Weight gain, overweight and obesity in solid organ transplantation--a study protocol for a systematic literature review.

Sonja Beckmann,Todd Ruppar,Sabina De Geest,Nataša Ivanović,Gerda Drent

doi:10.1186/2046-4053-4-2

Abstract

BackgroundOverweight and obesity, which have a substantial impact on health in the general population, have similar prevalence in solid organ transplant recipients but carry even more serious ramifications. As this group’s use of immunosuppressive medication increases the risk for comorbidities, e.g. metabolic syndrome and cardiovascular disease, the prevention of additional risk factors is vital. This systematic review will be the first to summarize the issue of weight gain, overweight and obesity concurrently within and across solid organ transplantation. The three research questions relating to solid organ transplantation are the following: (1) What are the prevalence and evolution of overweight and obesity from pre- to post-transplant?; (2) Which pre- and post-transplant risk factors are associated with post-transplant weight gain, overweight or obesity? and (3) Which post-transplant patient outcomes and comorbidities are associated with pre- and post-transplant weight gain, overweight and obesity?Methods/DesignMEDLINE via PubMed, The Cochrane Library, Cumulative Index to Nursing and Allied Health (CINAHL), PsycINFO and Excerpta Medica DataBase (EMBASE) will be searched for original quantitative studies in adult liver, heart, lung or kidney transplant patients. Topics of interest will be the prevalence and evolution of overweight and obesity over time, risk factors associated with changes in weight or body mass index (BMI), overweight and obesity, and the relationship of weight or BMI with post-transplant outcomes and comorbidities. Screening of titles and abstracts, full-text reading and data extraction will be divided between three researchers. Researchers will cross-check one another’s screening decisions for random samples of studies to adhere as closely as possible to the recommendations of The Cochrane Collaboration. For quality assessment, a purpose-adapted 19-item instrument will be used. Effect sizes will be calculated for relationships investigated in a minimum of five studies. Random effects meta-analysis with moderator analyses will be conducted if applicable.DiscussionThis systematic review will comprehensively synthesize the existing evidence concerning weight gain, overweight and obesity in solid organ transplantation in view of magnitude, influencing factors and associations with patient outcomes and comorbidities. The results can fuel the development of interventions to prevent weight gain in the solid organ transplant population.Systematic review registrationPROSPERO CRD42014009151Electronic supplementary materialThe online version of this article (doi:10.1186/2046-4053-4-2) contains supplementary material, which is available to authorized users.

Highlights

Overweight and obesity, which have a substantial impact on health in the general population, have similar prevalence in solid organ transplant recipients but carry even more serious ramifications
To summarize the evidence on risk factors, we propose a model based on the dynamic energy balance framework incorporating the environmental, behavioural, psychological, biological and genetic factors as well as their interrelationships and we will expand the model with specific treatment- and disease-related factors in transplantation
Which pre- and post-transplant risk factors are associated with post-transplant weight gain, overweight or obesity in adult solid organ transplant recipients?

Summary

Introduction

Overweight and obesity, which have a substantial impact on health in the general population, have similar prevalence in solid organ transplant recipients but carry even more serious ramifications As this group’s use of immunosuppressive medication increases the risk for comorbidities, e.g. metabolic syndrome and cardiovascular disease, the prevention of additional risk factors is vital. In 2008, more than 1.4 billion adults were overweight, of whom roughly 500 million were obese, indicating that the worldwide prevalence of obesity doubled from 1980 to 2008 [2] This development is underpinned by the fact, between 1990 and 2010, in terms of worldwide ranking, “high BMI” climbed as a risk factor for disease burden from the tenth position to the sixth [3]. In Europe, North and South America, Central Asia and parts of Africa, “high BMI” even ranked among the top four risk factors for disease burden, following only high blood pressure, smoking and alcohol use [3]

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