AUTHOR=Wang Bo , Jiang Chunqi , Yu Pingping , Nie Zhen , Wang Ning , Zhang Xin TITLE=Curvilinear relationship between life's crucial 9 and metabolic syndrome in U.S. adults: a cross-sectional study JOURNAL=Frontiers in Endocrinology VOLUME=Volume 16 - 2025 YEAR=2025 URL=https://www.frontiersin.org/journals/endocrinology/articles/10.3389/fendo.2025.1559413 DOI=10.3389/fendo.2025.1559413 ISSN=1664-2392