The prevalence and incidence of type 2 diabetes (T2D) are increasing steadily worldwide. With approximately six million individuals diagnosed with T2D 1, Germany is among the countries with the highest prevalence of diabetes in Europe 2, not considering the probably significant number of individuals still undiagnosed.
The primary aim in the treatment of patients with manifest diabetes is to reduce disease-associated complications including macrovascular (coronary heart disease, myocardial infarction, stroke, peripheral occlusive disease) and microvascular disease (retinopathy, nephropathy) as well as neuropathy, diabetic foot syndrome, and in general quality of life. Early diagnosis of diabetes, lifestyle changes, and efficient, individualized therapies initiated early in the course of the disease can prevent subsequent complications that make diabetes one of the most expensive chronic diseases in Germany 3.
There is an ongoing scientific discussion on the targets of glycemic control (fasting or postprandial glucose or HbA1c) and the optimal strategy for glycemia control in individuals with diabetes. Although an individual approach should be followed, there is a relatively broad consensus to recommend an HbA1c below 7.0% (53 mmol/ml) for the prevention of diabetes-associated complications.
The guidelines of the American Diabetes Association recommend an HbA1c below 7.0% to reduce microvascular complications 4. A consensus paper of European Association for the Study of Diabetes and American Diabetes Association calls upon an individual approach, metabolic control, and individualized treatment taking into account patient age, duration of disease, comorbidities, and life expectancy 5. Besides the promotion of prevention and early detection of diabetes, health care systems still strive to improve disease management.
Furthermore, the recommendations include an improvement of blood pressure (BP) and lipid management as these interventions have proven to be very efficient in reducing cardiovascular risk 6.
Background of the campaign
In 2005, the campaign ‘To know what counts in diabetes: stay healthy below 7’ was initiated to contribute toward activities addressing unresolved problems in diabetes. Carried out with many different partner organizations, the campaign aimed at raising awareness about the problem, to identify those at high risk, and to inform those who are already affected by T2D about the different aspects of risk factor management and measures to optimize their disease management.
More than 31 000 individuals have participated voluntarily since the start of the campaign by completing standardized questionnaires and undergoing specific investigations as described in the methodology section.
This paper summarizes the findings of risk factor management in patients who already had a diagnosis of T2D (because of the low number, individuals with type 1 diabetes are not considered). Data analysis included detection of possible trends over time.
Between 2005 and 2014, during the ‘Knowing what matters in diabetes: healthier below 7’ campaign, 45 single campaigns were organized in shopping centers in several German cities. During these action days, center visitors were offered information on the metabolic disorder diabetes and had the opportunity to have their own individual diabetes risk determined by experts. Participants reporting to have diabetes (type 1 or 2) were offered to have their metabolic status checked including measurements of plasma glucose and HbA1c as an indicator for long-term metabolic control and quality of treatment.
The following data were collected from all participants using the modified FINDRISK questionnaire developed by Lindström and colleagues 7,8.
- Sex (male, female).
- Weight (kg).
- Height (cm).
- Age (<45, 45–54, 55–64 and >64 years).
- BMI (<25 kg/m2=normal range, 25–30 kg/m2=overweight and >30 kg/m2=obesity) classified according to the WHO criteria 9.
- Waist circumference (<94, 94–102 and >102 cm for men and <80, 80–88, and >88 cm for women).
- Familial diabetes risk (diabetes in first-degree relative/second-degree relative; yes/no).
- Physical activity (≥30 min on most days a week; yes/no).
- Nutritional habits (daily consumption of vegetables, fruits, or whole grain bread; yes/no).
- History of diabetes (type 1, type 2, no history).
- Elevated plasma glucose level at any time in the past (yes/no).
- History of antihypertensive drug therapy (yes/no).
- Systolic and diastolic BP (mmHg) classified according to the ESH/ESC Guideline or management of arterial hypertension 10. Hypertension was diagnosed when antihypertensive medication was taken or when random BP was more than 140/85 mmHg.
Participants could also have their plasma glucose levels checked voluntarily. Participants already diagnosed with T2D (as well as those without a known history of diabetes, but a moderate or a high diabetes risk score in the FINDRISK≥15) were proposed to have their HbA1c value determined as one of the most important diagnostic criteria, with a value over 7.0% indicating poorly controlled diabetes (or a high probability of diabetes in nondiabetic participants).
In this paper, only the data collected from participants with known T2D are presented.
All data collected between 2005 and 2014 were checked for completeness and plausibility. Implausible data were excluded from the statistical analysis. Missing data were not replaced.
For data analysis, descriptive methods were used. For quantitative parameters, the following statistical features were determined: mean, standard deviation, median, 25th and 75th percentiles, minimum and maximum values, 95% confidence intervals as well as the P values. For qualitative parameters, the absolute and relative frequencies were calculated and the results were presented as histograms or stack diagrams.
On the basis of the year of collection, the data were categorized into 10 annual slices (2005–2014).
The statistical procedures and the resulting P values were used exclusively for exploratory description of the results, without having any confirmatory nature.
The level of significance was generally set to 0.05 with α adjustment according to Bonferroni.
The results of all 10 single years have been examined, thus enabling the detection of changes and trends in patient characteristics as well as frequency and severity of risk factors and final outcomes over time.
As the questionnaire used in 2005 did not include differentiation between the types of diabetes and offered no possibility to establish whether diabetes was already diagnosed or not, the year 2005 was not included in any table or graph using these separate categories or in the following analysis.
Biometric evaluation was performed using the IBM SPSS Statistics 20 statistical software (IBM, Armonk, New York, USA).
In total, of 45 single campaigns conducted in 25 cities all over Germany, a total of 31 085 questionnaires were collected.
Finally, a total of 26 522 questionnaires were evaluated (2006–2014). Of these 26 522 participants with valid questionnaires in the years 2006–2014, 5098 reported known T2D (19.2%).
Whereas in 2006 13.3% were people with diabetes (PWD), in 2014 21.7% had T2D; thus, the proportion of individuals with T2D has increased markedly over time (Fig. 1).
Participants older than 64 years of age were the largest group of T2D patients, with an average frequency of 67.3% (ranging from 48.8% in 2013 to 71.6% in 2008) during the 10-year period. Only 3.2% of the participants with T2D belonged to the youngest age category (<45 years); 7.4% of the participants were between 45 and 54 years of age and 22.1% were between 55 and 64 years of age.
The ratio between the age groups remained constant over the years.
In all, 51.6% of T2D patients were women and 48.4% were men. The sex ratios remained constant over the years.
More than one-third (34.4%) of all the T2D participants were obese, 43.6% were overweight, and only 22.5% of the diabetics had a BMI in the normal range (Fig. 2).
The median BMI was 28.1 kg/m2, whereas it was 26.0 in the entire population (n=30 119).
Whereas the proportion of individuals with low BMI (<25 kg/m2) was significantly higher in the entire population studied than among individuals with T2D, it was the opposite for high BMI (>30 kg/m2; Table 1).
In contrast to the entire population studied, there was no trend toward increasing BMI values over time (Fig. 3).
Waist circumference values were above the critical values (>102 cm in men and >88 cm in women) in 69.2% of T2D without changes over time.
Lifestyle: exercise and nutrition
Almost half (40.7%) of the T2D participants reported that they did not exercise regularly, whereas 16.2% reported that they did not eat fruits, vegetables, and whole grain bread on a daily basis. Similar to nondiabetic participants, a trend toward less favorable nutritional habits was found over the years (P<0.001).
Diabetes in the family
Overall, 55.9% of T2D participants reported the presence of this disease in first-degree and/or second-degree relatives, whereas this proportion was 39.8% among nondiabetics.
Blood pressure and antihypertensive medications
Compared with 42% of all participants, almost 73% of the participants with T2D reported that they are taking – or have taken at any time in the past – antihypertensive medication; these PWD should be considered known hypertensives as they were, or had been, treated with antihypertensive medication.
The mean systolic BP in PWD was 149.9 mmHg (n=4763) and the mean diastolic BP was 85.8 mmHg (n=4760). No trend toward improvement in BP control over the years was observed.
In all participants, the mean BP was 143.5 mmHg (systolic; n=29 283) and 85.3 mmHg (diastolic; n=29 268), respectively.
When considering the threshold values of 140 mmHg (systolic) and 85/90 mmHg (diastolic) for differentiation of participants with versus without hypertension, 69.9% of participants with T2D had manifest hypertension compared with 57.8% (15 933 out of 27 589) of all participants (Table 2), which is consistent with the proportion defined by intake of antihypertensives.
A total of 4170 HbA1c measurements were performed in PWD (about 82% of participating PWD had their HbA1c measured during the campaign).
Almost half of the participants with already diagnosed T2D had HbA1c values greater than 7.0%, which indicates suboptimal plasma glucose control. Furthermore, one-tenth of these participants had HbA1c values between 8.0 and 9.0% and ∼4% had HbA1c values above 9.0% (Table 3). These proportions were comparable in men and women.
Only 54% had their HbA1c at target (<7%).
Over the years, a temporal trend toward higher HbA1c values was observed in T2D patients (P<0.001; Fig. 4).
Discussion and conclusion
Initiated in 2005, the nationwide campaign ‘Knowing what matters in diabetes: healthier below 7’ generated considerable interest among the German population.
During the 10-year period (2005–2014), a total of 31 085 individuals participated. For most variables, 26 522 valid questionnaires were collected between 2006 and 2014 including 5098 questionnaires of participants with a history of T2D (21% of the total population) and 369 questionnaires of participants with type 1 diabetes (1.4%); in this report, we have only analyzed those with known T2D.
In these 10 years, the proportion of participants with known diabetes mellitus increased markedly from 14.3% in 2006 to 23.4% in 2014. This increase may at least in part be attributed to increasing awareness of the campaign among individuals with known or suspected diabetes, and thus may not reflect a factual increase in the prevalence of diabetes of the same magnitude. However, there are several reports on a similar increase in the prevalence of T2D in the general population including such different countries as Sweden 11, Portugal 12, and Iran 13 and even in children 14. Consequently, the prevalence of prediabetes was also reported to increase, for example, in the UK from 2003 to 2011 15.
The results of the ‘Knowing what matters in diabetes: healthier below 7’ campaign also confirm earlier findings by the Robert Koch-Institute, which show an increasing prevalence of diabetes mellitus in the German adult population between 2003 and 2009 16. This increase can at least partially be explained by an increasing prevalence of risk factors such as an unhealthy lifestyle, and consequently the prevalence of overweight and obesity.
Lifestyle risk factors
As expected, a large proportion of PWD showed established risk factors. The prevalence of overweight and obesity was observed in more than three quarters (78%) of the participants, with 44% being overweight and 34% being obese. Also, 69.2% had a waist circumference above 88/102 cm, which, together with plasma glucose, BP, and serum lipids, which have not been investigated in this study, is indicative of metabolic syndrome 17.
Lifestyle management remains suboptimal as 41% of the PWD admitted that they do not exercise on a daily basis; furthermore, about 15% did not follow a diet rich in fiber. Considering that there is usually an underreporting/reporting bias, the proportion of patients actually adhering to a diet and therapeutic lifestyle change should be expected to be even much lower.
Importantly, desirable glycemic control, as indicated by an actual measured HbA1c, turned out to be suboptimal in almost 50% of the patients as 46.3% had an HbA1c more than or equal to 7.0% and more than 10% had an HbA1c more than or equal to 8.0%, the latter not fulfilling even less stringent criteria for glycemic control 6.
This finding is in accordance with other observations, which indicate that a considerable proportion of patients with diabetes mellitus do not achieve their targets 18. The recent report of the ARIC (Atherosclerosis Risk in Communities) study, however, indicated somewhat better metabolic control in that population as about 72% had an HbA1c below 7% 19.
Blood pressure control
Furthermore, in many intervention studies 20,21, it was clearly shown that T2D patients benefit from good BP control. Therefore, the guidelines for the management of arterial hypertension 9 set a target less than 140 mmHg for systolic BP of, and less than, 85 mmHg for diastolic BP. In this analysis, only 30% of the participants had adequate BP control. BP management in PWD is often not adequate; many studies indicate suboptimal BP control 22,23. As an exception, the ARIC population showed BP less than 140/090 mmHg among 73% of PWD 19.
However, the limitations of the campaign have to be considered. As the data collection took place in the context of several single campaigns in German cities, there is an evident selection bias: individuals were from geographically restricted regions in the vicinity of campaign sites that cannot be considered representative for the entire German population. Also, participants might represent a positive selection of individuals with known T2D as these might have been more interested in obtaining additional information about their disease and volunteered to participate in the metabolic testing. Certainly, therefore, the data are not representative for the entire German population and our results are not comparable with the results of population-based studies, in which the frequency and distribution of diabetes risk factors have been determined 24–26.
However, even if one takes this into account, it is important to note that even in that somewhat ‘preselected’ group, measures of individual lifestyle and the assessed risk factor management were shown to be suboptimal in most individuals with T2D.
Thus, the results of the present study provide a view on the current risk factor management and treatment quality in already diagnosed T2D in Germany.
Our results show that activities such as the ‘Knowing what matters in diabetes: healthier below 7’ campaign are necessary and important as they can increase awareness and draw attention to a widespread disease such as diabetes mellitus and its risk management. The campaign showed that those with already diagnosed diabetes have a marked deficit in good cardiometabolic risk factor control; therefore, reminding them of the importance of a good and comprehensive risk management such as good plasma glucose and BP control and, most importantly, improvement of their individual lifestyle could contribute toward better management of diabetes.
The results of this campaign should have implications and consequences for all parties involved in diabetes care: general practitioners, diabetes specialists, and clinicians as well as health insurance companies. Individuals with diabetes should be aware that they benefit from a more comprehensive risk factor management including good glycemic control but also strict BP and lipid management. However, most importantly, a better lifestyle is required.
Overall, with respect to individuals with known T2D, our campaign showed that these individuals often show unsatisfactory risk factor control. It has to be pointed out that these results have been found in a highly developed Western country with a sophisticated medical infrastructure and providing free access to medical care and a multitude of elaborate patient education programs. This is why it is very important that programs such as the ‘Knowing what matters in diabetes: healthier below 7’ campaign increase public awareness of this disease and its complications, and also the importance of a broad risk factor management.
Conflicts of interest
Stephan Jacob received honoraria from Abbott, Astra-Zeneca, Bayer, Berlin-Chemie, Bristol-Myers Squibb, Boehringer Ingelheim, Daiichi Sankyo Germany, Essex, Eumecom medical information training, GlaxoSmithKline, Janssen-Cilag, Johnson & Johnson, LighterLife UK, Lifescan, Lilly Germany, Merck, MSD Sharp & Dohme, Novo Nordisk, Novartis, Pfizer Germany, Roche, Sanofi-Aventis Germany, UCB, Solvay, Takeda, and Viatris. Franz-Werner Dippel and Andrea Klimke-Hübner are employees of Sanofi-Aventis Germany. Werner Hopfenmüller received a fee for the statistical analysis. All authors were equally involved in the conception and design of the research and in the interpretation of the results.
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