Emory College, Emory University, Atlanta, GA 30322, USA.
Division of Endocrinology, Department of Pediatrics, Emory University School of Medicine, Atlanta, GA 30322, USA.
Nutrients. 2021 Nov 12;13(11):4048. doi: 10.3390/nu13114048.
Cystic fibrosis-related diabetes (CFRD) affects up to half of the people with cystic fibrosis (CF) by adulthood. CFRD is primarily caused by pancreatic dysfunction that leads to insufficient insulin release and/or insulin resistance. Exocrine pancreatic insufficiency in people with CF is associated with fat-soluble vitamin malabsorption, including vitamins A, D, E, and K. This study examined the relationship between vitamin D status, assessed by serum 25-hydroxyvitamin D (25(OH)D), and the development of CF-related diabetes (CFRD) in adults with CF.
This was a retrospective cohort study of adults seen at a single CF center. The data were extracted from the electronic medical records and the Emory Clinical Data Warehouse, a data repository of health information from patients seen at Emory Healthcare. We collected age, race, the first recorded serum 25-hydroxyvitamin D (25(OH)D) concentration, body mass index (BMI), and onset of diabetes diagnosis. Log-rank (Mantel-Cox) tests were used to compare the relative risk of CFRD onset in the subjects with stratified vitamin D status and weight status. A sub-group analysis using chi-square tests assessed the independence between vitamin D deficiency and CFRD risk factors, including gender and CF mutation types (homozygous or heterozygous for F508del, or others). Unpaired -tests were also used to compare the BMI values and serum 25(OH)D between the CF adults based on the CFRD development.
This study included 253 subjects with a mean age of 27.1 years (±9.0), a mean follow-up time period of 1917.1 (±1394.5) days, and a mean serum 25(OH)D concentration of 31.8 ng/mL (±14.0). The majority (52.6%) of the subjects developed CFRD during the study period. Vitamin D deficiency (defined as 25(OH)D < 20 ng/mL) was present in 25.3% of the subjects. Close to two thirds (64.1%) of the subjects with vitamin D deficiency developed CFRD during the study. Vitamin D deficiency increased the risk of developing CFRD (chi-square, 0.03) during the course of the study. The time to the onset of CFRD stratified by vitamin D status was also significant (25(OH)D < 20 ng/mL vs. 25(OH)D ≥ 20 ng/mL) (95% CI: 1.2, 2.7, < 0.0078).
Our findings support the hypothesis that adults with CF and vitamin D deficiency are at a higher risk of developing CFRD and are at risk for earlier CFRD onset. The maintenance of a serum 25(OH)D concentration above 20 ng/mL may decrease the risk of progression to CFRD.
囊性纤维化相关糖尿病（CFRD）在成年期影响多达一半的囊性纤维化（CF）患者。CFRD 主要是由导致胰岛素释放不足和/或胰岛素抵抗的胰腺功能障碍引起的。CF 患者的外分泌胰腺功能不全与脂溶性维生素吸收不良有关，包括维生素 A、D、E 和 K。本研究检查了维生素 D 状态（通过血清 25-羟维生素 D（25（OH）D）评估）与 CF 成人中 CF 相关糖尿病（CFRD）发展之间的关系。
这是一项对单一 CF 中心就诊的成年人进行的回顾性队列研究。数据从电子病历和埃默里临床数据仓库中提取，该数据库是埃默里医疗保健患者健康信息的存储库。我们收集了年龄、种族、首次记录的血清 25-羟维生素 D（25（OH）D）浓度、体重指数（BMI）和糖尿病诊断的发病时间。对数秩（Mantel-Cox）检验用于比较分层维生素 D 状态和体重状态下 CFRD 发病的相对风险。使用卡方检验的亚组分析评估了维生素 D 缺乏与 CFRD 风险因素（包括性别和 CF 突变类型（纯合或杂合 F508del 或其他））之间的独立性。未配对的 t 检验还用于根据 CFRD 发展情况比较 CF 成年人的 BMI 值和血清 25（OH）D。
本研究纳入了 253 名平均年龄为 27.1 岁（±9.0）、平均随访时间为 1917.1（±1394.5）天、平均血清 25（OH）D 浓度为 31.8ng/ml（±14.0）的患者。在研究期间，大多数（52.6%）患者发生 CFRD。维生素 D 缺乏（定义为 25（OH）D <20ng/ml）在 25.3%的患者中存在。在研究期间，近三分之二（64.1%）维生素 D 缺乏的患者发生了 CFRD。维生素 D 缺乏增加了 CFRD 发病的风险（卡方，0.03）在研究过程中。按维生素 D 状态分层的 CFRD 发病时间也有显著差异（25（OH）D <20ng/ml 与 25（OH）D≥20ng/ml）（95%CI：1.2，2.7，<0.0078）。
我们的研究结果支持这样一种假设，即 CF 合并维生素 D 缺乏的成年人发生 CFRD 的风险更高，且发生 CFRD 的风险更早。维持血清 25（OH）D 浓度高于 20ng/ml 可能会降低进展为 CFRD 的风险。
