To investigate tear neuropeptide Y (NPY) and substance P concentrations in individuals with type 1 diabetes, comparing those with and without both diabetic retinopathy (DR) and peripheral neuropathy. This cross-sectional study involved 41 participants with type 1 diabetes and none to moderate DR, and 22 healthy controls. Assessments included clinical ocular surface parameters, quantification of corneal nerve attributes (based on confocal microscopy imaging), DR grading, and evaluation for small and large fibre neuropathy. Concentrations of NPY and substance P in tear samples were measured using enzyme-linked immunosorbent assay. Mean (± standard deviation) tear NPY concentrations in participants with type 1 diabetes and length-dependent small fibre neuropathy (SFN) was lower than in controls (10.84 ± 4.10 ng/mL vs 14.72 ± 3.12 ng/mL; 0.004), but not significantly different from type 1 diabetes participants without SFN (13.39 ± 4.66 ng/mL; 0.11). Tear NPY levels were lower in individuals with type 1 diabetes and mild/moderate non-proliferative DR (10.44 ± 3.46 ng/mL) compared to none/minimal DR (13.79 ± 4.76 ng/mL; 0.0005) and controls. In separate linear regression models, both the presence of SFN (β = −0.75, 0.02) and the presence of mild/moderate DR (β = −0.84, 0.009) were significantly associated with tear NPY levels relative to controls, after adjusting for participant age, sex, and dry eye disease. There were no inter-group differences for tear substance P concentrations. Tear NPY has potential utility as an indicator of peripheral microvascular complications associated with type 1 diabetes.

中文翻译：

---

泪液神经肽 Y 作为 1 型糖尿病外周微血管并发症的非侵入性标志物


旨在研究 1 型糖尿病患者的泪液神经肽 Y (NPY) 和 P 物质浓度，比较患有和不患有糖尿病视网膜病变 (DR) 和周围神经病变的患者。这项横断面研究涉及 41 名患有 1 型糖尿病且无至中度 DR 的参与者，以及 22 名健康对照者。评估包括临床眼表参数、角膜神经属性的量化（基于共聚焦显微镜成像）、DR 分级以及小纤维神经病和大纤维神经病的评估。使用酶联免疫吸附测定法测量泪液样本中 NPY 和 P 物质的浓度。患有 1 型糖尿病和长度依赖性小纤维神经病 (SFN) 的参与者的平均（±标准差）泪液 NPY 浓度低于对照组（10.84 ± 4.10 ng/mL vs 14.72 ± 3.12 ng/mL；0.004），但并非如此与没有 SFN 的 1 型糖尿病参与者显着不同（13.39 ± 4.66 ng/mL；0.11）。与无/轻度 DR (13.79 ± 4.76 ng/mL; 0.0005) 和对照组相比，1 型糖尿病和轻度/中度非增殖性 DR 患者的泪液 NPY 水平较低 (10.44 ± 3.46 ng/mL)。在单独的线性回归模型中，在对参与者进行调整后，相对于对照组，SFN（β = -0.75，0.02）的存在和轻度/中度 DR（β = -0.84，0.009）的存在与泪液 NPY 水平显着相关年龄、性别和干眼病。泪液 P 物质浓度没有组间差异。 Tear NPY 作为 1 型糖尿病相关外周微血管并发症的指标具有潜在实用性。