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Background and Objective: Many factors are known to be involved in a number of human pathologies of obesity including serum leptin and thyroid hormones levels. The purpose of this study was to compare the serum levels of leptin and thyroid hormones in obese and non-obese women, in Shiraz-Iran during 2006. Materials and Methods: In this case- control study, 35 women with BMI≥30 Kg/m2 recruited as an obese group (Case group) and 35 women with healthy BMI (BMI<25 Kg/m2) were selected as a control group. General information data were gathered from each sample using questionnaires and face-to-face interviews. Body weight, height, waist and hip circumferences were measured and BMI, WHR and percent of body fat (%TBF) were calculated for each subject. Venous blood samples were drawn from subjects and serum was separated to determine the concentrations of serum leptin and thyroid hormones (T4, T3 and TSH) levels. Results: Mean serum concentration of leptin was significantly higher in obese group than control group (p<0.001). Serum leptin levels positively correlated to anthropometric indices (BMI, WHR, %TBF). No significant difference was observed between obese and non-obese groups in serum thyroid hormones concentration. Serum leptin levels positively related to serum T3 levels (P<0.05). Conclusion: This study indicated that obese women had higher leptin levels compared to non-obese. The interaction between thyroid hormone in particular T3 and leptin can be one of the reason for increasing the serum leptin level among obse women.

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Background and Objective: Stress has been known as an important causative factor in irritable bowel syndrome. Various studies have indicated the relationship between serum leptin levels and stress levels. This study was undertaken to investigate the relationship between serum leptin levels with irritable bowel syndrome. Materials and Methods: In This case-control study, eighty irritable bowel syndrome patients and 80 controls were recruited. All participants were asked to fill in a questionnaire included demographic information and medical history as well as a stress questionnaire. Serum leptin level was measured by ELISA method. Chi-square, student t-test, pearson correlation and logistic regression were used for investigating the relationships between variables. Results: Participants in irritable bowel syndrome group had significantly higher stress levels than controls (p<0.05). In the other hand, Serum leptin levels were significantly lower in irritable bowel syndrome group than the other one (p<0.05). Multivariate logistic regression analysis showed that after adjustment of stress level and body mass index, serum leptin level was still significantly lower in irritable bowel syndrome group (Odds ratio=0.9 CI95%:0.85-0.94). Conclusion: The present study indicated that there is a relationship between leptin and irritable bowel syndrome and serum leptin level is significantly lower in irritable bowel syndrome group than controls. This relationship is independent of other variables such as stress levels, BMI.

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Background and Objective: Unsaturated fatty acids such as turpentine oil can decrease serum leptin level. In regard to this effect and the key role of thyroid hormones and leptin in metabolism. This study was designed to investigate the impact of dietary wild pistachio oil on serum leptin concentration and its relationship with thyroid hormones in experimental hyperthyroidism in male rat. Materials and Methods: In this experimental study thirty white Sprague Dawely adult male rats were divided randomly into the five groups with six rats in each. The first group as a natural control I received only ordinary diet and water during the study period. The second group as a control II received ordinary diet in addition to administration of 12mg Sigma levothyroxine in one liter of water daily for one month. Third, fourth and fifth groups with administration of considered dosage of levothyroxine were received respectively 5%, 10% and 20% concentrations of wild pistachio oil for one month. Blood samples were obtained at 10-day intervals. T4, T3, fT4, fT3 and leptin were measured by RIA and ELISA methods. Serum lipid profiles were measured by enzymatic method. Results: Thyroidal hormones, lipids and leptin level did not show any statistically significant differences between experimental days in the rats of control group I.The serum concentrations of T4, T3, fT4, fT3 in third, T4 in fourth and fifth groups showed significant differences(P<0.05). The serum leptin concentration decreased significantly during the experiment in the third, fourth and fifth groups (P<0.05), but serum lipids did not show any significant differences between various days of experiment. Conclusion: This study showed that the level of T4, T3, fT4, fT3 and HDLc / LDLc ratio at 30th day of study in case groups compaing to controls were decreased and increased, respectively.

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Background and Objective: Leptin has a key role in obesity and type 2 of diabetes. This study was done to compare the effects of eight weeks aerobic and combined training on serum levels of leptin and glucose in type 2 diabetic men. Method: This clinical trial study was performed on 24 men with type 2 diabetes whom reffered to Taleghani Hospital in Kermanshah, West of Iran during June to August 2012. The patients were randomly divided into 3 groups including aerobic training, combined training (aerobic and resistance training) and control groups. Training protocols included three 1-hour sessions per week for eight weeks. Subjects in the control group did not participate in any physical activities. Serum levels of leptin and glucose were measured 48 hours before and 48 hours after intervention as fasting values in pre-and post-tests. Results: There was no significant difference between groups at pre-test for serum levels of leptin and glucose. After intervention, serum level of glucose in the aerobic group and serum level of glucose and leptin in the combined group were significantly reduced in compared to the controls (P<0.05). Conclusion: Aerobic and combined training with beneficial effects on the sera glucose level are recommended for patients with type 2 diabetes. However, combined training, regarding reducing leptin level seems to be more useful for these subjects.

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Background and Objective: Leptin is associated with metabolic disorders and promotes the development of liver steatosis to steatohepatitis. It selectively increases the secretion of Tumor-necrosis factor-α (TNF-a) in response to saturated fatty acid. The general purpose of this research was to determine the effects of eight weeks of continuous training and silymarin supplementation on the serum levels of TNF-α and leptin in Wistar rats with fatty liver disease.
Methods: In this experimental study, 40 male Wistar rats aged three weeks and weighting 159±3 grams were randomly divided into five groups: normal diet/saline, high-fat diet/saline (control), high-fat diet/supplemented, high-fat diet/exercise/saline, and high-fat diet/exercise/supplement. The rats were fed 10 grams per 100 grams of body weight (standard diet 13% fat and high-fat diet 41% fat) for eight weeks, and silymarin (140 mg per kilogram body weight) were given by gavage for 2 weeks. The continuous aerobic exercise protocol consisted 30 minutes of treadmill running at 70-75% of VO₂max for eight weeks, five days a week. After sacrificing the animals, samples were taken and sent to the laboratory for histological analysis. The expression of leptin and TNF-α in the liver was measured using commercial ELISA kits.
Results: The findings showed a greater decrease in hepatic leptin concentration in the high-fat diet + continuous exercise + supplement group (P<0.05) compared to the high-fat diet + continuous exercise + saline group (P<0.05). Tukey's post hoc test showed a greater decrease in the concentration of hepatic TNF-α in the high-fat diet + saline group (compared to the high-fat diet + supplement group) (P<0.05), and the high-fat + exercise + saline group (P<0.05). The weight of the rats in the normal diet + saline group differed significantly from other groups (P<0.05).
Conclusion: The results indicated that the combination of continuous training with silymarin supplementation can help reduce leptin and TNF-α in rats with a high-fat diet, an effect not observed by silymarin supplementation alone. Therefore, the combination of continuous aerobic exercises and silymarin supplementation can further oxidize fat and reduce inflammation in the body.