AUTHOR=Zhang Min , Bai Ye , Wang Yutong , Cui Huijie , Zhang Wenqiang , Zhang Li , Yan Peijing , Tang Mingshuang , Liu Yunjie , Jiang Xia , Zhang Ben 

TITLE=Independent association of general and central adiposity with risk of gallstone disease: observational and genetic analyses

JOURNAL=Frontiers in Endocrinology

VOLUME=15

YEAR=2024

URL=https://www.frontiersin.org/journals/endocrinology/articles/10.3389/fendo.2024.1367229

DOI=10.3389/fendo.2024.1367229

ISSN=1664-2392

ABSTRACT=<sec><title>Background</title><p>General obesity is a well-established risk factor for gallstone disease (GSD), but whether central obesity contributes additional independent risk remains controversial. We aimed to comprehensively clarify the effect of body fat distribution on GSD.</p></sec><sec><title>Methods</title><p>We first investigated the observational association of central adiposity, characterized by waist-to-hip ratio (WHR), with GSD risk using data from UK Biobank (N=472,050). We then explored the genetic relationship using summary statistics from the largest genome-wide association study of GSD (<italic>n<sub>case</sub></italic>=43,639, <italic>n<sub>control</sub></italic>=506,798) as well as WHR, with and without adjusting for body mass index (BMI) (WHR: <italic>n</italic>=697,734; WHR<sub>adj</sub>BMI: <italic>n</italic>=694,649).</p></sec><sec><title>Results</title><p>Observational analysis demonstrated an increased risk of GSD with one unit increase in WHR (HR=1.18, 95%CI=1.14-1.21). A positive WHR-GSD genetic correlation (<inline-formula><mml:math display="inline" id="im1" xmlns:mml="http://www.w3.org/1998/Math/MathML"><mml:mrow><mml:msub><mml:mi>r</mml:mi><mml:mi>g</mml:mi></mml:msub></mml:mrow></mml:math></inline-formula> =0.41, <italic>P</italic>=1.42×10<sup>-52</sup>) was observed, driven by yet independent of BMI (WHR<sub>adj</sub>BMI: <inline-formula><mml:math display="inline" id="im2" xmlns:mml="http://www.w3.org/1998/Math/MathML"><mml:mrow><mml:msub><mml:mi>r</mml:mi><mml:mi>g</mml:mi></mml:msub></mml:mrow></mml:math></inline-formula> =0.19, <italic>P</italic>=6.89×10<sup>-16</sup>). Cross-trait meta-analysis identified four novel pleiotropic loci underlying WHR and GSD with biological mechanisms outside of BMI. Mendelian randomization confirmed a robust WHR-GSD causal relationship (OR=1.50, 95%CI=1.35-1.65) which attenuated yet remained significant after adjusting for BMI (OR=1.17, 95%CI=1.09-1.26). Furthermore, observational analysis confirmed a positive association between general obesity and GSD, corroborated by a shared genetic basis (<inline-formula><mml:math display="inline" id="im3" xmlns:mml="http://www.w3.org/1998/Math/MathML"><mml:mrow><mml:msub><mml:mi>r</mml:mi><mml:mi>g</mml:mi></mml:msub></mml:mrow></mml:math></inline-formula> =0.40, <italic>P</italic>=2.16×10<sup>-43</sup>), multiple novel pleiotropic loci (N=11) and a causal relationship (OR=1.67, 95%CI=1.56-1.78).</p></sec><sec><title>Conclusion</title><p>Both observational and genetic analyses consistently provide evidence on an association of central obesity with an increased risk of GSD, independent of general obesity. Our work highlights the need of considering both general and central obesity in the clinical management of GSD.</p></sec>