Changes In Serum Leptin Levels Research Articles

Lactoferrin intake and changes in serum leptin level in obese school age children

Lactoferrin intake and changes in serum leptin level in obese school age children

Effect of resistance exercise on serum leptin levels in a prospective longitudinal study of women patients with rheumatoid arthritis

BackgroundExercise has an anti-inflammatory effect and reduces fat mass. Leptin has been known to be proinflammatory adipokines mainly produced by adipocytes. However, few studies have investigated the association between exercise and changes in serum leptin levels of patients with RA. This study evaluated the effect of an individualized resistance exercise on inflammatory markers including leptin as well as muscle strength and exercise capacity in patients with rheumatoid arthritis (RA).MethodsA total of 42 age- and sex-matched participants were assigned to a resistance exercise program (60 min, once a week for 12 weeks, and self-exercise twice a week) or to a control group. Muscle strength, exercise capacities, and inflammatory markers such as cytokines and adipokines were assessed at baseline and at 12 weeks follow-up. Longitudinal changes in muscle strength, exercise capacity, cytokines, and adipokines between groups were tested with repeated measures analysis of variance or using the generalized estimating equation, with adjustment for baseline disease activity score 28-C response protein as a covariate.ResultsA total of 37 of 42 female patients with RA completed this prospective intervention study. Grip strength improved significantly in the exercise group (P < 0.05), while no between-group changes were found. Quadriceps contraction power (P for group-time interaction = 0.035 for the right side and P for group-time interaction = 0.012 for the left side) and 6-minute walking distance (P for group-time interaction = 0.021) were all improved significantly in the exercise group compared with the control group. In addition, serum leptin levels were significantly decreased in the exercise group compared with the control group (P for group-time interaction = 5.22 × 10−5), but not the other cytokines or adipokines. The change in serum leptin levels correlated with the changes in fat mass (Rho = 0.491, P= 0.015) and visceral fat area (Rho = 0.501, P= 0.013).ConclusionIn addition to muscle strength and exercise capacity, the 12 weeks of individualized resistance exercise reduced serum leptin levels in keeping with body fat mass or visceral fat area, suggesting that serum leptin levels might be a surrogate marker of exercise in RA.

Elevated Serum Leptin Levels as a Predictive Marker for Polycystic Ovary Syndrome.

BackgroundLeptin may have important implications in polycystic ovary syndrome (PCOS)-related metabolic disorders. However, the changes in serum leptin levels in patients with PCOS and its predictive value for PCOS remain obscure. We intend to analyze the association between leptin and PCOS in this study.Materials and MethodsThe study comprised 89 patients with PCOS and 139 individuals without PCOS. Each group was stratified as either normal- or hyper-fasting serum insulin (FSI), and lean or overweight/obese; and the patients were further categorized as normal- or hyper-androgenic. The validity of leptin toward the diagnosis of PCOS, or leptin combined with total testosterone, dehydroepiandrosterone sulfate (DHEAS), and free testosterone was estimated by receiver operating characteristic (ROC) curves, and correlations between paired variables was estimated by Spearman’s rank correlation coefficient. Associations between the clinical and metabolic variables and PCOS were analyzed via logistic regression.ResultsThe serum leptin levels of patients with PCOS were significantly higher than that of the control, and especially the PCOS in hyper-FSI, hyperandrogenimic and overweight/obese subgroups. The area under the ROC curve (AUC) of leptin was 74%, with cutoff value, sensitivity, specificity, positive predictive value (PPV) and negative predictive value (NPV) 11.58 ng/mL, 77.5%, 62.6%, 57.0%, and 81.3%, respectively. Combined leptin and anti-Müllerian hormone (AMH) had the highest AUC (92.3%), excellent sensitivity (93.3%), moderate specificity (78.3%), PPV (73.5%) and NPV (94.8%). Serum leptin levels of the patients were correlated with the FSI, fasting plasma glucose (FPG), homeostasis model assessment of insulin resistance (HOMA-IR), body mass index (BMI), and total testosterone levels. Elevated serum leptin was associated with a high risk of PCOS [P = 0.015; OR (95% CI) 1.128 (1.024–1.244)].ConclusionSubstantially elevated serum leptin is significantly associated with PCOS. These findings warrant further investigations into the function of leptin in the pathogenesis of PCOS.

The supplementary effects of omega-3 fatty acid alone and in a combination with vitamin D3 on serum leptin levels: A randomized clinical trial on men and women with vitamin D deficiency

Purpose: This randomized clinical trial (RCT) was designed to assess the effect of VD3, n-3FA, and their combination on serum leptin levels in people with vitamin D deficiency (VDD). Subjects and methods: One hundred and forty six participants, were randomly assigned into four groups supplemented with the dose of 50,000 IU VD3 taken weekly (D), 300 mg n-3FA taken daily (Om), and their combination (D+Om) or control (C) for eight weeks. Fasting baseline and follow-up (10 weeks; 8 weeks supplementation plus washout period of 2 weeks) of serum 25 hydroxyvitamin D (25OHD), leptin, glucose, triglycerides (TG), parathyroid hormone (PTH), calcium, and phosphorus were assayed. A paired T-test was used to assess the changes in serum leptin levels over of the follow-up period. Results: Significant increase in follow-up serum leptin (10.62 ± 7.18 to 14.42 ± 8.29 ng/mL, P = 0.002) and TG (154 ± 84.4 to 200.1 ± 79, P = 0.015) levels were observed in n-3-FA supplemented group. Combination therapy (VD3 plus n-3 FA) significantly increased serum 25OHD (13.49 ± 4.64 to 37.09 ± 11.13 ng/mL, P &amp;lt; 0.001), TG levels (114.3 ± 57.3 to 139.1 ± 60.7 mg/mL, P = 0.007) and insignificantly serum leptin (6.74 ± 4.87 to 8.01 ± 6.77 ng/mL, P = 0.269). Conclusion: Our study referred that notable elevation in leptin and TG levels might be linked to leptin resistance. However, further RCTs are required to clarify possible consequences resulted from the extensive administration of n-3FA supplements and their combinations with high doses of VD3 supplements on humans’ health.

Association between septal deviation and OSA diagnoses: a nationwide 9-year follow-up cohort study.

Obstructive sleep apnea (OSA) is a multilevel problematic disease. Major septal deviation (SD) can lead to severe nasal congestion, which, in turn, can lead to sleep apnea. Although SD seems to be related to OSA, very few studies have quantitatively examined this relationship. In this study, we investigate this using a 9-year large-scale cohort study. The SD group was selected out of 1 million individuals randomly extracted by the National Health Insurance Service. The non-SD group was obtained through propensity score matching considering several variables. The primary end point was OSA diagnosis. The study (SD) group included 11,238 individuals and the non-SD group (control group) included 22,476 persons. The overall hazard ratio for OSA in the SD group was 4.39 (95% confidence interval [CI]: 3.56-5.42). In subgroup analysis, the hazard ratio for OSA of male individuals was 3.77 (95% CI: 2.83-5.03), high economic status was 1.27 (95% CI: 1.05-1.56), metropolitan area was 1.31 (95% CI: 1.07-1.62), young age was 0.79 (95% CI: 0.64-0.98), hypertension was 1.00 (95% CI: 0.37-2.7), and diabetes mellitus was 2.44 (95% CI: 1.15-5.21). In the SD group, the hazard ratio for OSA after septoplasty was 0.71 (95% CI: 0.54-0.94). From long-term follow-up, the prevalence of OSA was 4.39 times higher in the SD group compared with the control group. This phenomenon was more pronounced with increasing body mass index and decreased significantly after septoplasty. Yeom SW, Chung SK, Lee EJ, etal. Association between septal deviation and OSA diagnoses: a nationwide 9-year follow-up cohort study. J Clin Sleep Med. 2021;17(10):2099-2106.

Zinc Supplementation Might Not Affect Serum Leptin and Adiponectin Levels in Adults: A Systematic Review and Meta-Analysis of Randomized Controlled Clinical Trials.

Background:Zinc as one of the important trace elements in human health has been suggested to be a supplement for modifying the level of adipokines, whereas findings from studies have been inconsistent. This study aimed to systematically review the evidence provided by randomized controlled trials (RCTs) regarding the effect of zinc supplementation on serum adipokines levels.Methods:PubMed, Google Scholar, Web of Science, and Scopus were systematically searched up to June 2019. The mean differences and their corresponding standard deviations (SDs) of changes in serum adipokines levels were used as effect size.Results:Eight eligible RCTs (leptin n=6, adiponectin n=3) were included in the current study. There were no significant changes in serum leptin levels [weighted mean difference (WMD) =0.60 ng/ml, 95% confidence interval (CI): −1.78, 2.99; I-squared (I2) = 64.3%] and adiponectin levels (WMD = 1.09 ng/ml, 95% CI: −0.76, 3.18, I2 = 78.8%) following zinc supplementation compared to placebo group. These findings did not change after considering several subgroups including gender, study duration, health status, body weight and the type of zinc used for supplementation.Conclusion:No evidence was found to support the efficacy of dietary zinc supplements on serum levels of adipokines. Further, high-quality, long-term controlled clinical trials are warranted to confirm these findings.

Changes in Serum Leptin Level After Multilevel Surgery in Patients with Obstructive Sleep Apnea.

Leptin hormone plays an important role in metabolic control and is elevated in obstructive sleep apnea (OSA). The aim of this study was to assess the hypothesis that surgical treatment will reduce leptin levels in OSA patients. Prospective study. Twenty-three patients with multilevel OSA underwent modified genioglossus muscle advancement with anterolateral advancement pharyngoplasty between April 2018 and September 2019. Serum leptin level was measured preoperatively and 3 months postoperatively for all patients and 18 control subjects. All patients were evaluated before and 3 months after surgery by history taking, clinical examination, polysomnography, cephalometry, and Epworth Sleepiness Scale. Preoperatively, patients with OSA had a higher Leptin level (18.46 ± 4.73 ng/mL) than did control subjects (7.07 ± 1.26 ng/mL) (P < .001). Surgery resulted in a significant reduction in the level of leptin from 18.46 ± 4.73 ng/mL to 8.03 ± 2.22 ng/mL (P < .001). Reductions in leptin level was correlated with changes in apnea hypopnea index (AHI) (r = 0.61, P = .002) and minimum oxygen saturation (SaO2) (r = -0.54, P = .008). Effective multilevel surgery in the form of modified genioglossus muscle advancement with anterolateral advancement pharyngoplasty could significantly reduce leptin level in OSA patients and this reduction is correlated with the degree of OSA improvement in term of AHI and SaO2. 4 Laryngoscope, 131:E665-E670, 2021.

Effect of Dietary Fiber on Serum Leptin Level: A Systematic Review and Meta-Analysis of Randomized Controlled Trials.

Dietary fibers may induce satiety through affecting gastro-intestinal and peripheral appetite regulating hormones. Thus, we aimed to investigate the effect of dietary fiber consumption on serum leptin level compared to control diet, in short- and long- term trials, through a systematic review and meta-analysis. We searched PubMed, web of science, Scopus, ProQuest, EMBASE, and Cochrane Library to find randomized controlled clinical trials that evaluated effect of any type of dietary fiber on serum leptin level compared to control diet, until April 2019. Both short-term (1-4 days) and long-term (longer than 2 weeks) studies were selected. Mean differences (MD) of changes in serum leptin level and 95% confidence intervals were extracted from eligible studies, and random effects model was used to analyze data. Thirteen studies included the systematic review and 11 entered in the meta-analysis. No significant change was seen in serum leptin level in short-term (MD=0.02, 95% CI; -0.15, 0.20, Tau2=0.0) and long-term studies (MD=-0.10, 95% CI; -0.28, 0.08, Tau2=0.0), followed by fiber consumption. However, this effect was statistically significant in obese participants (MD=-0.36, 95% CI; -0.71, -0.02, Tau2=0.0) in long-term studies. Moreover, we found no significant results in subgroups of baseline serum leptin level, intervention duration, fiber dose, and fiber type. This meta-analysis found that taking dietary fiber for long term could lower serum leptin level, just in obese persons. However, further clinical trials are needed in this field to clarify this issue.

Changes in pre- and postoperative serum leptin concentrations in dogs with gallbladder mucocele and cholelithiasis

BackgroundLeptin has been shown to have various physiological and pathological roles in the canine gallbladder. In this study, we performed pre- and postoperative short-term follow-up analyses to confirm changes in serum leptin levels before and after cholecystectomy due to gallbladder mucocele (GBM) or cholelithiasis in dogs.ResultsTwenty-six cholecystectomized dogs (GBM: n = 14; cholelithiasis: n = 12) for prophylactic or clinical symptom relief were enrolled in the present study. Dogs were subgrouped according to clinical symptoms and prognosis after surgery as follows: 1) asymptomatic group (n = 13), 2) recovery group (n = 8), and 3) death group (n = 5). Liver enzymes, total bilirubin, lipid profiles, and leptin concentrations were determined from sera on the pre-operative day and at 1, 3, and 7 days postoperation. Serum leptin concentrations were gradually but significantly decreased in the asymptomatic group (p = 0.008, 0.004, and 0.004 on days 1, 3, and 7, respectively, compared with that before surgery) and the recovery group (p = 0.048 and 0.048 on days 3 and 7, respectively, compared with that before surgery). However, in the death group, leptin concentrations did not differ significantly over time (p = 0.564). Additionally, serum leptin levels in the recovery group (p = 0.006) and death group (p = 0.021) were significantly higher than those in the asymptomatic group. Liver enzymes and total bilirubin (T-Bil) were significantly decreased only in the recovery group, particularly on day 7. In the asymptomatic group, liver enzymes and T-Bil were not changed significantly over time, and in the death group, only T-Bil was significantly decreased on day 7. Total cholesterol and triglyceride levels were not significantly decreased over time in all groups.ConclusionsThese results indicate that leptin is a potential biomarker reflecting the severity and prognosis of GBM and cholelithiasis both before and after cholecystectomy in dogs.

Changes in serum leptin levels as well as sICAM-1 and sVCAM-1 soluble adhesion molecules during carotid endarterectomy.

Leptin is an adipokine, known to be associated with oxidative stress, inflammation, and atherogenesis. Leptin plays an essential role in atheromatosis-associated inflammatory cascade through stimulation of inflammatory mediators such as soluble intracellular adhesion molecule-1 (sICAM-1) and soluble vascular cell adhesion molecule-1 (sVCAM-1). However, little is known about this association in patients with atherosclerosis and severe internal carotid artery (ICA) stenosis undergoing carotid endarterectomy (CEA). Our objective was to evaluate the variations of serum leptin levels, as well as sICAM-1 and sVCAM-1 levels in these patients during the process of CEA and 24 hours postoperatively. The study group enrolled 50 patients undergoing CEA for ICA stenosis (> 70%). Serum leptin, sICAM-1 and sVCAM-1 plasma concentration measurements were performed at 4 distinct time points: before clamping of the ICA, 30 minutes after clamping of the ICA, 60 minutes after declamping of ICA and 24 hours postoperatively. Leptin was significantly decreased during CEA, but an overshooting in its levels was observed at 24 hours after the operation. Both sICAM-1 and sVCAM-1 initially followed the pattern of leptin changes but after completing CEA and up to 24 hours postoperatively a steep increase in their levels was not established. sVCAM-1 and sICAM-1 correlated with indices of oxidative stress at peak inflammatory burden. Leptin is a circulating marker of carotid atherosclerosis. Oxidative stress and expression of sVCAM-1 and sICAM-1 on vascular endothelial cells are key features in the pathophysiological process of atherosclerosis.

Leptin concentration and oxidative stress in diabetic ketoacidosis.

Diabetes is a common metabolic state during ageing, and one in five elderly individuals suffers from diabetes. However, few studies have been performed in elderly diabetic patients, and large randomized clinical trials in this population are rare. The purpose of this study was to investigate changes in serum leptin levels in elderly patients with diabetic ketoacidosis (DKA) before and after treatment and assess its relationship with oxidative stress parameters. Serum leptin levels, plasma superoxide dismutase (SOD) activity, plasma malondialdehyde (MDA) levels, plasma total antioxidant capacity (TAC) and plasma 8-iso-prostaglandin F2α (8-iso-PGF2α ) levels were measured in elderly patients aged 81.76 ± 9.42 years with DKA before and after treatment. Plasma SOD activity, TAC and serum leptins before treatment were significantly lower in elderly patients with DKA compared with the control group (P < 0.05), whereas plasma MDA and 8-iso-PGF2α levels before treatment were significantly higher in elderly patients with DKA (P < 0.05). Plasma SOD activity, TAC and serum leptin levels in elderly patients with DKA were significantly elevated after treatment, whereas their plasma MDA and 8-iso-PGF2α levels were significantly reduced (P < 0.05). Leptin levels negatively correlated with plasma 8-iso-PGF2α after treatment in elderly DKA patients (r = -0.36, P < 0.05). Stepwise multiple regression analysis showed that 8-iso-PGF2α was a significant factor affecting serum leptin levels. Serum leptin levels in the elderly patients with DKA were significantly reduced after treatment, which was associated with oxidative stress.

Effects of 6 weeks resistance training on Body Composition, serum Leptin and muscle strength in non-athletic men

Aims: Leptin is a polypeptide that is correlated with body weight changes and energy consumption and affected by exercise training. The aim of the present study was to determine the effect of 6 weeks resistance training on body composition, serum leptin and muscle strength in non-athletic men. Materials & Methods: In this semi-experimental trial, 22 non-athletes male living in dormitory of Zanjan University, who were enrolled in 2011-12 academic year were selected with purposive sampling method and randomly assigned to experimental (n=12) and control (n=10) groups. The experimental group performed training program based on the protocol of Kramer and Ratns for 6 weeks (3 sessions per week). At the beginning and end of the research, muscle strength, body composition and serum leptin were measured. Serum leptin was measured by ELISA. Independent T and paired T tests were used to analysis the data in SPSS 16 software. Findings: After 6 weeks of strength training, changes in serum leptin levels and body composition (fat mass without fat) between the two groups was not statistically significant (p>0.05). But in experimental group, the upper and lower body strength training was significantly increased compared with pretest in control group (p<0.05). Conclusion: It seems that no significant changing in serum leptin levels after a period of resistance training is due to no changing in body fat and not enough exercise, but this training cause in increasing muscle strength.

Does omega-3 fatty acids supplementation affect circulating leptin levels? A systematic review and meta-analysis on randomized controlled clinical trials.

Omega-3 fatty acids have attracted researchers for their effect on circulatory hormone-like peptides affecting weight control. Our objective was to conduct a systematic review and meta-analysis on randomized controlled trials (RCTs) assessed the effects of omega-3 supplementation on serum leptin concentration and to find the possible sources of heterogeneity in their results. We searched PubMed/Medline, Google Scholar, Ovid, SCOPUS and ISI web of science up to April 2014. RCTs conducted among human adults, examined the effect of omega-3 fatty acid supplements on serum leptin concentrations as an outcome variable were included. The mean difference and standard deviation (SD) of changes in serum leptin levels were used as effect size for the meta-analysis. Summary mean estimates with their corresponding SDs were derived using random effects model. Totally 14 RCTs were eligible to be included in the systematic review, and the meta-analysis was performed on 13 articles. Our analysis showed that omega-3 supplementation significantly reduces leptin levels (mean difference (MD) = -1·71 ng/ml 95% confidence interval (CI): -3·17 to -0·24, P = 0·022). Subgroup analysis based on BMI status showed that the omega-3 supplementation reduces leptin when used for nonobese subjects (MD = -3·60 ng/ml; 95% CI -6·23 to -0·90; P = 0·011); however, this was not true for obese participants (MD = -0·86 ng/ml; 95% CI: -2·63 to -0·90; P = 0·296). Subgroup analysis based on omega-3 source also showed that omega-3 from marine sources may significantly reduce leptin levels (MD = -1·73 ng/ml; 95% CI -3·25 to -0·2; P = 0·026), but plant sources do not significantly affect serum leptin levels (MD = -1·48 ng/ml; 95% CI -6·78 to 3·23; P = 0·585). Our results were highly sensitive to one study. Omega-3 supplementation might moderately decrease circulatory leptin levels only among nonobese adults. RCTs with longer follow-up period, using higher doses for obese adults and exploring the effect in different genders, are needed to replicate our results.

Effects of photoperiod and temperature on the body mass, thermogenesis, and serum leptin levels of Apodemus draco (Rodentia: Muridae) in the Hengduan Mountain region, China

BackgroundEnvironmental cues play important roles in the regulation of physiology and behavior in small mammals. In the present study, we performed a factorial experiment (temperature × photoperiod) in which the South China field mouse Apodemus draco (Rodentia: Muridae) was acclimated to different photoperiods (a long photoperiod of 16 h light/8 h dark and a short photoperiod of 8 h light/16 h dark) and temperatures (warm at 30°C and cold at 5°C) to test the hypothesis that photoperiod, temperature, or both together can trigger changes in serum leptin levels, body mass, thermogenesis, and energy intake.ResultsBody mass, the resting metabolic rate (RMR), nonshivering thermogenesis (NST), and energy intake significantly decreased in the cold condition. Cold exposure induced increases in mitochondrial protein contents, cytochrome C oxidase (COX) activity, and α-glycerophosphate oxidase (α-GPO) in the liver and brown adipose tissue (BAT). There were no significant differences in mitochondrial protein contents, COX, or α-GPO under different photoperiods. Cold also induced an increase in uncoupling protein 1 in the BAT but showed no significant differences with photoperiod.ConclusionsAll of the results indicated that A. draco was more sensitive to temperature. Further, serum leptin levels were involved in the processes of thermogenesis and body mass regulation in A. draco.

Comparative Effects of Carbohydrate versus Fat Restriction on Serum Levels of Adipocytokines, Markers of Inflammation, and Endothelial Function among Women with the Metabolic Syndrome: A Randomized Cross-Over Clinical Trial

Background and Aims: Despite the efficacy of low-carbohydrate diets in the management of metabolic syndrome (MetS), it remains unknown if these favorable effects are mediated through changes in inflammation and endothelial dysfunction. We aimed to assess the effects of moderate substitution of dietary fats for carbohydrates on serum levels of adipocytokines, inflammatory indices, and biomarkers of endothelial function among women with the MetS. Methods: In a randomized cross-over clinical trial, 30 overweight or obese (BMI >25) women with the MetS were randomly allocated to follow either a high-carbohydrate (HC) (60-65% carbohydrates, 20-25% fats) diet or a moderately restricted carbohydrate (MRC) (43-47% carbohydrate, 36-40% fats) diet, each for 6 weeks. After a 2-week washout period, individuals were switched to the alternate diet for an additional 6 weeks. In a fasted state, markers of inflammation [high-sensitivity C-reactive protein (hs-CRP), high-sensitivity interleukin-6 (hs-IL-6), high-sensitivity tumor necrosis factor-α (hs-TNF-α), and serum amyloid A (SAA)], endothelial function [E-selectin, serum intercellular adhesion molecule 1 (sICAM-1), and serum vascular cell adhesion molecule 1 (sVCAM-1)], and adipocytokines (leptin and adiponectin) were measured in both study arms at baseline and after 6 weeks. Results: Consumption of an HC diet was associated with increased levels of SAA (3.27 ± 1.22 μg/ml) and decreased levels of adiponectin (-1.68 ± 2.30 ng/ml), while consumption of an MRC diet did not result in such unfavorable effects. Serum concentrations of leptin were reduced by the HC diet (p = 0.02), while they were not affected by the MRC diet. Changes in serum leptin levels were not significant between the two diets (p = 0.09). Serum concentrations of hs-CRP, hs-TNF-α, and IL-6 were not influenced by either diet. No significant differences between the two diets were found in terms of their effect on sICAM-1 and sVCAM-1 concentrations. Adherence to both diets resulted in a 9 ng/ml decrease in serum E-selectin levels (p < 0.05 for both). Conclusions: Partial replacement of dietary carbohydrates by unsaturated fats prevents the increased levels of markers of systemic inflammation among women with the MetS.

Energy Budget, Behavior and Leptin in Striped Hamsters Subjected to Food Restriction and Refeeding

Food restriction induces a loss of body mass that is often followed by rapid regaining of the lost weight when the restriction ends, consequently increasing a risk of development of obesity. To determine the physiological and behavioral mechanisms underlining the regaining, striped hamsters were restricted to 85% of initial food intake for 4 weeks and refed ad libitum for another 4 weeks. Changes in body mass, energy budget, activity, body composition and serum leptin level were measured. Body mass, body fat mass and serum leptin level significantly decreased in food-restricted hamsters, and increased when the restriction ended, showing a short “compensatory growth” rather than over-weight or obesity compared with ad libitum controls. During restriction, the time spent on activity increased significantly, which was opposite to the changes in serum leptin level. Food intake increased shortly during refeeding, which perhaps contributed to the rapid regaining of body mass. No correlation was observed between serum leptin and energy intake, while negative correlations were found in hamsters that were refed for 7 and 28 days. Exogenous leptin significantly decreased the time spent on activity during food restriction and attenuated the increase in food intake during refeeding. This suggests that low leptin in restricted animals may function as a starvation signal to induce an increase in activity behavior, and high leptin likely serves as a satiety signal to prevent activity during refeeding. Leptin may play a crucial role in controlling food intake when the restriction ends, and consequently preventing overweight.

Body weight gain and serum leptin levels of non-overweight and overweight/obese pregnant women

BackgroundOur objective was to evaluate changes in serum leptin levels during pregnancy in overweight/obese and non-obese women and to assess total and percent weight gain during pregnancy as possible factors that influence leptin levels.Material/MethodsIn a prospective study of 42 low-risk pregnant women receiving prenatal care, we assessed serum leptin levels at gestational weeks 9–12, 25–28, and 34–37. Based on their pre-pregnancy body mass indices (BMIs), the cohort was divided into: non-overweight (BMI <25 kg/m2) and overweight/obese (BMI ≥25 kg/m2) subjects.ResultsWe found a progressive increase in maternal weight gain during pregnancy in both groups. There was also a progressive increase in leptin levels in the 2 strata; however, the increase was significantly higher in the non-overweight patient group. We found that non-overweight pregnant women had a noticeably larger total weight gain. When analyzing the percent weight gain during pregnancy compared to the pre-pregnancy weight, the non-overweight group had a significantly greater percent weight gain than the overweight/obese group.ConclusionsOur results suggest that the greater increase in leptin levels in non-overweight pregnant women can be explained by the higher percent weight gain in this group compared to overweight/obese women. These findings suggest that controlling the percent weight gain may be an important preventive measure when controlling leptin levels during pregnancy and subsequent medical complications.

Changes of serum leptin levels in patients with premature ejaculation after sertraline treatment

Fifty nine patients with premature ejaculation (PE) received sertraline treatment for 8 weeks.The average intravaginal ejaculation latency time (IELT) and the scores of Chinese index of premature ejaculation (CIPE) were evaluated and the fasting serum leptin levels were measured before and after treatment,all the values were compared with those of 64 normal male controls.The serum leptin levels were higher,the IELT and CIPE scores were lower in PE patients than those in normal controls before treatment.After 8 weeks of treatment with sertraline,the levels of serum leptin in PE patients decreased to normal levels,CIPE and IELT increased.The results indicate that serum leptin can be used as a bioindicator for diagnosis of premature ejaculation and assessment of therapeutic efficacy in PE patients. Key words: Premature ejaculation; Leptin

Changes of energy metabolism, thermogenesis and body mass in the tree shrew (Tupaia belangeri chinensis Tupaiidae, Scandebtia) during cold exposure

Environmental cues play important roles in the regulation of an animal's physiology and behaviour. The purpose of the present study was to test the hypothesis that ambient temperature was a cue to induce adjustments in body mass, body temperature and thermogenic capacity, associated with changes in serum leptin levels in the tree shrew (Tupaia belangeri chinensis). The results showed that the tree shrew increased resting metabolic rate (RMR), nonshivering thermogenesis (NST) and body mass when exposed to the cold. Uncoupling protein 1 (UCP1) content of brown adipose tissue (BAT) increased in the cold exposure. Also serum leptin levels were positively correlated with body mass. Together, these data supported our hypothesis that ambient temperature was a cue to induce changes in body mass and metabolism. Serum leptin participated in the regulation of energy balance and body weight in the tree shrew.

Energy metabolism, thermogenesis and body mass regulation in tree shrew (Tupaia belangeri) during subsequent cold and warm acclimation

Environmental cues play important roles in the regulation of an animal's physiology and behavior. The purpose of the present study was to test the hypothesis that ambient temperature is a cue to induce adjustments in body mass, energy intake and thermogenic capacity, associated with changes in serum leptin levels in tree shrews (Tupaia belangeri). We found that tree shrews increased basal metabolic rate (BMR), energy intake and subsequently showed a significant decrease in body mass after being returned to warm ambient temperature. Uncoupling protein 1 (UCP1) content in brown adipose tissue (BAT) increased during cold acclimation and reversed after rewarming. The trend of energy intake increased during cold acclimation and decreased after rewarming; the trend of energy intake during cold acclimation was contrary to the trend of energy intake during rewarming. Further, serum leptin levels were negatively correlated with body mass. Together, these data supported our hypothesis that ambient temperature was a cue to induce changes in body mass and metabolic capacity. Serum leptin, as a starvation signal in the cold and satiety signal in rewarming, was involved in the processes of thermogenesis and body mass regulation in tree shrews.