Sedentary behavior and health outcomes: an overview of systematic reviews.

Leandro Fornias Machado De Rezende,Juan Pablo Rey-López,Olinda Do Carmo Luiz,Victor Keihan Rodrigues Matsudo,Maurício Rodrigues Lopes,Alejandro Lucia

doi:10.1371/journal.pone.0105620

Abstract

Objective1) To synthesize the current observational evidence for the association between sedentary behavior and health outcomes using information from systematic reviews. 2) To assess the methodological quality of the systematic reviews found.Methodology/Principal FindingsMedline; Excerpta Medica (Embase); PsycINFO; and Web of Science were searched for reviews published up to September 2013. Additional publications were provided by Sedentary Behaviour Research Network members. The methodological quality of the systematic reviews was evaluated using recommended standard criteria from AMSTAR. For each review, improper use of causal language in the description of their main results/conclusion was evaluated. Altogether, 1,044 review titles were identified, 144 were read in their entirety, and 27 were included. Based on the systematic reviews with the best methodological quality, we found in children and adolescents, strong evidence of a relationship between time spent in sedentary behavior and obesity. Moreover, moderate evidence was observed for blood pressure and total cholesterol, self-esteem, social behavior problems, physical fitness and academic achievement. In adults, we found strong evidence of a relationship between sedentary behavior and all-cause mortality, fatal and non-fatal cardiovascular disease, type 2 diabetes and metabolic syndrome. In addition, there is moderate evidence for incidence rates of ovarian, colon and endometrial cancers.ConclusionsThis overview based on the best available systematics reviews, shows that sedentary behavior may be an important determinant of health, independently of physical activity. However, the relationship is complex because it depends on the type of sedentary behavior and the age group studied. The relationship between sedentary behavior and many health outcomes remains uncertain; thus, further studies are warranted.

Highlights

Based on the systematic reviews with the best methodological quality, we found in children and adolescents, strong evidence of a relationship between time spent in sedentary behavior and obesity
There is moderate evidence for incidence rates of ovarian, colon and endometrial cancers. This overview based on the best available systematics reviews, shows that sedentary behavior may be an important determinant of health, independently of physical activity
The relationship is complex because it depends on the type of sedentary behavior and the age group studied

Summary

Introduction

Lack of moderate to vigorous physical activity, [1] is strongly related to the main non-communicable diseases such as coronary heart disease, [2] type 2 diabetes [3] and certain types of cancer. [4] In addition, many studies have demonstrated that physical inactivity is an important determinant of all-cause mortality. [5,6].recently a new paradigm in the physical activity field has emerged. [7] Many epidemiological studies have consistently shown that spending excessive time engaged in sedentary behaviors may have a negative impact on several health outcomes, independently of moderate to vigorous physical activity. [8,9] Sedentary behavior is defined as time spent engaged in sitting or lying down activities that require an energy expenditure of 1.0 to 1.5 basal metabolic rates. [10] Sedentary activities are described in different domains, such as work, leisure/entertainment and commuting.[11,12,13] In addition, these activities have been categorized as nondiscretionary or discretionary. [7] Many epidemiological studies have consistently shown that spending excessive time engaged in sedentary behaviors may have a negative impact on several health outcomes, independently of moderate to vigorous physical activity. An overview of systematic reviews is needed to cover all types of sedentary behavior, health outcomes and age groups, taking into account the methodological quality of the systematic reviews. This overview method has been used in medical and behavioral studies. This overview method has been used in medical and behavioral studies. [42,43]

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Conclusion