The Chair of Epidemiology headed by Prof. Dr. Stefanie Klug in cooperation with the Institute of Epidemiology of the Helmholtz Zentrum München has published a new article in the journal “BMJ Open Diabetes Research & Care” on the “Association of endothelial dysfunction with incident prediabetes, type 2 diabetes and related traits: the KORA F4/FF4 study”. The journal is an open access periodical dedicated to the publication of high-quality articles from basic and clinical research on type 1 and type 2 diabetes and its complications. It has an impact factor of 3.183.
KORA is the German abbreviation for “Cooperative Health Research in the Augsburg Region”. Helmholtz Zentrum München carries out the KORA studies at regular intervals to investigate the state of health of the population in Augsburg and its surroundings. These studies investigate the connections between health, illnesses and the population's living conditions. The focus lies on diabetes, cardiovascular and lung diseases as well as environmental issues.
The origin of the data comes from the S4 KORA study, which was conducted from 1999 to 2001 with 4,261 participants aged 25 to 74 years and focused on diabetes, cardiovascular diseases and their risk factors. Both F4 (2006-2008) with 3,080 participants and FF4 (2013-2014) with 2,279 participants were follow-up studies to the S4 study. For the current publication, data from F4 was used for the baseline study and data from FF4 for the follow-up study.
The now published article is based on the master thesis of Marie-Theres Huemer, who successfully completed the master’s program “Sport and Exercise Science” at the Department of Sport and Health Sciences. She is now a PhD student at the Institute of Epidemiology at Helmholtz Zentrum München. “I am very pleased that we were able to cooperate with Helmholtz Zentrum München and the Institute of Epidemiology under the direction of Prof. Dr. Annette Peters during the course of this project and that with the appointment of Mrs. Huemer, a graduate of our faculty is now working there”, explains Prof. Klug. “We attach great value to interdisciplinarity, which has been exemplary in this case.”
“In the course of my master thesis, which was supervised by Prof. Dr. Barbara Thorand, I dealt with the F4/FF4 KORA studies subpopulation in which, in addition to F4, endothelial function was measured and no clinically diagnosed diabetes was present”, commented Huemer explaining the procedure. “The subjects were between 52 and 71 years old - an age range in which there is a certain degree of risk of developing prediabetes and type 2 diabetes.”
The endothelium is a thin layer of cells that line the inside of blood vessels. It plays a central role in processes such as blood pressure regulation. Endothelial dysfunction leads to a functional disorder of the endothelium. In principle, this covers practically all functional areas, such as vessel width regulation or blood vessel permeability.
The study included a total of 673 participants (328 men and 345 women), aged 52 to 71 years, who underwent oral glucose tolerance testing at both the initial and follow-up exams. Among others, type 2 diabetes, pre-diabetes, fasting glucose, fasting insulin, 2-hour glucose and insulin resistance were tested. Furthermore, peripheral arterial tonometry (PAT) was used to measure the pulse wave in the subjects' fingertips. Using this user-independent and non-invasive measuring method, the peripheral vascular tone can be measured thanks to a special sensor. During the study, the pulse wave amplitude was measured five minutes before, during and five minutes after a five-minute stasis of blood flow in the non-dominant upper arm using a blood pressure cuff.
In the baseline study it was determined that the mean value of the measurement of pulse wave amplitude of both arms of participants with normal blood glucose levels was positively associated with (pre-)diabetes and fasting glucose at the follow-up stage. Moreover, the measurement of reactive hyperaemia (increased blood flow) at baseline was inversely related to type 2 diabetes, fasting insulin, and insulin resistance at the follow-up stage.
“We have discovered that reactive hyperaemia and the mean value of the measurement of the pulse wave amplitude of both arms are associated with various diabetes parameters”, Huemer concludes. “This would suggest that these parameters reflect different mechanisms and are associated with different outcomes with respect to diabetes."
The authors around Marie-Theres Huemer and Prof. Klug therefore concluded that microvascular endothelial dysfunction seems to be involved in the development of early glucose metabolism disorders and insulin resistance, which could trigger the development of prediabetes and type 2 diabetes.
Prof. Dr. Stefanie Klug
Chair of Epidemiology
phone: 089 289 24950
Text: Romy Schwaiger
Photos: „BMJ Open Diabetes Research & Care”/Chair of Epidemiology/Helmholtz Zentrum München