Melatonin plays a key role in the circadian timing system. At present, many other functions of melatonin are known. Question remains whether changes in endogenous melatonin may be associated with food intake. Hence, the levels of melatonin, C-peptide and glucose were followed during a daily regimen (16 hours) including standardized food intake using commercial kits. The diurnal profiles of the hormones and serum glucose were evaluated using ANOVA with Period and Subject as independent factors. Pearson’s correlations and using a multiple stepwise backward regression model consisting of the time factor as a polynomial, and serum C-peptide and glucose assessed the correlations between melatonin and the remaining parameters. Our results showed a significant negative correlation between melatonin and C-peptide. The profile of melatonin was physiological, decreasing after wake-up, showing minor changes during the daytime and increasing in the evening. As documented, lesser alterations were indicated in the course of the melatonin daytime profile, which may reflect periodic food intake. Food intake is not the primary factor influencing the melatonin course. While previous studies have mostly considered the protective effect of melatonin in diabetic subjects, our study brought the results suggesting food intake as a factor contributing to daytime melatonin variation in humans. However, the physiological role of melatonin association with food intake in daytime remains in question and should be further investigated., L. Stárka, M. Dušková, B. Rácz, K. Šimůnková, M. Hill, R. Kancheva., and Obsahuje bibliografii a bibliografické odkazy
Neuromedin beta (NMB) is a member of the bombesin-like peptide family expressed in brain, gastroin testinal tract, pancreas, adrenals and adipose tissue. The aim of our study was to compare the frequency of P73T polymorphism in overweight and obese patients (37 men: age 50.6±11.7 years, BMI 41.1±7.8 kg/m2; 255 women: age 49.0±11.9 years, BMI 37.9±6.8 kg/m2) with that of healthy normal weight subjects (51 men: age 28.2±7.1 years, BMI 22.3±2.0 kg/m2; 104 women: age 29.1±9.1 years, BMI 21.5±1.9 kg/m2) and to investigate the polymorphism’s influence on anthropometric, nutritional and psychobehavioral parameters in overweight/obese patients both at the baseline examination and at a control visit carried out 2.5 years later, regardless of the patient́s compliance with the weight reduction program. No significant differences in the genotype distribution were demonstrated between normal weight and overweight/obese subjects. Male T allele non-carriers compared to T allele carriers had higher energy (p=0.009), protein (p=0.018) and fat (p=0.002) intakes and hunger score (p=0.015) at the beginning of treatment. Male T allele non-carriers had a more favorable response to weight management at the follow-up, as they exhibited a significant reduction in waist circumference, energy intake and depression score as well as a significant increase in dietary restraint. No significant differences between carriers and non-carriers were demonstrated in women at the baseline examination. Both female T allele carriers and non-carriers demonstrated similar significant changes in nutritional parameters and in restraint score at the follow-up. Nevertheless, only female non-carriers showed a significant decrease in the hunger score., J. Spálová, H. Zamrazilová, J. Včelák, M. Vaňková, P. Lukášová, M. Hill, K. Hlavatá, P. Šrámková, M. Fried, B. Aldhoon, M. Kunešová, B. Bendlová, V. Hainer., and Obsahuje bibliografii a bibliografické odkazy
Obestatin is a recently discovered peptide produced in the stomach, which was originally described to suppress food intake and decrease body weight in experimental animals. We investigated fasting plasma obestatin levels in normal weight, obese and anorectic women and associations of plasma obestatin levels with anthropometric and hormonal parameters. Hormonal (obestatin, ghrelin, leptin, insulin) and anthropometric parameters and body composition were examined in 15 normal weight, 21 obese and 15 anorectic women. Fasting obestatin levels were significantly lower in obese than in normal weight and anorectic women, whereas ghrelin to obestatin ratio was increased in anorectic women. Compared to leptin, only minor differences in plasma obestatin levels were observed in women who greatly differed in the amount of fat stores. However, a negative correlation of fasting obestatin level with body fat indexes might suggest a certain role of obestatin in the regulation of energy homeostasis. A significant relationship between plasma obestatin and ghrelin levels, independent of anthropometric parameters, supports simultaneous secretion of both hormones from the common precursor. Lower plasma obestatin levels in obese women compared to normal weight and anorectic women as well as increased ghrelin to obestatin ratio in anorectic women might play a role in body weight regulation in these pathologies., H. Zamrazilová, V. Hainer, D. Sedláčková, H. Papežová, M. Kunešová, F. Bellisle, M. Hill, J. Nedvídková., and Obsahuje bibliografii a bibliografické odkazy
Free fatty acids (FFAs) are natural ligands of the PPARγ2 receptor. FFA plasma concentration and composition may represent one of the factors accounting for high heterogeneity of conclusions concerning the effect of the Pro12Ala on BMI, insulin sensitivity or diabetes type 2 (DM2) susceptibility. Our objective was to investigate the relation and possible interactions between the Pro12Ala polymorphism and FFA status, metabolic markers, and body composition in 324 lean nondiabetic subjects (M/F: 99/225; age 32±11 years; BMI 23.9±4.0 kg/m2) with and without family history of DM2. Family history of DM2 was associated with lower % PUFA and slightly higher % MUFA. The presence of Pro12Ala polymorphism was not associated with fasting plasma FFA concentration or composition, anthropometric or metabolic markers of glucose and lipid metabolism in tested population. However, the interaction of carriership status with FFA levels influenced the basal glucose levels, insulin sensitivity and disposition indices, triglycerides, HDL-cholesterol and leptin levels, especially in women. The metabolic effects of 12Ala carriership were influenced by FFA levels – the beneficial role of 12Ala was seen only in the presence of low concentration of plasma FFA. Surprisingly, a high PUFA/SFA ratio was associated with lower insulin sensitivity, the protective effect of 12Ala allele was apparent in subjects with family history of DM2. On the basis of our findings and published data we recommend the genotyping of diabetic patients for Pro12Ala polymorphism of the PPARγ2 gene before treatment with thiazolidinediones and education of subjects regarding diet and physical activity, which modulate metabolic outcomes., B. Bendlová, D. Vejražková, J. Včelák, P. Lukášová, D. Burkoňová, M. Kunešová, J. Vrbíková, K. Dvořáková, K. Vondra, M. Vaňková., and Obsahuje bibliografii a bibliografické odkazy