生物谷：来自Warwick大学医学院的科学家最近发现维生素B1缺乏是造成糖尿病人的多种血管问题的主要原因。糖尿病是目前世界范围内最主要的健康问题之一，它会造成微血管问题，对肾脏、视网膜和手臂以及腿部的神经造成损伤，并可能导致心脏病和中风等。
由Paul Thornalley领导的小组最终发现这些病人血浆中缺少维生素B1。他们同时发现了维生素B1如何作用于糖尿病人并导致血管损伤。结果发表在8月4日的Diabetologia上。小组发现在1型糖尿病患者血浆中，维生素B1浓度下降了76%，而对于2型糖尿病患者这一数字是75%。由于之前科学家通过测量红血球中的转羟乙醛酶来间接测量维生素B1浓度，而这一酶的活性由于THTR-1和RFC-1蛋白维持正常，因此科学家一直没有发现维生素B1的下降。
科学家发现血管细胞中维生素B1的减少和微血管并发症密切相关，这似乎和内皮细胞有关，并且会使得患动脉硬化症的风险大大增加。小组同时发现糖尿病人血浆维生素B1的减少不是由于食物摄取引起的，而是和血液中大量维生素B1进入尿中有关。
科学家认为还需要进行下列研究：确认其它国家糖尿病人群的血液维生素B1情况；评估使用维生素B1和相关维生素衍生物治疗和预防血管损伤的作用；确认大量维生素B1从血液进入尿液中的机制。 ( 教育部科技发展中心)
英文原文链接：http://www.physorg.com/news105715539.html
原始出处:
High prevalence of low plasma thiamine concentration in diabetes linked to a marker of vascular disease
2007年8月4日
DOI 10.1007/s00125-007-0771-4
P. J. Thornalley1, 2 , R. Babaei-Jadidi1, H. Al Ali1, N. Rabbani1, 2, A. Antonysunil1, 2, J. Larkin1, 2, A. Ahmed3, G. Rayman4 and C. W. Bodmer3
(1) Department of Biological Sciences, University of Essex, Colchester, Essex, UK
(2) Clinical Sciences Research Institute, Warwick Medical School, University of Warwick, University Hospital, Clifford Bridge Road, Coventry, CV2 2DX, UK
(3) Department of Diabetes and Endocrinology, Colchester General Hospital, Colchester, Essex, UK
(4) Ipswich Diabetic Foot Unit and Diabetes Centre, Ipswich Hospital NHS Trust, Ipswich, UK
Received: 23 February 2007 Accepted: 22 June 2007 Published online: 4 August 2007
Abstract
Aims/hypothesis To assess thiamine status by analysis of plasma, erythrocytes and urine in type 1 and type 2 diabetic patients and links to markers of vascular dysfunction.
Methods Diabetic patients (26 type 1 and 48 type 2) with and without microalbuminuria and 20 normal healthy control volunteers were recruited. Erythrocyte activity of transketolase, the concentrations of thiamine and related phosphorylated metabolites in plasma, erythrocytes and urine, and markers of metabolic control and vascular dysfunction were determined.
Results Plasma thiamine concentration was decreased 76% in type 1 diabetic patients and 75% in type 2 diabetic patients: normal volunteers 64.1 (95% CI 58.5–69.7) nmol/l, type 1 diabetes 15.3 (95% CI 11.5–19.1) nmol/l, p < 0.001, and type 2 diabetes 16.3 (95% CI 13.0–9.6) nmol/l, p < 0.001. Renal clearance of thiamine was increased 24-fold in type 1 diabetic patients and 16-fold in type 2 diabetic patients. Plasma thiamine concentration correlated negatively with renal clearance of thiamine (r = −0.531, p < 0.001) and fractional excretion of thiamine (r = −0.616, p < 0.001). Erythrocyte transketolase activity correlated negatively with urinary albumin excretion (r = −0.232, p < 0.05). Thiamine transporter protein contents of erythrocyte membranes of type 1 and type 2 diabetic patients were increased. Plasma thiamine concentration and urinary excretion of thiamine correlated negatively with soluble vascular adhesion molecule-1 (r = −0.246, p < 0.05, and −0.311, p < 0.01, respectively).
Conclusions/interpretation Low plasma thiamine concentration is prevalent in patients with type 1 and type 2 diabetes, associated with increased thiamine clearance. The conventional assessment of thiamine status was masked by increased thiamine transporter content of erythrocytes.
Keywords Adhesion molecules - Microalbuminuria - Thiamine - Type 1 diabetes - Type 2 diabetes
