Higher Leptin Values Research Articles

Peculiarities of Metabolism and Cardiac Electrical Activity in Patients with Chronic Obstructive Pulmonary Disease and Coronary Heart Disease in the Presence of Metabolically-Associated Liver Steatosis

While the development of specific steatohepatitis-associated cardiomyopathy (SHACMP) in the context of fatty liver disease has been documented, it remains unclear whether any cardiac changes occur during the initial stage of fatty liver disease, known as metabolic-associated liver steatosis (LS). Objective — to evaluate the characteristics of metabolism and electrical activity of the heart in patients with chronic obstructive pulmonary disease and chronic forms of coronary heart disease and concomitant liver steatosis. Materials and methods. 35 patients with chronic obstructive pulmonary disease, respiratory insufficiency stages I and II, coronary heart disease, atherosclerotic cardiosclerosis, and heart failure functional classes I and II, were examined. Their diagnosis and treatment were conducted in accordance with established protocols and international recommendations. Depending on the occurrence of LS, patients, matched for age, gender and lung function parameters, were divided into two groups: those suffering from it (n = 26) or not suffering from it (n = 9). Additionally, leptin level was determined, body mass index (BMI), leptin to BMI ratio, De Ritis ratio, hepatic steatosis index, glomerular filtration rate (according to MDRD) were calculated, and automatic ECG test was run. The results were processed statistically; the significance assumed at р < 0.05. Results and discussion. It was established that LS was diagnosed in patients with a higher BMI and was accompanied by clear metabolic changes — higher values of leptin, leptin-to-BMI ratio, fasting blood glucose and total cholesterol levels. The criteria of LS are not only an increase in echogenicity and size of the liver, but also higher values of ALT, De Ritis ratio and hepatic steatosis index. According to the correlation analysis, the deterioration of the liver condition was accompanied by changes in the heart — tachycardia and a decrease in the angle of the QRS complex, which can be considered as signs of the development of SHACMP, characteri­zed by a prolongation of the PQ interval (р = 0.07) and a significant deviation of the angle of the QRS complex. Inflammation and endogenous intoxication are the leading mechanisms of progression of both LS and SHACMP. Conclusions. Patients with chronic obstructive pulmonary disease and chronic forms of coronary heart disease, alongside with liver steatosis, exhibit signs of steatohepatitis-associated cardiomyopathy caused by metabolic changes, inflammation and endogenous intoxication.

Body Composition, Sarcopenia and Physical Performance After Bariatric Surgery: Differences Between Sleeve Gastrectomy and Roux-En-Y Gastric Bypass.

Evaluate the differences between surgical techniques in the modifications of body composition and the interference in skeletal muscle health, risk of sarcopenia, and reduced physical performance. This is a cross-sectional prospective study. A total of 71 patients, who underwent sleeve gastrectomy (SG) or underwent Roux-en-Y gastric bypass (RYGB). Both groups underwent anthropometric, laboratory analysis, body composition assessment, presence of sarcopenia, and physical performance tests. The study found a higher percentage of weight loss and lower BMI in RYGB compared to SG. The other assessments of sarcopenia and physical performance showed similarity between the surgical models. Baumgartner index (7.9kg/m2 vs. 7.3kg/m2), FNIH (9.0 vs. 3.0), handgrip strength (27.3kg vs. 25.2kg), and SPPB (9.5 vs. 9.3). Leptin in the general SG group was higher than in RYGB (14.2ng/ml vs. 8.0ng/ml). RYGB and SG have a similar presence of sarcopenia and physical performance. However, SG allows greater preservation of bone and muscle mass and is associated with higher values of leptin, which may represent protection from long-term postoperative complications.

The Effect of Leptin on the Blood Hormonal Profile (Cortisol, Insulin, Thyroid Hormones) of the Ewe in Acute Inflammation in Two Different Photoperiodical Conditions.

As a day animal with sensitivity to inflammation similar to that of humans, the sheep may highly outperform the rodent model in inflammation studies. Additionally, seasonality makes sheep an interesting model in endocrinology research. Although there are studies concerning inflammation’s influence on leptin secretion and vice versa, a ewe model, with its possible ‘long-day leptin resistance’, is still not examined enough. The present study aimed to examine whether leptin may modulate an acute inflammation influence on plasma hormones in two photoperiodical conditions. The experiment was conducted on 48 ewes divided into four groups (control, lipopolysaccharide (LPS), leptin, LPS + leptin) during short and long days. Blood sampling started 1 hour before and continued 3 h after LPS/saline administration for further hormonal analysis. The results showed that the photoperiod is one of the main factors influencing the basal concentrations of several hormones with higher values of leptin, insulin and thyroid hormones during long days. Additionally, the acute inflammation effect on cortisol, insulin and thyroid hormones was photoperiod-dependent. The endotoxemia may also exert an influence on leptin concentration regardless of season. The effects of leptin alone on hormone blood concentrations are rather limited; however, leptin can modulate the LPS influence on insulin or thyroxine in a photoperiod-dependent way.

New Insights on the Relationship between Leptin, Ghrelin, and Leptin/Ghrelin Ratio Enforced by Body Mass Index in Obesity and Diabetes.

Currently, adipose tissue is considered an endocrine organ, however, there are still many questions regarding the roles of adipokines—leptin and ghrelin being two adipokines. The purpose of the study was to assess the relationship between the adipokines and their ratio with obesity and diabetes. Methods: Sixty patients (mean age 61.88 ± 10.08) were evaluated. Cardiovascular risk factors, leptin, ghrelin, and insulin resistance score values were assessed. The patients were classified according to their body mass index (BMI) as normal weight, overweight, and obese. Results: 20% normal weight, 51.7% overweight, 28.3% obese, and 23.3% diabetic. Obese patients had higher leptin values (in obese 34,360 pg/mL vs. overweight 18,000 pg/mL vs. normal weight 14,350 pg/mL, p = 0.0049) and leptin/ghrelin ratio (1055 ± 641 vs. 771.36 ± 921 vs. 370.7 ± 257, p = 0.0228). Stratifying the analyses according to the presence of obesity and patients’ gender, differences were found for leptin (p = 0.0020 in women, p = 0.0055 in men) and leptin/ghrelin ratio (p = 0.048 in women, p = 0.004 in men). Mean leptin/BMI and leptin/ghrelin/BMI ratios were significantly higher, and the ghrelin/BMI ratio was significantly lower in obese and diabetic patients. In conclusion, obesity and diabetes are associated with changes not only in the total amount but also in the level of adipokines/kg/m2. Changes appear even in overweight subjects, offering a basis for early intervention in diabetic and obese patients.

The effect of long-term beta-blockers on melatonin secretion, sleep quality, and vascular brain damage

The influence of long-term administration of beta-blockers to melatonin synthesis, sleep quality and vascular brain damage. The main study group included 114 patients, aged 47-83, with cardiovascular diseases, who were under a complex therapy with long-term administration of beta-blockers. The comparison group included 110 patients with cardiovascular diseases, similar in age and sex, who did not receive beta-blockers in their complex therapy. The circadian dynamics of melatonin synthesis was observed by excretion of 6-sulfatoxymelatonin (6-SM), the major metabolite of melatonin, in three urinary samples (day, evening, night). All the patients underwent night polysomnography to assess the severity of sleep disorders. The severity of vascular brain damage was assessed using magnetic resonance imaging. The analyses showed large variability in individual values of 6-SM circadian excretion of patients with cardiovascular diseases (from 0.9 to 133 μg/24h with a mid-point 16.8 μg/24h). A considerable decrease of 6-SM circadian excretion is detected in the group of patients taking beta-blockers comparing to those not Me [q 25; q 75]: 12.8 [6.2; 21.1] and 24.0 [12.5; 41.5] μg/24h, respectively (p<0.001), with no differences in sleep values and severity of vascular brain damage. Comparing subgroups of patients with 6-SM circadian excretion lower and higher than 16.8 μg/24h showed a significant increase of sleep latency, decrease of rapid eye movement sleep (REM sleep), increasing number of gliosis foci in white matter of the brain with higher values of leptin, leptin/adiponectin ratio and glycohemoglobin in the group of patients with 6-SM circadian excretion ≤16.8 μg/24h. A low level of endogenous melatonin is a risk factor for development of sleep structure and quality disorders, vascular white matter brain damages with a higher risk for metabolic disorders. Long-term beta-blockers administration decrease endogenous melatonin synthesis to 50% increasing the risk for insomnia and vascular brain damage, mostly in patients with lower initial level of 6-SM circadian excretion.: melatonin, 6-sulfatoxymelatonin, beta-blockers, insomnia, vascular white matter brain damage, leptin, adiponectin.

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

Background:Psoriasis and obesity are somewhat related to a low-grade systemic inflammatory response.Objectives:To determine leptin and adiponectin levels in psoriasis patients compared to control patients matched for weight.Methods:A case-control study was performed, evaluating 113 psoriasis patients and 41 controls with other dermatologic diseases.Results:The prevalence of obesity was 33% in cases and 21.9% in controls. All evaluated comorbidities were more prevalent among cases. When stratified by weight, the comorbidities were more frequent in overweight patients. We found no correlation between being overweight (p=0.25), leptin (p=0.18) or adiponectin (p=0.762) levels and psoriasis severity. When overweight cases and controls were compared, we found differences in the adiponectin values (p= 0.04). The overweight cases had lower adiponectin levels than the overweight controls. We found no differences in the leptin dosage between cases and controls. The overweight cases had higher leptin values than the normal weight cases (p<0.001).Study limitations:Several patients used systemic anti-inflammatory medication.Conclusions:The prevalence of obesity among psoriasis cases (33%) was higher than in the general population (17.4%). We did not find any correlation between severity of psoriasis and inflammatory cytokines and the condition of being overweight. The overweight cases had lower values of adiponectin than the overweight controls. It seems, therefore, that there is a relationship between adiponectin and psoriasis, but this relationship depends on the presence of obesity.

Influence of FTO rs9939609 polymorphism on appetite, ghrelin, leptin, IL6, TNFα levels, and food intake of women with morbid obesity.

BackgroundThe fat mass and obesity-related (FTO) gene has a strong relationship with obesity, extreme obesity and inflammatory state, and may also be associated with food intake regulation.ObjectiveThe aim of the present study was to evaluate the influence of the rs9939609 single-nucleotide polymorphism of the FTO gene on appetite, ghrelin, leptin, interleukin 6 (IL6), tumor necrosis factor α (TNFα) levels and food intake of morbidly obese women.Materials and methodsThe study comprised 70 women, aged between 20 and 48 years, from Rio de Janeiro, Brazil. The participants were selected according to the body mass index between 40 and 60 kg/m2. Anthropometric and biochemical data were measured during fasting. Hormones and inflammatory data were measured before and after the participants ate an isocaloric meal. Dietary records were calculated and analyzed using a nutritional assessment program. Visual analog scales were used for behaviors of the sensations of appetite and food preferences. The FTO rs9939609 variant was genotyped using real-time polymerase chain reaction.ResultsParticipants with the AA genotype had lower values of ghrelin and IL6 and higher values of leptin than those with TT and TA in the postprandial period. Comparing the plasma concentrations of ghrelin, insulin, IL6 and TNFα intragenotypes, it was observed that those with TT had decreased leptin and increased IL6 at the postprandial period. Subjects with TA showed increased postprandial IL6, and those with AA had decreased postprandial ghrelin. There was no difference in TNFα intra- and intergenotypes. The postprandial sensations of hunger were lower in AA than those with TT. There were differences between genotypes regarding ingested grams of protein by weight, cholesterol, B3, B5, B6 and B12 vitamins, and selenium potassium and sodium minerals.ConclusionThese findings suggest that genetics may exert an influence on physiologic factors and might alter eating behavior.

Association between leptin and IL-6 concentrations with cardiovascular risk in patients with rheumatoid arthritis.

Pro-inflammatory cytokines such as leptin and IL-6 play an important role in the development of cardiovascular risk. Determine the relationship between leptin and IL-6 concentrations with cardiovascular risk in patients with rheumatoid arthritis. We determined IL-6 and leptin levels in 77 patients with the diagnosis of rheumatoid arthritis. The cardiovascular risk was calculated using the modified Framingham scale. Statistical analysis was performed using SPSS 22 considering a significant p<0.05. Serum leptin concentrations and cardiovascular risk (CVR) factors were compared and found that there was a significant difference between higher leptin values and disease activity (p 0.047), obesity (p 0.038), positive rheumatoid factor (p 0.009), tobacco (p 0.009), and metabolic syndrome (p 0.001). Likewise, a significant relationship was found between lower leptin concentrations and hydroxychloroquine consumption (p=0.023). We found significant difference between IL-6 concentrations and disease activity (p 0.028), hypertriglyceridemia (p 0.023), LDL-C (p 0.029), and smoking (0.005). Similarly, an association between hydroxychloroquine consumption and low concentrations of IL-6 was found (p 0.005). Framingham CVR was calculated and the result obtained was multiplied by 1.5. The 35.2% of the population studied had a low Framingham CVR, 38.9% moderate, and 25.9% presented a high risk. We compared the level of CVR and serum leptin and IL-6 concentrations, finding that the highest CVR was the leptin and IL-6 values. There is a positive association between CVR and serum leptin concentrations. It is also significantly associated with traditional and non-traditional risk factors.

The relationship between leptin and arterial stiffness in patients on dialysis

Introduction-Aim : Leptin modifies the systemic inflammatory response and insulin action, but the mechanisms by which it affects vascular disease is unclear.We studied the relationship between leptin serum concentrations and arterial stiffness in dialysis patients. Methods : We studied 76 patients on on-line hemodiafiltration . Dialysis adequacy was defined by Kt/V for urea.Leptin and insulin were measured by radioimmunoassays.Insulin resistance was calculated using the homeostasis model assessment of insulin resistance (HOMA-IR).High sensitivity C-reactive protein (hsCRP) and oxidized LDL (ox-LDL) serum concentrations were measured by ELISA. The ratio of LDL / HDL was calculated and serum bicarbonate levels were measured in gas machine. Arterial stiffness was assessed as carotid-femoral pulse wave velocity (c-f PWV) and carotid augmentation index (Aix). Results : We observed significantly positive correlation between leptin and BMI, insulin and hsCRP (r=0.397, p=0.001, r=0.284, p=0.02 and r=0.244, p=0.04 respectively), but the correlation between leptin and Aix was significantly reverse (r=-0.251, p=0.04). The higher leptin values were correlated with mildly elevated serum bicarbonate levels, which were inversely associated with hsCRP, c-f PWV and Aix (r=-0.384, p=0.005, r=-0.719, p=0.001 and r=-0.527, p=0.001 respectively). Conclusion : We observed an inverse association between leptin and arterial stiffness may confounded by metabolic acidosis and obesity in dialysis patients.

Adipocytokines during pregnancy and postpartum in women with gestational diabetes and healthy controls.

This study aims to explore the changes in maternal serum adipocytokines during pregnancy and post partum in normal and complicated with gestational diabetes (GDM) pregnancies and to investigate the relationship between serum adipocytokines and some of major metabolic parameters. 236 pregnant women (127 with GDM and 109 control group) and 50 postpartum women (30 with GDM during pregnancy and 20 controls). Using ELISA and EIA kits, serum levels of adipocytokines were tested during pregnancy and post partum. Maternal adipocytokines levels were correlated with some metabolic parameters. Women with GDM had lower values of adiponectin and higher values of leptin during pregnancy (p<0.001; 0.0001) and post partum (p<0.002; 0.0001). Serum apelin was significantly lower in GDM group (p<0.009). However, we did not find significance for resistin (p<0.317) and apelin (p<0.218). Positive correlation for leptin and negative for adiponectin was found for pre-pregnancy and pregnancy body mass index, glycated hemoglobin and homeostasis model assessment of insulin resistance index. Using cut point of 8.2 μg/ml for adiponectin and 28.7 ng/ml for leptin could exclude GDM with a sensitivity of 83.6%/81.2% and specificity of 56.6%/64.2% (area under the curve 0.702 and 0.827). There are constant differences in adiponectin and leptin levels between GDM and control group during pregnancy and post partum. Apelin was decreased in our GDM group and no differences were found for resistin and visfatin. Further studies are required to verify the mechanism of this alteration and whether the adipocytokines can be predictors for GDM at an early stage of pregnancy.

Heterogeneity of pregnancy outcomes and risk of LGA neonates in Caucasian females according to IADPSG criteria for gestational diabetes mellitus

ObjectiveThe International Association of Diabetes and Pregnancy Study Group (IADPSG) guidelines for gestational diabetes mellitus (GDM) diagnosis determines that fasting, 1-h and 2-h glucose values may contribute independently to adverse outcomes. However, given the different physiological bases of impaired fasting glucose (IFG) and impaired glucose tolerance (IGT), differences in pregnancy outcomes are to be expected. This study aimed to determine whether classification of GDM women according to glucose homoeostasis results in heterogeneity in maternal and/or fetal outcomes. Material and methodsOf the 75 pregnant women included after a 75-g 2-h OGTT performed between weeks 24–32 of gestation as per WHO criteria, 55 were classified as GDM (16 with IFG and 39 with IGT) according to IADSPG criteria. Their anthropometric and metabolic characteristics were compared with those of non-GDM women with IFG or IGT. Maternal and neonatal outcomes were prospectively recorded for each group. ResultsGDM women with IFG, including isolated IFG and combined IFG+IGT, were significantly heavier, had higher leptin values and were more frequently multiparous than GDM women with isolated IGT. HOMA-IR was significantly higher when fasting glucose was impaired. There were no significant differences in maternal outcomes according to metabolic status. In addition, large for gestational age (LGA) neonates were significantly seen more often in the IFG group. Fasting glucose was significantly associated with LGA independently of BMI and 2-h OGTT glucose. The>5.1mmol/L cut-off value for fasting glucose was highly predictive of delivery of LGA infants. ConclusionIFG in GDM women was associated with increases in BMI, fat mass and hepatic insulin resistance. Delivery of LGA neonates was more frequent when fasting glycaemia was increased during the third trimester of pregnancy, and was independent of BMI and 2-h OGTT glucose values.

Leptin and Endocrine Parameters in Marathon Runners

Endurance training may lead to different hormonal alterations e. g., exercised induced hypothalamic ovarian/testicular dysfunction. The aim of this study was to reveal new connections between physical exercise, leptin and hormonal responses. 36 male participants of the Berlin-Marathon had their blood samples taken 2 days before the marathon. Hormones of the hypothalamic-pituitary axis and leptin were correlated with the training status and the achieved marathon time. Leptin correlated with the achieved marathon time after being adjusted for age and BMI (r=0.607, p<0.001) and was lowest in the best trained runners. Additionally, when the group was divided into quartiles of their achieved marathon time, significantly increased cortisol, fT4, cortisol/DHEAS ratio and decreased IGF-1 levels were observed in the slowest group. In the better trained group, a decrease of testosterone/DHT ratio and an increase of testosterone/cortisol ratio were observed. Our study supports the thesis of a linear relationship between physical fitness and leptin variations in the physiological range. We found an increased anabolic hormonal response in well trained marathon runners and hormonal reactions of increased stress in less trained runners. As the stress-induced neuroendocrine adaptations in our study group are associated with more higher leptin values, the pathophysiological role of decreased leptin values seems to be limited to overtrained athletes.

Prevalence of metabolic syndrome and serum profile of adipokines (leptin and adiponectin) in children with overweight or obesity

Background. Metabolic syndrome is an important risk factor for cardiovascular diseases. Objective. To evaluate the prevalence of metabolic syndrome and serum profile of adipokines in children with overweight or obesity. Methods. Fifty two out of 62 referred children were included in the study, with a body mass index (BMI) that exceeded 85 th percentile. Waist circumference and blood pressure (BP) were recorded, followed by the determination of: glucose, cholesterol, triglycerides, HDL cholesterol, insulin, adiponectin and leptin. The insulin resistance was then calculated by HOMA2 index. Results. Of the 52 children included, 28.8% have met the criteria for diagnosis of metabolic syndrome. BMI and BP values were higher in children with metabolic syndrome. The higher values of leptin (69.59 ± 50;89 vs. 58.44 ± 42.28 ng/ml) and insulin resistance (1.65 ± 0.74 vs. 1.41± 0.78) in the group with metabolic syndrome were without statistical significance. We found a positive correlation, statistically significant between BMI and serum leptin (r = 0.32, p =0.02), BMI and plasma insulin (r = 0.33, p =0.01), BMI and insulin resistance (r=0.33, p=0.01), respectively. This was not noticed for serum adiponectin. Conclusion. Metabolic syndrome has a high prevalence in childhood obesity. Serum leptin (but not adiponectin) seem to have a very good correlation with some clinical and bioumoral features of the metabolic syndrome.

Serum leptin level in hypothyroid males.

To determine the correlation of serum leptin with thyroid hormones in primary hypothyroid male patients and euthyroid lean and obese control subjects. Comparative study. Atomic Energy Medical Center, JPMC, Karachi, from 2001 to 2003. In this study, three male groups were included. Those were 21 newly-diagnosed, untreated hypothyroid male patients (BMI, 25.12+/-2.31), 24 age and BMI matched euthyroid lean male subjects (BMI, 24.01+/-1.97) and 27 euthyroid obese male subjects (BMI, 33.02+/-2.67). Patients were selected from the thyroid OPD of Atomic Energy Medical Centre, JPMC, Karachi, while healthy, age and BMI matched euthyroid (lean and obese) were selected from general population after checking their thyroid profile. Patients and control subjects suffering from diabetes or other endocrinal diseases and taking thyroxin or steroid were excluded from the study. Serum leptin was measured by ELISA and FT4, FT3 and TSH were measured by radioimmunoassay (RIA), triacylglycerol (TG), total cholesterol (TC), high density lipoprotein cholesterol (HDL-C) by kit method, low density lipoprotein cholesterol (LDL-C) was calculated by the Friedwald s formula, and fasting blood sugar (FBS) by glucose oxidase method. The mean +/- SEM values of leptin in male hypothyroid patients were 10.71+/-2.5 ng/ml, 8.27+/-1.91 in control group and 21.34+/-3.4 ng/ml in obese group, respectively. No significant difference was found in serum leptin levels between hypothyroid patients and their age, BMI matched control group, while obese control group had significantly higher values of leptin (<0.05). There was no significant correlation of leptin found with T4, T3, and TSH in hypothyroid patients and lean and obese control subjects. Triacylglycerol (TG, p < 0.005), total cholesterol (TC, p < 0.005) and low density lipoprotein cholesterol (LDL-C, p < 0.05) were significantly higher in hypothyroid patients as compared to control groups. This study observed that serum leptin level was significantly correlated with the BMI (r = 0.732, p < 0.005, r = 0.783, p < 0.005, r = 0.653, p < 0.005), in normal lean, obese and hypothyroid male patients respectively. The results of this study suggest that there is no correlation between serum leptin and thyroid hormones in hypothyroid patients as well as in euthyroid subjects. Serum leptin is directly related with BMI.

Alleles on Rat Chromosome 4 (D4Got41‐Fabp1/Tacr1) Regulate Subphenotypes of Obesity

The use of inbred animal models is an essential component of the genetic dissection of complex diseases. Because quantitative trait loci for serum triglycerides, total cholesterol, and body weight were mapped on chromosome 4 in a cross of BioBreeding/OttawaKarlsburg (BB/OK) and spontaneously hypertensive (SHR) rats, we established a congenic BB.SHR rat strain by introgressing a SHR segment of chromosome 4 (D4Got41-Tacr1) into a BB/OK background. The phenotype of these BB.SHR rats (BB.4S) confirmed the quantitative trait loci. To discover whether the phenotype of BB.4S can only be attributed to the SHR segment per se, we established an additional congenic BB.WOKW strain by introgressing a similar segment of chromosome 4 (D4Got41-Fabp1) of the Wistar Ottawa Karlsburg RT1(u) rat into a BB/OK background, termed briefly BB.4W. Male normoglycemic BB/OK (20), BB.4S (20), and BB.4W (16) rats were longitudinally studied for body weight, serum triglycerides, total and high-density lipoprotein-cholesterol, and glucose tolerance. At the end of the observation period (32 weeks), serum insulin, leptin, and adiposity index (AI) were determined. Congenic BB.4S and BB.4W were significantly heavier, and AI, serum triglycerides, and total cholesterol values were significantly elevated in BB.4S and BB.4W compared with BB/OK but more pronounced in BB.4S. The highest serum insulin was found in BB.4W and highest leptin in BB.4S. Because the body weight gain and AI were comparable between BB.4S and BB.4W, the obviously higher insulin levels in BB.4W and higher leptin values in BB.4S suggest that the two congenics most probably define two subphenotypes of obesity and provide the unique opportunity to study their genetics.

Breast-fed Infants have Higher Leptin Values than Formula-fed Infants in the First Four Months of Life

Leptin is a hormone present in breast milk, which regulates food intake and energy metabolism. To investigate whether leptin levels are different in breast-fed (BF) or formula-fed (FF) infants in the first months of life. We evaluated serum leptin by radio-immunoassay and anthropometric parameters in 51 infants at the average age of 62.8+/-30 days, 25 exclusively BF and 26 exclusively FF. Leptin serum values were higher in BF (7.1+/-10.4 ng/ml) than in FF (3.7+/-3.87 ng/ml) infants (p <0.05). Leptin values were higher in females (6.9+/-9.87 ng/ml) than in males (3.5+/-3.88 ng/ml) (p <0.05). No differences were found in anthropometric measurements and body mass index. The kind of feeding might be a factor affecting serum leptin concentration in term infants. The long-term consequences of this difference between BF and FF infants and leptin's role in promoting obesity later in life are unknown.