Differences In Leptin Concentrations Research Articles

Ghrelin and Leptin Concentrations in Patients after SARS-CoV2 Infection.

SARS-CoV2 infection can lead to severe cytokine storm especially in obese patients. Ghrelin acts not only as an appetite regulator but can also play a key role in the immune reaction. Leptin, secreted mainly by the white adipose tissue, can act as a pro-inflammatory cytokine. The crucial question is whether or not the cytokine storm in COVID-19 patients with obesity is linked to adipokine dysregulation. The aim of this study was to assess ghrelin and leptin concentrations in patients 6 months after SARS-CoV2 infection in comparison to a control group considering the influence of sex. The study group included 53 patients with a history of COVID-19 and 87 healthy subjects in the control group. Leptin and ghrelin concentrations as well as hormonal and biochemical parameters were measured. A significantly higher ghrelin concentration was observed in the COVID-19 group in comparison to the control group, with a statistically significant impact of sex on the relationship between COVID-19 and ghrelin concentration, which was lower in the males. No statistically significant differences in leptin concentration were observed between the groups. A significant negative correlation was observed between ghrelin and testosterone and morning cortisol levels in the COVID-19 group. The current study showed that ghrelin levels were significantly higher in patients 6 months after a mild course of SARS-CoV2 infection. To confirm the hypothetical protective role of ghrelin in the inflammatory process, it would be necessary to compare serum ghrelin levels between patients after mild and severe courses of COVID-19. Due to the small sample size and the lack of patients with a severe course of COVID-19, these observations need further investigation. There were no differences in leptin concentrations between the COVID-19 patients and the control group.

Serum leptin and neuropeptide Y in patients with cystic fibrosis-A single center study.

Along with the significant elongation in the average life expectancy of patients with cystic fibrosis (CF), there are still significant discrepancies in the height, weight, and body mass index (BMI) of patients compared to controls without CF. The correlation between hormones that regulate appetite and body fat mass may be an additional factor in weight loss or poor weight gain in CF patients. Our objective was to estimate serum concentrations of leptin and neuropeptide Y in patients with CF as well as to assess correlations between studied hormones and the clinical parameters of CF. Leptin and neuropeptide Y serum concentrations after an overnight fast were measured using an enzyme-linked immunosorbent assay. All study participants had anthropometric tests and spirometry. In addition, fasting serum lipid profile was also analyzed. Fasting leptin levels in CF were significantly higher in patients with CF patients (13.9 ± 6.9 vs. 6.5 ± 2.6 ng/mL, p < 0.001) compared to controls. There were no differences in leptin concentration between female and male CF participants (15.7 ± 7.8 vs. 12.2 ± 5.6 ng/mL, p = 0.13). Leptin was correlated with age (R = 0.64, p < 0.001), BMI (R = 0.65, p < 0.001), spirometry results (R = −0.49, p < 0.01), and body fat (R = 0.5, p < 0.05). There were no differences in neuropeptide Y concentration between participants with CF and controls as well as neuropeptide Y was not correlated with any studied parameters. The results of our study suggest that weight loss may be associated with a decreased level of leptin, while reduced pulmonary function in CF may be related to an elevated level of leptin.

Novel Marker for Premature Ejaculation: Serum Leptin Level.

BackgroundLeptin, which was only discovered in humans in 1994, has recently been shown to have a possible link with premature ejaculation.AimTo evaluate whether serum leptin levels differed between patients with premature ejaculation and healthy men, and to analyze the changes in leptin levels before and after treatment.MethodsSix studies assessing the relationship between leptin and premature ejaculation published up to October 2021 were identified from multiple databases (PubMed, Web of Science, Cochrane) and the data were analyzed by Stata software.OutcomesDifferences in leptin levels in premature ejaculation patients and healthy people, and changes of leptin levels in premature ejaculation population before and after treatment.ResultsAnalysis of studies assessing differences in leptin concentrations between patients with PE and healthy men showed that there was a statistically significant difference in leptin levels between PE patients and controls (WMD (95% CI) = 17.89 (8.64, 27.14), P < .001). On the other hand, the analysis of data from 3 studies describing serum leptin levels in PE patients before and after treatment with selective serotonin reuptake inhibitors (SSRIs) showed that there was a significant decrease with leptin levels in PE patients after treatment (WMD (95%CI) = 22.06 (17.21, 26.92), P < .001).Clinical ImplicationsIt is possible that leptin can be used as a new marker for premature ejaculation.Strength & LimitationsThe strength of this study is that it is the first meta- analysis to assess the differences of serum leptin levels between patients with premature ejaculation and healthy subjects and the changes of leptin levels before and after treatment in patients with premature ejaculation. A major limitation is that a greater heterogeneity was identified through our analysis, however we did not find a definitive source of heterogeneity.ConclusionThere was a statistically significant relationship between serum leptin levels and patients with PE. In addition, serum leptin levels in patients with PE decreased significantly after 8 weeks of treatment with SSRIs.Liu G, Zhang Y, Zhang W, et al. Novel Marker for Premature Ejaculation: Serum Leptin Level. Sex Med 2022;10:100509.

Maternal Serum and Cord Blood Leptin Concentrations at Delivery in Normal Pregnancies and in Pregnancies Complicated by Intrauterine Growth Restriction

Introduction: Leptin is a polypeptide hormone, and in pregnancy, it is secreted by the placenta and maternal and fetal adipose tissues. Normal leptin production is a factor responsible for uncomplicated gestation, embryo development, and fetal growth. The study compared maternal serum and cord blood leptin concentrations at delivery in normal pregnancies and in pregnancies complicated by intrauterine growth restriction (IUGR). Methods: The study was performed in 25 pregnant women with isolated IUGR and in 194 pregnant women without any complications. Leptin concentrations in maternal serum and in cord blood samples collected at delivery were measured by ELISA and subsequently analyzed by maternal body mass index (BMI), mode of delivery, and infant gender and birth weight. For comparative analyses of normally distributed variables, parametric tests were used, that is, the Student t test and a one-way ANOVA. The nonparametric Mann-Whitney test was used when the distribution was not normal. The Pearson correlation coefficient was calculated to assess the correlation between normally distributed variables (p < 0.05). Results: In pregnancies complicated by IUGR, the mean maternal serum leptin concentration at delivery was significantly higher (52.73 ± 30.49 ng/mL) than in normal pregnancies (37.17 ± 28.07 ng/mL) (p = 0.01). The mean cord blood leptin concentration in pregnancies complicated by IUGR was 7.97 ± 4.46 ng/mL and significantly lower than in normal pregnancies (14.78 ± 15.97 ng/mL) (p = 0.04). In normal pregnancies, but not in pregnancies complicated by IUGR, a statistically significant correlation was established between maternal serum leptin concentrations and maternal BMI at delivery (r = 0.22; p = 0.00). No statistically significant correlation was found between cord blood leptin concentrations and maternal BMI in either study subjects or controls. In normal pregnancies, but not in pregnancies complicated by IUGR, a strong correlation was observed between cord blood leptin concentrations and birth weight (r = 0.23; p = 0.00). Conclusions: Elevated maternal blood leptin concentrations in pregnancies complicated by IUGR may indicate a significant adverse effect of elevated leptin on fetal growth. The differences in leptin concentrations, measured in maternal serum and in cord blood, between the study subjects and controls suggest that deregulated leptin levels may increase the risk of obstetric complications associated with placental insufficiency.

Interaction of FTO rs9939609 and the native American-origin ABCA1 p.Arg230Cys with circulating leptin levels in Mexican adolescents diagnosed with eating disorders: Preliminary results

Eating disorders (ED) are characterized by disruption of eating behaviour and alteration of food intake. Leptin, is one of the main hormones that modulate food intake and are altered in individuals diagnosed with ED. Genetic risk variants for obesity, like those reported inFTO and ABCA1, have also been associated to ED disorders. The present study aimed to analysed leptin circulating levels and the interaction between obesity-risk variants in FTO and ABCA1, in adolescents diagnosed with ED. A total of 99 individuals diagnosed with ED were genotype using Taqman probes for FTO (rs9939609) and ABCA1 (p.Arg230Cys, rs9282541). Commercial enzyme-linked immunosorbent assays were utilized to determined circulating leptin. Differences in leptin concentration were analysed by t-Student or ANOVA test. Gene-gene interaction were analysed using general estimation equations. Circulating leptin levels differed between the three diagnostic groups, lead by individuals diagnosed with binge eating-disorder. In individuals with more than 3 of episodes of binge-eating per week having the highest leptin levels. Also, we found that carriers of both risk alleles had the highest leptin levels. Our observations found an interaction between FTO rs9969609 and the native American-origin ABCA1 p.Arg230Cys to modulate circulating leptin levels in Mexican adolescents diagnosed with eating-disorders.

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.

Changes in milk production, hematology, metabolites, mineral and hormonal parameters of primiparous and multiparous Maghrebi dairy she-camel during nonbreeding season

ABSTRACT This study aimed to evaluate changes in milk production, hematological, metabolites, mineral and hormonal parameters of primiparous (PP) and multiparous (MP) Maghrebi she-camels during nonbreeding season in Egypt. A total of 12 Maghrebi she-camels at lactation period, 6 PP (4–5 years of age) and 6 MP (6–13 years old) and 2–7 parities, were used in this study. Average milk yield was higher in MP than in PP at each lactation month. Milk fat, protein and total solid contents were higher in PP than in MP. The differences in hematological indices, biochemical parameters and mineral contents between PP and MP were not significant. The differences in leptin concentration between PP and MP were not significant. The differences in concentration of progesterone (P4) or estradiol (E2) between PP and MP were not significant, although both P4 and E2 concentrations tended to be higher in PP than in MP. Both P4 and E2 levels in PP or MP showed nearly similarity at nonbreeding months from May to August, then sharply increased during September and October. Results from this study suggested nonbreeding season of she-camels during May–August interval and longer breeding season from September to April of she-camel in Egypt.

Developing a method of co‐incubating murine adipocytes and macrophages for evaluating cellular communication

Adipose tissue, an organ containing both adipocytes and adipose tissue macrophages (ATMs), secretes cytokines known as adipokines. Of these two cell types, ATMs have a larger role in the production and release of proinflammatory adipokines. The objective of this research was to develop a system of co‐incubating adipocytes and macrophages that allowed us to quantitatively measure the cross‐talk between these two cell types. Nitric Oxide (NO) and interleukin‐6 (IL‐6) concentrations were quantified to determine macrophage activation and production of a proinflammatory adipokine, respectively. Leptin concentrations were used as a measure of adipocyte‐specific adipokine production. The cell lines used were RAW 264.7 (murine macrophages) and 3T3‐L1 (murine fibroblasts). 3T3‐L1 fibroblasts were differentiated into adipocytes, which was confirmed by the presence of lipid droplets. Transwell plates with permeable inserts were used to co‐incubate the macrophages and adipocytes; the confluent adipocytes were maintained in the 12‐well plate (lower compartment) and the macrophages were added to the transwell insert (upper compartment). Macrophages were stimulated with 0.01 mg/ml of LPS either before or after the addition of the the macrophages to the insert. The treatments were: 3T3+media, 3T3+media+LPS, 3T3+unstimulatedRAW, 3T3+RAW+LPS, 3T3+stimulatedRAW (in fresh media), and 3T3+stimulatedRAW (in conditioned media). There was no difference in IL‐6 concentration measured in the upper compartment of the transwell insert vs the lower compartment, while measured NO levels were higher in the upper compartment and leptin levels were higher in the lower compartment (p&lt;0.001, matched pairs t‐test). The 3T3+RAW+LPS, 3T3+stimulatedRAW (in fresh media) and 3T3+stimulatedRAW (in conditioned media) co‐incubation protocols resulted in the highest concentration of IL‐6 (p=0.0006). The 3T3+RAW+LPS and 3T3+stimulatedRAW (in conditioned media) co‐incubation methods yielded the highest concentrations of NO in both the upper and bottom compartments of the plate (p&lt;0.001). There was no difference in leptin concentrations due to co‐incubation protocol. There was a positive relationship between NO and IL‐6 in both the top and bottom compartments (p&lt;0.001, linear regression) and between NO and leptin in the top (p=0.03) but not in the bottom compartment. There was no significant relationship between IL‐6 and leptin concentrations in either the top or bottom compartments. For future experiments, our lab will utilize the co‐incubation protocols that resulted in the highest production of NO and IL‐6: 3T3+RAW+LPS and 3T3+stimulatedRAW (in conditioned media).This abstract is from the Experimental Biology 2019 Meeting. There is no full text article associated with this abstract published in The FASEB Journal.

Abstract MP54: Sex-Related Differences in the Association of Social Isolation With Plasma Leptin Concentration

Introduction: Studies have reported a positive associations of depression and psychosocial stress and plasma leptin concentration. Social isolation has been linked to increased leptin signaling in male rats, but this association has not been investigated in humans. Methods: We investigated the cross-sectional association of social isolation and plasma leptin concentration among 2,729 Framingham Offspring Cohort participants at the 7 th examination (1999-2001, mean age = 60.1 years, 42% men). Social isolation was measured using the Berkman-Syme Social Network Index: we assigned 1 point for being married, 1 point each for &gt;2 close friends and &gt;2 close relatives, 1 point for participation is social groups, and 1 point for participation in religious meetings ≥1-2 times per month. Social isolation was defined as a total of 0 points. Non-fasting plasma leptin levels were measured using a commercial immunoassay. The primary outcome was plasma leptin concentration. Secondary outcomes included caloric intake, measured by food frequency questionnaire, and volumes of abdominal subcutaneous adipose tissue (SAT), and visceral adipose tissue (VAT), measured by CT among 1,210 of the subjects between 2002 and 2005. Leptin concentration and adipose tissue volume were log-transformed due to skewed distributions. We estimated the associations of social isolation with all outcomes using linear regression. Models included age, body mass index, years of education, smoking status, physical activity index, hypertension, high blood glucose, and CES-D score as covariates. Because leptin levels and responses to social stress may vary among men and women, analyses were stratified by sex. Results: Socially isolated participants were younger and had higher CES-D scores than those who were not. Other characteristics were similar between the two groups. Plasma leptin concentration was 20% lower among socially isolated men (95% CI: -31, -6%) compared with men who were not isolated. Social isolation was also associated with lower caloric intake as well (β = -144.5 kcal, 95% CI: -287.1, -1.87 kcal). Among the subset of men for whom we had adipose tissue depot volume measurements (n=552), VAT volume appeared to be 10% lower among socially isolated men compared with non-isolated men (95% CI: -19, 1%), but this was not true of SAT (β = 1%, 95% C: -9, 10%). We did not observe differences in leptin concentration (β = -1%, 95% CI: -10, 15%), caloric intake (β = -39.1 kcal, 95% CI: -136.0, 57.7 kcal) or SAT β=4%, 95% CI: -3, 14%) according to social isolation among women. Socially isolated women appeared to have higher VAT (β = 10, 95% CI: -1, 10%) Conclusions: In our population of middle-aged and older adults, social isolation was associated with lower leptin levels among men, but not women. The lower leptin concentration observed among isolated men may reflect decreased caloric intake in response to social stress.

Feeding Immunity: Physiological and Behavioral Responses to Infection and Resource Limitation.

Resources are a core currency of species interactions and ecology in general (e.g., think of food webs or competition). Within parasite-infected hosts, resources are divided among the competing demands of host immunity and growth as well as parasite reproduction and growth. Effects of resources on immune responses are increasingly understood at the cellular level (e.g., metabolic predictors of effector function), but there has been limited consideration of how these effects scale up to affect individual energetic regimes (e.g., allocation trade-offs), susceptibility to infection, and feeding behavior (e.g., responses to local resource quality and quantity). We experimentally rewilded laboratory mice (strain C57BL/6) in semi-natural enclosures to investigate the effects of dietary protein and gastrointestinal nematode (Trichuris muris) infection on individual-level immunity, activity, and behavior. The scale and realism of this field experiment, as well as the multiple physiological assays developed for laboratory mice, enabled us to detect costs, trade-offs, and potential compensatory mechanisms that mice employ to battle infection under different resource conditions. We found that mice on a low-protein diet spent more time feeding, which led to higher body fat stores (i.e., concentration of a satiety hormone, leptin) and altered metabolite profiles, but which did not fully compensate for the effects of poor nutrition on albumin or immune defenses. Specifically, immune defenses measured as interleukin 13 (IL13) (a primary cytokine coordinating defense against T. muris) and as T. muris-specific IgG1 titers were lower in mice on the low-protein diet. However, these reduced defenses did not result in higher worm counts in mice with poorer diets. The lab mice, living outside for the first time in thousands of generations, also consumed at least 26 wild plant species occurring in the enclosures, and DNA metabarcoding revealed that the consumption of different wild foods may be associated with differences in leptin concentrations. When individual foraging behavior was accounted for, worm infection significantly reduced rates of host weight gain. Housing laboratory mice in outdoor enclosures provided new insights into the resource costs of immune defense to helminth infection and how hosts modify their behavior to compensate for those costs.

The central effect of 3-iodothyronamine on brain neuropeptides in mice

3-Iodothyronamine (T1AM) is an endogenous metabolite of thyroid hormone with noticeable metabolic and neurological effects. Alteration of feeding behaviour by this compound was different at various doses in experimental models and it is not clear whether this effect is partially accounted by changes in neuropeptide secretion. In this study, we attempted to find out whether chronic low dose 3-iodothyronamine treatment could modulate some food intake regulatory neuropeptides such as leptin, ghrelin, and galanin in mice brain. Eighteen male mice were divided randomly into control (n = 8) and treatment (n = 10) groups. The experimental procedure was applied for 7 days during which treatment group received T1AM (i.p) whereas the control group received DMSO and normal saline. The brain was analyzed for leptin, ghrelin, and galanin concentrations. There were significant differences in leptin concentration (1.75 ± 0.05 versus 2.9 ± 0.07 ng/ml) and ghrelin concentration (8.4 ± 0.35 versus 5 ± 0.08 ng/ml) between control and treatment groups (P < 0.05). There was no significant difference in galanin concentration (745.87 ± 34.91 ng/l) in control group compared with the treatment group (698.05 ± 66.88 ng/l). Interestingly, the treatment group mice lost weight (~1 g) whereas non-significant increase in weight mean was seen in control group before (day 1) and after the procedure (day 8). Clearly, further works in this area will be required to delineate the central role of T1AM, but based on our findings described here, we propose that some of peripheral metabolic effects of this compound may be accomplished by brain peptide regulation.

Soluble Leptin Receptor and Risk of Gestational Diabetes in a Multiethnic Population: A Prospective Cohort Study.

Soluble leptin receptor (sOb-R), a potential marker of leptin resistance, is inversely associated with risk of type 2 diabetes, independently of leptin concentrations. We have previously shown that ethnic difference in leptin concentration may partly explain the increased risk of gestational diabetes (GDM) in South Asians. Our objective was to investigate whether sOb-R concentrations are associated with risk of GDM, whether concentrations of sOb-R differ across ethnic groups, and whether ethnic differences in sOb-R explain the ethnic differences in GDM risk. The STORK Groruddalen study; a prospective cohort study of pregnant women living in Oslo, Norway, between May 2008 and May 2010. Of the total sample (n = 823), 680 (47.1% Europeans) had sOb-R measured in pregnancy week 15 and an oral glucose tolerance test performed in week 28. GDM was diagnosed according to World Health Organization 2013 criteria. sOb-R was inversely associated with GDM (odds ratio, 0.76 [95% confidence interval, 0.69-0.83] per ng/ml increase in sOb-R, P < .001) in crude analysis. The association was attenuated after adjustments for covariates and leptin (0.85 [0.77-0.95], P = .004). Compared to women with sOb-R higher than 5 ng/ml, the odds ratio of GDM was 0.29(0.11-0.78; P = .014) among women with sOb-R greater than 10 ng/ml and 0.59 (0.37-0.94; P = .026) among women with sOb-R 5-10 ng/ml, in adjusted analysis. sOb-R levels did not differ across ethnic groups, and sOb-R did not explain ethnic differences in GDM risk. There was an independent, inverse association between sOb-R and GDM, with the lowest risk of GDM observed among higher sOb-R concentrations.

Elevated levels of diabetes-associated peptide hormones in the follicular fluid and serum of obese polycystic ovary syndrome patients are associated with suboptimal ovarian response

Objective: To compare diabetes-associated peptide hormones (DAPHs) and inflammatory markers in the follicular fluid (FF) and serum among polycystic ovary syndrome (PCOS) patients as compared to controls undergoing in vitro fertilization (IVF). Study Design: Levels of DAPHs and inflammatory markers in FF and serum were measured and correlated to IVF cycle outcomes and clinical pregnancy rate in three IVF groups: obese PCOS (n = 8), lean PCOS (n = 12), and controls (n = 11). Methods: Follicular fluid and serum were prosectively collected from obese and lean pcos and control females undergoing IVF. BioFlex ® array was used to analyze all samples from subjects. IVF cycle outcomes were collected on all subjects. Results: Ten DAPHs were assessed. Obese PCOS had higher levels of C-peptide (194.4 ± 163.5 pg/mL, P< 0.03), insulin (172.6 ± 113.6 pg/mL, P< 0.01), and leptin (10,046.1 ± 4920.2 pg/mL, P< 0.05) in FF as compared to lean PCOS and controls. Obese PCOS patients had higher levels of serum leptin (5575.5 ± 1650.2 pg/mL), with a difference in leptin concentrations noted between obese PCOS and controls (P < 0.01) and between obese and lean PCOS patients (P < 0.01). Higher levels of C-peptide (P < 0.04) and leptin (P < 0.01) in the FF were associated with increased total gonadotropin drug usage. There was a trend toward fewer oocytes retrieved (P < 0.06) and significantly lower number of normally fertilized zygotes (P < 0.04), with higher C-peptide levels. A trend toward increased clinical pregnancy rates was noted with lower serum levels of leptin (P < 0.08). Conclusions: DAPHs may play a role in the suboptimal ovarian response seen in obese IVF patients with PCOS as compared to lean PCOS patients and controls. Further studies are needed to understand if the evaluations in DAPH are secondary to obesity itself or are specific to this subset of PCOS patients.

Serum reference values for leptin in healthy infants.

ObjectiveReports on leptin concentrations in pediatric populations lack reference values for infants in the first months of life. Our study was conducted on healthy full-term infants between 2002 and 2012 to determine serum leptin reference values in subjects less than 18 months old.MethodsRoutine outpatient blood tests for serum leptin were performed on 317 infants using a radioimmunoassay method. The median and 10th–90th percentiles were calculated to obtain reference values using quantile regression. Values established in this study were compared with another independent cohort of 110 infants.ResultsThe median (IQR) serum leptin concentration in the infants was 2.37 (3.26) ng/ml (n = 317). The median leptin concentration was 2.81 (3.49) ng/ml (n = 202) in infants younger than 6 months of age, 1.44 (2.27) ng/ml (n = 59) in infants between 6–12 months of age and 1.77 (2.05) ng/ml (n = 56) in infants between 12–18 months of age. We obtained leptin reference values based on age by estimating the lower and upper percentiles. In the entire cohort, the median (IQR) leptin concentration was 2.22 (3.11) ng/ml in males (n = 168) and 2.60 (3.32) ng/ml in females (n = 149). According to the type of feeding median serum leptin concentration was higher in breast-fed infants (n = 188) than in formula-fed infants (n = 129) (2.63 (3.34) ng/ml vs. 2.12 (2.77) ng/ml; p<0.05).ConclusionsOur data revealed no gender difference in leptin concentration in early infancy. After 6 months of life, leptin concentrations decreased slightly. We used a large cohort to confirm that breast-fed infants had significantly higher serum leptin levels than formula-fed infants during the first 6 months of life, although this difference disappeared later in life. In this study, we defined the leptin reference range in healthy infants in the first 18 months of life according to the Clinical and Laboratory Standards Institute (CLSI).

Sitagliptin and metformin alone or in combination in patients with polycystic ovarian syndrome (PCOS): a pilot study

OBJECTIVE: To identify the relationship between diabetes associated peptide hormones (DAPH) and inflammatory markers in follicular fluid and serum of obese and lean polycystic ovary syndrome (PCOS) patients with in vitro fertilization (IVF) cycle parameters and pregnancy outcomes. DESIGN: Prospective Descriptive Study. MATERIALS AND METHODS: An IRB approved study of three groups of IVF patients 30 kg/m2; n1⁄48), lean PCOS (BMI<25 kg/m2; n1⁄412), and donor or tubal factor controls (n1⁄411). PCOS was diagnosed by Rotterdam criteria. Serumwas collected prior to IVF cycle initiation. Follicular fluid was collected at retrieval. A Human Diabetes 10plex Assay was used to quantify DAPH. A Human Cytokine 27-plex Assay was used to quantify inflammatory markers. Results were analyzed using one-way ANOVA with Tukey post hoc analysis using SPSS v 21. Significance was defined as p<0.05. RESULTS: Of the 10 DAPH assessed, C-peptide, insulin, and leptin had significant associations. Obese PCOS patients had higher levels of C-peptide (194.4 163.5 pg/mL), insulin (172.6 113.6 pg/mL), and leptin (10,046.1 4920.2pg/mL) in follicular fluid compared to lean PCOS and controls. A difference in C-peptide (p<0.03), insulin (p<0.01), and leptin (p1⁄40.04) was noted between obese and lean PCOS follicular fluid. A difference in C-peptide (p<0.03) and insulin (p<0.01) was noted between obese PCOS and control follicular fluid. Obese PCOS had higher levels of serum leptin (5575.5 1650.2pg/mL), with a difference in leptin concentrations noted between obese PCOS and controls (p1⁄40.01), and obese and lean PCOS (p<0.01). Higher levels of C-peptide (p<0.04) and leptin (p1⁄40.01) in the follicular fluid were associated with increased gonadotropin usage. A trend toward fewer oocytes retrieved (p1⁄40.06), and significantly lower number of normally fertilized zygotes (p<0.04) was seen with higher C-peptide levels. A trend toward an increased clinical pregnancy rate was noted with lower serum leptin levels (p1⁄40.08). There was no significant difference in inflammatory marker concentration or pregnancy outcomes between the groups. CONCLUSION: Elevated levels DAPH, which are highly correlated with adverse long-term health outcomes, are present in young obese PCOS patients undergoing IVF. DAPHs may play a role in the need for higher gonadotropin dosing in IVF cycles and suboptimal oocyte fertilization in this patient population. Supported by: Funding provided through a Merck Investigator Studies Program Grant.

Serum leptin as an indicator of fat levels in white-tailed deer (Odocoileus virginianus) in the southeastern USA.

Leptin is a hormone that plays a key role in regulating energy intake, appetite, and metabolism. In some mammals, leptin has been shown to circulate at levels proportional to body fat, which could make it useful for nonlethal evaluation of body condition. Leptin's usefulness for estimating fat levels (i.e., body condition) of white-tailed deer (Odocoileus virginianus) is unknown. We quantified serum leptin concentrations in a sample of free-ranging, female deer collected in July 2008 and March 2009 from coastal North Carolina, USA. We compared leptin concentrations with kidney fat index, femur marrow fat index, and kidney fat mass. Additionally, we assessed differences in leptin concentrations between the two seasons, lactating and nonlactating females, and gestating and nongestating females. Leptin concentrations were similar between seasons but were lower in lactating and gestating females. We did not detect significant relationships between leptin and the body fat metrics, indicating that leptin may have limited value for estimating fat reserves in white-tailed deer.

Sleep duration and plasma leptin concentrations in early pregnancy among lean and overweight/obese women: a cross sectional study

BackgroundEarly-pregnancy short sleep duration is predictive of gestational diabetes and preeclampsia; mechanisms for these associations are unknown. Leptin, an adipocyte-derived peptide involved in regulating food intake and energy expenditure, may play a role in these observed associations. Given inconsistent reports linking short sleep duration with leptin, and absence of studies among pregnant women, we examined the association of maternal sleep duration with plasma leptin in early pregnancy.MethodsThis cross-sectional study included 830 pregnant women. Plasma leptin was measured in samples collected around 13 weeks gestation. Sleep duration was categorized as: ≤5, 6, 7–8 (reference), and ≥9 hours. Differences in leptin concentrations across categories were estimated using linear regression. Analyses were completed for lean and overweight/obese women.ResultsOverall, women with long sleep duration had elevated plasma leptin (p-value = 0.04). However, leptin concentrations were not statistically significantly elevated in women with a short sleep duration. There was no association of leptin with sleep duration among lean women. Among overweight/obese women, a U-shaped relation between leptin and sleep duration was observed: Mean leptin was elevated (β = 21.96 ng/ml, P < 0.001) among women reporting ≤5 hour of sleep compared with reference group; and women reporting ≥9 hours of sleep also had elevated leptin (β = 4.29 ng/ml, P = 0.09).ConclusionsShort sleep duration, and to a lesser extent long sleep duration, were associated with elevated leptin among overweight/obese women. These data add some evidence to help understand mechanistic relationships of sleep duration with pregnancy complications.

Association of Serum Adiponectin, Leptin, and Resistin Concentrations with the Severity of Liver Dysfunction and the Disease Complications in Alcoholic Liver Disease

Background and aims. There is growing evidence that white adipose tissue is an important contributor in the pathogenesis of alcoholic liver disease (ALD). We investigated serum concentrations of total adiponectin (Acrp30), leptin, and resistin in patients with chronic alcohol abuse and different grades of liver dysfunction, as well as ALD complications. Materials and Methods. One hundred forty-seven consecutive inpatients with ALD were prospectively recruited. The evaluation of plasma adipokine levels was performed using immunoenzymatic ELISA tests. Multivariable logistic regression was applied in order to select independent predictors of advanced liver dysfunction and the disease complications. Results. Acrp30 and resistin levels were significantly higher in patients with ALD than in controls. Lower leptin levels in females with ALD compared to controls, but no significant differences in leptin concentrations in males, were found. High serum Acrp30 level revealed an independent association with advanced liver dysfunction, as well as the development of ALD complications, that is, ascites and hepatic encephalopathy. Conclusion. Gender-related differences in serum leptin concentrations may influence the ALD course, different in females compared with males. Serum Acrp30 level may serve as a potential prognostic indicator for patients with ALD.

Differences in the Association between Serum Leptin Levels and Body Mass Index in Black and White Women: A Report from the Southern Community Cohort Study

Background/Aims: Leptin may be an important link between obesity and many high-burden diseases, including cancer and cardiovascular disease, but leptin levels and correlates in individuals of diverse racial backgrounds have not been well characterized despite racial differences in incidence and mortality patterns for many obesity-related diseases. Methods: In a cross-sectional study of 915 white and 892 black women enrolled in the Southern Community Cohort Study (age 40–79 years, half postmenopausal), serum leptin levels were compared between the race groups and across categories of body mass index (BMI). Potential correlates of leptin were assessed via race-stratified linear regression models. Results: Blacks had higher unadjusted leptin levels than whites (geometric mean 22.4 vs. 19.0 ng/ml; p < 0.0001). Leptin increased with increasing BMI, and racial differences in leptin were most pronounced in women with BMI ≥25. Significant correlates of leptin included BMI, age, alcohol consumption, cigarette smoking, diabetes (both races) and fat consumption (black women only). Leptin remained higher in black women (22.7 vs. 18.8 ng/ml) after adjustment for these factors. Conclusions: Persistent racial differences in leptin concentrations exist after adjustment for BMI and other factors. Leptin assessment may be informative in future studies that investigate racial differences in the development of obesity-related diseases.

Leptin, Fat Mass, and Bone Mineral Density in Healthy Pre- and Postmenopausal Women

The purpose was to examine relationships between age, fat mass, and bone mineral density (BMD) with resting leptin levels in premenopausal and postmenopausal women. Young (aged 18–30 yr, n = 30) and estrogen-deficient postmenopausal (aged 55–75 yr, n = 43) women were recruited. Total body and segmental fat mass and bone-free lean body mass (BFLBM) and total body, lumbar spine, and proximal femur BMD were assessed using dual-energy X-ray absorptiometry. Serum-resting, fasted leptin levels were measured by Immunoradiometric Assay (IRMA), and leptin-to-fat mass ratios were calculated. Young and older women had similar amounts of BFLBM, but older women had greater ( p < 0.05) amounts of fat mass and 35% higher leptin levels. Age differences in leptin concentrations were no longer significant after controlling for fat mass. Older women had significantly ( p < 0.05) lower hip BMD values. Age was negatively related ( r = −0.29, p < 0.05) to leptin:trunk fat ratio. Increases in fat mass, not menopause per se, contributes to higher leptin levels in older women. Relationships between leptin and BMD may be age dependent.