Association between body mass index and sex hormones among men: Evidence from cross-sectional and Mendelian randomization studies - 03/09/24

Doi : 10.1016/j.orcp.2024.08.004

Junhao Chen ^a,^{^{1
https://orcid.org/0000–0003-1836–7524},}^{^{2
Contributed equally}}, Zilin Wang ^b,^{^{2
Contributed equally},}^{^{3
https://orcid.org/0009–0005-8464–0674}}, Yi Zhou ^a,^{^{4
https://orcid.org/0009–0002-2106–5375}}, Zhien Zhou ^a,^{^{5
https://orcid.org/0009–0002-4357–3303}}, Weigang Yan ^a,^⁎,^{^{6
https://orcid.org/0000–0002-8995–1456}}
^a Department of Urology, Peking Union Medical College Hospital, Chinese Academy of Medical Sciences, Beijing 100730, China
^b Department of Urology, Institute of Urology, West China Hospital, Sichuan University, Chengdu, Sichuan 610041, China

^⁎Correspondence to: Department of Urology, Surgical Building of Peking, Union Medical College Hospital, No.1 Shuaifuyuan, Wangfujing, Dong Cheng District, Beijing 100730, China.Department of Urology, Surgical Building of Peking, Union Medical College HospitalNo.1 Shuaifuyuan, Wangfujing, Dong Cheng DistrictBeijing100730China

Sous presse. Épreuves corrigées par l'auteur. Disponible en ligne depuis le Tuesday 03 September 2024

Abstract

Purpose

This study aims to investigate the association between Body Mass Index (BMI) and sex hormone levels utilizing a cross-sectional study design alongside Mendelian randomization (MR) analysis.

Materials and methods

A cross-sectional study was performed based on National Health and Nutrition Examination Survey (NHANES) 2013–2016. Additionally, a two-sample MR analysis was performed, utilizing Single Nucleotide Polymorphisms (SNPs) associated with BMI identified in a genome-wide association study (GWAS) comprising 339224 individuals. Data on outcomes, including total testosterone (TT, 199569 samples), estradiol (E₂, 17134 samples), and sex hormone binding globulin (SHBG, 185211 samples), were sourced from the United Kingdom Biobank (UKB).

Results

In cross-sectional analysis involving 4092 males, multivariable linear regression demonstrated that each unit increase in BMI was positively correlated with an elevated risk of testosterone deficiency (TD), increased E₂ levels, and a reduced TT, SHBG, free androgen index and TT/E₂. Subsequent quartile division of BMI revealed, through multivariable logistic regression, that higher BMI quartiles were associated with a greater TD risk, elevated E₂ levels, and reduced TT, SHBG, and TT/E₂ levels compared to quartile 1 (P for trend <0.001). In the MR analysis, a causal effect was established, with each unit increase in BMI being associated with decreased TT (β = −0.17; 95 % CI −0.24 to −0.09) and SHBG (β = −0.13; 95 % CI −0.21 to −0.05) levels.