Effects of night work on circadian rhythms of inflammation markers

• Grant number: 11/12379-9
• Support type: Scholarships in Brazil - Doctorate
• Effective date (Start): May 01, 2012
• Effective date (End): June 30, 2015
• Field of knowledge: Health Sciences - Collective Health - Public Health
• Principal researcher: Claudia Roberta de Castro Moreno
• Grantee: Leana Gonçalves Araujo
• Home Institution: Faculdade de Saúde Pública (FSP). Universidade de São Paulo (USP). São Paulo , SP, Brazil

Abstract

Introduction: As a result of night work, there is the loss of temporal phase relationship between biological rhythms and environmental cycles, ie, desynchronization of biological rhythms. This loss of internal temporal order results in pathophysiological changes. Objective: This study aims to evaluate the effects of the night shift in the circadian rhythm of inflammatory cytokines. Material and Methods: This is a cross-sectional study, to be held in a company's beverage industry in the city of Uberlândia-MG. In the first stage of the study will be evaluated by questionnaire, in 232 production line workers and machine operators, sociodemographics, living and leisure conditions and work organization, morbidity, musculoskeletal symptoms, fatigue, excessive sleepiness and anthropometric data. From the inclusion criteria, 20 volunteers from day shift and 20 night shift will be selected for the second stage. These subjects will be followed for seven days (Monday to Sunday), in which data will be collected related to the pattern of sleep and wakefulness through actimetry and daily activities protocols. Over the last two days working week (Thursday and Friday) and a day off (Saturday), data of biological rhythms will be collected every three hours, starting on waking and the last collection before bed time: melatonin, cytokines (IL-1², IL-6 and TNF-±), cortisol, somnolence, fatigue and pain. After performing the Kolmogorov Smirnov normality test, descriptive analysis will be performed by absolute and relative frequencies, mean and standard deviation or median and percentiles. In order to compare the groups, will be applied Student's t test or Mann-Whitney test. In addition, we will use the chi-square test of Pearson, the Pearson correlation test and Odds Ratio (OR). Only the variables that presented p d 0.05 will be included in the model of linear and logistic regression. In the second stage of analysis will be applied the method of Cosinor and analysis of variance for repeated measures (ANOVA) of a factor. In case of statistical significance, a post-hoc Tukey's test will be applied. The adopted power test will be 80% and the significance level will be ± d 0.05.