Beijing Tongren Hospital, Capital Medical University, Beijing, China.
Department of Endocrinology, Beijing Tongren Hospital, Capital Medical University, Beijing, China.
Respir Res. 2020 Nov 4;21(1):292. doi: 10.1186/s12931-020-01538-2.
There is increasing evidence that the lung is a target organ of diabetes. This study aimed to examine in detail the association between diabetes mellitus and pulmonary function using a national cohort. We also aimed to explore the non-linear association between pulmonary function and blood glucose, insulin resistance, and C-reactive protein (CRP).
A total of 30,442 participants from the National Health and Nutrition Examination Survey from the period between 2007 and 2012 were included. The cross-sectional association between diabetes mellitus and pulmonary function was assessed using multiple linear regression. Where there was evidence of non-linearity, we applied a restricted cubic spline with three knots to explore the non-linear association. Partial mediation analysis was performed to evaluate the underlying mechanism. All analyses were weighted to represent the US population and to account for the intricate survey design.
A total of 8584 people were included in the final study population. We found that diabetes was significantly associated with reduced forced expiratory volume in one second (FEV) and forced vital capacity. We further found L-shaped associations between hemoglobin A1c (HbA1c) and pulmonary function. There was a negative association between HbA1c and FEV in diabetes participants with good glucose control (HbA1c < 7.0%), but not in patients with poor glucose control. A non-linear association was also found with fasting plasma glucose, 2 h-plasma glucose after oral glucose tolerance test, insulin resistance, and CRP. Finally, we found that diabetes duration did not affect pulmonary function, and the deleterious effect of diabetes on pulmonary function was mediated by hyperglycemia, insulin resistance, low-grade chronic inflammation (CRP), and obesity.
Diabetes mellitus is non-linearly associated with pulmonary function. Our finding of a negative association between HbA1c and FEV in diabetes patients with good glucose control but not in patients with poor glucose control indicates that a stricter glycemic target should be applied to diabetic patients to improve pulmonary function. Given, the cross-sectional nature of this research, a longitudinal study is still needed to validate our findings.
越来越多的证据表明，肺是糖尿病的靶器官。本研究旨在使用全国队列详细研究糖尿病与肺功能之间的关系。我们还旨在探讨肺功能与血糖、胰岛素抵抗和 C 反应蛋白 (CRP) 之间的非线性关系。
共纳入 2007 年至 2012 年期间国家健康和营养检查调查的 30442 名参与者。使用多元线性回归评估糖尿病与肺功能之间的横断面关联。在存在非线性证据的情况下，我们应用带有三个结的限制立方样条来探索非线性关联。进行部分中介分析以评估潜在机制。所有分析均经过加权处理，以代表美国人口并考虑到复杂的调查设计。
共有 8584 人纳入最终研究人群。我们发现糖尿病与一秒用力呼气量 (FEV) 和用力肺活量降低显著相关。我们进一步发现血红蛋白 A1c (HbA1c) 与肺功能之间呈 L 形关联。在血糖控制良好 (HbA1c<7.0%) 的糖尿病患者中，HbA1c 与 FEV 之间存在负相关，但在血糖控制不佳的患者中则没有。还发现空腹血糖、口服葡萄糖耐量试验后 2 小时血糖、胰岛素抵抗和 CRP 与肺功能之间存在非线性关联。最后，我们发现糖尿病病程不会影响肺功能，糖尿病对肺功能的有害影响是由高血糖、胰岛素抵抗、低度慢性炎症 (CRP) 和肥胖介导的。
糖尿病与肺功能呈非线性相关。我们发现血糖控制良好的糖尿病患者 HbA1c 与 FEV 之间存在负相关，而血糖控制不佳的患者则没有，这表明应向糖尿病患者应用更严格的血糖目标以改善肺功能。鉴于本研究的横断面性质，仍需要进行纵向研究来验证我们的发现。
