule, thick ascending limb of Henle and collecting duct. More than ten years later, this mechanism was found to be accounted for by three different K⁺ -Cl^- cotransporters (KCC1, KCC3 and KCC4) that are differentially distributed along the renal epithelium. Two of these isoforms (KCC1 and KCC3) were also found to be expressed in arterial walls, the myocardium and a variety of neurons. Subsequently, valuable insights have been gained into the molecular and physiological properties of the KCCs in both the mammalian kidney and cardiovascular system. There is now robust evidence indicating that KCC4 sustains distal renal acidification and that KCC3 regulates myogenic tone in resistance vessels. However, progress in understanding the functional significance of these transporters has been slow, probably because each of the KCC isoforms is not identically distributed among species and some of them share common subcellular localizations with other KCC isoforms or sizeable conductive Cl^- pathways. In addition, the mechanisms underlying the process of K⁺ -Cl^- cotransport are still ill defined. The present review focuses on the knowledge gained regarding the roles and properties of KCCs in renal and cardiovascular tissues.

The identification of gene signature and critical pathway associated with childhood-onset type 2 diabetes

In general, type 2 diabetes (T2D) usually occurs in middle-aged and elderly people. However, the incidence of childhood-onset T2D has increased all across the globe. Therefore, it is very important to determine the molecular and genetic mechanisms of childhood-onset T2D. In this study, the dataset GSE9006 was downloaded from the GEO (Gene Expression Omnibus database); it includes 24 healthy children, 43 children with newly diagnosed Type 1 diabetes (T1D), and 12 children with newly diagnosed T2D. These data were used for differentially expressed genes (DGEs) analysis and weighted co-expression network analysis (WGCNA). We identified 192 up-regulated genes and 329 down-regulated genes by performing DEGs analysis. By performing WGGNA, we found that blue module (539 genes) was highly correlated to cyan module (97 genes). Gene ontology (GO) and pathway enrichment analyses were performed to figure out the functions and related pathways of genes, which were identified in the results of DEGs and WGCNA. Genes with conspicuous logFC and in the high correlated modules were input into GeneMANIA, which is a plugin of Cytoscape application. Thus, we constructed the protein-protein interaction (PPI) network (92 nodes and 254 pairs). Eventually, we analyzed the transcription factors and references related to genes with conspicuous logFC or high-degree genes, which were present in both the modules of WGCNA and PPI network. Current research shows that EGR1 and NAMPT can be used as marker genes for childhood-onset T2D. Gestational diabetes and chronic inflammation are risk factors that lead to the development of childhood-onset T2D.

Study rationale and protocol of the BARICO study: a longitudinal, prospective, observational study to evaluate the effects of weight loss on brain function and structure after bariatric surgery

INTRODUCTION

Weight loss after bariatric surgery (BS) is often associated with improved cognition and structural brain recovery. However, improved cognition after BS is not always exhibited by patients, in fact, in some cases there is even a decline in cognition. Long-term consequences of BS weight loss, in terms of obesity and related diseases, can be hard to determine due to studies having short follow-up periods and small sample sizes.The aim of the BARICO study (BAriatric surgery Rijnstate and Radboudumc neuroImaging and Cognition in Obesity) is to determine the long-term effect of weight loss after BS on brain function and structure, using sensitive neuropsychological tests and (functional) MRI ((f)MRI). Secondary study endpoints are associated with changes in metabolic and inflammation status of adipose tissue, liver and gut, in relation to brain structure and function. Also, the possible correlation between weight loss, gut microbiota composition change and neuropsychological outcomes will be investigated.

METHODS AND ANALYSIS

Data from 150 Dutch BS patients (ages between 35 and 55, men and women) will be collected at various time points between 2 months before and up to 10 years after surgery. Neuropsychological tests, questionnaires, blood, faeces and tissue samples will be collected before, during and after surgery to measure changes in cognition, microbiota, metabolic activity and inflammation over time. A subgroup of 75 participants will undergo (f)MRI in relation to executive functioning (determined by the Stroop task), grey and white matter volumes and cerebral blood flow. Regression analyses will be used to explore associations between weight loss and outcome measures.

ETHICS AND DISSEMINATION

This study has been approved by the medical review ethics committee CMO Region Arnhem and Nijmegen (NL63493.091.17). Research findings will be published in peer-reviewed journals and at conferences.

TRIAL REGISTRATION NUMBER

NTR7288.

Effects of Genetic Variants of Nuclear Receptor Y on the Risk of Type 2 Diabetes Mellitus

Nuclear factor-Y (NF-Y) consists of three evolutionary conserved subunits including NF-YA, NF-YB, and NF-YC; it is a critical transcriptional regulator of lipid and glucose metabolism and adipokine biosynthesis that are associated with type 2 diabetes mellitus (T2DM) occurrence, while the impacts of genetic variants in the NF-Y gene on the risk of T2DM remain to be investigated. In the present study, we screened five single-nucleotide polymorphisms (SNPs) with the SNaPshot method in 427 patients with T2DM and 408 healthy individuals. Subsequently, we analyzed the relationships between genotypes and haplotypes constructed from these SNPs with T2DM under diverse genetic models. Furthermore, we investigated the allele effects on the quantitative metabolic traits. Of the five tagSNPs, we found that three SNPs (rs2268188, rs6918969, and rs28869187) exhibited nominal significant differences in allelic or genotypic frequency between patients with T2DM and healthy individuals. The minor alleles G, C, and C at rs2268188, rs6918969, and rs28869187, respectively, conferred a higher T2DM risk under a dominant genetic model, and the carriers of these risk alleles (either homozygotes of the minor allele or heterozygotes) had statistically higher levels of fasting plasma glucose, cholesterol, and triglycerides. Haplotype analysis showed that SNPs rs2268188, rs6918969, rs28869187, and rs35105472 formed a haplotype block, and haplotype TTAC was protective against T2DM (OR = 0.76, 95% CI = 0.33-0.82, P = 0.004), while haplotype GCCG was associated with an elevated susceptibility to T2DM (OR = 2.33, 95% CI = 1.43-3.57, P = 0.001). This study is the first ever observation to our knowledge that indicates the genetic variants of NF-YA might influence a Chinese Han individual's occurrence of T2DM.

Circulating levels of adipose tissue-derived inflammatory factors in elderly diabetes patients with carotid atherosclerosis: a retrospective study

BACKGROUND

Inflammation has been recognized as a key feature of both type 2 diabetes mellitus (T2DM) and atherosclerosis. However, the relationships between circulating levels of novel adipose tissue-derived inflammatory factors, including resistin, vaspin, and visfatin, and the severity of atherosclerosis have not been determined. Moreover, the associations between these inflammatory factors and obesity and insulin resistance in elderly patients remain to be clarified.

METHODS

A cross-sectional study of 256 elderly patients with T2DM admitted in our center was performed. Baseline circulating levels of resistin, vaspin and visfatin were measured with enzyme-linked immunosorbent assays. Ultrasonic evaluations of the carotid arteries of the patients were performed to reflect the severity of systemic atherosclerosis. Patients were classified as having mild, moderate, or severe atherosclerosis according to the results of carotid ultrasonic examination. Circulating levels of the inflammatory factors listed above also were correlated with body mass index (BMI) and homeostasis model assessment of insulin resistance (HOMA-IR).

RESULTS

With more severe carotid atherosclerosis, circulating levels of resistin (mild: 2.01 ± 0.23; moderate: 2.89 ± 1.01; severe: 3.12 ± 1.12; p < 0.05) and visfatin (mild: 11.63 ± 7.48; moderate: 15.24 ± 2.19; severe: 17.54 ± 2.98; p < 0.05) gradually increased, while level of vaspin decreased (mild: 317 ± 23.12; moderate: 269 ± 32.12; severe: 229 ± 14.24; p < 0.05). Subsequent results of Pearson coefficient analyses indicated that all of the tested adipose tissue-derived inflammatory factors were positively correlated with the BMI and HOMA-IR of the patients (all p < 0.05), even after adjustment for hs-CRP.

CONCLUSIONS

The adipose tissue-derived inflammatory factors resistin, vaspin and visfatin may be involved in the pathogenesis of atherosclerosis in elderly T2DM patients.

Dysregulated lipid storage and its relationship with insulin resistance and cardiovascular risk factors in non-obese Asian patients with type 2 diabetes

The prevalence of non-obese type 2 diabetes in Asians is up to 50%. This review aims to summarize the role of regional fat in the development of insulin resistance and cardiovascular risk in non-obese Asian type 2 diabetes as well as the role of intra-pancreatic fat and β-cell dysfunction. The body fat content of non-obese Asian type 2 diabetic patients is not different from that of non-diabetic subjects but the proportion of intra-abdominal and intra-hepatic fat are greater. Visceral fat contributes to insulin resistance and cardiovascular risk in non-obese Asian type 2 diabetes. Intra-hepatic fat and the hypertrophic abdominal subcutaneous adipocytes are associated with insulin resistance and cardiovascular risk in non-obese, non-diabetic Asian subjects. It may be true in non-obese Asian type 2 diabetic patients. The role of intra-myocellular lipid and insulin resistance is uncertain. Intra-pancreatic fat may not be involved in β-cell dysfunction in non-obese Asian type 2 diabetes.

Differential effect of metformin and/or glyburide on apelin serum levels in patients with type 2 diabetes mellitus: Concepts and clinical practice

Type 2 diabetes mellitus (T2DM) is a metabolic disorder associated with abundant adipocytokine changes which may play an important role in the progression of insulin resistance and micro- and macro-vascular complications. Therefore, the objective of this study was to assess the differential effect of metformin alone or in combination with glyburide on apelin serum levels in patients with T2DM. In this case–control study, fifty patients with T2DM in the age range of 45–65 years and twenty-five healthy controls matched for age and body weight were recruited from single endocrinology center, subdivided according to the diabetic pharmacotherapy into: Group I: healthy controls (n = 25), Group II: T2DM patients on metformin (n = 15), Group III: T2DM patients on glyburide (n = 17), and Group IV: T2DM patients on metformin plus glyburide (n = 28). Biochemical and anthropometric variables in relation to apelin serum levels were estimated. Apelin serum levels were low in normal healthy controls compared to T2DM patients (P < 0.01). The differential effect of diabetic pharmacotherapy on apelin serum level was statistically significant (P < 0.01) compared to the controls, but insignificant when compared among used drugs (P > 0.05). Apelin level was high in T2DM compared to the controls; both metformin and glyburide might play a role in this elevation.