Jiang Wenwen, Li Ling, Wang Wei, Liang Yue, Bai Xiaoyong, Xu Yixin, Guo Qingyu, Ge Lichao, Liang Jingjing, Lu Bin, Shao Jiaqing
Department of Endocrinology, Jinling Hospital, Nanjing Medical University, Nanjing, Jiangsu, China.
Department of Endocrinology, Chinese Navy No.971.Hospital, Qingdao, Shandong, China.
Front Endocrinol (Lausanne). 2025 Jul 7;16:1573963. doi: 10.3389/fendo.2025.1573963. eCollection 2025.
To explore the association of circulating 25-hydroxyvitamin D [25(OH)D] with time in range and insulin secretion in type 2 diabetes.
911 patients diagnosed with type 2 diabetes mellitus (T2DM) were included, and they underwent 3-day continuous glucose monitoring (CGM) and serum 25(OH)D measurements. The subjects were categorized into three groups based on the tertiles of their serum 25(OH)D levels: G1 (25(OH)D ≤ 21.22 ng/mL), G2 (21.22 ng/mL ≤ 25(OH)D < 26.43 ng/mL), and G3 (25(OH)D ≥ 26.43 ng/mL). TIR and glycemic variability (GV) parameters were evaluated with CGM. Insulin resistance was evaluated via the homeostatic model assessment of insulin resistance (HOMA-IR). The pancreatic β-cell function was determined using the homeostasis model assessment of β-cell function (HOMA-β). Among the 911 enrolled subjects, 582 individuals underwent a 100g standardized steamed bread meal test to comprehensively evaluate the pancreatic β-cell secretory function.
A higher TIR and time in tight range (TITR) were observed among individuals in the upper tertile for 25(OH)D, surpassing those in the middle and lower tertiles. The results of correlation analysis revealed that serum 25(OH)D levels were significantly positively correlated with TIR and TITR. Conversely, serum 25(OH)D levels were negatively associated with time above range, GV parameters, hemoglobin A1c (HbA1c), and HOMA-IR. However, no significant association was observed between serum 25(OH)D levels and HOMA-β. Additionally, the correlation between 25(OH)D and TIR (=0.217, <0.001) was slightly stronger than that between 25(OH)D and HbA1c (=-0.130, <0.001). Multiple stepwise linear regression analysis indicated that serum 25(OH)D levels were an independent influencing factor for TIR. Among individuals who underwent the steamed bread meal test, serum 25(OH)D exhibited a positive correlation with indicators of early-phase and overall pancreatic β-cell secretion capacity.
This study demonstrated that in patients with T2DM, 25(OH)D levels exhibited positive correlations with TIR and glucose-stimulated insulin secretion parameters, while showing negative correlations with GV parameters. Lower serum 25(OH)D levels may adversely impact glucose homeostasis and pancreatic β-cell secretory function in T2DM patients.
探讨2型糖尿病患者循环25-羟维生素D[25(OH)D]水平与血糖达标时间及胰岛素分泌的关系。
纳入911例2型糖尿病（T2DM）患者，进行为期3天的连续血糖监测（CGM）及血清25(OH)D检测。根据血清25(OH)D水平三分位数将研究对象分为三组：G1组（25(OH)D≤21.22 ng/mL）、G2组（21.22 ng/mL＜25(OH)D＜26.43 ng/mL）和G3组（25(OH)D≥26.43 ng/mL）。通过CGM评估血糖达标时间（TIR）和血糖波动（GV）参数。采用稳态模型评估胰岛素抵抗（HOMA-IR）评估胰岛素抵抗。使用β细胞功能稳态模型评估（HOMA-β）测定胰岛β细胞功能。在911例入组对象中，582例进行了100g标准馒头餐试验，以综合评估胰岛β细胞分泌功能。
25(OH)D水平处于上三分位数的个体TIR和严格血糖控制时间（TITR）更高，超过中、下三分位数个体。相关性分析结果显示，血清25(OH)D水平与TIR和TITR显著正相关。相反，血清25(OH)D水平与血糖高于目标范围时间、GV参数、糖化血红蛋白（HbA1c）和HOMA-IR呈负相关。然而，血清25(OH)D水平与HOMA-β之间未观察到显著相关性。此外，25(OH)D与TIR的相关性（=0.217，＜0.001）略强于25(OH)D与HbA1c的相关性（=-0.130，＜0.001）。多元逐步线性回归分析表明，血清25(OH)D水平是TIR的独立影响因素。在进行馒头餐试验的个体中，血清25(OH)D与胰岛β细胞早期及整体分泌能力指标呈正相关。
本研究表明，在T2DM患者中，25(OH)D水平与TIR及葡萄糖刺激的胰岛素分泌参数呈正相关，与GV参数呈负相关。较低的血清25(OH)D水平可能对T2DM患者的葡萄糖稳态和胰岛β细胞分泌功能产生不利影响。
