Graduate Studies


First Advisor

Heather Rasmussen

Second Advisor

Robert Hutkins

Third Advisor

Weiwen Chai

Date of this Version


Document Type



Reis, V.E.T. (2020). Relation between C-Reactive Protein and obesity, diet quality, sleep pattern, and food timing in circadian disrupted adults (Master's thesis). University of Nebraska-Lincoln, USA.


A THESIS Presented to the Faculty of The Graduate College at the University of Nebraska In Partial Fulfillment of Requirements For the Degree of Master of Science, Major: Nutrition & Health Sciences, Under the Supervision of Professor Heather Rasmussen. Lincoln, Nebraska: July 2020

Copyright 2020 Victoria Esther Teixeira Reis


Introduction: Systemic inflammation is a common factor contributing to multiple chronic health conditions. However, the relation between inflammatory biomarkers, including C-Reactive Protein (CRP), and dietary intake, sleep patterns, and food timing among circadian disrupted obese individuals is not fully known.

Purpose: The purpose of this study was to determine the relation between inflammatory status (CRP) and obesity, diet quality, sleep patterns, and food timing in a sample of circadian-disrupted adults.

Methods: Self-reported questionnaires about dietary intake, gastrointestinal and sleep disturbance symptoms, and circadian misalignment, including sleep schedule and food timing, were answered by obese night-shift workers. C-reactive protein was collected after an 8-hour fast at the same study visit. Mann Whitney U, Spearman’s rank correlation, and partial Spearman’s rank correlation were used to compare CRP to study outcomes.

Results: Participants (n=11) were primarily Caucasian, with a median age of 32 (29, 49) and BMI of 38.2 kg/m2. The majority (65%) of participants had elevated CRP and consumed a low-quality diet. Most worked from 11 p.m. to 7 a.m. at least 3 days a week, with a median sleep duration of 7.0 (4.5, 7.0) hours. Time difference of mid-sleep and mid-eating between work and free days was 7.5 (2.0, 11.2) and 5.5 (1.2, 16.0) hours, respectively. CRP was positively associated with BMI (r= 0.883, p=0.002) and waist circumference (WC) (r= 0.850, p=0.004), and empty calories was negatively related to CRP (p=0.025). Both shorter sleep duration and the later the time of fall asleep on work days were positively correlated to CRP (p=0.008, p=0.030). The influence of BMI and WC on CRP remained after accounting for diet and circadian factors.

Conclusion: Our results suggest that, in obese night-shift workers, BMI and WC is the main driver of inflammatory response, but diet quality and sleep patterns may also contribute to inflammation. Further research is needed to determine the primary contributors to inflammation in obese night-shift workers.

Advisor: Heather Rasmussen