Fetmaparadoxen, myt eller sanning hos vuxna med kardiovaskulär sjukdom
Sahlgrenska AcademyAt University of GothenburgDepartment of Internal Medicine and Clinical NutritionAbstractTitle: The obesity paradox, myth or truth in adults with cardiovascular disease.Author: Louise Svensson och Amanda NilssonSupervisor: Fredrik BertzExaminer: Ingrid LarssonProgramme: Dietician study programme, 180/240 ECTSType of paper: Examination paper, 15 hpDate: May 30, 2013Background: It has long been generally accepted that obesity is a risk factor for many diseases. Despite this, new research indicates that a higher BMI could be a protective factor for those with a chronic cardiovascular disease. This discovery is called the obesity paradox and could change the perception of patients' BMI in both public health and clinical work.Objective: The objective of this systematic review article is to examine the scientific evidence for the existence of the obesity paradox in chronic cardiovascular disease, i.e. if a BMI >25 kg/m2 is associated with lower mortality among adults with chronic cardiovascular disease.Search strategy: The databases used in the literature study were PubMed, Summon, Scopus and Cochrane. The keywords were: obesity paradox, cardiovascular, heart, male, BMI, intentional weight loss, cardiovascular mortality and mortality heart failure.Selection criteria: Studies, which had an adult population classified after BMI that suffered from chronic cardiovascular disease and had all-cause mortality and cardiovascular mortality as endpoints, were included.Data collection and analysis: Ten studies were included. They were all estimated to be of medium to high study quality. The conclusions were graded according to GRADE on the endpoints of all-cause mortality and cardiovascular mortality.Main results: A correlation between increasing BMI and decreasing mortality was found in the studies. In participants with very low BMI and extreme obesity, mortality was the highest.Conclusions: In studies where the reference group was BMI 18,5-24,9m2, there was no evident correlation between BMI and mortality among patients with chronic heart disease. The evidence level was low (++). In studies where there was no lower BMI-limit defined, underweight could be included and therefore the evidence level was very low (+). In these cases a high BMI could be protective for mortality particularly in short term. The contributing effects of a high BMI and effects of a lifestyle are difficult to distinguish.