Li Qing, Zhang Wen, Han Bing, Wang Yu-Ying, Wan Heng, Zhang Min, Wang Ning-Jian, Lu Ying-Li
Institute and Department of Endocrinology and Metabolism, Shanghai Ninth People's Hospital, Shanghai Jiaotong University School of Medicine, Shanghai, 200011, China.
Institute and Department of Endocrinology and Metabolism, Qingpu Branch of Zhongshan Hospital Affiliated to Fudan University, Shanghai, 201700, China.
Curr Med Sci. 2023 Oct;43(5):919-926. doi: 10.1007/s11596-023-2780-z. Epub 2023 Sep 12.
Islet α cells input is essential for insulin secretion from β cells. The present study aims to investigate the association between 25-hydroxyvitamin D [25(OH)D] and islet function homeostasis in type-2 diabetes (T2D) patients.
A total of 4670 T2D patients from seven communities in Shanghai, China were enrolled. The anthropometric indices, biochemical parameters, serum 25(OH)D, and islet function [including C-peptide (C-p) and glucagon] were measured.
The fasting plasma glucose (FPG), glycated hemoglobin (HbA1c), glucagon, and C-p levels exhibited a significantly decreasing trend in T2D patients as the 25(OH)D levels increased. Next, the population was divided into two groups: abdominal obesity and non-abdominal obesity groups. After adjustment, the 25(OH)D level was found to be associated with HbA1c, glucagon, and homeostasis model assessment of β (HOMA-β) in the non-abdominal obesity group. There was a significant relationship between 25(OH)D and HbA1c, glucagon, HOMA-IR, baseline insulin or C-p in the abdominal obesity group. In the abdominal obesity group, the ordinary least squares (OLS) regression and quantile regression revealed that 25(OH) D was obviously associated with glucagon and fasting C-p levels. In the abdominal obesity group, the moderate analysis revealed a significant interaction effect of 25(OH)D and glucagon on C-p (P=0.0124). Furthermore, the conditional indirect effect of 25(OH)D on the glucagon/C-p ratio was significantly lower at 1 standard deviation (SD) below the mean (P=0.0002), and lower at the mean of the course of diabetes (P=0.0007).
25(OH)D was found to be negatively correlated to glucagon and C-p in T2D patients with abdominal obesity. The 25(OH)D influenced C-p in part by influencing glucagon. The effect of 25(OH)D on the glucagon/C-p ratio in T2D patients with abdominal obesity, in terms of islet homeostasis, is influenced by the course of diabetes.
胰岛α细胞输入对于β细胞分泌胰岛素至关重要。本研究旨在探讨2型糖尿病（T2D）患者中25-羟基维生素D [25(OH)D]与胰岛功能稳态之间的关联。
纳入了来自中国上海七个社区的4670例T2D患者。测量了人体测量指标、生化参数、血清25(OH)D和胰岛功能[包括C肽（C-p）和胰高血糖素]。
随着25(OH)D水平升高，T2D患者的空腹血糖（FPG）、糖化血红蛋白（HbA1c）、胰高血糖素和C-p水平呈现出显著下降趋势。接下来，将人群分为两组：腹型肥胖组和非腹型肥胖组。调整后发现，在非腹型肥胖组中，25(OH)D水平与HbA1c、胰高血糖素和β细胞稳态模型评估（HOMA-β）相关。在腹型肥胖组中，25(OH)D与HbA1c、胰高血糖素、HOMA-IR、基础胰岛素或C-p之间存在显著关系。在腹型肥胖组中，普通最小二乘法（OLS）回归和分位数回归显示，25(OH)D与胰高血糖素和空腹C-p水平明显相关。在腹型肥胖组中，中介分析显示25(OH)D和胰高血糖素对C-p有显著的交互作用（P = 0.0124）。此外，在低于均值1个标准差（SD）时，25(OH)D对胰高血糖素/C-p比值的条件间接效应显著降低（P = 0.0002），在糖尿病病程均值时也降低（P = 0.0007）。
在腹型肥胖的T2D患者中，发现25(OH)D与胰高血糖素和C-p呈负相关。25(OH)D部分通过影响胰高血糖素来影响C-p。就胰岛稳态而言，25(OH)D对腹型肥胖T2D患者胰高血糖素/C-p比值的影响受糖尿病病程影响。
