Introduction:
Human health such as cardio-metabolic and mental health is related to sleeping habits, suggested by epidemiological evidence(1, 2). Most of evidence suggest that sleep duration and quality can influence on health of variety of systems in human body(3). Sleep is also very important for strengthening memory, improving vision, maintaining body temperature, maintaining and recovering energy(4), and restoration of the brain energy metabolism(5). Therefore, sleep disorders may significantly affect the occupational, physical, cognitive and social performance of people and impair their quality of life(6).
Hormonal disruption, metabolic impairment and inflammatory process can play a role in the relationship between sleep and health status(7, 8).
The quality of diet can affect sleep quality and health of individuals and for this reason, has recently been considered by researchers(9).
Studies have shown that diet plays an important role in causing or modulating inflammation in the body. Accordingly, it has been shown that following a Western diet increases inflammation, and following healthy diets such as the Mediterranean diet can be effective in reducing inflammation(10-12).
CRP, -glutamyl transferase (GGT), carotenoids, uric acid, vitamin C, and vitamin D, are several biomarkers of inflammation and antioxidants, that have been related to sleep quality parameters and duration(13).
Evidence shows that there is an association between diet quality and inflammation, and a healthy dietary pattern can result in lower CRP levels(14).
Various diet quality scores have been developed to assess adherence to desirable priori-defined diets and patterns comprehensively and to investigate the health effects of these diets(15).
The Dietary Inflammatory Index (DII®) is a literature-derived score that has been developed to evaluate the inflammatory potential of the diet and link diet to inflammation. It takes into account six inflammatory markers (i.e., CRP, IL-1beta, IL-4, IL-6, IL-10, and TNF-alpha). The DII has proven to be of value for its association with health status in the general population(16, 17).
Of the other priori-defined dietary patterns, the Dietary Approaches to Stop Hypertension (DASH) diet, which recommends higher intakes of whole grains, fruits, vegetables, nuts, seeds, legumes, and low-fat dairy, and lower intakes of processed meat, sodium, and sweetened beverages, was originally developed to manage high blood pressure(18). The other score for evaluating the dietary quality is HEI score. The HEI is designed to examine the overall quality of diets, its adaptation and compatibility and coordination with dietary guidelines and food pyramid in 1995. This index is designed to evaluate diet quality in different societies with different dietary patterns(19).
Technical-administrative employees at universities mainly perform office tasks, in some cases involving much responsibility and demanding high levels of concentration. As a result, this population of workers might be more exposed to situations which might interfere with the duration of sleep. Given that the role of nutrition in employees’ sleep quality has not been investigated to date, this study aims to investigate the relationship between Dietary Inflammatory Score, HEI score and DASH score, and sleep quality in employees.