Strength and independence of associations between ghrelin, leptin, adiponectin and insulin in stimulating basic functions to energy metabolism

Thermally oxidized sunflower oil diet alters leptin/ghrelin balance and lipid profile in rats: Possible role of reactive aldehydes in dyslipidemia

Sunflower oil is a common edible oil in the world, which is highly prone to oxidative degradation during the frying process. The present study aimed to investigate the effects of products obtained from the thermal oxidation process of sunflower oil on metabolic indices, and the secretion status of leptin and ghrelin in rats. In vivo studies were designed after determining the rate of formation of active aldehydes and peroxide value in sunflower oil following 300°C in a period of 30-240 min. To this end, 36 rats in 6 separate groups were fed with 2 ml of normal saline, fresh sunflower oil, and heated oils at 30, 60, 120, and 240 min for 45 days. Finally, lipid profile changes and leptin/ghrelin secretion were examined, along with histological changes in the liver tissue. The results indicated a significant increase in serum LDL, VLDL and triglycerides, and a decrease in HDL, in the groups treated with heated oils. These changes were associated with a higher accumulation of triglycerides, active aldehydes, and histological changes in the hepatic tissue. Although the serum ghrelin level in the groups receiving heated oil did not change significantly compared to the fresh oil, the serum leptin level increased significantly in the groups receiving heated oil. According to our findings, increasing the time of sunflower oil heating enhanced the formation of active aldehydes, so that daily consumption of such oxidized oils might be associated with the occurrence of dyslipidemia, fatty liver and the development of leptin resistance. PRACTICAL APPLICATIONS: Sunflower oil is highly prone to oxidative degradation during the frying process. Increasing time of sunflower oil heating enhanced the formation of active aldehydes. Daily consumption of oxidized oils might be associated with the occurrence of dyslipidemia, fatty liver and the development of leptin resistance.

Job Stress and Neuropeptide Response Contributing to Food Intake Regulation

The purpose of the present study is to investigate the correlations between food intake behavior and job stress level and neuropeptide hormone concentrations. Job strain and food intake behavior were first identified using a self-reported questionnaire, concentrations of neuropeptide hormones (adiponectin, brain derived neurotrophic factor [BDNF], leptin, and ghrelin) were determined, and the correlations were analyzed. In the results, job strain showed significant correlations with adiponectin (odds ratio [OR], 1.220; 95% confidence interval [CI], 1.001~1.498; p < 0.05) and BDNF (OR, 0.793; 95% CI, 0.646~0.974; p < 0.05), and ghrelin exhibited a significant correlation with food intake score (OR, 0.911; 95% CI, 0.842~0.985, p < 0.05). These results suggest that job stress affects food intake regulation by altering the physiological concentrations of neuropeptide hormones as well as emotional status.