Assessment of EN-RAGE, sRAGE, and its isoforms: cRAGE, esRAGE in obese patients treated by moderate caloric restriction combined with physical activity conducted in hospital condition.

BACKGROUND: AGEs, their receptor (RAGE), and the extracellular newly identified receptor for AGEs product-binding protein (EN-RAGE) are implicated in the pathogenesis of inflammation. AIM: We analyzed serum EN-RAGE, soluble RAGE (sRAGE), and their isoforms: endogenous secretory - esRAGE and cleaved - cRAGE concentrations in lean controls (n = 74) and in patients with obesity (n = 71) treated for three weeks with moderate calorie restriction (CR) combined with physical activity in a hospital condition. METHODS: Using the ELISA method, serum sRAGE, esRAGE, and EN-RAGE were measured before and after CR. RESULTS: The serum level of sRAGE and esRAGE in patients with obesity was lower than that in non-obese individuals, contrary to cRAGE. EN-RAGE concentration was about three times higher in obese patients. Gradually, a rise in BMI resulted in sRAGE, esRAGE reduction, and EN-RAGE increase. The sRAGE concentration was sex-dependent, indicating a higher value in lean men. A moderate negative correlation was observed between BMI and all RAGE isoforms, whereas EN-RAGE displays a positive correlation. CR resulted in an expected decrease in anthropometric, metabolic, and proinflammatory parameters and EN-RAGE, but no RAGE isoforms. The ratio EN-RAGE/sRAGE was higher in obese humans than in control and was not modified by CR. CONCLUSION: Obesity decreases sRAGE and esRAGE and increases EN-RAGE concentration. Moderate CR and physical activity by decreasing inflammation reduces EN-RAGE but is insufficient to increase sRAGE and esRAGE to the extent observed in lean patients. EN-RAGE instead of sRAGE could be helpful to indicate a better outcome of moderate dietary intervention in obese subjects.

No Significant Effect of the Individual Chronotype on the Result of Moderate Calorie Restriction for Obesity-A Pilot Study.

BACKGROUND: Chronotype is the pattern of the circadian rhythm that allows an individual to optimize times of sleep and activity. It has been observed that chronotypes may associate with some conditions and diseases, including obesity. It is not known, however, whether chronotypes determine the effectiveness of weight loss regimens. Therefore, in the present study, we compared the outcomes of a 3-week moderate calorie restriction undertaken by individuals with obesity under the same controlled hospital conditions. METHODS: A total of 131 participants with obesity (median BMI 40.0) were studied. The subjects underwent the same dietary intervention over 3 weeks, with a 30% reduction in daily caloric intake. The individual chronotypes were assessed by the morning and evening questionnaire (MEQ) according to Horne and Östberg. Anthropometric and biochemical parameters were assessed by routine methods. RESULTS: Of all patients examined, 75% had the morning (lark) chronotype and 25% had the evening (owl) chronotype. These patient sub-groups did not differ in terms of demographic, anthropometric and biochemical characteristics at baseline. After 3 weeks of calorie restriction, both groups experienced a similar loss of weight and BMI (Body Mass Index) (3.4 ± 0.38% for larks vs. 4.1 ± 0.47% for owls, p = 0.45), with owls exhibiting a marginally greater loss of body fat (3.1 ± 0.79%) compared with larks (2.6 ± 0.64%), p = 0.02. On the other hand, the larks had a more discernable, but not statistically significant from owls, decrease in glycated haemoglobin and CRP (C Reactive Protein). CONCLUSIONS: The chronotype of individuals with obesity does not have a significant effect on the magnitude of the body weight loss, but there is a tendency observed towards the reduction in body fat content in owls through changing their meal and sleep timing to earlier hours, in response to moderate calorie restriction applied under the same controlled conditions.