Serum Leptin Concentrations Research Articles

Long-Term Changes in Leptin, Chemerin, and Ghrelin Levels Following Roux-en-Y Gastric Bypass and Laparoscopic Sleeve Gastrectomy.

Published reports showed conflicting results regarding the sustained alterations in leptin, chemerin, and ghrelin concenratios after metabolic surgery. Therefore, we performed the present work to contrast the alterations in leptin, chemerin, and ghrelin levels one year after Roux-en-Y gastric bypass (RYGB) versus laparoscopic sleeve gastrectomy (LSG). The present research is a prospective, comparative one that followed 100 cases for whom RYGB or LSG was done. We assessed the serum values of adiposity-associated mediators, including adipokcytokines (leptin and active chemerin) and gastrointestinal hormones (total ghrelin). The primary outcome in the present study was the alterations in leptin, chemerin, and ghrelin values at 12 months after RYGB and LSG. The serum leptin level decreased significantly in the LSG group with a mean change of - 170.8 ± 29.4 ng/mL (p < 0.001). Similarly, the serum leptin concentration decreased significantly in the RYGB group, with a mean change of - 165.42 ± 53.4 (p < 0.001). In addition, the mean reduction in baseline chemerin levels 12 months after the operation was considerable in the LSG cohort (- 23.24 ± 9.5 ng/mL) and RYGB group (- 22.12 ± 15.9 ng/mL). The ghrelin values demonstrated a notable reduction in the LSG cohort (- 0.083 ± 0.11 pg/mL) and RYGB group (- 0.068 ± 0.097 pg/mL). However, the changes in the three hormones were not substantially different between both groups (p > 0.05). Both RYGB and LSG result in a considerable, comparable decrease in the postoperative serum concentrations of leptin, chemerin, and ghrelin.

Association of serum leptin and adiponectin concentrations with echocardiographic parameters and pathophysiological states in patients with cardiovascular disease receiving cardiovascular surgery.

Leptin and adiponectin are important regulators of energy metabolism and body composition. Leptin exerts cardiodepressive effects, whereas adiponectin has cardioprotective effects, but several conflicting findings have been reported. The aim of the present study was to assess the relationship between serum leptin and adiponectin levels and echocardiographic parameters and pathophysiological states in patients with cardiovascular disease (CVD) receiving cardiovascular surgery. A total of 128 patients (79 males, average age 69.6 years) that had surgery for CVD including coronary artery bypass graft (CABG) and valve replacement were recruited in this study. Preoperative serum adiponectin and leptin concentrations were measured by enzyme-linked immunosorbent assay and compared with preoperative echocardiographic findings. Body fat volume and skeletal muscle volume index (SMI) were estimated using bioelectrical impedance analysis. We also measured grip strength and gait speed. Sarcopenia was diagnosed based on the recommendations of the Asian Working Group on Sarcopenia. Positive correlations were found between adiponectin and brain natriuretic peptide (BNP), age, left atrial diameter (LAD), E/e' (early-diastolic left ventricular inflow velocity / early-diastolic mitral annular velocity), and left atrial volume index (LAVI). Negative correlations were observed between adiponectin and body mass index (BMI), estimated glomerular filtration rate (eGFR), triglyceride, hemoglobin, and albumin. Serum leptin was positively correlated with BMI, total cholesterol, triglyceride, albumin, body fat volume, and LV ejection fraction (LVEF), whereas it was negatively correlated with BNP and echocardiographic parameters (LAD, LV mass index (LVMI), and LAVI). Multiple regression analysis showed associations between log (leptin) and log (adiponectin) and echocardiographic parameters after adjusting for age, sex, and BMI. Serum adiponectin was negatively correlated with leptin, but positively correlated with tumor necrosis factor α (TNFα), an inflammatory cytokine. In males, serum leptin level had a positive correlation with skeletal muscle volume and SMI. However, adiponectin had a negative correlation with anterior mid-thigh muscle thickness, skeletal muscle volume and SMI. And, it was an independent predictive factor in males for sarcopenia even after adjusted by age. These results suggest that leptin and adiponectin may play a role in cardiac remodeling in CVD patients receiving cardiovascular surgery. And, adiponectin appears to be a marker of impaired metabolic signaling that is linked to heart failure progression including inflammation, poor nutrition, and muscle wasting in CVD patients receiving cardiovascular surgery.

Maternal serum and cord blood leptin concentrations at delivery.

IntroductionStudies have demonstrated leptin involvement in the physiology and pathophysiology of pregnancy and suggest that leptin may be a prognostic marker for some complications of pregnancy although the association remains unclear. To date no studies have reported leptin reference intervals established in normal pregnancy, which could be used for interpreting the differences in leptin levels found in normal and pathological pregnancies.ObjectiveTo determine leptin concentrations at delivery, in maternal serum in normal pregnancy and in cord blood and to establish reference intervals for leptin.Material and methodsThe study was performed in 194 pregnant women without any comorbid health conditions. Leptin concentrations in maternal serum and in cord blood were measured by ELISA and subsequently analyzed by gestational age (weeks), maternal Body Mass Index (BMI), mode of delivery and infant gender and birth weight. For comparative analyses of normally distributed variables, parametric tests such as the Student–t were used to test the assumption of homogeneity or non-homogeneity of variance and a One-Way ANOVA when more than two groups were compared. The Pearson correlation coefficient was calculated to assess the correlation between normally distributed variables (p<0.05). The reference intervals for leptin were obtained by referring to the central 95% of laboratory test values.ResultsIn normal pregnant women, the mean serum leptin concentration at delivery was 37.17 ± 28.07 ng/mL and the established reference interval was 33.19–41.14 ng/mL. The mean leptin concentration in cord blood was 14.78 ± 15.97 ng/mL and the established reference interval was 12.32–17.67 ng/mL. There was a statistically significant positive correlation between maternal serum and cord blood leptin concentrations (r = 0.37; p = 0.00). Mean leptin concentrations in cord blood increased with gestational age (p = 0.00). No statistically significant differences in maternal serum and cord blood leptin concentrations were found in regard to mode of delivery and neonatal gender. A statistically significant correlation was found between maternal serum leptin and third-trimester BMI (r = 0.22; p = 0.00), but there was no association between maternal BMI and cord blood leptin concentration. There was a statistically significant positive correlation between cord blood leptin concentration and birth weight (r = 0.23; p = 0.00).ConclusionsReference intervals for leptin in maternal serum and in cord blood established in normal pregnancy could be used in clinical practice for interpreting the differences in leptin concentrations found in normal pregnancy and in complications of pregnancy. The results indicate a strong association between maternal serum leptin levels and obesity and between cord blood leptin levels and birth weight.

Poor Vitamin D Status in Active Pulmonary Tuberculosis Patients and Its Correlation with Leptin and TNF-α.

Vitamin D deficiency (VDD) is common in tuberculosis (TB) and may be implicated in the etiology of the disease and in its clinical course. The aim of this study was to investigate the association between leptin, inflammatory markers and VD status in TB patients, stratified for presence or absence of diabetes mellitus (DM). Two hundred ninety-nine TB patients were recruited from October 2015 to August 2016. Also, 91 normal controls were included. The information including socio-demographics, dietary intake and living habits was obtained by face-to-face interview. Serum concentrations of leptin and TNF-α, CRP and IL-6 were compared between TB patients with and without severe VDD (SVDD). Pearson's correlation was used to analyze the association between TNF-α, leptin and 25-hydroxyvitamin D (25(OH)D). A significantly higher prevalence of VDD and SVDD was observed in TB patients compared with normal controls (93.0% vs 70.3%, 65.9% vs 3.3% respectively). Concentration of leptin was significantly lower, while TNF-α higher in TB patients with SVDD compared to those without (p<0.05). After adjustment for confounders, leptin was positively associated with 25(OH)D (r=0.210, p=0.002) with similar correlation in TB patients with DM (r=0.240, p=0.020). A negative association between TNF-α and 25(OH)D was observed (r=-0.197, p=0.003), which was significant only in the subgroup without DM (r=-0.304, p=0.001). Our findings indicate that a higher VD status in TB patients may be related to higher immune activity and less serious tissue damage, and that this relation is different according to presence or absence of DM co-morbidity.

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&#x0D; 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.&#x0D; 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.&#x0D; 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.&#x0D; 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.&#x0D; 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.

Bone Metabolism Parameters in Hemodialysis Patients With Chronic Kidney Disease and in Patients After Kidney Transplantation.

Chronic kidney disease adversely affects the structure and metabolism of bone tissue, which may be a result of disturbed biochemical processes in adipose tissue. Renal replacement therapy is a life-saving therapy but it does not restore all metabolic functions and sometimes even escalates some disturbances. The study included 126 subjects: 47 hemodialysis patients (HD), 56 patients after renal transplantation (Tx) and 23 healthy controls (K). Bone density at the femoral neck (FN) and lumbar spine (LS), as well as body composition (adipose tissue content and lean body mass) were measured in each patient using the DXA method. In addition, serum concentrations of glucose, calcium, phosphorus, parathormone, FGF23, Klotho, osteocalcin, leptin, adiponectin and 1,25-dihydroxyvitamin D3 were measured. We observed significantly higher concentrations of leptin, FGF23 and Klotho proteins in the HD patients (77.2±48.1 ng/ml, 54.7±12.4 pg/ml, 420.6±303.8 ng/ml, respectively) and the Tx group (33.2±26.5 ng/ml; 179.8±383.9 pg/ml; 585.4±565.7, respectively) compared to the control group (24.4±24.6 ng/ml, 43.3±37.3 pg/ml, 280.5±376.0 ng/ml). Significantly lower bone density at FN was observed in the HD and Tx patients in comparison to the controls and in the HD patients compared to the Tx group. There were no significant differences in body mass composition between the studied groups. The results of this study indicate that both hemodialysis and transplantation are associated with increased serum concentrations of leptin, FGF23 and Klotho proteins, as well as lower bone density at femoral neck.

Ghrelin deficiency in patients with type 2 diabetes: the relationships with obesity, adipose tissue dysfunction and glucose variability

Ghrelin, a peptide hormone mostly produced by stomach, plays an important role in regulation of feeding behavior, energy balance and glucose homeostasis. to determine the relationships between fasting serum levels of ghrelin, body composition, adipose tissue endocrine function and glucose variability (GV) in type 2 diabetic subjects with and without obesity. We observed 124 individuals with type 2 diabetes, including 42 non - obese subjects and 82 patients with obesity. Thirty non - obese healthy subjects were acted as control. The concentrations of ghrelin, leptin, resistin, and visfatin in the fasting serum were determined by Multiplex analysis. Body composition was assessed with DEXA. The 24-hour and nocturnal GV parameters were derived from continuous glucose monitoring. Ghrelin levels in patients with diabetes were decreased significantly as compared to control (p.

Effects of a Structured Physical Activity Program on Serum Adipokines and Markers of Inflammation and Volume Overload in Kidney Transplant Recipients.

BackgroundKidney transplantation (KTx) reverses most abnormalities related to chronic kidney disease (CKD), but sedentary lifestyle persists in most kidney graft recipients. Physical inactivity has been associated with altered adipokine profile and inflammation in CKD. We postulated that increased physical activity achieved through an individually-tailored program can reverse these changes.Material/MethodsWe included 25 clinically stable KTx recipients at least 12 months after transplantation and with eGFR >30 mL/min and 15 age-matched non-dialysis patients with CKD stage 3. Body composition, pattern of daily physical activity, and serum concentrations of leptin, adiponectin, NT-proBNP, and hsCRP were assessed at baseline. All patients in both groups participated in a 12-week supervised exercise program with short cell phone text reminders. All measurements were repeated after 3 months.ResultsActive energy expenditure increased significantly during the 3 months in both the KTx and CKD patients, compared with baseline by 47% (p<0.001) and 20% (p=0.01), respectively. Time spent daily on physical activity was also increased (129±83 vs. 194±142 and 81±56 vs. 124±57 min, respectively, p<0.001). Adipose tissue mass decreased significantly in the KTx group (from 40.8±11 to 38.5±10.3 kg, p=0.01). Serum leptin decreased significantly in both KTx and CKD patients (from 11.5±7.0 to 10.0±5.6, p=0.03 and from 14.1±8.3 to 12.2±6.1 ng/mL, p=0.01, respectively). Serum adiponectin increased only in the KTx group (from 1900±953 to 2015±1133 ng/L, p=0.004). Serum CRP decreased in both groups (from 15.1±5.2 to 14.0±5.6 mg/L, p=0.01 in the KTx group and from 16.5±3.9 to 15.4±4.3 mg/L in the CKD group p=0.05). NTpro-BNP was unchanged during the study.ConclusionsIncreased physical activity induces beneficial effects on adipokine profile and inflammation but does not seem to affect volume overload in kidney transplant recipients and CKD patients.

P3482Leptin, receptor to leptin and expression in adipocytes isolated from different adipose depots in patients with ischemic heart disease

Abstract Purpose To study the peculiarities of the content of leptin and the leptin receptor in adipocyte culture of subcutaneous (SAT), epicardial (EAT) and perivascular (PVAT) adipose tissue and the expression of their genes. Methods 29 patients with coronary heart disease were examined. Adipocytes were isolated from SAT, EAT and PVAT samples obtained during coronary artery bypass grafting, followed by evaluation (after 24 hours) of the leptin concentration (Human resistin ELISA, R&amp;D Systems, USA) and leptin gene expression in cell culture. Magnetic resonance imaging (MRI) was used to determine the area of the visceral (VAT) and subcutaneous adipose tissue (SAT) of the abdominal region, the thickness of epicardial adipose tissue (EAT). The calculation of the free leptin index (FLI) was determined by the formula: leptin/SOB-R * 100. Leptin resistance was defined as an FLI &gt;0.25. All study was carried out in compliance with the Helsinki Declaration, and its protocol was approved by the Ethical Committee of Research Institute. Statistical analysis was performed using Statistica 10.0. Results In adipocytes of EAT, leptin secretion was 1.2 times higher than in adipocytes of PVAT, which is consistent with the expression of the leptin gene. The content of leptin soluble receptor was opposite in the adipocytes of PVAT higher than in EAT and SAT 2.3 and 3.1 times, respectively. At the same time, the index of free leptin was higher in SAT adipocytes 1.3 and 3.2 times in comparison with EAT and PVAT. The correlation analysis confirmed the relationship between EAT thickness and the serum concentrations of leptin. Thus, in patients with VO, the leptin concentration had a negative dependence on the thickness of the left and right ventricle (r=−0.28, p=0.02; r=−0.33, p=0.02, respectively). A negative dependence on the EAT thickness was also established for the FLI (r=−0.28; p=0.03). PVAT of the abdominal aorta is similar to the properties of visceral AT. An analysis of the possible relationship between perivascular adipocytes and adipokine exchange rates showed a direct relationship between the volume PVAT of the abdominal aortic ventricle and leptin (r=0.44, p=0.01), as well as the FLI (r=0.56; p=0.03). Conclusion Adipocytes SAT, EAT and PVAT differed in the level of secretion of leptin. In epicardial and, to a greater extent, in perivascular adipocytes, a protective mechanism against a high concentration of leptin was observed due to increased secretion of the soluble receptor to leptin. The high content of leptin and the low soluble receptor for leptin led to the development of leptin resistance, which was more pronounced in the culture of adipocytes SAT. Meanwhile, the EAT thickness was inversely related to the concentration of leptin and the FLI index (one of the main leptin-resistance markers).

Obesity and childhood asthma in male schoolchildren in Saudi Arabia: Is there a role for leptin, interleukin-4, interleukin-5, and interleukin-21?

ABSTRACTBACKGROUND: Adiposity is associated with high serum levels of adipokines and chemokines which are possibly implicated in a co-existence of obesity and asthma.OBJECTIVES: Elucidate the possible roles of leptin, interleukin (IL)-4, IL-5 and IL-21 in linking obesity with childhood asthma.DESIGN: Cross-sectional, analytical.SETTING: Population of schoolchildren in a small Saudi city.SUBJECTS AND METHODS: The study included a representative sample of Saudi schoolchildren grouped as obese asthmatics, non-obese asthmatics, or obese nonasthmatics, with nonobese nonasthmatics as a control group. An asthma control test was done for the asthmatic groups.MAIN OUTCOME MEASURES: Serum levels of leptin, IL-4, IL-5, and IL-21.SAMPLE SIZE: 345 male schoolchildren with a mean (SD) age of 13.0 (2.3) years.RESULTS: Median serum leptin concentrations in obese asthmatics were significantly higher than in nonobese asthmatics (P<.001). Uncontrolled asthmatics also had significantly higher leptin levels than controlled asthmatic children (P<.002). Leptin levels were weakly but significantly correlated with the cytokines IL-4, IL-5, and IL-21.CONCLUSIONS: Leptin may contribute to a link between obesity and childhood asthma. Differences in IL-21 levels between nonobese and obese asthmatics suggest that the co-existence of asthma and obesity increased IL-21 levels. Leptin plus some proinflammatory cytokines especially IL-21 may be potential predictors for asthma control in children.LIMITATIONS: Blood sampling at different stages of asthma might influence cytokine expression.CONFLICT OF INTEREST: None.

Diet-induced Generalized Periodontitis in Lewis Rats.

Periodontitis is an important public health concern worldwide. Because rodents from the genus Rattus are resistant to spontaneous periodontitis, experimental periodontitis must be initiated by mechanical procedures and interventions. Due to their exacerbated Th1 response and imbalanced Th17 regulatory T-cell responses, Lewis rats are highly susceptible to inducible inflammatory and autoimmune diseases. We hypothesized that feeding Lewis rats a diet high in sucrose and casein (HSC) would alter the oral microenvironment and induce inflammation and the development of periodontitis lesions without mechanical intervention. A baseline group (BSL, n = 8) was euthanized at age 6 wk. Beginning at 6 wk of age, 2 groups of Lewis rats were fed standard (STD, n = 12) or HSC (n = 20) chow and euthanized at 29 wk of age. We evaluated the degree of periodontitis through histology and μCT of maxillae and mandibles. The HSC-induced inflammatory response of periodontal tissues was assessed by using immunohistochemistry. Gene expression analysis of inflammatory cytokines associated with Th1 and Th17 responses, innate immunity cytokines, and tissue damage in response to bacteria were assessed also. The potential systemic effects of HSC diet were evaluated by assessing body composition and bone densitometry endpoints; serum leptin and insulin concentrations; and gene expression of inflammatory cytokines in the liver. Placing Lewis rats on HSC diet for 24 wk induced a host Th1-immune response in periodontal tissues and mild to moderate, generalized periodontitis characterized by inflammatory cell infiltration (predominantly T cells and macrophages), osteoclast resorption of alveolar bone, and hyperplasia and migration of the gingival epithelium. HSC-fed Lewis rats developed periodontitis without mechanical intervention in the oral cavity and in the absence of any noteworthy metabolic abnormalities. Consequently, the rat model we described here may be a promising approach for modeling mild to moderate periodontitis that is similar in presentation to the human disease.

P5302Significant correlation of visceral adiposity and adipocytokines with arterial inflammation in genetic dyslipidaemias

Abstract Background The adipose tissue is now established as a major regulator of cardiovascular status, mediated by the secretion of several bioactive molecules, including adipocytokines. Individuals with genetic dyslipidaemias of either familial combined hyperlipidemia (FCH) or heterozygous familial hypercholesterolemia (heFH) subtype are characterized by accelerated atherosclerosis. Nonetheless, limited data exists on the relationship between adiposity and arterial inflammation, a marker of cardiovascular risk, in this setting. Purpose To investigate the relationship between adiposity indices and arterial inflammation evaluated by 18F fluorodeoxyglycose positron emission tomography (PET/CT) in patients with hereditary lipid metabolism disorders. Methods Consecutive patients with either FCH or heFH, free of statin therapy, and normolipidaemic individuals underwent PET/CT imaging. Arterial FDG uptake was estimated as the average value of target-to-background ratio (TBR) within aortic and carotid wall. Volumes of subcutaneous adipose tissue (SAT) and visceral adipose tissue (VAT) were measured from CT images between the proximal (cephalic) end of the L1 and distal (caudal) end of the L3 vertebrae by selecting all voxels with attenuation between −190 and −30 Hounsfield Units (HU). Serum adiponectin and leptin levels were measured with ELISA by available commercial kits. For comparisons with arterial TBR, adiponectin and leptin concentrations above and below the 25th percentile, were stratified as high and low, respectively. Results In total, 60 individuals (20 FCH, 20 heFH and 20 controls) were included. A modest but significant correlation between SAT volume and arterial TBR (R=0.386, p=0.004) was detected. This relationship did not remain significant after controlling for VAT volume (p=0.303). A strong correlation between VAT volume and arterial TBR (R=0.621, p=0.001) was observed. This relationship remained significant after controlling for SAT volume (R=0.541, p&lt;0.001). Arterial TBR values were higher in individuals with low plasma adiponectin levels (p=0.010). In addition, patients with higher leptin levels exhibited increased arterial FDG uptake compared to subjects with low serum leptin concentrations (p=0.05) Conclusions Abdominal adipose tissue imaging markers and serum adipocytokines correlate with arterial inflammation as assessed by PET/CT in patients with familial dyslipidaemias highlighting the role of abdominal adipose tissue for atherosclerosis progression in this population.

Leptin, adiponectin, tumor necrosis factor α, and irisin concentrations as factors linking obesity with the risk of atrial fibrillation among inpatients with cardiovascular diseases.

The endocrine function of adipose tissue and skeletal muscles mediates the risk of cardiovascular complications of obesity. The aim of this study was to determine the associations of leptin, adiponectin (ADA), tumor necrosis factor α (TNF‑α), and irisin levels with the diagnosis of atrial fibrillation (AF) on admission to the hospital as well as parameters of transthoracic echocardiography among inpatients with cardiovascular diseases (CVDs). The study included 80 consecutive patients hospitalized due to paroxysmal or persistent AF and a control group of 165 age- and sex‑matched individuals admitted due to exacerbation of chronic CVD. In all participants, we assessed serum leptin, ADA, TNF‑α, and irisin concentrations, body composition determined by bioelectrical impedance analysis, and transthoracic echocardiographic parameters. Compared with controls, patients with AF had greater fat mass (FM), higher serum leptin levels and lower levels of ADA, TNF‑α, and irisin when indexed to body surface area, FM, and visceral adiposity. Hyperleptinemia slightly increased the risk of AF (odds ratio [OR], 1.02; 95% CI, 1.01-1.03; P <0.01). The correlation was stronger after indexation to FM (OR, 1.34; 95% CI, 1.01-1.81; P <0.05). The coefficients of significant correlations with echocardiographic parameters were stronger for irisin than for adipocytokines: 0.16 to 0.35 and 0.12 to 0.22, respectively. Adipocytokines and irisin exert a significant but weak effect on heart chamber size and affect the risk of AF occurrence. Their blood concentrations do not seem to be related simply to body composition but probably depend on individual variations in adipocytokine and myokine secretion as a result of numerous factors.

Comparing serum concentration of spexin among patients with metabolic syndrome, healthy overweight/obese, and normal-weight individuals.

Background: There are many factors related to etiology of metabolic syndrome (MetS) including obesity. Spexin, a peptide hormone released from adipose tissue, is the most down-regulated gene in obese, compared to non-obese adipose tissue. Hence, it potentially contributes to the progression and development of metabolic diseases. This study was designed to evaluate serum concentration of spexin in patients with MetS compared to weight-matched and normal-weight controls. Methods: In this case-control study, 153 participants (51 per group) were collected from October 2014 to June 2016. The study groups were all matched for age and sex and included overweight/obese individuals with MetS and 2 control groups without MetS (including weight-matched and normal-weight participants). Body composition and serum concentration of spexin and leptin were measured. Results: Serum leptin and spexin levels were significantly higher and lower, respectively, in normal-weight compared to overweight/obese groups with/without MetS (p< 0.02). No significant difference was observed in serum leptin and spexin concentrations between the overweight/obese groups with/without MetS (p≥ 0.05). Also, spexin, with cutoff value of 4.6, had 78% sensitivity and 82% specificity for diagnosing overweight/obese from normal-weight participants. Spexin had 78% sensitivity and specificity, with cutoff value of 4.35, in diagnosing MetS participants from normal-weight group. Conclusion: This study found no correlation between the circulating level of spexin and MetS development. Higher serum concentration of spexin in normal-weight adults compared to the obese participants illustrated the potential role of this novel peptide in obesity.

Insulin Resistance and its Relevance with Age, Sex, Season and Obesity in Darehshori Horse Breed

BACKGROUND: Equine metabolic syndrome is an endocrinopathy that affects different breeds of horses and ponies. This metabolic disorder is a multifactorial syndrome and it is primarily linked to obesity, dyslipidemia and insulin resistance. OBJECTIVES: The present study was performed to evaluate insulin resistance in Darehshori horses with regards to age, sex, season and obesity. METHODS: Twelve adult stallions and 14 non-pregnant Darehshori breed mares were selected between January and November 2015. Fourteen horses were under and others were above 10 years old. Body condition scores of the animals were estimated based on Hennekes’ 1 to 9 scoring system, thus, 1 is poor and 9 is extremely fat horse. Body condition score of 12 horses was under 5 and the others above 5. The horses were studied during a period of one year, every 45 days and blood sampling and body condition scoring were performed at each time. Insulin resistance was assessed based on screening test. Serum concentrations of glucose, insulin and leptin were determined. RESUTLS: This study comprehensively used multiple detailed parameters to scan thoroughly the concept of insulin resistance in Darehshori horses on a long term basis. The levels of insulin, glucose and leptin in aged and obese stallions in warmer months were significantly higher than the others and reference range (P<0.05), hence, insulin resistance was detected in these groups of studied animals. CONCLUSIONS: These findings represented insulin resistance phenomenon in a specific breed in Iran. The physiologic characteristics of this breed may be different from other ones and the conditions in Iran such as climate are different from other countries. Hence, it should be considered that Darehshori horses have unique characteristics compared with other breeds. The study may be used as a guideline for evaluating the insulin resistance in Darehshori horses.

Preconception Leptin and Fecundability, Pregnancy, and Live Birth Among Women With a History of Pregnancy Loss.

ContextWith the increase of obesity, it is imperative to understand the neuroendocrine mechanisms, including the neuroendocrine hormone leptin, by which obese or overweight women are at increased risk for subfertility and infertility.ObjectiveThe objective was to examine associations between preconception serum leptin concentrations, fecundability, pregnancy, and live birth.DesignSecondary analysis of a prospective cohort among women with prior pregnancy losses.SettingThe study was conducted at four US medical centers (2006 to 2012).InterventionNot available.Materials and MethodsPreconception serum leptin concentrations were measured at baseline, and women were followed for up to six menstrual cycles, and throughout pregnancy if they conceived. Discrete Cox proportional hazard regression models were used to assess fecundability odds ratios (FORs) and log-binomial regression to estimate risk ratios (RRs) for pregnancy and live birth. Models were adjusted for age, physical activity, treatment arm, and adiposity, either by measured waist-to-hip ratio or body mass index (BMI).ResultsHigh leptin concentrations were associated with decreased fecundability (FOR 0.72, 95% CI 0.58, 0.90), reduced risk of pregnancy (RR 0.87, 95% CI 0.78, 0.96) and live birth (RR 0.76, 95% CI 0.65, 0.89) comparing the upper to the lower tertile. However, adjustment for BMI in lieu of waist-to-hip ratio nullified observed associations.ConclusionsIn women with a history of pregnancy loss, relations between higher preconception leptin and fecundability were attenuated after adjustment for BMI, although not after adjustment for other markers of adiposity. Leptin may serve as a complementary marker of adiposity for assessment of obesity and reproductive outcomes.

Arachidonic acid exacerbates diet-induced obesity and reduces bone mineral content without impacting bone strength in growing male rats

Long-chain polyunsaturated fatty acids modulate bone mass and adipocyte metabolism. Arachidonic acid (AA, C20:4 n-6) is elevated in obesity and postulated to stimulate bone resorption. This study aimed to determine the effect of AA on bone mass, quality, and adiposity in diet-induced obesity during growth. Male Sprague–Dawley rats (n=42, 4-week) were randomized into groups fed a control diet (CTRL, AIN-93G), high-fat diet (HFD, 35% kcal fat) or HFD + AA (1% w/w diet) for 6 weeks. Body composition, bone mineral density and microarchitecture were measured using dual-energy X-ray absorptiometry and micro-computed tomography. Red blood cell fatty acid profile was measured with gas chromatography. Group differences were evaluated using repeated measures two-way analysis of variance with Tukey–Kramer post hoc testing. Total energy intake did not differ among diet groups. At week 6, HFD + AA had significantly greater body fat % (12%), body weight (6%) and serum leptin concentrations (125%) than CTRL, whereas visceral fat (mass and %, assessed with micro-computed tomography) was increased in both HFD and HFD + AA groups. HFD + AA showed reduced whole body bone mineral content and femur mid-diaphyseal cortical bone cross-sectional area than HFD and CTRL, without impairment in bone strength. Contrarily, HFD + AA had greater femur metaphyseal trabecular vBMD (35%) and bone volume fraction (5%) compared to controls. Inclusion of AA elevated leptin concentrations in male rats. The early manifestations of diet-induced obesity on bone mass were accelerated with AA. Studies of longer duration are needed to clarify the effect of AA on peak bone mass following growth cessation.

The Effect of Zinc Supplementation on Serum Leptin Levels: A Systematic Review and Meta-Analysis of Randomized Controlled Trials.

Recently, obesity has become a common worldwide concern. Leptin, as an adipocytokine, plays a major role in the etiology of obesity. Prior studies have demonstrated that zinc potentially affects serum leptin levels. However, clinical trials carried out in this regard are not consistent. Therefore, current meta-analysis was conducted to ascertain the actual effect of zinc supplementation on serum leptin levels in adults. Databases of PubMed, SCOPUS, and Google Scholar were methodically searched to identify relevant articles up to April 2018. Clinical trials that examined the effect of zinc supplementation on serum leptin concentrations as outcome variables in human adults were included. The mean difference (SD) of leptin changes in the intervention and placebo groups were used to calculate the overall effect size. Totally, 663 articles were identified, of which 6 studies were eligible randomized controlled trials (RCTs) with 7 treatment arms. The analysis suggested that zinc supplementation exerts no significant effect on overall serum leptin (WMD: 0.74 ng/ml; 95% CI: -1.39 to 2.87, p=0.49). Nevertheless, sex and duration of intervention seemed to impact the extent of zinc's influence. In trials with female subjects, zinc consumption led to a significant decrease in serum leptin level (WMD: -1.93 ng/ml; 95% CI: -3.72 to -0.14, p=0.03) as well as trials that lasted for more than 6 weeks (WMD: -1.71 ng/ml; 95% CI: -3.07 to -0.35, p=0.01), in comparison to the control group. Zinc supplementation did not significantly improve leptin concentrations, but it may result in a decreased circulating leptin level in studies with a duration of more than 6 weeks especially among females.

Human relaxin-2 attenuates hepatic steatosis and fibrosis in mice with non-alcoholic fatty liver disease

Human relaxin-2 reduces hepatic fibrosis in mice. However, the effects of relaxin-2 on hepatic steatosis and fibrosis in animals with non-alcoholic fatty liver disease (NAFLD) remain to be elucidated. C57BL/6 mice fed a high-fat diet (HFD) or methionine–choline-deficient (MCD) diet were randomly assigned to receive recombinant human relaxin-2 (25 or 75 μg/kg/day) or vehicle for 4 weeks. In HFD-fed mice, relaxin-2 decreased systemic insulin resistance and reduced body weight, epididymal fat mass and serum leptin and insulin concentrations. In livers of HFD-fed mice, relaxin-2 attenuated steatosis and increased phosphorylation of insulin receptor substrate-1, Akt and endothelial nitric oxide synthase (eNOS), and activated genes that regulate fatty acid oxidation and suppressed acetyl-CoA carboxylase. Relaxin-2 had no direct anti-steatotic effect on primary mouse hepatocytes, but S-nitroso-N-acetylpenicillamine attenuated palmitic acid-induced steatosis and activated genes regulating fatty acid oxidation in hepatocytes. In mice fed an MCD diet, relaxin-2 attenuated steatosis, inflammation and fibrosis. Relaxin-2 increased eNOS and Akt phosphorylation and transcript levels of cytochrome P450-4a10 and decreased acetyl-CoA carboxylase in MCD-fed mouse livers. Moreover, expression levels of Kupffer cell activation, hepatic stellate cell activation and hepatocyte apoptosis were decreased in MCD diet-fed mice receiving relaxin-2. In conclusion, relaxin-2 reduces hepatic steatosis by activating intrahepatic eNOS in HFD-fed mice and further attenuates liver fibrosis in MCD diet-fed mice. Therefore, human relaxin-2 is a potential therapeutic treatment for NAFLD.

Lean body mass accretion is elevated in response to dietary vitamin D: A dose–response study in female weanling rats

Vitamin D status positively relates to lean body mass in infants. This study tested the effect of vitamin D on body composition and growth-related hormones. It was hypothesized that low vitamin D status programs for higher fat mass accretion. Female weanling Sprague–Dawley rats (4 weeks; n = 6/diet) were randomized to AIN-93G diets with modified vitamin D contents for 8 weeks: group 1 (1 IU vitamin D3/g diet), group 2 (2 IU vitamin D3/g diet), and group 3 (4 IU vitamin D3/g diet). At week 0, 4, and 8 of study, measurements included: serum 25(OH)D3, IGF-1, IGFBP3, leptin, and whole body composition assessed with DXA. Differences among groups were tested using mixed model ANOVA with Tukey's post hoc t-tests. No differences were observed in baseline body composition and biomarkers, nor did body weight and food intake differ over the study. At week 8, serum 25(OH)D3 in group 3 was higher (P < .0001) compared to groups 1 and 2. At 8 weeks, lean mass (P < .05) and lean mass accretion (P < .05) were significantly higher in groups 2 and 3 compared to group 1. Serum IGF-1 concentration declined over time (P < .001) with smaller declines at week 8 in group 3 (P < .05). Serum IGFBP3 concentration was lower at week 4 in group 2 compared to groups 1 and 3. Serum leptin concentration and fat mass were not affected by diet. These results suggested that the achievement of higher vitamin D status may support a lean body phenotype without altering weight gain.