Body mass index in an Australian population with chronic kidney disease

Helen G. Healy,Samuel Chan,Anne Cameron,Wendy E. Hoy,Ken S. Tan,Zaimin Wang,Sree K. Venuthurupalli

doi:10.1186/s12882-018-1006-2

Abstract

BackgroundObesity emerged as the leading global health concern in 2017. Although higher body mass index (BMI) is a health risk in the general population, its implications for chronic kidney disease (CKD) are not entirely clear. Our aim was to compare BMI in an Australian CKD population with BMI in a sample of the general Australian population, and, in the same group of CKD patients, to describe associations of higher BMI categories with demographic and clinical features.MethodsA cross-sectional study of BMI in CKD patients was conducted from three major sites who were enrolled in the CKD.QLD registry between May 2011 and July 2015. BMI was categorized according to the World Health Organisation (WHO) guidelines. The prevalence of obesity was compared with a sample of the general Australian population from the most recent National Health Survey (NHS). Associations of BMI with demographic and clinical characteristics of the CKD patients were also analysed.ResultsThere were 3382 CKD patients in this study (median age 68, IQR 56–76 years); 50.5% had BMI ≥30, the WHO threshold for obesity, in contrast with 28.4% having BMI ≥30 in the NHS cohort. Higher BMI categories were correlated with age < 70 years, male gender, and lower socioeconomic status. After adjustment for age and gender, characteristics which significantly correlated with higher BMI category included hypertension, dyslipidemia, diabetes, diabetic nephropathy, coronary heart disease, other cardiovascular diseases, gout, obstructive sleep apnoea, depression and chronic lung disease.ConclusionsPatients with CKD in public renal specialty practices in Queensland have strikingly higher rates of obesity than the general Australian population. Within the CKD population, low socio-economic position strongly predisposes to higher BMI categories. Higher BMI categories also strongly correlated with important co-morbidities that contribute to burden of illness. These data flag major opportunities for primary prevention of CKD and for reductions in morbidity in people who already have CKD, which should be considered in public health policy in relation to obesity.

Highlights

IntroductionHigher body mass index (BMI) is a health risk in the general population, its implications for chronic kidney disease (CKD) are not entirely clear
Obesity emerged as the leading global health concern in 2017
Earlier studies have suggested that a higher body mass index (BMI) was associated with an increased risk of developing chronic kidney disease (CKD) [6,7,8,9], whilst other investigations found no association between BMI and CKD [10–14]

Summary

Introduction

Higher body mass index (BMI) is a health risk in the general population, its implications for chronic kidney disease (CKD) are not entirely clear. Our aim was to compare BMI in an Australian CKD population with BMI in a sample of the general Australian population, and, in the same group of CKD patients, to describe associations of higher BMI categories with demographic and clinical features. Body mass index (BMI) has been proposed to drive the development and/or progression of chronic kidney disease (CKD) [4, 5]. There is no conclusive evidence that the impact of obesity in the CKD population is the same as in the general population without CKD, where most of the health association research has been performed. Unknown are the contributions of patient demographics, clinical phenotype or a combination of both, to the obesity signal in CKD

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