Diabetes Research Unit, The Ipswich Hospital NHS Trust, Ipswich, United Kingdom.
Department of Diabetes, The Kings College NHS Foundation Trust, London, United Kingdom.
PLoS One. 2018 Mar 8;13(3):e0193452. doi: 10.1371/journal.pone.0193452. eCollection 2018.
The laser Doppler imaging (LDI) FLARE and corneal confocal microscopy (CCM) are reliable markers of small fibre function (SFF) and structure (SFS), respectively, but the impact of potential confounding variables needs to be defined. The objective of this study was to determine the influence of age, anthropometric and biochemical variables on LDI and CCM.
80 healthy volunteers (43 males) (age: 39.7±15.2 yrs.) underwent LDIFLARE and CCM assessment and the effect of age, anthropometric and biochemical variables was determined using multivariate analysis.
There was an age-related decline in LDIFLARE (0.07cm2/yr; R2 = 0.669; p = <0.0001) and CCM parameters (CNFD: 0.05 fibres/mm2 /yr; R2 = 0.590; p = <0.0001, CNBD: 0.06 branches/mm2/yr; R2 = 0.549; p = 0.001and CNFL 0.07 mm/mm2/yr; R2 = 0.369; p = 0.009). BMI did not influence SFF (p = 0.08) but had a significant independent association with CNFD (p = 0.01). Fasting triglycerides (TG) independently influenced the LDIFLARE (βc:-0.204; p = 0.008) and all CCM indices (βc:-0.191 to -0.243; p = <0.05). HbA1c was significantly associated with CNFD only (p = 0.001) but not with LDIFLARE, CNBD or CNFL (p = ≥0.05). Blood pressure and total cholesterol were not associated with LDIFLARE or any CCM parameters. There was a significant correlation between LDIFLARE and all CCM parameters (p = ≤0.01).
This study shows that in healthy controls, both SFF measured by LDIFLARE and SFS assessed by CCM showed a significant inverse correlation with age and triglycerides, perhaps suggesting the use of age-specific normative values when interpreting these outcomes. Furthermore, this study shows that in healthy controls, despite measuring different neural parameters, both methods correlated significantly with each other.
激光多普勒成像（LDI）FLARE 和角膜共焦显微镜（CCM）分别是小纤维功能（SFF）和结构（SFS）的可靠标志物，但需要确定潜在混杂变量的影响。本研究的目的是确定年龄、人体测量学和生化变量对 LDI 和 CCM 的影响。
80 名健康志愿者（43 名男性）（年龄：39.7±15.2 岁）接受 LDIFLARE 和 CCM 评估，并使用多元分析确定年龄、人体测量学和生化变量的影响。
LDI FLARE（0.07cm2/yr；R2=0.669；p<0.0001）和 CCM 参数（CNFD：0.05 纤维/mm2/yr；R2=0.590；p<0.0001，CNBD：0.06 分支/mm2/yr；R2=0.549；p=0.001 和 CNFL 0.07 mm/mm2/yr；R2=0.369；p=0.009）与年龄呈负相关。BMI 不影响 SFF（p=0.08），但与 CNFD 有显著独立关联（p=0.01）。空腹甘油三酯（TG）独立影响 LDIFLARE（βc：-0.204；p=0.008）和所有 CCM 指数（βc：-0.191 至-0.243；p<0.05）。HbA1c 仅与 CNFD 显著相关（p=0.001），但与 LDIFLARE、CNBD 或 CNFL 无关（p≥0.05）。血压和总胆固醇与 LDIFLARE 或任何 CCM 参数均无关。LDIFLARE 与所有 CCM 参数均呈显著相关性（p≤0.01）。
本研究表明，在健康对照组中，LDIFLARE 测量的 SFF 和 CCM 评估的 SFS 均与年龄和甘油三酯呈显著负相关，这可能表明在解释这些结果时使用年龄特异性的正常值。此外，本研究表明，在健康对照组中，尽管测量了不同的神经参数，但这两种方法彼此之间存在显著相关性。
