Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP)ObjectiveShift work is associated with circadian rhythm disorder, impaired sleep and behavioural changes, including eating habits, predisposing to obesity and metabolic dysfunctions. It involves a neuro-hormonal dysregulation of appetite towards positive energy balance, including increased ghrelin and decreased leptin, but little is known about other hormones, such as xenin, derived from the upper gut (like ghrelin), and lower gut hormones. Our objective was to compare night workers with day workers in relation to appetite-regulating hormones and other metabolic parameters. DesignCross-sectional, observational study. ParticipantsTwenty-four overweight women, divided into night shift workers (n=12) and day shift workers (n=12). MeasurementsBMI, waist circumference, fat mass percentage; diet composition; Pittsburgh Sleep Quality Index; lipids; adipokines; meal tolerance test curves of glucose, insulin, ghrelin, PYY3-36, oxyntomodulin, xenin, GLP-1; insulin sensitivity (Stumvoll index). ResultsNight workers, as compared with day workers, had greater body fat mass percentage and tendency to greater waist circumference despite similar BMI; greater energy intake; impaired sleep; lower insulin sensitivity; increased triglycerides and tendency to increased C-reactive protein; similar levels of leptin and other adipokines. Night workers had a blunted post-meal suppression of ghrelin (AUCi(0-60min) 19<bold>41399</bold> vs -141<bold>9</bold>+/- 9<bold>0</bold>ng/ml<bold>60</bold>min, P<0<bold>01</bold>); blunted rise of xenin (AUC(0-180min) 8690<bold>9</bold>+/- 2988<bold>2</bold> vs 28504<bold>4</bold>+/- 20308<bold>3</bold>pg/ml<bold>180</bold>min, P<0<bold>01</bold>) and similar curves of PYY3-36, oxyntomodulin and GPL-1. ConclusionCompared with day workers within the same BMI range, night workers presented a disrupted control of ghrelin and xenin, associated with behavioural changes in diet and sleep and increased adiposity and related metabolic alterations.796807811Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP)Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP)