AUTHOR=Yang Ming , Shangguan Qing , Xie Guobo , Sheng Guotai , Yang Jingqi TITLE=The U-shaped association of fasting plasma glucose to HbA1c ratio with mortality in diabetic and prediabetic populations: the mediating role of systemic immune-inflammation index JOURNAL=Frontiers in Endocrinology VOLUME=16 YEAR=2025 URL=https://www.frontiersin.org/journals/endocrinology/articles/10.3389/fendo.2025.1465242 DOI=10.3389/fendo.2025.1465242 ISSN=1664-2392