The potential role of leptin and adiponectin in obesity: a comparative review

Examining the Potential Applicability of Orexigenic and Anorexigenic Peptides in Veterinary Medicine for the Management of Obesity in Companion Animals

This review article comprehensively explores the role of orexigenic and anorexigenic peptides in the management of obesity in companion animals, with a focus on clinical applications. Obesity in domestic animals, particularly dogs and cats, is prevalent, with significant implications for their health and well-being. Factors contributing to obesity include overfeeding, poor-quality diet, lack of physical activity, and genetic predispositions. Despite the seriousness of this condition, it is often underestimated, with societal perceptions sometimes reinforcing unhealthy behaviors. Understanding the regulation of food intake and identifying factors affecting the function of food intake-related proteins are crucial in combating obesity. Dysregulations in these proteins, whether due to genetic mutations, enzymatic dysfunctions, or receptor abnormalities, can have profound health consequences. Molecular biology techniques play a pivotal role in elucidating these mechanisms, offering insights into potential therapeutic interventions. The review categorizes food intake-related proteins into anorexigenic peptides (inhibitors of food intake) and orexigenic peptides (enhancers of food intake). It thoroughly examines current research on regulating energy balance in companion animals, emphasizing the clinical application of various peptides, including ghrelin, phoenixin (PNX), asprosin, glucagon-like peptide 1 (GLP-1), leptin, and nesfatin-1, in veterinary obesity management. This comprehensive review aims to provide valuable insights into the complex interplay between peptides, energy balance regulation, and obesity in companion animals. It underscores the importance of targeted interventions and highlights the potential of peptide-based therapies in improving the health outcomes of obese pets.

Therapeutic perspectives on PDE4B inhibition in adipose tissue dysfunction and chronic liver injury

INTRODUCTION

Chronic liver disease (CLD) is a complex disease associated with profound dysfunction. Despite an incredible burden, the first and only pharmacotherapy for metabolic-associated steatohepatitis was only approved in March of this year, indicating a gap in the translation of preclinical studies. There is a body of preclinical work on the application of phosphodiesterase 4 inhibitors in CLD, none of these molecules have been successfully translated into clinical use.

AREAS COVERED

To design therapies to combat CLD, it is essential to consider the dysregulation of other tissues that contribute to its development and progression. As such, proper therapies must combat this throughout the body rather than focusing only on the liver. To detail this, literature characterizing the pathogenesis of CLD was pulled from PubMed, with a particular focus placed on the role of PDE4 in inflammation and metabolism. Then, the focus is shifted to detailing the available information on existing PDE4 inhibitors.

EXPERT OPINION

This review gives a brief overview of some of the pathologies of organ systems that are distinct from the liver but contribute to disease progression. The demonstrated efficacy of PDE4 inhibitors in other human inflammatory diseases should earn them further examination for the treatment of CLD.

Central obesity may affect bone development in adolescents: association between abdominal obesity index ABSI and adolescent bone mineral density

PURPOSE

Previous studies have suggested that obesity defined by body mass index(BMI) is a protective factor for bone mineral density(BMD), but have overlooked the potential influence of different types of obesity. This study aims to evaluate the correlation between abdominal obesity index A Body Shape Index(ABSI) and adolescent bone density, and analyze the relationship between abdominal obesity and bone metabolism.

METHODS

A total of 1557 adolescent participants were included in NHANES from 2007 to 2018. Calculate the ABSI using a specific formula that takes into account waist circumference and BMI. A weighted multiple linear regression model is used to evaluate the linear correlation between ABSI and BMD. Forest plots are used to analyze the correlations between subgroups, and cubic splines are limited to evaluate the nonlinear correlations and saturation effects between ABSI and BMD.

RESULTS

After adjusting for confounding factors, there was a significant linear correlation (P < 0.01) between ABSI and femoral BMD, both as a continuous variable and an ordered categorical variable. The restrictive cubic spline curve indicates a significant nonlinear correlation and saturation effect between adolescent ABSI and BMD.

CONCLUSION

Research has shown a significant negative correlation between ABSI and BMD at the four detection sites of the femur, and this correlation may vary slightly due to age, race, family income, and different detection sites. The research results indicate that compared to overall body weight, fat distribution and content may be more closely related to bone metabolism.

Soy Supplementation Does Not Affect Serum Adiponectin Levels in Adults: A Systematic Review and Meta-Analysis of Randomized Controlled Trials

Numerous studies have indicated that low levels of serum adiponectin are linked with the development of various chronic diseases. While some recent research has suggested that soy has a positive impact on serum adiponectin levels, the results are inconsistent. Therefore, we aim to conduct a thorough systematic review and meta-analysis of randomized controlled trials (RCTs) that investigate the effects of soy on serum adiponectin levels in adults. The search was conducted until March 2024 on PubMed, Scopus, Web of Science, and Cochrane Library databases to identify RCTs that studied the effects of soy supplementation on serum adiponectin levels. A random-effects model was used to pool the weighted mean differences (WMDs). Ten and nine RCTs were selected for the systematic review and meta-analysis, respectively. After analyzing data from 9 eligible RCTs, it was found that soy supplementation did not significantly impact the concentrations of adiponectin (WMD = -0.24 μg/mL; 95% confidence interval, -1.56 to 1.09; p = 0.72). However, there was significant heterogeneity between the studies (I2 = 89.8%, p < 0.001). Sensitivity analysis showed that overall estimates were not affected by the elimination of any study. We did not observe any evidence regarding publication bias. In conclusion, soy supplementation did not have a significant effect on adiponectin levels in adults. However, further RCTs are needed with longer intervention duration, higher doses, and studies conducted in different countries.

Therapeutic applications of ginseng for skeletal muscle-related disorder management

Skeletal muscle (SM) is the largest organ of the body and is largely responsible for the metabolism required to maintain body functions. Furthermore, the maintenance of SM is dependent on the activation of muscle satellite (stem) cells (MSCs) and the subsequent proliferation and fusion of differentiating myoblasts into mature myofibers (myogenesis). Natural compounds are being used as therapeutic options to promote SM regeneration during aging, muscle atrophy, sarcopenia, cachexia, or obesity. In particular, ginseng-derived compounds have been utilized in these contexts, though ginsenoside Rg1 is mostly used for SM mass management. These compounds primarily function by activating the Akt/mTOR signaling pathway, upregulating myogenin and MyoD to induce muscle hypertrophy, downregulating atrophic factors (atrogin1, muscle ring-finger protein-1, myostatin, and mitochondrial reactive oxygen species production), and suppressing the expressions of tumor necrosis factor-α (TNF-α) and interleukin-6 (IL-6) in cachexia. Ginsenoside compounds are also used for obesity management, and their anti-obesity effects are attributed to peroxisome proliferator activated receptor gamma (PPARγ) inhibition, AMPK activation, glucose transporter type 4 (GLUT4) translocation, and increased phosphorylations of insulin resistance (IR), insulin receptor substrate-1 (IRS-1), and Akt. This review was undertaken to provide an overview of the use of ginseng-related compounds for the management of SM-related disorders.

The relationship between weight-adjusted-waist index and total bone mineral density in adults aged 20-59

Introduction

According to reports, obesity has a significant impact on bone health. And the weight-adjusted-waist index (WWI), superior to BMI and waist circumference (WC), is a new obesity indicator arising in recent years. This research investigated the relationship between WWI and total bone mineral density (BMD) for adults aged 20 to 59.

Methods

Using data from the 2011-2018 NHANES, we looked into the independent link between WWI and total BMD as well as its nonlinearity using weighted multiple linear regression and smooth curve fitting. Two-stage linear regression models were employed to calculate the threshold effects. There were additional subgroup analyses and testing for interactions.

Results

Multiple linear regression studies on a total of 10,372 individuals showed a significant inverse link between WWI and total BMD in adults between 20 and 59 [β = -0.04, 95% CI: (-0.04, -0.03), P<0.0001]. And smoking, race, and chronic kidney disease (CKD) had no significant effect on this negative connection (P for interaction >0.05). In addition, we found a nonlinear relationship between WWI and total BMD in diabetic and CKD patients, for which the saturation point was 11.38 cm/√kg in the CKD patient group and 10.29 cm/√kg in the diabetic patient group.

Conclusion

Our analysis demonstrated a significant inverse association between WWI and total BMD in adults aged 20-59.

Dietary pulses as a means to improve the gut microbiome, inflammation, and appetite control in obesity

A dysbiotic intestinal microbiome has been linked to chronic diseases such as obesity, which may suggest that interventions that target the microbiome may be useful in treating obesity and its complications. Appetite dysregulation and chronic systemic low-grade inflammation, such as that observed in obesity, are possibly linked with the intestinal microbiome and are potential therapeutic targets for the treatment of obesity via the microbiome. Dietary pulses (e.g., common beans) are composed of nutrients and compounds that possess the potential to modulate the gut microbiota composition and function which can in turn improve appetite regulation and chronic inflammation in obesity. This narrative review summarizes the current state of knowledge regarding the connection between the gut microbiome and obesity, appetite regulation, and systemic and adipose tissue inflammation. More specifically, it highlights the efficacy of interventions employing dietary common beans as a means to improve gut microbiota composition and/or function, appetite regulation, and inflammation in both rodent obesity and in humans. Collectively, results presented and discussed herein provide insight on the gaps in knowledge necessary for a comprehensive understanding of the potential of beans as a treatment for obesity while highlighting what further research is required to gain this understanding.

Adiponectin and leptin levels of patients after sleeve gastrectomy, Roux-en-Y gastric bypass, and single anastomosis sleeve ileal bypass surgeries

Background

Bariatric surgery is an appropriate treatment for obese patients with metabolic syndrome. Adipose tissue is an active endocrine tissue secreting leptin and adiponectin that affect body metabolism. Nowadays, a high incidence of metabolic syndrome with an increased risk of serious diseases has been detected in Shiraz. This study aimed to assess the levels of leptin and adiponectin as well as the adiponectin-to-leptin ratio in three different bariatric surgeries among obese patients in Shiraz. The results will play an important role in physicians' choice of surgery by distinguishing the effects of these three bariatric surgeries.

Materials and Methods

The serum adiponectin and leptin levels were measured using enzyme-linked immunosorbent assay. Blood glucose, lipid profile, weight, and liver enzyme level were measured before and 7 months after surgery.

Results

This clinical trial was conducted on 81 obese patients who underwent sleeve gastrectomy (SG), Roux-en-Y gastric bypass (RYGB), and single anastomosis sleeve ileal (SASI) bypass surgeries. The results revealed a decrease in fasting blood sugar and triglyceride (TG) levels 7 months after the surgeries. In addition, decrease of body mass index (BMI) was more significantly in the SASI group (12.8 ± 3 4.95) compared to the Roux-en-Y gastric group (8.56 ± 4.61) (P = 0.026). Besides, a more significant improvement in liver function was observed in SG (P < 0.05). Furthermore, the results revealed a significant difference among the three groups regarding the increase in the adiponectin level (P = 0.039). Decrease in the leptin level and increase in the adiponectin level were more significant after the RYGB surgery compared to the SG group (P < 0.05).

Conclusion

The three bariatric surgeries were effective in increasing the adiponectin level and decreasing the leptin levels. The surgeries also changed the metabolic risk factors including TGs, high-density lipoprotein, fasting blood glucose, and BMI.

Changes in gut microbiota and short-chain fatty acids are involved in the process of canine obesity after neutering

Neutering is a significant risk factor for obesity in dogs. Changes in gut microbiota and its metabolites have been identified as a key player during obesity progression. However, the mechanisms that promote neuter-associated weight gain are not well understood. Therefore, in this study, sixteen clinically healthy Beagle dogs (6 male and 10 female, mean age = 8.22 ± 0.25 mo old) were neutered. Body weight (BW) and body condition score (BCS) were recorded at 1 d before neutering, 3, 6, 10, 16, and 21 mo after neutering. Dogs were grouped based on their BCS as ideal weight group (IW, n = 4, mean BW = 13.22 ± 1.30 kg, mean BCS = 5.00 ± 0.41) and obese group (OB, n = 12, mean BW = 18.57 ± 1.08 kg, mean BCS = 7.92 ± 0.82) at 21 mo after neutering. Serum lipid profile, glucose, and hormones and fecal microbiota and short-chain fatty acids (SCFAs) were measured. Our results showed that OB dogs had greater (P < 0.0001) BW (18.57 vs. 13.22 kg), BCS (7.92 vs. 5.00), and average daily gain (12.27 vs. 5.69 g/d) than IW dogs at 21 mo after neutering, and the obesity rate was up to 60%. In addition, significant increases (P < 0.05) in serum triglyceride (TG, 1.10 vs. 0.56 mmol/L) and high-density lipoprotein cholesterol (HDL-C, 6.96 vs. 5.40 mmol/L) levels and a significant decrease (P < 0.05) in serum adiponectin (APN, 54.06 vs. 58.39 μg/L) level were observed in OB dogs; serum total cholesterol (4.83 vs. 3.75 mmol/L) (P = 0.075) and leptin (LEP, 2.82 vs. 2.53 μg/L) (P = 0.065) levels tended to be greater in OB dogs; there was a trend towards a lower (P = 0.092) APN/LEP (19.32 vs. 21.81) in OB dogs. Results of fecal microbial alpha-diversity showed that Observed_species and Chao1 indices tended to be lower (P = 0.069) in OB dogs. The STAMP and LEfSe analyses revealed that OB dogs had a greater (P < 0.05 and LDA > 2) reduction in relative abundances of Bacteroides, Prevotella_9, and Megamonas than IW dogs. In addition, OB dogs also had greater (P < 0.05) reduction in fecal acetate, propionate, and butyrate concentrations than IW dogs. Moreover, clear negative correlations (|r| > 0.5 and P < 0.05) were found between SCFAs-producing bacteria and BW, TG, and HDL-C. The functional predictions of microbial communities based on PICRUSt2 analysis revealed that lipid metabolism and endocrine system were significantly disturbed in obese dogs after neutering. Thus, intervention with SCFAs-producing bacteria might represent a new target for the prevention or treatment of canine obesity after neutering. Moreover, weight control before neutering may also contribute to the prevention of canine obesity after neutering.

Effects of decaffeinated green coffee extract supplementation on anthropometric indices, blood glucose, leptin, adiponectin and neuropeptide Y (NPY) in breast cancer survivors: a randomized clinical trial

Objective: This study aimed to evaluate the effects of decaffeinated green coffee extract (DGCE) supplementation on anthropometric indices, blood glucose, leptin, adiponectin, and neuropeptide Y (NPY) in breast cancer survivors with obesity. Method: A total of 44 breast cancer survivors with obesity aged between 18 and 70 years and with a mean body mass index (BMI) of 31.62 ± 4.97 kg m^-2 participated in this double-blind randomized clinical trial. Eligible patients were randomized to the intervention (n = 22) and control (n = 22) groups. They received two 400 mg capsules of DGCE or two identical placebos daily for 12 weeks. Serum concentrations of leptin, adiponectin, NPY, fasting blood sugar, insulin, and homeostatic model assessment for insulin resistance (HOMA-IR) were measured at the baseline and after completion of the intervention. Also, weight, waist circumference, fat percentage, muscle percentage, and visceral fat were measured. Results: There were no significant differences in terms of changes of anthropometric indices and concentrations of leptin, adiponectin, NPY, and blood sugar between the two studied groups. Conclusion: Supplementation with DGCE in breast cancer survivors with obesity had no significant effect on anthropometric indices and blood glucose, leptin, adiponectin, and NPY levels.

A Physiological Approach to Inflammatory Markers in Obesity

Obesity is one of the most critical health problems all over the world; it is associated with metabolic dysfunction and overnutrition. Changes in the physiological function of adipose tissue, leading to altered secretion of adipocytokines, inflammatory mediators release, and chronic low-grade inflammation, are seen in obesity. Macrophages, neutrophils, CD4+ and CD8+ T cells, B cells, natural killer T (NKT) cells, eosinophils, mast cells, and adipocytes are involved in the inflammatory response that occurs during obesity. Various inflammatory markers are released from these cells. In this chapter, we will mention inflammatory mechanisms and markers of obesity.

Systematic review and meta-analysis of randomized, controlled trials on the effects of soy and soy products supplementation on serum adiponectin levels

BACKGROUND AND AIMS

Our aim in this meta-analysis was to determine the effect of soy and soy product supplementation on serum adiponectin levels.

METHOD

A systematic search was conducted using Medline (PubMed and Web of Science), Scopus, and Cochrane Library for eligible trials up to August 2020. A random-effects model was used to pool calculated effect sizes.

RESULTS

Seven trials were included in the overall analysis. Our analysis showed that soy and soy product supplementation did not significantly affect adiponectin concentrations (WMD = -0.77 μg/ml, 95% CI: -0.61, 2.15, P = 0.27) in comparison with a placebo. The between-study heterogeneity was high (I2: 68.2%, P = 0.004). Subgroup analysis, based on participants' health status and duration of the supplementation, could not detect the potential source of the observed heterogeneity. In addition, subgroup analysis showed that the effect was not statistically significant in all subgroups.

CONCLUSION

Overall, soy and soy product supplementation did not change the circulatory adiponectin levels. In addition, the results were not affected by the participant's health status and duration of supplementation. However, further studies are needed to confirm the present results.

Anti-Obesity Effect of Porcine Collagen Peptide in 3T3-L1 Adipocytes and High-Fat Diet-Fed Mice by Regulating Adipogenesis

Obesity is one of the most common diseases caused by an imbalance in the intake and expenditure of energy, and it is associated with various metabolic complications. This study aimed at investigating the anti-obesity effects and mechanisms of porcine collagen peptide (PCP) using 3T3-L1 preadipocytes and high-fat diet (HFD)-fed mice. The PCP treatment significantly inhibited the adipocyte differentiation and attenuated the mRNA expression of transcription factors (CCAAT/enhancer-binding protein alpha [C/EBPα] and peroxisome proliferator-activated receptor gamma [PPARγ]) and the lipogenic gene (fatty acid synthase [FAS]) expression in 3T3-L1 preadipocytes. In the in vivo study, HFD-fed mice were fed low- (1.5 g/kg body weight/day) and high- (4.5 g/kg body weight/day) PCP for 12 weeks and compared with the normal diet-fed group and HFD-fed control group. The PCP-fed groups showed significantly lower body weight gain, white fat weight gain, serum triglycerides, and adipocyte size compared with the HFD-fed group. The changes in body fat were associated with the upregulation of adiponectin and the downregulation of leptin, C/EBPα, PPARγ, and FAS. These results suggest that PCP has the potential to reduce obesity by suppressing adipogenesis and could be applied as a functional food material.

Serum adiponectin and cortisol levels are not affected by studied ADIPOQ gene variants: Tehran lipid and glucose study

BACKGROUND

Obesity is a major public health concern in developed and even developing countries worldwide. Adiponectin is a protein secreted by adipose tissue that modulates many metabolic processes and plays a vital role in obesity. This study aimed to determine the association of four variants of the ADIPOQ gene with serum adiponectin, cortisol levels and obesity status.

METHODS

This case-control study was performed on 164 obese individuals compared by 156 control from the Tehran Lipid and Glucose Study (TLGS). Standard procedures obtained anthropometric measures and metabolic parameters. Cortisol and adiponectin levels were measured by ELISA method. rs1501299, rs266729, rs17300539, and rs17366743 on the ADIPOQ gene were genotyped using the PCR-RFLP. The correlation between adiponectin gene SNPs and obesity were calculated by Additive, dominant, and recessive genetic models. Pearson's or Spearman's found correlations between adiponectin levels and metabolic and anthropometric variables. Data were analyzed using SPSS software Version 20.

RESULTS

Adiponectin and cortisol levels were significantly lower in obese subjects compared to the control group (p < 0.05). There was a significant negative correlation between serum adiponectin level and BMI, waist circumference (WC), waist-hip ratio, hip circumference (HC), Fasting blood sugar (FBS) Triglyceride (TG), Total cholesterol (TC), Systolic blood pressure (SBP), Diastolic blood pressure (DBP) (r = - 0.147, r = - 0.324, r = 0.371, r = - 0.179, r = - 0.299, r = - 0.277, r = - 0.041, r = - 0.134, and r = - 0.149, respectively). A positive correlation was found between adiponectin and high-density lipoprotein cholesterol (HDL-C) (r = 0.29), but no significant correlations were found between adiponectin and Low-density lipoprotein cholesterol(LDL-C) and cortisol. ADIPOQ variant rs1501299 was significantly associated with cortisol levels in subjects with BMI ≥ 25 (P-value =0.039).

CONCLUSIONS

Adiponectin and cortisol levels were associated with obesity. No ADIPOQ gene variants and haplotypes were associated with cortisol, Adiponectin, and obesity.

Different Isocaloric Meals and Adiposity Modify Energy Expenditure, Clinical and Metabolomic Biomarkers During Resting and Exercise States in a Randomized Cross-over Acute Trial of Normal Weight and Overweight/obese Men

BACKGROUND

Few studies have assessed the integrative effects of diet, BMI, and exercise on postprandial changes of energy and circulating metabolic profiles.

OBJECTIVES

We aimed to assess the collective effects of three isocaloric diets high in carbohydrate (74.2% energy), fat (64.6% energy), or protein (39.5% energy) on energy expenditure, clinical and metabolomic biomarkers under resting and exercise conditions in normal-weight and overweight/obese men.

METHODS

This cross-over controlled acute trial included 20 normal-weight (BMI: 18.5- <24) and 20 overweight/obese (BMI ≥ 24 kg/m2) men aged 18-45 years. Each of three test meals was provided for two continuous days: "Resting Day" without exercise, followed by "Exercise Day" with a bicycling exercise of 50% maximal oxygen consumption (postprandial 90-120 min). Energy expenditure (exploratory outcome of primary interest) was measured using indirect calorimetry. Fasting and postprandial 2-hour serum clinical and metabolomic biomarkers (secondary interest) were measured. Mixed models were used to examine the effects of diet, time, and/or BMI category.

RESULTS

On Resting Day, no significant between-meal differences were detected for energy expenditure. However, high-carbohydrate and high-fat meals induced the highest postprandial 2-hour increase in glucose (0.34 ± 0.15 mmol/L) and triglyceride (0.95 ± 0.09 mmol/L) respectively, while high-protein meal reduced glucose (-0.48 ± 0.08 mmol/L) and total cholesterol (-0.01 ± 0.03 mmol/L, all Pdiet < 0.001). On Exercise Day, high-carbohydrate diet significantly promoted carbohydrate oxidation rate but suppressed fat oxidation rate (Pdiet < 0.05), while its postprandial glucose response was attenuated by bicycling (-0.31 ± 0.03 mmol/L, Pexercise < 0.001). 69 metabolites were identified as key features in discriminating the three meals, and overweight/obese men had more varieties of metabolites than normal-weight men.

CONCLUSIONS

Three isocaloric meals induced unique postprandial changes in clinical and metabolomic biomarkers, while exercise prevented high-carbohydrate meal induced hyperglycemia. Overweight/obese men were more responsive to the meal challenges than normal-weight men. This trial was registered at clinicaltrials.gov as NCT03231618.

Clinical and biological risk factors associated with inflammation in patients with type 2 diabetes mellitus

BACKGROUND

Chronic inflammation has been associated with insulin resistance and related metabolic dysregulation, including type 2 diabetes mellitus (T2DM). Several non modifiable (i.e. genetic predisposition) and modifiable (i.e. sedentary lifestyle, energy-dense food) risk factors were suggested to explain the mechanisms involved in the development of inflammation, but are difficult to assess in clinical routine. The present study aimed to identify easy to asses clinical and biological risk factors associated with inflammation in patients with T2DM.

METHODS

One hundred nine patients (51 men, 58 women), 28-60 years old, from seven primary healthcare centers in Gaza City, Palestine, took part to the cross-sectional study (November 2013-May 2014). Study participants had T2DM with no history of inflammatory diseases, cardiovascular diseases, medication and/or any health condition that might affect the inflammatory markers, interleukin 6 (IL-6) and C-reactive protein (CRP). Inflammation was defined for IL-6 ≥ 2 pg/mL and CRP ≥ 6 mg/L. Multivariable logistic regressions were used to identify the relationship between inflammation and clinical and biological risk factors.

RESULTS

After adjustment for age and gender, inflammation seems to increase with increased body mass index (BMI) (OR: 1.427 [1.055-1.931]), increased fasting blood glucose (OR: 1.029 [1.007-1.052]) and decreased adiponectin values (OR: 0.571 [0.361-0.903]). There were also significant relationships between inflammation and BMI (OR: 1.432 [1.042-1.968]), fasting blood glucose (OR: 1.029 [1.006-1.052]) and adiponectin (OR: 0.569 [0.359-0.902]), after adjustment for smoking habits and physical activity.

CONCLUSION

Managing obesity and associated complications (i.e. hyperglycemia, high adiponectin levels) might help decreasing inflammation in individuals with T2DM.

Nandrolone decanoate and resistance exercise affect body composition and energy metabolism

Our aim was to evaluate the independent and associated effects of nandrolone decanoate (DECA) and resistance exercise (REx) on central and peripheral hormones and neuropeptides related to energy balance in male rats. The experimental protocol was performed for eight weeks and comprised four groups: control (C) - exposed to vehicle 3x/wk; trained (T) - REx 5x/wk and vehicle 3x/wk; decanoate (D) - exposed to DECA (5 mg/kg) 3x/wk, and REx with DECA (TD) - submitted to REx 5x/wk and DECA (5 mg/kg) 3x/wk. Cross-sectional area analysis of the gastrocnemius muscle was higher in the T and TD groups compared to the C group. Biometrical analyses showed a decrease in body weight only in the TD compared to the C group, however, a reduction in total fat mass was observed in both the T and TD when compared to the C group. In respect of hypothalamic mRNA expression, there was an increase in prepro-orexin in the T compared to the C group. In mesenteric fat there was a decrease in leptin expression in the T and TD compared to the C group. Plasma evaluations showed reduced leptin concentrations in D, T and TD compared to C, and an increase in orexin-A in the D group compared to the C and T groups. Our data showed that REx was related to central and peripheral changes in energy metabolism, while DECA changed only peripheral components. REx associated with DECA promoted peripheral changes in energy metabolism and decreased body and fat weights.

Determination of risk factors associated with inflammation in hypertensive patients with type-2 diabetes mellitus in a Palestinian Diabetes Study

OBJECTIVE

To determine the risk factors associated with inflammation in hypertensive patients with type-2 diabetes mellitus.

METHODS

A total of 164 hypertensive patients with type 2 diabetes patients aged 38-60 years were selected from 7 primary healthcare centers in Gaza city, Palestine. Interview questionnaire were employed to collect data related to age, gender, smoking habits, and physical activity pattern. Laboratory biochemical tests included fasting blood glucose (FBG), triglyceride (TG), total cholesterol (TC), interleukin 6 (IL-6), high sensitive C reactive protein (hs-CRP), and adiponectin were estimated in all patients.

RESULTS

The study involved 118 (72%) women and 46 (28%) men; the mean of age was 53.7 ± 0.46 years. A tertile of inflammation feature with hs-CRP was developed. The highest tertile of hs-CRP was significantly associated with women, higher obesity indices, metabolic dysregulation involving lipid profile markers, FBG and blood pressure, IL-6, and lower adiponectin. After adjusting for age, gender, smoking habits, and physical activity; the risk factor of high level of hs-CRP were the increased body mass index [OR: 1.17, p = .018], IL-6 [OR: 2.22, p = .025] and FBG [OR: 1.01, p = .007], as well as reduced adiponectin [OR: 0.81, p = .002].

CONCLUSION

The inflammation state was affected by obesity and had been related to altered adipokines levels of IL-6 and adiponectin, as well as affected by the glycemic control, as evidenced by higher serum level of FBG.

Anti-Obesity Effects of Morus alba L. and Aronia melanocarpa in a High-Fat Diet-Induced Obese C57BL/6J Mouse Model

The present study investigated the synergic effect of extracts of Morus alba (MA) and Aronia melanocarpa (Michx.) (AR) against high-fat diet induced obesity. Four-week-old male C57BL/6J mice were randomly divided into five groups that were fed for 14 weeks with a normal diet (ND), high-fat diet (HD), HD with M. alba 400 mg/kg body weight (MA), HD with A. melanocarpa 400 mg/kg body weight (AR), or HD with a mixture (1:1, v/v) of M. alba and A. melanocarpa (400 mg/kg) (MA + AR). Treatment with MA, AR, and MA + AR for 14 weeks reduced high fat diet-induced weight gain and improved serum lipid levels, and histological analysis revealed that MA and AR treatment markedly decreased lipid accumulation in the liver and adipocyte size in epididymal fat. Furthermore, micro-CT images showed MA + AR significantly reduced abdominal fat volume. Expression levels of genes involved in lipid anabolism, such as SREBP-1c, PPAR-γ, CEBPα, FAS, and CD36 were decreased by MA + AR treatment whereas PPAR-α, ACOX1, and CPT-1a levels were increased by MA + AR treatment. Protein expression of p-AMPK and p-ACC were increased in the MA + AR group, indicating that MA + AR ameliorated obesity by upregulating AMPK signaling. Together, our findings indicate that MA and AR exert a synergistic effect against diet-induced obesity and are promising agents for managing obesity.

The Nature of Immune Responses to Influenza Vaccination in High-Risk Populations

The current pandemic has brought a renewed appreciation for the critical importance of vaccines for the promotion of both individual and public health. Influenza vaccines have been our primary tool for infection control to prevent seasonal epidemics and pandemics such as the 2009 H1N1 influenza A virus pandemic. Certain high-risk populations, including the elderly, people with obesity, and individuals with comorbidities such as type 2 diabetes mellitus, are more susceptible to increased disease severity and decreased vaccine efficacy. High-risk populations have unique microenvironments and immune responses that contribute to increased vulnerability for influenza infections. This review focuses on these differences as we investigate the variations in immune responses to influenza vaccination. In order to develop better influenza vaccines, it is critical to understand how to improve responses in our ever-growing high-risk populations.

Inhibition of Lipid Accumulation and Cyclooxygenase-2 Expression in Differentiating 3T3-L1 Preadipocytes by Pazopanib, a Multikinase Inhibitor

Pazopanib is a multikinase inhibitor with anti-tumor activity. As of now, the anti-obesity effect and mode of action of pazopanib are unknown. In this study, we investigated the effects of pazopanib on lipid accumulation, lipolysis, and expression of inflammatory cyclooxygenase (COX)-2 in differentiating and differentiated 3T3-L1 cells, a murine preadipocyte. Of note, pazopanib at 10 µM markedly decreased lipid accumulation and triglyceride (TG) content during 3T3-L1 preadipocyte differentiation with no cytotoxicity. Furthermore, pazopanib inhibited not only expression of CCAAT/enhancer-binding protein-α (C/EBP-α), peroxisome proliferator-activated receptor-γ (PPAR-γ), and perilipin A but also phosphorylation of signal transducer and activator of transcription (STAT)-3 during 3T3-L1 preadipocyte differentiation. In addition, pazopanib treatment increased phosphorylation of cAMP-activated protein kinase (AMPK) and its downstream effector ACC during 3T3-L1 preadipocyte differentiation. However, in differentiated 3T3-L1 adipocytes, pazopanib treatment did not stimulate glycerol release and hormone-sensitive lipase (HSL) phosphorylation, hallmarks of lipolysis. Moreover, pazopanib could inhibit tumor necrosis factor (TNF)-α-induced expression of COX-2 in both 3T3-L1 preadipocytes and differentiated cells. In summary, this is the first report that pazopanib has strong anti-adipogenic and anti-inflammatory effects in 3T3-L1 cells, which are mediated through regulation of the expression and phosphorylation of C/EBP-α, PPAR-γ, STAT-3, ACC, perilipin A, AMPK, and COX-2.

Serum spexin concentration, body condition score and markers of obesity in dogs

Background

Spexin (SPX) is a peptide hormone that regulates body weight, adipose tissue metabolism, and food intake.

Hypothesis

Serum SPX concentration correlates with body condition score (BCS) and markers of obesity in dogs.

Animals

Fifty‐seven dogs of varying body condition assessed using a 5‐point BCS.

Methods

Prospective, nonblinded, observational cohort study. Serum SPX concentration was measured using commercially available radioimmunoassay (RIA) in dogs with varying BCS. Spexin mRNA and protein expression were detected using real‐time quantitative polymerase chain reaction and immunofluorescence staining.

Results

Serum SPX concentration was lower in dogs with BCS4 (8.56 +/‐ 2.86) and BCS5 (6.7 +/‐ 2.12) compared to BCS2 (11.96 +/‐ 2.23) and BCS3 (10.51 +/‐ 2.19; BCS2 vs BCS5, P < .001 and BCS2 vs BCS4, P = .005; BCS3 vs BCS5, P = .002). Spexin mRNA was detected in adipose tissue, liver and pancreas. Spexin protein was expressed in adipose tissue and liver but not in pancreas. There were negative correlations between SPX and serum concentration of insulin (P < .05); leptin (P < .01), triglycerides (P < .01), total cholesterol (P < .01), nonesterified fatty acids (P < .01), and fructosamine (P < .01). There was a positive correlation between SPX and serum concentration of adiponectin (P < .01).

Conclusions and Clinical Importance

Spexin could be involved in pathogenesis of obesity in dogs, and might be considered as a potential marker for obesity.

Scopolin Prevents Adipocyte Differentiation in 3T3-L1 Preadipocytes and Weight Gain in an Ovariectomy-Induced Obese Mouse Model

Obesity is prevalent in modern human societies. We examined the anti-obesity effects of scopolin on adipocyte differentiation in preadipocyte 3T3-L1 cells and weight loss in an ovariectomy (OVX)-induced obese mouse model. Scopolin inhibited adipocyte differentiation and lipid accumulation in the preadipocyte cells by suppressing the transcription of adipogenic-related factors, including adiponectin (Adipoq), peroxisome proliferator-activated receptor gamma (Pparg), lipoprotein lipase (Lpl), perilipin1 (Plin1), fatty acid-binding protein 4 (Fabp4), glucose transporter type 4 (Slc2a4), and CCAAT/enhancer-binding protein alpha (Cebpa). In OVX-induced obese mice, administration of scopolin promoted the reduction of body weight, total fat percentage, liver steatosis, and adipose cell size. In addition, the scopolin-treated OVX mice showed decreased serum levels of leptin and insulin. Taken together, these findings suggest that the use of scopolin prevented adipocyte differentiation and weight gain in vitro and in vivo, indicating that scopolin may be a potential bioactive compound for the treatment and prevention of obesity in humans.

Compartmental fat distribution in the abdomen of dogs relative to overall body fat composition

Background

Adipose tissue may have different metabolic and endocrine functions depending on the region of the body in which it is located. While visceral or intra-abdominal fat has been found to contribute to leptin concentrations, insulin resistance and obesity-related diseases, there are only a few imaging studies documenting the preferential distribution of body fat to either the intra-abdominal or subcutaneous compartments in dogs. This study aimed to determine if CT-measured abdominal fat distributed preferentially to the visceral space (V) relative to the subcutaneous space (SQ), with increasing DXA-determined total body fat percentage; and if ultrasound measurements of the ventral midline subcutaneous (SAT) and visceral adipose thickness (VAT) can be used to estimate the distribution of fat to the subcutaneous and visceral abdominal spaces, in a sample of 22 dogs with variable body condition.

Results

Multivariate analysis showed no statistically significant correlation between visceral to subcutaneous fat ratio (V/SQ) and increasing total body fat percentage (β = − 0.07, p = 0.733), but strong correlation with age (β = 0.71 p = 0.002). A substantial amount of variation for the ultrasound visceral adipose thickness to subcutaneous fat thickness (VAT/SAT) could be explained by both CT V/SQ and sex (R²_Adjusted = 0.477, p = 0.001), with female dogs having significant lower VAT/SAT ratios compared to the male dogs (p = 0.047). The ultrasound fat measurements appeared moderately reliable, but a larger sample number is required to confirm this.

Conclusions

The findings suggest that dogs with a relatively healthy to slightly overweight body condition score, distribute fat relatively similarly between their peritoneal (visceral) and subcutaneous abdominal compartments with increasing total body fat percentage. However, there was increased fat distribution to the peritoneal space relative to the subcutaneous space with increasing age. Further, abdominal ultrasound may be useful in estimating the ratio of fat distribution to both the abdominal visceral and subcutaneous spaces.

Usefulness of Urinary Creatinine/Urea Nitrogen Ratio as Indicator of Body Protein Catabolism in Dogs Fed Low Protein Diets

Low protein diets (LPs) constitute a reportedly effective form of nutritional therapy for canine chronic kidney disease and cirrhosis. These diets have long been feared to result in reduced muscle mass due to protein catabolism. This adverse effect, however, remains largely unrecognized in veterinary medicine as there are no easily applicable catabolism indicators. Therefore, we focused on urinary creatinine, a metabolite of protein in the urine, and examined whether its ratio to urinary urea nitrogen (UCrn/UN) can be used to assess protein catabolism. In Experiment 1, we first consecutively fed seven healthy beagles an LP, standard protein (SP), and high protein (HP) diet for 1 week each and then measured the UCrn/UN ratio at 2-h intervals from fasting to 16 h post-prandially. We consequently found that the UCrn/UN ratio was significantly elevated in the LP pre-prandially and at all post-prandial measurement points (P < 0.01). No significant differences were observed between the SP and HP. Analysis of fasting plasma amino-acid concentrations revealed that the concentration of methionine was significantly lower in the LP than in the other diets (P < 0.05). Although the effects of this change in amino-acid concentration were unclear, the UCrn/UN ratio was considered having increased due to a deficiency in protein and/or amino acids during LP feeding. In Experiment 2, we continuously fed five healthy beagles an LP for 18 weeks and then measured the UCrn/UN ratio as described above. We also measured changes in body composition with computed tomography. At weeks 10 and 18, the fasting UCrn/UN ratio was significantly higher than it was prior to the start of the LP; however, post-prandially, the UCrn/UN ratio decreased to the point that the significant difference disappeared. Muscle mass decreased at weeks 10 and 18. These results suggest that the fasting UCrn/UN ratio could be used as an indicator of protein catabolism in LP feeding. Our experiments thus indicate that examination of potential increases in the UCrn/UN ratio 1 week after introduction of LP feeding to healthy dogs could enable detection of body protein catabolism in long-term feeding of LP before muscle breakdown occurs.

Psoriasis in obesity: comparison of serum levels of leptin and adiponectin in obese subjects - cases and controls

BACKGROUND

Psoriasis and obesity are somewhat related to a low-grade systemic inflammatory response.

OBJECTIVES

To determine leptin and adiponectin levels in psoriasis patients compared to control patients matched for weight.

METHODS

A case-control study was performed, evaluating 113 psoriasis patients and 41 controls with other dermatologic diseases.

RESULTS

The prevalence of obesity was 33% in cases and 21.9% in controls. All evaluated comorbidities were more prevalent among cases. When stratified by weight, the comorbidities were more frequent in overweight patients. We found no correlation between being overweight (p=0.25), leptin (p=0.18) or adiponectin (p=0.762) levels and psoriasis severity. When overweight cases and controls were compared, we found differences in the adiponectin values (p= 0.04). The overweight cases had lower adiponectin levels than the overweight controls. We found no differences in the leptin dosage between cases and controls. The overweight cases had higher leptin values than the normal weight cases (p<0.001).

STUDY LIMITATIONS

Several patients used systemic anti-inflammatory medication.

CONCLUSIONS

The prevalence of obesity among psoriasis cases (33%) was higher than in the general population (17.4%). We did not find any correlation between severity of psoriasis and inflammatory cytokines and the condition of being overweight. The overweight cases had lower values of adiponectin than the overweight controls. It seems, therefore, that there is a relationship between adiponectin and psoriasis, but this relationship depends on the presence of obesity.

Polysaccharides from fermented Momordica charantia ameliorate obesity in high-fat induced obese rats

Momordica charantia (M. charantia) has been widely used to treat obesity due to its bioactive ingredients.

Iso-alpha acids from hops (Humulus lupulus) inhibit hepatic steatosis, inflammation, and fibrosis

Non-alcoholic fatty liver disease (NAFLD) is considered to be the hepatic manifestation of the metabolic syndrome. Iso-alpha acids (IAAs), hop-derived bitter compounds in beer, have been shown to beneficially affect different components of the metabolic syndrome such as insulin resistance and dyslipidemia. However, IAAs have not yet been studied in the context of chronic liver disease. Here we analyzed the effect of IAA on the pathogenesis of NAFLD. Once, we applied IAA to mice in combination with a NAFLD-inducing Western-type diet (WTD), and observed that IAA significantly inhibited WTD-induced body weight gain, glucose intolerance, and hepatic steatosis. Fitting to this, IAA dose-dependently inhibited cellular lipid accumulation in primary human hepatocytes (PHH) in vitro. Reduced expression of PPAR-gamma and key enzymes of lipid synthesis as well as increased expression of PPAR-alpha, indicative for increased lipid combustion, were identified as underlying mechanisms of reduced hepatocellular steatosis in vitro and in vivo. Analysis of hepatic HMOX1 expression indicated reduced oxidative stress in IAA-treated mice, which was paralleled by reduced activation of the JNK pathway and pro-inflammatory gene expression and immune cell infiltration. Furthermore, IAA reduced hepatic stellate cell (HSC) activation and pro-fibrogenic gene expression. Similarly, IAA also dose-dependently reduced oxidative stress and JNK activation in steatotic PHH, inhibited HSC activation, and reduced proliferation and pro-fibrogenic gene expression in already activated HSC in vitro. In conclusion, IAAs inhibit different pathophysiological steps of disease progression in NAFLD. Together with previous studies, which demonstrated the safety of even long-term application of IAA in humans, our data suggest IAA as promising therapeutic agent for the prevention and treatment of (non)alcoholic (fatty) liver disease.

The behaviour of overweight dogs shows similarity with personality traits of overweight humans

Excessive food intake and the resulting excess weight gain is a growing problem in human and canine populations. Dogs, due to their shared living environment with humans, may provide a beneficial model to study the causes and consequences of obesity. Here, we make use of two well-established research paradigms (two-way choice paradigm and cognitive bias test), previously applied with dogs, to investigate the role of obesity and obesity-prone breeds for food responsiveness. We found no evidence of breed differences in food responsiveness due to one breed being more prone to obesity than another. Breed differences found in this study, however, can be explained by working dog status, i.e. whether the dog works in cooperation with, or independently from, humans. Our results also confirm that overweight dogs, as opposed to normal weight dogs, tried to maximize food intake from the higher quality food and hesitated to do the task when the food reward was uncertain. These results are very similar to those expected from the parallel models that exist between certain personality traits and being overweight in humans, suggesting that dogs are indeed a promising model for experimentally investigating obesity in humans.

Increased Circulation and Adipose Tissue Levels of DNAJC27/RBJ in Obesity and Type 2-Diabetes

Heat shock response is an essential cellular stress response. Dysregulation of various heat shock proteins (HSPs), within the heat shock response (HSR) pathway, play a vital role in this host-defense mechanism contributing to obesity-induced insulin resistance and type 2 diabetes (T2D). Previously, we have reported changes in the expression levels of several HSPs such as HSP40, HSP60, HSP70, and HSP90 in obese compared with lean individuals. DNAJC27 is a member of the HSP40 protein family that was previously identified as a body mass index (BMI) associated locus in genome-wide association (GWAS) studies. However, not much is known about the changes in DNAJC27 expression levels in obesity and T2D. In the present study, we aimed at understanding changes in DNAJC27 expression levels in plasma, peripheral blood mononuclear cells (PBMCs) and adipose tissue in association with obesity and T2D. A total of 277 individuals enrolled including 160 non-diabetic (96 non-obese and 64 obese) and 117 T2D (45 non-obese and 72 obese) individuals. Plasma level of DNAJC27 was significantly higher in obese individuals (6.28 ± 0.64 ng/mL) compared with non-obese individuals (4.8 ± 0.45 ng/mL) with P = 0.043. Dividing the population based on diabetes status showed that there was a significant increase in the plasma level of DNAJC27 in obese (6.90 ± 1.3 ng/mL) compared with non-obese individuals (3.81 ± 0.43 ng/mL) (P = 0.033) in the non-diabetic group. Similarly, DNAJC27 expression level was also higher in PBMCs and adipose tissue of obese individuals. DNAJC27 was found to be associated with leptin and resistin, adipokines known to be dysregulated in obesity, that stimulate inflammatory processes leading to metabolic disorders. In conclusion, our data show that DNAJC27 is elevated in obese and T2D individuals and was positively associated with obesity biomarkers such as leptin and resistin suggesting that this protein may play a role in the pathophysiology of these disorders.

Obesity and inflammation: the linking mechanism and the complications

Obesity is the accumulation of abnormal or excessive fat that may interfere with the maintenance of an optimal state of health. The excess of macronutrients in the adipose tissues stimulates them to release inflammatory mediators such as tumor necrosis factor α and interleukin 6, and reduces production of adiponectin, predisposing to a pro-inflammatory state and oxidative stress. The increased level of interleukin 6 stimulates the liver to synthesize and secrete C-reactive protein. As a risk factor, inflammation is an imbedded mechanism of developed cardiovascular diseases including coagulation, atherosclerosis, metabolic syndrome, insulin resistance, and diabetes mellitus. It is also associated with development of non-cardiovascular diseases such as psoriasis, depression, cancer, and renal diseases. On the other hand, a reduced level of adiponectin, a significant predictor of cardiovascular mortality, is associated with impaired fasting glucose, leading to type-2 diabetes development, metabolic abnormalities, coronary artery calcification, and stroke. Finally, managing obesity can help reduce the risks of cardiovascular diseases and poor outcome via inhibiting inflammatory mechanisms.

Alternatives to the Streptozotocin-Diabetic Rodent

The study of diabetic neuropathy has relied primarily on the use of streptozotocin-treated rat and mouse models of type 1 diabetes. This chapter will review the creation and use of other rodent models that have been developed in order to investigate the contribution of factors besides insulin deficiency to the development and progression of diabetic neuropathy as it occurs in obesity, type 1 or type 2 diabetes. Diabetic peripheral neuropathy is a complex disorder with multiple mechanisms contributing to its development and progression. Even though many animal models have been developed and investigated, no single model can mimic diabetic peripheral neuropathy as it occurs in humans. Nonetheless, animal models can play an important role in improving our understanding of the etiology of diabetic peripheral neuropathy and in performing preclinical screening of potential new treatments. To date treatments found to be effective for diabetic peripheral neuropathy in rodent models have failed in clinical trials. However, with the identification of new endpoints for the early detection of diabetic peripheral neuropathy and the understanding that a successful treatment may require a combination therapeutic approach there is hope that an effective treatment will be found.

Leptin and Adiponectin Modulate the Self-renewal of Normal Human Breast Epithelial Stem Cells

Multiple mechanisms are likely to account for the link between obesity and increased risk of postmenopausal breast cancer. Two adipokines, leptin and adiponectin, are of particular interest due to their opposing biologic functions and associations with breast cancer risk. In the current study, we investigated the effects of leptin and adiponectin on normal breast epithelial stem cells. Levels of leptin in human adipose explant-derived conditioned media positively correlated with the size of the normal breast stem cell pool. In contrast, an inverse relationship was found for adiponectin. Moreover, a strong linear relationship was observed between the leptin/adiponectin ratio in adipose conditioned media and breast stem cell self-renewal. Consistent with these findings, exogenous leptin stimulated whereas adiponectin suppressed breast stem cell self-renewal. In addition to local in-breast effects, circulating factors, including leptin and adiponectin, may contribute to the link between obesity and breast cancer. Increased levels of leptin and reduced amounts of adiponectin were found in serum from obese compared with age-matched lean postmenopausal women. Interestingly, serum from obese women increased stem cell self-renewal by 30% compared with only 7% for lean control serum. Taken together, these data suggest a plausible explanation for the obesity-driven increase in postmenopausal breast cancer risk. Leptin and adiponectin may function as both endocrine and paracrine/juxtacrine factors to modulate the size of the normal stem cell pool. Interventions that disrupt this axis and thereby normalize breast stem cell self-renewal could reduce the risk of breast cancer.

Metabolic syndrome and obesity among users of second generation antipsychotics: A global challenge for modern psychopharmacology

Second generation antipsychotics (SGAs), such as clozapine, olanzapine, risperidone and quetiapine, are among the most effective therapies to stabilize symptoms schizophrenia (SZ) spectrum disorders. In fact, clozapine, olanzapine and risperidone have improved the quality of life of billions SZ patients worldwide. Based on the broad spectrum of efficacy and low risk of extrapyramidal symptoms displayed by SGAs, some regulatory agencies approved the use of SGAs in non-schizophrenic adults, children and adolescents suffering from a range of neuropsychiatric disorders. However, increasing number of reports have shown that SGAs are strongly associated with accelerated weight gain, insulin resistance, diabetes, dyslipidemia, and increased cardiovascular risk. These metabolic alterations can develop in as short as six months after the initiation of pharmacotherapy, which is now a controversial fact in public disclosure. Although the percentage of schizophrenic patients, the main target group of SGAs, is estimated in only 1% of the population, during the past ten years there was an exponential increase in the number of SGAs users, including millions of non-SZ patients. The scientific bases of SGAs metabolic side effects are not yet elucidated, but the evidence shows that the activation of transcriptional factor SRBP1c, the D1/D2 dopamine, GABA2 and 5HT neurotransmitions are implicated in the SGAs cardiovascular toxicity. Polypharmacological interventions are either non- or modestly effective in maintaining low cardiovascular risk in SGAs users. In this review we critically discuss the clinical and molecular evidence on metabolic alterations induced by SGAs, the evidence on the efficacy of classical antidiabetic drugs and the emerging concept of antidiabetic polyphenols as potential coadjutants in SGA-induced metabolic disorders.

The associations between serum adiponectin, leptin, C-reactive protein, insulin, and serum long-chain omega-3 fatty acids in Labrador Retrievers

Obesity has been associated with an increased inflammatory response and insulin resistance due to adipose tissue–derived adipokines and increases in C-reactive protein (CRP). Dogs appear to be similar to other species with the exception of adiponectin, which might not be affected by obesity status. Serum long-chain polyunsaturated fatty acid concentrations have been positively and negatively associated with serum adipokines. The aim of the study was to examine the relationship between leptin, CRP, adiponectin, and insulin to body condition score (BCS) and to the long-chain omega-3 fatty acids in serum lipoproteins, including alpha-linolenic acid, eicosapentaenoic acid (EPA), docosapentanenoic acid (DPA), and docosahexaenoic acid (DHA) as a reflection of dietary omega-3 status in the Labrador Retriever. Seventy-seven Labrador Retrievers were evaluated for BCS, percent fasting serum lipoprotein fatty acid concentrations, as well as serum leptin, adiponectin, insulin, and CRP. A multivariable general linear regression model was constructed to examine the association between the dependent variables leptin, CRP, adiponectin, and insulin and the predictor variables of BCS, age, and sex, as well as concentrations of alpha-linolenic acid, EPA, DHA, and DPA. Adiponectin concentration was positively associated with age (P<0.0008), EPA (P=0.027) and negatively associated with DHA (P=0.008). Leptin concentration was positively associated with an increased DHA (P=0.009), BCS (P<0.0001), age (P=0.02), and decreased DPA (P=0.06). Insulin concentration was only associated with BCS (P<0.0001), and no meaningful associations were found for CRP. Longer chain omega-3 fatty acids may play a role in regulating adiponectin concentrations in dogs. However, because insulin concentrations were associated only with BCSs, further examination of the role of adiponectin in canine obesity is warranted. EPA and DPA may reduce the overall inflammatory state in dogs as these omega-3 fatty acids reflect increased adiponectin (increased EPA and decreased DHA) and decreased leptin (decreased DHA and increased DPA).

Translational value of animal models of obesity-Focus on dogs and cats

A prolonged imbalance between a relative increase in energy intake over a decrease in energy expenditure results in the development of obesity; extended periods of a positive energy balance eventually lead to the accumulation of abnormally high amounts of fat in adipose tissue but also in other organs. Obesity is considered a clinical state of impaired general heath in which the excessive increase in adipose tissue mass may be associated with metabolic disorders such as type 2 diabetes mellitus, hyperlipidemia, hypertension and cardiovascular diseases. This review discusses briefly the use of animal models for the study of obesity and its comorbidities. Generally, most studies are performed with rodents, such as diet induced obesity and genetic models. Here, we focus specifically on two different species, namely dogs and cats. Obese dogs and cats show many features of human obesity. Interestingly, however, dogs and cats differ from each other in certain aspects because even though obese dogs may become insulin resistant, this does not result in the development of diabetes mellitus. In fact, diabetes in dogs is typically not associated with obesity because dogs present a type 1 diabetes-like syndrome. On the other hand, obese cats often develop diabetes mellitus which shares many features with human type 2 diabetes; feline and human diabetes are similar in respect to their pathophysiology, underlying risk factors and treatment strategies. Our review discusses genetic and endocrine factors in obesity, discusses obesity induced changes in lipid metabolism and includes some recent findings on the role of gut microbiota in obesity. Compared to research in rodent models, the array of available techniques and tools is unfortunately still rather limited in dogs and cats. Hence, even though physiological and pathophysiological phenomena are well described in dogs and cats, the underlying mechanisms are often not known and studies investigating causality specifically are scarce.

Canine and feline obesity: a review of pathophysiology, epidemiology, and clinical management

Canine and feline obesity rates have reached pandemic proportions and are similar to those in humans, with approximately 30%-40% of dogs and cats being overweight to obese. Obesity has been associated with other health problems, including osteoarthritis, renal disease, skin disease, insulin resistance, and neoplasia in dogs, while in cats obesity is associated with dermatological issues, diabetes mellitus, neoplasia, and urolithiasis. The health issues appear to be slightly different across the two species, which may be due to some inherent differences in the hormonal milieu involved in obesity that differs between the dog and the cat. In this review, we discuss the complicated nature of the pathogenesis of obesity, the hormonal stimulus for orexigenic and anorexigenic behavior, adipose tissue as an endocrine organ, and most importantly, clinical management of the number one disease in canine and feline medicine.

Characterization of diabetic neuropathy in the Zucker diabetic Sprague-Dawley rat: a new animal model for type 2 diabetes

Recently a new rat model for type 2 diabetes the Zucker diabetic Sprague-Dawley (ZDSD/Pco) was created. In this study we sought to characterize the development of diabetic neuropathy in ZDSD rats using age-matched Sprague-Dawley rats as a control. Rats were examined at 34 weeks of age 12 weeks after the onset of hyperglycemia in ZDSD rats. At this time ZDSD rats were severely insulin resistant with slowing of both motor and sensory nerve conduction velocities. ZDSD rats also had fatty livers, elevated serum free fatty acids, triglycerides, and cholesterol, and elevated sciatic nerve nitrotyrosine levels. The corneas of ZDSD rats exhibited a decrease in subbasal epithelial corneal nerves and sensitivity. ZDSD rats were hypoalgesic but intraepidermal nerve fibers in the skin of the hindpaw were normal compared to Sprague-Dawley rats. However, the number of Langerhans cells was decreased. Vascular reactivity of epineurial arterioles, blood vessels that provide circulation to the sciatic nerve, to acetylcholine and calcitonin gene-related peptide was impaired in ZDSD rats. These data indicate that ZDSD rats develop many of the neural complications associated with type 2 diabetes and are a good animal model for preclinical investigations of drug development for diabetic neuropathy.

Effect of physiological determinants and cardiac disease on plasma adiponectin concentrations in dogs

Background

In humans, a high concentration of adiponectin is associated with a favorable cardiovascular risk profile whereas, in patients with heart failure (HF), a high concentration of adiponectin is associated with a less favorable prognosis.

Hypothesis/Objectives

To evaluate the physiological determinants of plasma adiponectin concentration in dogs and the influence of heart disease, myxomatous mitral valve disease (MMVD), and dilated cardiomyopathy (DCM).

Animals

One hundred and fourteen client‐owned dogs and 9 Beagles from the research colony of the Clinical Veterinary Unit of the University of Liège.

Methods

We prospectively measured circulating adiponectin concentration in healthy control dogs (n = 77), dogs with MMVD (n = 22) and dogs with DCM (n = 15) of various degrees of severity. Diagnosis was confirmed by Doppler echocardiography. Plasma adiponectin concentration was measured by a canine‐specific sandwich ELISA kit.

Results

An analysis of covariance showed an association between adiponectin concentration and age, neuter status, and heart disease. No association between adiponectin concentration and class of HF, sex, body condition score, body weight, circadian rhythm, or feeding was found. Plasma adiponectin concentration was negatively correlated with age (P = .001). Adiponectin was lower in neutered (P = .008) compared to intact dogs. Circulating adiponectin concentration was increased in dogs with DCM compared to healthy dogs (P = .018) and to dogs with MMVD (P = .014).

Conclusions and Clinical Importance

Age and neutering negatively influence circulating adiponectin concentration. Plasma adiponectin concentration increased in dogs with DCM. Additional research is required to investigate if this hormone is implicated in the pathophysiology of DCM and associated with clinical outcome.

Exogenous hydrogen sulfide alleviates high glucose-induced cardiotoxicity via inhibition of leptin signaling in H9c2 cells

Hydrogen sulfide (H₂S) protects cardiomyoblasts against high glucose (HG)-induced injury by inhibiting the activation of p38 mitogen-activated protein kinase (MAPK). This study aims to determine whether the leptin-p38 MAPK pathway is involved in HG-induced injury and whether exogenous H2S prevents the HG-induced insult through inhibition of the leptin-p38 MAPK pathway in H9c2 cells. H9c2 cells were treated with 35 mM glucose (HG) for 24 h to establish a HG-induced cardiomyocyte injury model. Cell viability; mitochondrial membrane potential (ΔΨ m); apoptosis; reactive oxygen species (ROS) level; and leptin, leptin receptor, and p38 MAPK expression level were measured by the methods indicated. The results showed pretreatment of H9c2 cells with NaHS before exposure to HG led to an increase in cell viability, decrease in apoptotic cells, ROS generation, and a loss of ΔΨ m. Exposure of H9c2 cells to 35 mM glucose for 24 h significantly upregulated the expression levels of leptin and leptin receptors. The increased expression levels of leptin and leptin receptors were markedly attenuated by pretreatment with 400 μM NaHS. In addition, the HG-induced increase in phosphorylated (p) p38 MAPK expression was ameliorated by pretreatment with 50 ng/ml leptin antagonist. In conclusion, the present study has demonstrated for the first time that the leptin-p38 MAPK pathway contributes to the HG-induced injury in H9c2 cells and that exogenous H₂S protects H9c2 cells against HG-induced injury at least in part by inhibiting the activation of leptin-p38 MAPK pathway.

Thiazolidinediones improve hepatic fibrosis in rats with non-alcoholic steatohepatitis by activating the adenosine monophosphate-activated protein kinase signalling pathway

Thiazolidinediones (TZDs) markedly reduce hepatic steatosis in both rodents and humans. However, the effects and mechanisms of action of TZDs on hepatic fibrosis remain unclear. The aim of the present study was to determine the effects of TZDs on histological changes in the liver and on the modulation by adiponectin via the AMP-activated protein kinase (AMPK) signalling pathway in rats with non-alcoholic steatohepatitis (NASH). Forty rats were divided into normal control, high-fat diet (HFD), pioglitazone control and pioglitazone intervention groups. After 24 weeks treatment with pioglitazone (10 mg/kg per day by gavage), changes in liver histology, serum aminotransaminase, triglyceride (TG), free fatty acid (FFA), glucose, insulin, adiponectin and transforming growth factor (TGF)-β1 concentrations and hepatic adiponectin, AMPK, α-smooth muscle actin (α-SMA) and collagen I expression were evaluated. The degree of hepatic steatosis and fibrosis was significantly higher in HFD-induced NASH rats compared with normal controls, as were serum concentrations of aminotransaminase, TG, FFA, glucose, insulin and TGF-β1 and hepatic expression of α-SMA and collagen I protein. Serum adiponectin concentrations and hepatic expression of adiponectin mRNA and AMPK protein were significantly lower in the HFD-induced NASH rats compared with the normal control. Pioglitazone significantly reduced the degree of hepatic steatosis and fibrosis, as well as serum concentrations of aminotransaminase, TG, FFA, glucose, insulin and TGF-β1 and hepatic expression of α-SMA and collagen I protein. In addition, pioglitazone significantly increased serum adiponectin concentrations and hepatic expression of adiponectin mRNA and AMPK protein. In conclusion, the TZD pioglitazone improved hepatic fibrosis in rats with NASH by upregulating adiponectin expression and activating AMPK, thus subsequently inhibiting the activation of hepatic stellate cells and the overproduction of extracellular matrix.

Atorvastatin treatment modulates the interaction between leptin and adiponectin, and the clinical parameters in patients with type II diabetes

The aim of this study was to examine the effect of atorvastatin treatment on levels of leptin, adiponectin and insulin resistance, and their correlation with clinical parameters, in patients with type II diabetes. Patients with diabetes (n=394) were divided into two groups, comprising 161 patients who received 20 mg/day atorvastatin (statin group), and 233 patients who did not receive statins (statin-free group). The results showed that atorvastatin treatment of patients with diabetes was not associated with changes in leptin, adiponectin, the leptin/adiponectin (L/A) ratio or homeostasis model assessment-insulin resistance (HOMA-IR). However, low-density lipoprotein cholesterol (LDL-C), triglycerides (TG) and total cholesterol (Tchol) were positively correlated with leptin and L/A ratio in the statin group only (P<0.05). By contrast, high-density lipoprotein cholesterol (HDL-C) showed a significant positive correlation with adiponectin in the statin and statin-free groups (P<0.05). Additionally, a positive correlation was found between HOMA-IR and glycated hemoglobin (HbA1c), and TG, in both groups, whereas Tchol was positively correlated with HOMA-IR in the statin group only (P<0.05). When multivariate analysis was performed with HOMA-IR as the dependent variable, and with adjustment for age, body mass index (BMI) and waist circumference, HbA1c was found to be a significant predictor of HOMA-IR or insulin resistance. In conclusion, atorvastatin treatment may have several effects on the interaction between leptin and adiponectin, and on clinical parameters in patients with type II diabetes.

Adiponectin enhances the responsiveness of the olfactory system

The peptide hormone adiponectin is secreted by adipose tissue and the circulating concentration is reversely correlated with body fat mass; it is considered as starvation signal. The observation that mature sensory neurons of the main olfactory epithelium express the adiponectin receptor 1 has led to the concept that adiponectin may affect the responsiveness of the olfactory system. In fact, electroolfactogram recordings from olfactory epithelium incubated with exogenous adiponectin resulted in large amplitudes upon odor stimulation. To determine whether the responsiveness of the olfactory sensory neurons was enhanced, we have monitored the odorant-induced expression of the immediate early gene Egr1. It was found that in an olfactory epithelium incubated with nasally applied adiponectin the number of Egr1 positive cells was significantly higher compared to controls, suggesting that adiponectin rendered the olfactory neurons more responsive to an odorant stimulus. To analyze whether the augmented responsiveness of sensory neurons was strong enough to elicit a higher neuronal activity in the olfactory bulb, the number of activated periglomerular cells of a distinct glomerulus was determined by monitoring the stimulus-induced expression of c-fos. The studies were performed using the transgenic mOR256-17-IRES-tauGFP mice which allowed to visualize the corresponding glomerulus and to stimulate with a known ligand. The data indicate that upon exposure to 2,3-hexanedione in adiponectin-treated mice the number of activated periglomerular neurons was significantly increased compared to controls. The results of this study indicate that adiponectin increases the responsiveness of the olfactory system, probably due to a higher responsiveness of olfactory sensory neurons.

Dog obesity--the need for identifying predisposing genetic markers

Incidence of overweight and obesity in dogs exceeds 30%, and several breeds are predisposed to this heritable phenotype. Rapid progress of canine genomics and advanced knowledge on the genetic background of human obesity bring a unique opportunity to perform such studies in dogs. Natural candidate genes for obesity are these encoding adipokines. Extended studies in humans indicated that polymorphisms of three of them, i.e. ADIPOQ, IL1 and TNF, are associated with predisposition to obesity. On the other hand, the use of genome-wide association studies revealed an association between human obesity and polymorphism of more than 50 other genes. Until now only few preliminary reports on polymorphism of canine FTO, MC4R, MC3R and PPARG genes have been published. Since the dog is a valuable model organism for human diseases one can foresee that such studies may also contribute to an in-depth understanding of human obesity pathogenesis.