Open Access Highly Accessed Original investigation

Do patients with type 1 and type 2 diabetes really have an impaired endothelial function? A population-based propensity score matching analysis

Klaus Empen1*, Roberto Lorbeer2, Henry Völzke25, Thorsten Reffelmann15, Sabine Schipf3, Matthias Nauck35, Wolfgang Kerner4, Henri Wallaschofski35, Stephan B Felix15 and Marcus Dörr15

Author Affiliations

1 Department of Internal Medicine, Medizinische Klinik B, Universitätsmedizin, Greifswald, Sauerbruchstrasse, D-17475, Germany

2 Institute for Community Medicine, University Medicine, Greifswald 17475, Germany

3 Institute for Clinical Chemistry and Laboratory Medicine, University Medicine, Greifswald 17475, Germany

4 Diabetes Center, Karlsburg 17495, Germany

5 DZHK (German Center for Cardiovascular Research), partner site Greifswald, Greifswald 17475, Germany

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Cardiovascular Diabetology 2013, 12:174  doi:10.1186/1475-2840-12-174

Published: 5 December 2013



Previous studies suggested an impaired endothelial function in patients with diabetes. However, the validity of this finding may be limited by the lack of adequate adjustment for further cardiovascular confounders. We assessed endothelial function as measured by flow-mediated dilation (FMD) of the brachial artery in patients with either type 1 or type 2 diabetes in comparison with non-diabetic controls.


The study population comprised 1487 subjects including 122 subjects with type 2 diabetes, aged 25 to 85, from the population-based Study of Health in Pomerania, and 65 outpatients, aged 23 to 75, with type 1 diabetes. FMD measurements were performed using standardized ultrasound techniques. Subjects with type 1 and type 2 diabetes were matched 1:4 to healthy controls using propensity score matching.


Neither type 1 diabetes (β = 0.142; SE = 0.568, p = 0.803) nor type 2 diabetes (β = 0.107; SE = 0.340, p = 0.752) were significantly associated with FMD in comparison with their non-diabetic controls after adjustment for major cardiovascular confounders like age, gender, body mass index, smoking status, hypertension, antihypertensive medication, LDL and HDL cholesterol levels.


In this population-based study comparing adjusted FMD values of diabetic individuals with adequately matched controls, propensity score analyses revealed no association between diabetes and endothelial function. Since these findings are in discordance with the majority of previous reports, we suggest performing similar analyses using data from other population-based studies.

Type 1 diabetes; Type 2 diabetes; Flow-mediated dilation; FMD; Endothelial function; Epidemiology