Leptin Assay Research Articles

Elevated Serum Levels of Pro-Inflammatory Markers Are Associated with Glucose Intolerance in Metabolic Syndrome Patients from Jordan = ارتفاع مستويات العلامات ما قبل الالتهابية في المرضى الأردنيين الذين يعانون من خلل في الجلوكوز ومتلازمة التمثيل الأيضي

Objective: Metabolic syndrome (MetS) is tightly associated with cardiovascular atherosclerosis development and diabetes. However, the association between these markers and glucose intolerance and other clinical parameters in Jordanian MetS patient is not clear. Therefore, the objective of this study was to evaluate the potential association of atherosclerotic/metabolic inflammatory markers in Jordanian MetS patients with their glucose tolerance and other clinical parameters. Methods: A total of 190 MetS obese or overweight subjects (men = 61, women = 129) were enrolled. ELISA assays of plasma hs-CRP, MCP-1, PAI-1, MMP-9, resistin, adiponectin, leptin, MIF, TNF-α, TSP-1, IL-10, and IL-6 were performed. Results: It was found that hs-CRP and TNF-α were significantly and positively correlated with HbA1c (r=0.274; and 0.406; p<0.0001)and FPG (r=0.272; p<0.0001 and r= 0.163; p<0.05) , while IL10 was negatively correlated with HbA1c (r=-0.264; p<0.001). MIF positively correlated with FPG (r=0.207; p<0.001), and along with TSP-1(r=0.580; p<0.0001), it was linked positively to insulin resistance as measured by HOMA-IR (r=0.252; p<0.001). Conclusions: This study showed that most of proinflammatory markers have direct association with indicators of glucose tolerance parameters, namely, FPG and HbA1c. Therefore, these markers can be used as indicators for glucose intolerance and disease progression in patients with metabolic syndrome.

Interaction between Esophageal Squamous Cell Carcinoma and Adipose Tissue in Vitro

Esophageal squamous cell carcinoma (ESCC) develops within the squamous epithelial layer and invades the submucosa to the subadventitia that has adipose tissue (AT). AT seems critical to ESCC progression, but the underlying mechanism is unknown. We aimed to address the association between ESCC and AT invitro. ESCC cells were cultured on rat or human subcutaneous AT-embedded or -non-embedded collagen gel. AT promoted the growth of ESCC cells and inhibited their apoptosis. AT promoted the expression of the squamous differentiation marker involucrin in ESCC cells. AT accelerated the expression of invasion-related factors in poorly differentiated ESCC cells only. AT promoted the expression of phosphorylated-insulin-like growth factor-1 receptor in ESCC cells, whereas it inhibited that of the human epidermal growth factor receptor 2. Insulin-like growth factor-1, but not leptin, adiponectin, or resistin, promoted and inhibited the growth and apoptosis of ESCC cells, respectively. In turn, ESCC cells decreased the production of these adipokines in AT and the number of preadipocytes and mesenchymal stem cell-like cells, which developed from AT. These results suggest that i) AT may influence the progression of ESCC with increased growth or invasion and decreased apoptosis through insulin-like growth factor-1/insulin-like growth factor-1 receptor signaling, ii) AT may affect human epidermal growth factor receptor 2-targeted therapy; and iii) the cancer cells may affect adipokine production in AT.

Serum leptin level as a marker of neonatal sepsis

Objectives: For evaluation of serum leptin level in neonates with sepsis to aid early and accurate diagnosis and treatment. Background: Leptin is a polypeptide hormone that is mainly, but not exclusively, produced in adipose tissue and plays an important role in the innate immune defense. This study was designed to evaluate the level of serum leptin in cases of neonatal sepsis. Materials and methods: This study was carried out on 50 neonates divided into a case group (30 neonates with sepsis) and a control group (20 healthy neonates). All patients in the study were subjected to adequate assessment of history, full clinical examination, complete blood cell, C-reactive protein with titer, blood culture, and serum leptin assay by ELISA at the time of diagnosis and after recovery from sepsis. Results: The study showed that neonates who developed sepsis had significantly higher serum leptin levels than those of the control group and leptin levels were significantly higher in patients before antimicrobial therapy than after antimicrobial therapy. Also, there were no significant correlations between serum leptin and complete blood cell parameters or C-reactive protein, but there was a significant positive correlation with the sepsis score. A significantly higher level of serum leptin was found in patients with positive blood cultures compared with those with negative blood cultures, but there was no difference in the serum leptin level between survivors and nonsurvivors. The study showed that the best cut off value for serum leptin in the detection of sepsis was 2.75 ng/ml with a sensitivity of 75% and a specificity of 70%. Conclusion: Serum leptin plays a role in neonatal sepsis.

Leptin level correlates with obesity and health related quality of life in obstructive sleep apnea syndrome patients

BackgroundLeptin takes part in regulation of energy balance, neuronal functions, pain and mood. It may act as intermediary marker for various components of HRQOL in patients of obstructive sleep apnea syndrome. AimsTo document the correlation among leptin levels, obesity and HRQoL in OSAS patients. MethodsA tertiary care hospital based cross-sectional study was done in 224 subjects aged 18–65 years, after taking informed consent. Subjects with previous history of smoking, Liver disease, COPD, CHD, T2 DM, asthma, cancer, end stage renal disease, heart failure, any endocrine disorder including Cushing syndrome, thyroid, on systemic steroid or any continuous medication for last 6 months, on dieting or suffering from any disability condition (other than obesity and OSAS) affecting their HRQoL were excluded from the study. All subjects underwent Polysomnography. Leptin assay was done by ELISA method. Hindi version of HRQoL tool SF-36 was used to evaluate HRQoL. ResultsSPSS 20 was used to analyse data. Three groups (AHI <5, 5 to 15 and >15) were compared. Significant differences were observed in BMI, NC, WC, WHR and ESS. Differences were not significant in sleep architecture and Leptin level. SF-36 HRQoL, scores were observed decreased with increase in severity of disease. Leptin level was found significantly correlated with “Role limitations due to physical health problems”, “Social functioning”, Hypopnea and obesity indices. ConclusionsIn these subjects Obesity indices are the most important correlates of Leptin level. Oxygen desaturation indices with exception of Hypopnea and HRQoL may not be exclusively correlated to leptin levels.

Metabolomics in nutrition research: biomarkers predicting mortality in children with severe acute malnutrition.

Millions of the world's children suffer from malnutrition, which predisposes to death from diarrhea and a variety of infectious diseases. Mortality rates among infants and toddlers remain staggeringly high, in part because the pathogenesis of acute malnutrition and its complications remains poorly understood. We used metabolomic analysis to characterize the metabolic status of Ugandan children with severe acute malnutrition (SAM) and to delineate changes in hormones, metabolites, growth factors, and cytokines during nutritional therapy. We hypothesized that hormonal and metabolic factors measured at presentation would associate with, or predict, subsequent mortality during treatment. This was a prospective cohort study of 75 severely malnourished children 6 months to 5 years of age treated as inpatients with F-75 and F-100 and supplemental micronutrients; after discharge, they received ready-to-use therapeutic food (RUTF). This increased the mean weight-for-height z-score (WHZ) from -4.27 to -1.75 SD. Blood samples were obtained at presentation, after 2 weeks of inpatient therapy, and after 4 to 10 weeks of RUTF. Plasma samples were analyzed by tandem mass spectrometry and microassays. At presentation there were high levels of nonesterified fatty acids (NEFA), ketones, and even-chain acylcarnitines, indicating active lipolysis and fatty acid oxidation. In contrast, albumin, amino acids, and C3 carnitine, a by-product of branched-chain amino acids, were low. Levels of insulin, insulin-like growth factor 1 (IGF-1), adiponectin, and leptin were low, while levels of ghrelin, growth hormone, cortisol, interleukin 6 (IL-6), peptide YY (PYY), and glucagon-like peptide 1 (GLP-1) were high. The metabolic and hormonal changes were reversed by formula feeding and RUTF. Biomarkers associated with mortality included HIV, WHZ, and mid-upper-arm circumference (MUAC); the biochemical factor associated most strongly with mortality was low leptin, a marker of adipose reserve and modulator of immune function. Low leptin predicts mortality in edematous and nonedematous-patients with SAM. Leptin assays might be used to identify malnourished children at highest risk for death.

Influences of birth weight, gender, and pregnancy induced hypertension on cord blood leptin in growth restricted and normal neonates

Leptin synthesized by adipose tissue has significant association with birth weight, body mass index and insulin-glucose ratio. Fetuses with growth restriction (FGR) have substantial reduction in adipose tissue; hence lower levels of leptin in cord blood. Hyperleptinemia has been observed in pregnancy induced hypertension (PIH). Objectives: To estimate leptin levels in cord blood of growth restricted and normal neonates and study the factors influencing the same. Methods: In this prospective study, a sample size of 40 each of growth restricted and appropriate for gestational age neonates were included. Data included maternal illnesses, anthropometry, maturity and ponderal index (PI). Cord leptin assay was done using commercial solid phase competitive ELISA and was expressed in ng/ml. Statistical analysis was done using t test and Pearson correlation co-efficient using recommended software. Results: Maternal PIH was the major etiological factor contributing to FGR (12, 30%, P =0.000). Mean cord leptin in ng/ml was 2.80±0.4 in growth restricted group and 3.53±0.5 in normal neonates with P value of 0.074. There was no correlation between cord leptin and birth weight (r=0.08; p=0.61) and PI (r=0.03; p=0.89). In female neonates and those born to mothers with PIH, mean leptin levels were 3.16±0.6 and 3.13±0.7 ng/ml respectively, higher in comparison with males and those born to mothers without hypertension. Conclusion: Mean cord leptin levels were lower in the growth restricted and higher in female gender and those born to maternal PIH. Cord leptin may be influenced by various maternal and fetal factors.

Increased TSH in obesity: Evidence for a BMI-independent association with leptin

AimThis study aimed to determine whether the association between thyroid-stimulating hormone (TSH) and body mass index (BMI) is related to leptin concentration in obese individuals. MethodsPlasma TSH and leptin assays were performed in 800 consecutive patients, hospitalized for a nutritional checkup, with a BMI≥30kg/m2. Various anthropometric, hormonal and metabolic parameters, including age, weight, BMI, insulin, leptin and TSH, were measured or calculated. Univariate and multivariate regression analyses were performed to identify any significant relationships between these parameters. Also, characteristics of the patients in the lowest and highest quartiles of TSH distribution were compared. ResultsTSH was positively correlated with both BMI and leptin. When multiple regression analysis was performed, TSH and leptin maintained a significant association independent of BMI. Patients in the fourth quartile of TSH distribution displayed higher BMI and higher leptin levels in comparison to the first quartile. ConclusionOur study has confirmed an increase in TSH in conjunction with BMI in obese subjects. This increase was correlated with leptin independently of BMI. It is hypothesized that the increase in TSH observed in obese subjects was the consequence of both fat mass accumulation and a positive energy-balance.

Relationship Between Serum Leptin Level and Serum Lipid Profile in Male Obstructive Sleep Apnea Syndrome Patients

High leptin concentrations have been linked to both obesity and an increased risk of dyslipidemia. Previous studies reported higher leptin levels in obstructive sleep apnea syndrome (OSAS) subjects compared with healthy subjects. As obesity is a determinant of serum lipids and lipoproteins in adults. Leptin might have a correlation with serum lipids and lipoproteins in OSAS subjects. The aim of this study was to examine correlation of leptin with serum lipid profile in male OSAS patients. In this tertiary hospital based cross-sectional study, one hundred thirty nonalcoholic and nonsmoker male subjects were indexed. Subjects with previous history of, liver disorder, asthma, chronic obstructive pulmonary disease, congestive heart disease, type 2 diabetes mellitus, cancer, end stage renal disease, heart failure, endocrine disorder, on systemic steroid or any continuous medication for last 6 months were excluded from the study. Anthropometric measurements, Polysomnography, fasting lipid profile and leptin assay was done. The data obtained was analysed using SPSS20. Leptin level was observed significantly positively correlated with only hypopnea events per hour in all studied oxygen desaturation indices while a strong significant positive correlation was found between leptin level and all studied obesity indices, BMI, NC, WC, HC and WHR. No correlation was observed between leptin level with total cholesterol, HDL-cholesterol and LDL, TG and VLDL. The study brings to light that leptin is related only to obesity related parameters and not with serum lipids and lipoprotein levels in male OSAS subjects. We conclude that in our study setting, leptin was not correlated with serum lipids and lipoproteins in obstructive sleep apnea patients. It seems that, leptin was correlated exclusively only with obesity indices parameters i.e. BMI, NC, WC, HC and WHR of these subjects.

Serum leptin and its relationship with psychopathology in schizophrenia.

Leptin plays an important role in the modulation of the dopaminergic system and has recently been implicated in schizophrenia. There have been conflicting reports on leptin levels in schizophrenia; as well as on the association between leptin levels and clinical symptoms. Therefore, this study aims to examine (i) leptin levels in schizophrenia relative to control, and (ii) the relationship between leptin and symptoms in schizophrenia. One hundred participants with schizophrenia and 89 healthy controls were recruited from the Institute of Mental Health in Singapore. Demographic information and medical histories were collected. Schizophrenia symptoms were assessed using the positive and negative syndrome scale (PANSS) and serum leptin was measured using a commercially available bioplex leptin assay. Linear regressions were performed to examine the relationship between serum leptin and the positive, negative, general psychopathology subscales and total PANSS scores. Contrary to previously published literature, we did not find any significant difference in leptin level between participants with schizophrenia compared to controls, which might be the result of recruited controls being of comparable body mass index. Serum leptin was found to be positively associated with positive symptoms, general psychopathology and total PANSS score. This study provides evidence to suggest a positive association between serum leptin level and symptomatology in schizophrenia. However, since conflicting results in this area of research exist, it is important to understand better the mechanism behind this relationship and to examine temporal fluctuations in leptin levels in relation with changes in clinical symptomatology.

Association between continuous positive airway pressure and changes in serum leptin in patients with obstructive sleep apnoea: a meta-analysis

The role of leptin in the development of obstructive sleep apnoea (OSA) has been identified. However, the effects of OSA treatment using continuous positive airway pressure (CPAP) on serum leptin levels remain controversial. To address this issue, a meta-analysis was conducted to evaluate the effects of CPAP therapy on serum leptin levels in OSA. A comprehensive literature search was performed to identify studies that focused on the effects of CPAP therapy (treatment duration, ≥4 weeks) on the serum leptin levels of OSA patients. Standardised mean difference (SMD) was used to analyse the summary estimates for CPAP therapy. Fifteen studies involving 427 patients were included in the meta-analysis. Results indicate that the overall SMD of the leptin levels before and after CPAP therapy was 0.137 (95% confidence interval (CI) 0.002 to 0.272); test for overall effect z=1.99 (P=0.046). Sources of heterogeneity were not found by subgroup and meta-regression analyses. Subgroup analyses showed that differences in OSA severity, baseline body mass index, compliance, CPAP duration and leptin assay did not affect the effectiveness of CPAP therapy. The evidence for the use of CPAP therapy on decrease of leptin levels in OSA patients is low, and stronger evidence is needed.

Alternatives to risk-reducing surgery for ovarian cancer

BRCA1 and BRCA2 mutation carriers have an 18%–60% and 11%–27% lifetime risk of developing ovarian carcinoma, respectively. Prophylactic bilateral salpingo-oophorectomy reduces the risk of this malignancy by up to 96%. Gynecological screening programs with periodical trans-vaginal ultrasound and serum CA125 assay have been widely used in women at hereditary high risk of ovarian carcinoma, but clinical results have been conflicting. These surveillance protocols have often fallen short of expectations because of the advanced stage of ovarian carcinoma in the identified screened women. Several investigations have been addressed to the detection of additional tumor markers able to generate more reliable screening tools. The combined serum assay of leptin, prolactin, osteopontin, CA125, macrophage inhibiting factor and insulin-like growth factor-II appears to have a significant better diagnostic reliability compared with serum CA125 alone in discriminating healthy individuals from ovarian carcinoma patients, and therefore, it could have a role in the screening of women at high risk for this malignancy. As far as chemoprevention is concerned, oral contraceptives significantly reduce the ovarian carcinoma risk also in BRCA mutation carriers, whereas the efficacy of fenretinide is still under investigation.

Effects of feed on plasma leptin and ghrelin concentrations in crib-biting horses

The reason why some horses begin an oral stereotypy such as crib-biting is not known. The aim of this study was to measure ghrelin and leptin concentrations in plasma concentrations to determine whether there is a link to crib-biting in horses. Plasma samples (n=3) were collected for plasma leptin and ghrelin assay before and during the morning first feeding in the usual environments of 15 horses with stereotypic crib-biting and 15 matched controls. The crib-biting intensity was scored in three 5-min phases, and a subgroup of verified crib-biters (n=8) was defined as horses that were seen to crib-bite during this study.Plasma leptin concentration (mean and 95% confidence interval [CI]) was lower in horses observed to crib-bite before and after feeding of concentrates (1.2, CI 0.8–1.7ng/mL and 1.0, CI 0.6–1.7) than in non-crib-biters (2.3, CI 1.6–3.4 and 2.3, CI 1.6–3.4ng/mL, respectively) and correlated negatively with crib-biting intensity. Crib-biting intensity was significantly higher shortly after feeding than before or 30min later. Plasma ghrelin concentration was significantly higher before feeding concentrate than before hay feeding or after the concentrate, but did not differ between groups. There was a significant negative correlation between body composition score and plasma ghrelin concentration. These findings suggest that leptin concentrations may be associated with crib-biting behaviour in horses.

Preservation of the Celiac Branch of the Vagus Nerve during Laparoscopy‐assisted Distal Gastrectomy: Impact on Postprandial Changes in Ghrelin Secretion

Ghrelin is a brain-gut peptide with GH-releasing and appetite-inducing properties. Because ghrelin is secreted mainly by the stomach, fasting levels fall after distal gastrectomy. The vagal nerve is responsible for periprandial changes. The presents study investigated the impact of preserving the celiac branch of the vagus nerve during laparoscopy-assisted distal gastrectomy on postoperative ghrelin secretion. Between May 2009 and July 2010, 42 consecutive patients who underwent LADG were divided into two groups, the first in which the celiac branch of the vagus was preserved ("Preserved," n = 21) and the second in which it was not ("Not Preserved," n = 21). Blood samples were collected for assays of several hormones, including ghrelin, leptin, and insulin; these were taken before and 2 h after breakfast on postoperative day 7. There were no significant differences in the background characteristics of the two groups. Plasma fasting ghrelin decreased significantly after LADG, by about 50 % of the baseline values in both groups. Postprandial plasma ghrelin levels in the Preserved group were significantly lower than those in the Not Preserved group (23 ± 8 vs 32 ± 9 fmol/ml; p = 0.0058). The ratio of the total ghrelin concentration after breakfast to that before was defined as the A/B ratio. The mean preoperative and postoperative A/B ratios were almost the same in the Preserved group (preoperative vs postoperative: 0.41 vs 0.44; p = 0.52). On the other hand, the mean A/B ratio in the Not Preserved group increased from 0.41 to 0.61 postoperatively (preoperative vs postoperative; p = 0.0003). Preservation of the celiac branch of the vagus nerve during LADG was related to the prandial ghrelin changes.

Brief daily postpartum separations from the litter alter dam response to psychostimulants and to stress

Neonatal handling induces several behavioral and neurochemical alterations in pups, including decreased responses to stress and reduced fear in new environments. However, there are few reports in the literature concerning the behavioral effects of this neonatal intervention on the dams during the postpartum period. Therefore, the aim of the current study was to determine if brief postpartum separation from pups has a persistent impact on the dam's stress response and behavior. Litters were divided into two neonatal groups: 1) non-handled and 2) handled [10 min/day, from postnatal day (PND) 1 to 10]. Weaning occurred at PND 21 when behavioral tasks started to be applied to the dams, including sweet food ingestion (PND 21), forced swimming test (PND 28), and locomotor response to a psychostimulant (PND 28). On postpartum day 40, plasma was collected at baseline for leptin assays and after 1 h of restraint for corticosterone assay. Regarding sweet food consumption, behavior during the forced swimming test or plasma leptin levels did not differ between dams briefly separated and non-separated from their pups during the postpartum period. On the other hand, both increased locomotion in response to diethylpropion and increased corticosterone secretion in response to acute stress were detected in dams briefly separated from their pups during the first 10 postnatal days. Taken together, these findings suggest that brief, repeated separations from the pups during the neonatal period persistently impact the behavior and induce signs of dopaminergic sensitization in the dam.

Reduction of ethnic inequalities in birthweight: a public health paradox

BackgroundBirthweight is a key predictor of infant and later adult health. Previous studies have shown substantially lower birthweight in infants of south Asian origin than in those of white European origin. Whether such differences mask increased adiposity in south Asian infants and whether they persist across generations in contemporary UK populations is unclear but important to the development of public health interventions aimed at increasing birthweight. We aimed to compare birthweight, skinfold thickness, and cord leptin between Pakistani and white British infants and to investigate whether the magnitude of any difference varies depending on whether the mother, father, and all four grandparents were born in the UK or south Asia. MethodsWe examined differences in birthweight, subscapular, and triceps skinfold thickness between 4649 Pakistani and 4055 white British infants born at term in the same UK maternity unit and compared cord leptin in a subgroup of 775 Pakistani and 612 white British infants. All infants were born to mothers recruited to the Born in Bradford cohort study between March, 2007, and December, 2010. Around 80% of women invited to take part were recruited to the study and levels of recruitment were broadly similar in both ethnic groups. We investigated whether the magnitude of any differences changed by Pakistani generation and used multiple linear regression models to adjust for a wide range of potential explanatory or masking factors (including smoking, alcohol, maternal glycaemia, body-mass index, height parity, sex, gestation, and socioeconomic factors). FindingsPakistani infants were lighter (adjusted mean difference −234 g, 95% CI −258 to −210) than were white British infants and were smaller in both subscapular and triceps skinfold measurements. The differences for subscapular and triceps skinfold thickness (mean Z score difference −0·27, 95% CI −0·34 to −0·20, and −0·23, 95% CI −0·30 to −0·16, respectively) were smaller than the difference in birthweight (mean Z score difference −0·52, 95% CI −0·58 to −0·47) and attenuated to the null with adjustment for birthweight (0·03, 95% CI −0·03 to 0·09, and −0·01, 95% CI −0·08 to 0·05, respectively). Cord leptin concentration (used as an indicator of fat mass) was similar in Pakistani and white British infants without adjustment for birthweight, but with adjustment became 30% higher (95% CI 17–44) in Pakistani infants than in white British infants. The magnitudes of difference did not differ by generation. InterpretationDespite being substantially lighter, Pakistani infants had similar skinfold thicknesses and greater total fat mass, as indicated by cord leptin, for a given birthweight than did white British infants. Our findings draw attention to a potential problem for WHO guidance and other health policy aimed at increasing birthweight in populations in low-income and middle-income countries and in migrant populations in high-income countries. If mean birthweight increases, but a fat-preserving tendency is maintained, the effect might be simply to increase adiposity, which in turn could worsen long-term cardiometabolic health and increase existing ethnic inequalities in diabetes and coronary heart disease. Policies to reduce ethnic inequalities in birthweight therefore need to consider differences in adiposity, and the possibility that increasing birthweight in south Asian infants might inadvertently worsen health by increasing relative adiposity. FundingJW was funded by a UK Medical Research Council (MRC) Special Training Fellowship in Health of the Public and Health Services Research (MRCGO601712), DAL works in a centre that receives funding from the MRC (G0600705). Cord leptin assays were funded by a British Heart Foundation Project Grant (PG/09/036/27380).

Plasma leptin and energy expenditure during prolonged, moderate intensity, treadmill exercise.

Current literature shows conflicting results regarding the possible direct role of exercise on leptin concentrations, mainly because of a non-homogeneous level of energy expenditure (EE) and the lack of standardization of energy balance. The aim of the study was to evaluate the effect of exercise duration and its corresponding EE on leptin levels, during prolonged treadmill exercise, in a well-controlled laboratory setting. Seven young trained males underwent a 4-h treadmill exercise. The starting intensity was set at 65% of maximal oxygen consumption. At the start of the test and throughout the exercise, venous blood samples were drawn for the assays of leptin, glucose, free fatty acids (FFA), cortisol, epinephrine (E) and norepinephrine (NE). Hourly and total EE was monitored with gas analysis. Plasma leptin levels decreased from 1.10±0.15 to 0.85±0.26 μg/l (p<0.01) at the end of the exercise, reaching a significant reduction already after the second hour. FFA and cortisol showed a progressive significant increase, while glucose did not significantly change throughout the test. Plasma E and NE significantly increased at all sampling times compared to basal values (48.1±30.3 to 352.3±187.7 pg/ml, p<0.001 and 238.1±118.9 to 1798.7±413.5 pg/ml, p<0.001). The random-effects model for panel data analysis showed negative correlation between leptin, NE and the values of progressive EE (r2=0.745, p<0.05). Our data demonstrate that, during a prolonged moderate intensity exercise, leptin decrease is significantly related to the total EE. Further, NE concentrations seem to play an important role in the inhibition of leptin secretion.

Adaptive Evolution of Leptin in Heterothermic Bats

Heterothermy (hibernation and daily torpor) is a key strategy that animals use to survive in harsh conditions and is widely employed by bats, which are found in diverse habitats and climates. Bats comprise more than 20% of all mammals and although heterothermy occurs in divergent lineages of bats, suggesting it might be an ancestral condition, its evolutionary history is complicated by complex phylogeographic patterns. Here, we use Leptin, which regulates lipid metabolism and is crucial for thermogenesis of hibernators, as molecular marker and combine physiological, molecular and biochemical analyses to explore the possible evolutionary history of heterothermy in bat. The two tropical fruit bats examined here were homeothermic; in contrast, the two tropical insectivorous bats were clearly heterothermic. Molecular evolutionary analyses of the Leptin gene revealed positive selection in the ancestors of all bats, which was maintained or further enhanced the lineages comprising mostly heterothermic species. In contrast, we found evidence of relaxed selection in homeothermic species. Biochemical assays of bat Leptin on the activity on adipocyte degradation revealed that Leptin in heterothermic bats was more lipolytic than in homeothermic bats. This shows that evolutionary sequence changes in this protein are indeed functional and support the interpretation of our physiological results and the molecular evolutionary analyses. Our combined data strongly support the hypothesis that heterothermy is the ancestral state of bats and that this involved adaptive changes in Leptin. Subsequent loss of heterothermy in some tropical lineages of bats likely was associated with range and dietary shifts.

Energetic consequences of seasonal breeding in female Japanese macaques (Macaca fuscata)

Japanese macaques inhabit a relatively cold environment and females of this species could have developed strategies of energy economy to face the sometimes-harsh seasonal conditions of temperate climates, as well as reproductive costs, and thus regulate their energy balance. Here, we explore the relationship between nutritional status, body composition, seasonality, and reproductive status using isotope-labeled water, anthropometric measurements, and leptin assays from 14 captive female Japanese macaques. Our results indicated that body mass provided the best predictor of fat-free mass and fat mass. These females varied in estimated percent body fat between 8 and 25% (18% on average at the beginning of the mating season and 13% during the birth season). Higher body mass and body fat content were observed at the beginning of the mating season, which supports the hypothesis that individual females need to attain a sufficient physical condition to cover energy costs associated with mating activity, and to survive under severe ecological conditions in winter with high thermoregulatory costs. We found a relationship between conception rates and energetic condition or body fat, with females that conceived during one mating season being fatter after the end of their previous mating season. Together, these results suggest that, even in captive settings with constant food availability, seasonal breeding entails relatively high energy costs, and that females with higher energy status could invest more in reproductive activities and could afford to reproduce more rapidly.

Increased Fat Mass and Cardiac Septal Hypertrophy in Newborn Infants of Mothers with Well-Controlled Diabetes during Pregnancy

Background: Improved glycaemic control during pregnancy in mothers with type 1 diabetes (T1DM) and gestational diabetes (GDM) has resulted in a marked reduction of perinatal mortality and morbidity, but the prevalence of macrosomia is usually high. Objective: We used non-invasive anthropometric methods to estimate the body composition and the thickness of the interventricular heart septum in 18 infants of mothers with well-controlled T1DM, 10 infants of mothers with GDM and 28 infants of healthy control mothers matched for gestational age and mode of delivery. Methods: Skinfold measurements were obtained with a Harpenden calliper within 48 h after delivery. Echocardiography was also performed to measure the thickness of the interventricular septum. Cord blood was sampled for assays of C-peptide, leptin and IGF-I. Results: The rates of macrosomia (gestational age-adjusted birth weight >2 standard deviation score, SDS) were 56 and 30% in infants of mothers with T1DM and GDM, respectively, compared to 10% in control infants. The body fat content was 40% (0.2 kg) higher and the interventricular heart septum thickness was increased by 20% in both groups of infants of diabetic mothers. We found no associations between maternal levels of HbA1c during pregnancy and body composition or interventricular heart septum thickness. Cord levels of C-peptide and leptin were significantly higher in infants of T1DM mothers than in control infants. Cord leptin level was associated with birth weight SDS and percent body fat in infants of T1DM mothers. IGF-I was associated with percent body fat in infants of GDM mothers and control mothers. A multiple-regression analysis showed that 50% of the variation in body weight SDS could be determined, with IGF-I, leptin and C-peptide as independent variables. Conclusion: Both fat mass and cardiac septal thickness are increased in newborn infants of women with T1DM and GDM in spite of efforts to achieve good glycaemic control during pregnancy.

Upregulation of growth signaling and nutrient transporters in cotyledons of early to mid-gestational nutrient restricted ewes

Multiparous ewes received 100% (control, C, n = 13) or 50% (nutrient restricted, NR, n = 14) of NRC dietary requirements from d28-d78 of gestation. On d78, 5 C and 6 NR ewes were necropsied. The remaining 8 C and 8 NR ewes were fed to 100% of NRC from d78-d135 and necropsied. Maternal blood was collected at both necropsies and at weekly intervals for assay of glucose, insulin and leptin. Fetal blood was collected at d78 and d135 necropsies for assay of glucose and lipids. Cotyledonary (COT) tissue was evaluated for protein and mRNA expression [fatty acid transporter (FATP)1, FATP4, CD36, glucose transporter (GLUT)1 and GLUT3], mRNA expression only [placenta fatty acid binding protein (FABPpm) and lipoprotein lipase (LPL)], or expression of phosphorylated and total protein forms [AMP kinase (AMPK)α, acetyl-CoA carboxylase (ACC), extracellular signal-regulated kinase (Erk)1/2, mammalian target of rapamycin (mTOR) and protein kinase B (Akt)]. On d78, but not d135, placental and fetal weights were reduced ( P < 0.05) in NR vs. C ewes. Maternal circulating glucose, insulin and leptin levels were decreased in NR vs. C ewes on d78 ( P < 0.05) but similar at d135. Fetal blood glucose and triglyceride levels were lower in NR vs. C ewes ( P < 0.05) on d78, but similar on d135. On d78, GLUT1, FATP4, CD36 mRNA and protein expression levels, FABPpm mRNA level, and leptin protein level were all increased ( P < 0.05) in COT of NR vs. C ewes. AMPK, ACC, and Erk1/2 activities were also increased ( P < 0.05) in NR vs. C COT on d78. In contrast, only FATP4 was increased ( P < 0.05) at both the mRNA and protein levels in COT of NR realimented vs. C ewes on d135. These data demonstrate placental adaptation to maternal NR through increasing nutrient transporter production and growth signaling activity.