Is There Any Association Between Body Mass Index and Severity of Dengue Infection?

Abstract

Introduction: Dengue, an acute infectious disease caused by a flavivirus, is a threat to global health. There is sparse evidence exploring obesity and the development of a more severe dengue cases in adults. With increasing prevalence of obesity in areas with high risk of dengue infection, obesity may increase the burden and mortality related to dengue infection. Our study aimed to determine the association between obesity and the development of a more severe dengue infection in the primary health care setting and whether these associations were modified by dengue fever phase. Methods: A cohort study was conducted among laboratory confirmed dengue patients aged > 18 years in the central region of Peninsular Malaysia from May 2016 to November 2017. We collected demographic, clinical history, physical examination, and laboratory examination information using a standardized form. Dengue severity (DS) was defined as either dengue with warning signs or severe dengue. Participants underwent daily follow-up during which we recorded their vital signs, warning signs and full blood count results. Incidence of DS were modelled using mixed-effects logistic regression. Changes in platelet and hematocrit were modelled using mixed-effects linear regression. The final multivariable models were adjusted for age, gender, ethnicity, and previous dengue infection. Results: A total of 173 patients were enrolled and followed up. The mean BMI was 37.4 ± 13.75 kg/m2. Majority of patients were malay (65.9%), followed by Chinese (17.3%), Indian (12.7%), and other ethnics (4.1%). A total of 90 (52.0%) patients were male while 36 (20.8%) patients have previous history of dengue infection. Body mass index (BMI, kg/m2) was significantly associated with DS (aOR=1.17; 95% CI:1.04,1.34) and hematocrit (%) (aβ=0.09; 95% CI:0.01,0.16), but not with platelet (x103/µL) (aβ=-0.01; 95% CI:-0.84,0.81). In the dose response analysis, we found that as BMI increases, the odds of DS, hematocrit levels, and platelet levels increase at the first phase of dengue fever. Discussion: Higher BMI and higher hematocrit levels were associated with higher odds of DS. Among those with high BMI, the development of DS was observed at phase one of dengue fever instead of at phase two. These novel results could be used by the clinicians to help them risk stratify dengue patients for closer monitoring and subsequent prevention of severe dengue complications. Trial Registration Number: Since the study was conducted at the public health clinics, application had also be made to the National Medical Research Register, Ministry of Health Malaysia (Registration number: NMRR-14-1777-20233 and Ref: (15)KKM/NIHSEC/P15-1089). Funding Statement: We acknowledge The University Malaya Research Grant Program - HTM (Wellness) (Grant No: RP034B-15HTM) and the University Malaya Postgraduate Research Grant - Research (Grant No: PG163-2015B) funded all the related expenses to run this study. Declaration of Interests: Dr. Zulkipli has nothing to disclose. All other authors have nothing to disclose. Ethics Approval Statement: Ethics approval had been granted by University Malaya Medical Centre Medical Ethics Committee (Ref: MECID.NO:20143-68).