Obestatin levels in response to a meal and association with subsequent appetite sensations in maintenance hemodialysis patients

Background: Obestatin, a physiological opponent of acylated ghrelin, is linked to appetite suppression regulation in mice but its anorexigenic properties in humans are controversial. We aimed to investigate obestatin's potential role in dietary intake regulation by examining response to a meal in maintenance hemodialysis (MHD) patients. Methods: In this prospective observational case series study, we investigated the response of obestatin to a fixed calorie meal (500 kcal) in 21 MHD patients (age 69.2 ± 13.1 years, 10 women, with a body mass index 27.2 ± 5.5 kg/m²). Parallel changes in serum obestatin and insulin levels and subjective scores of appetite (visual analogue scales for hunger, satiety, fullness and prospective food consumption) were recorded on fasting and 30, 60 and 120 min after the meal. Results: In a linear mixed effects model controlling for baseline demographics and clinical parameters including serum insulin concentrations, postprandial levels of obestatin did not change significantly from baseline in response to the meal. The response was the same in MHD patients treated with high- or low-flux dialyzers. However, postprandial obestatin levels were associated with the rate of change in sensation of fullness (linear estimate: 11.60 (95% confidence interval 0.17 to 23.04, P < 0.05)). The remaining sensations of appetite did not correlate with postprandial obestatin levels in time. Conclusions: Obestatin levels do not change acutely with food administration in MHD patients, but associate with the changes in sensation of fullness. This supports the possible role of obestatin in the long-term regulation of appetite in MHD patients.