Does increased body mass index lead to elevated prostate cancer risk? It depends on waist circumference

Jin Bong Choi,Jun-Pyo Myong,Jung Ho Kim,Yunhee Lee,Inah Kim,U-Syn Ha,Sung-Hoo Hong

doi:10.1186/s12885-020-07089-5

Abstract

BackgroundWe examined the association between obesity and prostate cancer based on both body mass index (BMI) and waist circumference (WC) using the National Health Insurance System (NHIS) database for the entire male population of Korea.MethodsA total of 1,917,430 men who underwent at least one health examination in 2009 without a previous diagnosis of any other cancer were tracked through December 2015. The hazard ratio (HR) and 95% confidence interval (CI) value for the association between prostate cancer and obesity were analyzed using multiple Cox regression model. Since there was a statistically significant interaction between WC and BMI, a multiple HR for prostate cancer was estimated with stratifying both WC and BMI to control the interaction between WC and BMI.ResultsWithout considering WC as an adjustment factor, very weak association between BMI and prostate cancer development risk was observed. When WC was considered as an adjustment factor, no significant change in the HRs for prostate cancer development beyond the reference BMI was observed in the group with WC < 85 cm in the multivariable-adjusted models. However, in the group with WC ≥ 85 cm, the HRs for prostate cancer increased as the BMI increased beyond the reference BMI. In addition, there was a discrepancy in the trend of prostate cancer development according to BMI among the groups with different categories for WC.ConclusionIn groups with abdominal obesity, a significant linear relationship was observed between increasing BMI and prostate cancer risk. Higher the WC category, the stronger was the association with BMI, signifying that the association of BMI with risk of prostate cancer development depends on abdominal obesity.

Highlights

We examined the association between obesity and prostate cancer based on both body mass index (BMI) and waist circumference (WC) using the National Health Insurance System (NHIS) database for the entire male population of Korea
In the obesity group categorized as WC ≥ 90 cm, 3.05% had a normal weight according to the BMI, and 20.65% of the men categorized as the non-obesity group (WC < 90 cm) were obese class 1 according to the BMI
Risk of prostate cancer according to BMI or WC The hazard ratio (HR) for prostate cancer was lowest in subjects with a BMI < 18.5 and highest in those with 23.0 ≤ BMI < 25 in the multivariate-adjusted model (HR 0.93, 95% confidence interval (CI) 0.85 to 1.02 and HR 1.12, 95% CI 1.08 to 1.16)

Summary

Introduction

We examined the association between obesity and prostate cancer based on both body mass index (BMI) and waist circumference (WC) using the National Health Insurance System (NHIS) database for the entire male population of Korea. Though African-American men have still the highest incidence rate, a constant increase has been This increasing trend may partly be explained by rapid population aging, westernized dietary habits, and increased prostate-specific antigen (PSA) screening [5]. In addition to these risk factors, obesity, which showed an upward trend among men, has been reported as a highrisk factor of prostate cancer in Korea [6]. Choi et al BMC Cancer (2020) 20:589 between obesity and prostate cancer risk have been analyzed in multiple studies worldwide [7,8,9,10]. In men, BMI correlates better with lean mass than with body adiposity, and it is hypothesized that metabolically obese but normal-weight (MONW) individuals might have a normal BMI [12]

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