Maddaloni E, Sabatino F, Del Toro R, Crugliano S, Grande S, Lauria Pantano A, Maurizi A R, Palermo A, Bonini S, Pozzilli P, Manfrini S
Department of Endocrinology and Diabetes, University Campus Bio-Medico of Rome, Rome, Italy.
Diabet Med. 2015 Feb;32(2):262-6. doi: 10.1111/dme.12583. Epub 2014 Sep 24.
To investigate whether small nerve fibre degeneration detected using corneal confocal microscopy is associated with cardiac autonomic neuropathy in people with Type 1 diabetes.
Thirty-six people with Type 1 diabetes and 20 age- and sex-matched healthy control subjects were enrolled. Tests to determine heart rate response to deep-breathing (expiratory-to-inspiratory ratio), heart rate response to lying-to-stand test (30:15 ratio) and blood pressure response to standing were performed to detect cardiac autonomic neuropathy. Corneal confocal microscopy was performed to assess: corneal nerve density and corneal nerve beadings; branching pattern; and nerve fibre tortuosity.
Compared with control participants, participants with Type 1 diabetes had fewer (mean ± SD 45.4 ± 20.2 vs 92.0 ± 22.7 fibres/mm²; P < 0.001) and more tortuous corneal nerve fibres (20 participants with Type 1 diabetes vs four control participants had nerve tortuosity grade 2/3; P = 0.022) and fewer beadings (mean ± SD 15.1 ± 3.5 vs 20.6 ± 5.0; P < 0.001). Of the participants with Type 1 diabetes, 11 met the criteria for the diagnosis of cardiac autonomic neuropathy. Corneal nerve density was significantly lower in participants with cardiac autonomic neuropathy than in those without (mean ± SD 32.8 ± 16.4 vs 51.7 ± 18.9 fibres/mm²; P = 0.008). This difference remained significant after adjustment for age (P = 0.02), gender (P = 0.04), disease duration (P = 0.005), insulin requirement (P = 0.02) and neuropathy disability score (P = 0.04).
This study suggests that corneal confocal microscopy could represent a new and non-invasive tool to investigate cardiac autonomic neuropathy in people with Type 1 diabetes. Larger studies are required to define the role of corneal confocal microscopy in the assessment of cardiac autonomic neuropathy.
研究使用角膜共焦显微镜检测到的小神经纤维变性是否与1型糖尿病患者的心脏自主神经病变相关。
招募了36名1型糖尿病患者和20名年龄及性别匹配的健康对照者。进行了测试以确定心率对深呼吸的反应（呼气与吸气比率）、心率对卧立位试验的反应（30:15比率）以及血压对站立的反应，以检测心脏自主神经病变。进行角膜共焦显微镜检查以评估：角膜神经密度和角膜神经珠状膨大；分支模式；以及神经纤维迂曲度。
与对照参与者相比，1型糖尿病患者的角膜神经纤维数量更少（平均值±标准差45.4±20.2对92.0±22.7根纤维/mm²；P<0.001），神经纤维更迂曲（20名1型糖尿病患者对4名对照参与者神经迂曲度为2/3级；P = 0.022），珠状膨大更少（平均值±标准差15.1±3.5对20.6±5.0；P<0.001）。在1型糖尿病患者中，11名符合心脏自主神经病变的诊断标准。有心脏自主神经病变的参与者的角膜神经密度显著低于无病变者（平均值±标准差32.8±16.4对51.7±18.9根纤维/mm²；P = 0.008）。在对年龄（P = 0.02）、性别（P = 0.04）、病程（P = 0.005）、胰岛素需求量（P = 0.02）和神经病变残疾评分（P = 0.04）进行调整后，这种差异仍然显著。
本研究表明，角膜共焦显微镜检查可能是一种用于研究1型糖尿病患者心脏自主神经病变的新型非侵入性工具。需要进行更大规模的研究来确定角膜共焦显微镜检查在评估心脏自主神经病变中的作用。
