Obesity and diabetes are on the rise in Germany despite an increase in people’s physical activity. The Germany-wide pre-diabetes lifestyle intervention study (PLIS), which is being carried out by the German Center for Diabetes Research, is now striving to explain this phenomenon.
The latest data of the Robert Koch Institute show that there has been a significant increase in the incidence of obesity (body mass index (BMI) of 30 or greater) in comparison to 1998. (BMI calculator in metric units: weight[kg] / ( height[m] x height[m]). The proportion has increased, especially in men (from 18.9% to 23.3%), but also in women (from 22.5% to 23.9%). It is striking that the incidence of type 2 diabetes, which is often associated with obesity, has increased in this period in adults from 5.2% to 7.2%. Taking into account the estimated 2.1% of adults with undetected diabetes, the incidence of diabetes in Germany thus amounts to 9.3%, which corresponds to 6 million adults. Surprisingly in this context, regular physical activity (sports or exercise at least once a week) has likewise increased during this period (by 14.1% in men, by 16.0% in women)*.
DZD scientists implement and monitor a lifestyle intervention
The data support previous observations that there is a difference in how well people respond to intervention programs for weight loss and diabetes prevention. Within the framework of funding by the German Center for Diabetes Research (DZD), a team of scientists led by diabetes experts at Tübingen University Hospital are conducting a Germany-wide study to explain this phenomenon.
The aim of the research is to find individuals who, despite increased physical activity in their everyday lives, have an elevated risk of type 2 diabetes. By means of an intensified lifestyle intervention monitored by trained personnel, the goal is to help these individuals benefit from a lifestyle modification.
In recent years, several studies have shown that prevention of type 2 diabetes is possible, and lifestyle intervention has shown the best results. But there are individuals who respond well to lifestyle intervention and individuals who hardly benefit at all, even though they lose weight. The former group is referred to as "responders", the latter as "non-responders". There are now genetic and phenotypic characteristics that predict the success of lifestyle intervention and thus enable individualized prevention strategies for type 2 diabetes.
Scientists at Tübingen University Hospital led by Prof. Hans-Ulrich Häring, Prof. Andreas Fritsche and Prof. Norbert Stefan have examined in detail more than 400 individuals with an elevated risk for type 2 diabetes as part of a 24-month lifestyle intervention program (Tübingen Lifestyle Intervention Program – TULIP). They were able to gain important insights into the mechanisms of non-response as part of a lifestyle intervention **. Besides the blood parameters, which are still the subject of ongoing research, decreased insulin sensitivity, weak insulin secretion, benign and malignant fat tissue distribution as well as non-alcoholic fatty liver also play a role.
New Germany-wide lifestyle study
In a Germany-wide pre-diabetes lifestyle intervention study (PLIS), people with an elevated risk of diabetes are now included in the study, based on their fasting blood glucose levels and a blood glucose tolerance test, which can also be performed during pregnancy. The German Diabetes Risk Test R, developed in collaboration with scientists at the German Institute of Human Nutrition Potsdam-Rehbrücke (DIfE), is used to assess diabetes risk. After a whole-body MRI to determine body fat distribution and the level of liver fat, the study participants are divided into two groups and receive individual and intensive lifestyle counseling about changing their diet and increasing their physical activity.
These interventions are accompanied by analyses of food journals and physical activity, which is accurately documented by acceleration measuring devices, which are handed out to the participants. In subgroups parallel to this, data on physical fitness will be collected as part of examinations on the cycle ergometer. The ability to control satiety will also be determined in tests of brain activity.
The study, the positive effects of which will benefit all 1000 participants, is funded by the Federal Ministry of Education and Research (BMBF) under the auspices of the German Center for Diabetes Research. The center in Tübingen is leading the study and is being supported by all four additional DZD partner sites in Düsseldorf, Dresden, Berlin/Potsdam and Munich.
** Stefan N, Fritsche A, Häring HU. Individualized prevention of type 2 diabetes. Bundesgesundheitsblatt Gesundheitsforschung Gesundheitsschutz. 2009 Jul;52(7):677-82