Time Trends in Cardiometabolic Risk Factors in Adults

Results from three nationwide German examination surveys from 1990–2011

Background: Data from three representative health examination surveys in Germany were analyzed to examine secular trends in the prevalence and magnitude of cardiometabolic risk factors.

Methods: The target variables were the following cardiometabolic risk factors: lack of exercise, smoking, obesity, systolic blood pressure, total cholesterol, serum glucose, self-reported high blood pressure, hyperlipidemia, and diabetes, and the use of antihypertensive, cholesterol-lowering, and antidiabetic drugs. 9347 data sets from men and 10 068 from women were analyzed. The calculated means and prevalences were standardized to the age structure of the German population as of 31 December 2010 and compared across the three time periods of the surveys: 1990–1992, 1997–1999, and 2008–11.

Results: Over the entire period of observation (1990–2011), the mean systolic blood pressure fell from 137 to 128 mmHg in men and from 132 to 120 mmHg in women; the mean serum glucose concentration fell from 5.6 to 5.3 mmol/L in men and from 5.4 to 5.0 mmol/l in women; and the mean total cholesterol level fell from 6.2 to 5.3 mmol/L in both sexes. In men, smoking and lack of exercise became less common. On the other hand, the prevalence of use of antidiabetic, cholesterol-lowering, and antihypertensive drugs rose over the same time period, as did that of self-reported diabetes. The first of the three surveys (1990–1992) revealed differences between persons residing in the former East and West Germany in most of the health variables studied; these differences became less marked over time, up to the last survey in 2008–2011.

Conclusion: The cardiometabolic risk profile of the German adult population as a whole improved over a period of 20 years. Further in-depth analyses are now planned.

Cardiovascular diseases and their underlying behavioral and metabolic risk factors cause an estimated 17.5 million deaths per year around the world, accounting for some 31% of all deaths (1, 2). In Germany, the nationwide, representative health examination surveys of the Robert Koch Institute (RKI) provide the opportunity to observe trends in cardiometabolic risk factors over a period of 20 years. In 1990, the last of three national examination surveys was carried out in the framework of the German Cardiovascular Prevention Study (Deutsche Herz-Kreislauf Präventionsstudie, DHP) (3). This survey, called NUST2, was representative for the western part of the country, i.e., the former West Germany and gained particular relevance as it was conducted just after the fall of the Berlin wall. A survey analogous to NUST2 was carried out in the former East Germany in 1991/92. The findings of these two surveys, collectively designated the East/West Health Survey 1991 (Gesundheitssurvey Ost/West 1991, OW91), yielded the earliest representative health data for Germany after national reunification. OW91 revealed differences in the health status, health-related behavior, and health care between the former East and West Germany (3): for example, lack of exercise, obesity, high blood pressure, and diabetes were much more common in the east than in the west, while the reverse was true for asthma and allergies (4, 5).

In 1998, a new representative health survey called the German National Health Interview and Examination 1998 was carried out (Bundes-Gesundheitssurvey 1998, BGS98). The third and latest nationwide examination study considered in this article was the German Health Interview and Examination Survey for Adults 2008-2011 (Studie zur Gesundheit Erwachsener in Deutschland 2008–2011, DEGS1) (7), carried out in the framework of the RKI’s health monitoring program (6). The results of all three examination surveys were integrated in the federal German health reporting system, which was first mandated by law in 1998 (8).

In this article, we report the first threefold cross-sectional trend analysis of the results of the OW91, BGS98, and DEGS1. Secular trends in the prevalence of lack of exercise, smoking, obesity, high blood pressure, hyperlipidemia, diabetes, the use of antihypertensive, cholesterol-lowering, and antidiabetic drugs, and the mean values of systolic blood pressure, total cholesterol, and serum glucose among adults in Germany are described and evaluated, with attention to differences between the sexes and between persons living in the former East and West Germany.

Methods

Study population

The design and methods of the three surveys were described previously (3, 7, 9); the main facts are summarized in eTable 1. Two-staged cluster sampling was used to select 120 to 180 communities at random for each survey (eTable 1). The Resident Registration Offices of each community sent randomly selected addresses of adult residents to the Robert Koch Institute (RKI), which then invited these persons to participate in the survey. The subjects were examined and asked to fill out survey questions in temporary study centers located in each community; afterwards, their blood and urine samples were analyzed in a standardized fashion in an epidemiological laboratory of the RKI. In all three surveys except the NUST2, the study population consisted of adults aged 18–79 living in Germany. The NUST2 was designed in conformity to the DHP study, of which it was a component, and included only 25- to 69-year-old subjects of German nationality. We therefore restricted our comparative analysis to persons in this age range. The response rates were 70% for the OW91, 61% for the BGS98, and 62% / 42% for the DEGS1 (longitudinal and cross-sectional study participants, respectively). Separate questioning of non-responders revealed no major differences against responders with respect to basic health variables (10). The distribution by sex and region of the participants whose data were analyzed is shown in Table 1.

Table 1

Description of the study samples*1

eTable 1

The three examination surveys, for adults, by the Robert Koch Institute (1990–2011)

Variables and methods of measurement

The criterion for including any particular cardiometabolic risk factor in the present comparative analysis was a (relative) consistency in the method of measurement across all three survey periods. Exercise, smoking, obesity, systolic blood pressure, total cholesterol level, serum glucose, use of a selection of drugs (antihypertensive, cholesterol-lowering, and antidiabetic drugs) and self-reported diabetes, high blood pressure, and hyperlipidemia were compared across the three surveys.

The methods of measurement are described in detail in eTable 2. Exercise level was assessed with the question, “How often do you engage in physical exercise?” Smoking behavior was assessed with questions on current and previous smoking. On the basis of their replies to these questions, respondents were characterized as exercisers or non-exercisers, and as current smokers or current non-smokers. Height and weight were measured in standardized fashion, providing the basis for calculating the body-mass index (BMI); in accordance with the WHO guidelines (15), obesity was defined as a BMI of 30 kg/m² or above. Individual lifetime prevalences of high blood pressure, hyperlipidemia, and diabetes were determined by a written questionnaire in the OW91, and by an interview with a physician in the BGS98 and the DEGS1. These data were used to categorize the subjects into those who did or did not report ever having had high blood pressure, hyperlipidemia, and diabetes. Drugs and food supplements consumed in the last 7 days were determined in a standardized personal interview. Drugs were classified according to their anatomic-therapeutic-chemical (ATC) code numbers (16); the ones considered in the analysis included antidiabetic drugs (A10), cholesterol-lowering drugs (C10), and antihypertensive drugs (ATC-Code C02/C03/C07/C08/C09).

eTable 2

Overview of measurement and data acquisition methods and quantitative variables used, by period of data acquisition

Study sample

The analysis included data sets from 7466 persons in the OW91, 5825 in the BGS98, and 6124 in the DEGS1. There were a total of 9347 data sets from men and 10068 from women (Table 1). The DEGS1 sample contained 3142 persons who had already participated in the BGS98. For some of the subjects in the surveys, only questionnaire responses and no data from physical examinations were available. The target variables were calculated on the basis of all the data available for each.

Statistical methods

All statistical analyses were performed with the survey procedures of Stata SE 14, with due attention to weighting and the cluster design effect. Adaptive weighting by age, sex, region, and educational level was performed in all surveys in a methodologically consistent manner, and the results were age-standardized to the German population structure as of 31.12.2010 (17). Means, prevalences, and their 95% confidence intervals (CI) were calculated with weighting and standardization for age. Developments over time were tested for statistical significance by analysis of variance (for means) and logistic regression (for prevalences). Differences in trends across subgroups were tested by adding interaction terms in the models (sex and region × year of survey). Trends were expressed in terms of relative differences, i.e. (value in period 2 minus value in period 1) / (value in period 1) × 100%. The basis for comparison is always the relevant figure from the first survey (OW91). The criterion for statistical significance was set at p<0.05.

Results

Weighted and age-standardized prevalences and means of cardiometabolic risk factors in the three survey periods 1990–1992, 1997–1999, 2008–2011, stratified by sex, are shown in Table 2.

Table 2

Comparison of weighted and age-standardized prevalences and means*1

Health-related behavior and obesity

The prevalence of lack of exercise dropped between the first and last periods (1990–1992 and 2008–2011) in both men and women (Table 2), but more in women than men, and more in the former East than in the former West Germany (eTable 3). Thus, by 2008–2011, the prevalence of lack of exercise was no longer higher in eastern Germany than in western Germany, as it had been in the period 1990–1992 (eTable 4), nor was it any higher in women than in men (Table 2). The prevalence of smoking fell among men, but rose in eastern Germany, between the first and last periods (Table 2). In the period 2008–2011, the prevalence of smoking in eastern Germany was no longer lower than in western Germany, as it had been in the period 1990–1992 (eTable 4). The narrowing of the gap in smoking prevalence between eastern and western Germany is largely accounted for by a rise in smoking among women in the eastern part of the country (eTable 5 a, b). The overall prevalence of obesity rose between the first and last periods, but this was largely accounted for by a rise in the prevalence of obesity among men in western Germany (Table 2 and eTable 5 a, b).

eTable 3

Differences in trends by sex, in eastern vs. western Germany, by sex in eastern Germany, and by sex in western Germany (effect modifications/interactions)

eTable 4

Comparison of weighted and age-standardized prevalences and means*1

eTable 5a

Comparison of weighted and age-standardized prevalences and means*1

eTable 5b

Comparison of weighted and age-standardized prevalences and means*1

Blood pressure, hypertension, and the use of antihypertensive drugs

The mean systolic blood pressure fell among both men and women between the first survey period (1990–1992) and the last (2008–2011) (Table 2), more in women than in men, and more in eastern than in western Germany (eTable 3). In the last period, the mean systolic blood pressure in eastern Germany was no longer higher than in western Germany, as it had been during the first period (Figure 1 and eTable 4). The prevalence of self-reported high blood pressure and use of antihypertensive drugs increased among both men and women over the same time period (Table 2), albeit to a greater extent in eastern German men than in eastern German women (eTable 5).

Figure 1

Trends in age-standardized means and prevalences of blood pressure

Cholesterol, hyperlipidemia, and the use of cholesterol-lowering drugs

From the first survey (1990–1992) to the last (2008–2011), the mean total cholesterol fell among both men and women (Table 2). The prevalence of self-reported hyperlipidemia remained unchanged, while the prevalence of use of cholesterol-lowering drugs rose over the same period in both men and women (Table 2), and to a greater extent in eastern than in western Germany (eTable 3). East-west differences in the prevalence of self-reported hyperlipidemia and the use of cholesterol-lowering drugs were smaller in 2008–2011 than in 1990–1992 (Figure 2 and eTable 4).

Figure 2

Trends in age-standardized means and prevalences of total cholesterol

Blood sugar, diabetes, and the use of antidiabetic drugs

The mean serum glucose level fell between 1990–1992 and 2008–2011 in both men and women (Table 2), and to a greater extent in eastern than in western Germany (eTable 3). The mean serum glucose level in eastern Germany in 2008–2011 was no higher than that in western Germany in 1990–1992 (Figure 3 and eTable 4). The prevalences of self-reported diabetes and the use of antidiabetic drugs rose over the same interval, with two exceptions: self-reported diabetes in men and antidiabetic drug use in women (Table 2).

Figure 3

Trends in age-standardized means and prevalences of serum glucose

Discussion

In this study of nationwide trends, based on three representative cross-sectional surveys, we found that the prevalences and mean values of cardiometabolic risk factors decreased overall between 1990 and 2011, in both men and women. Differences between eastern and western Germany that were present in 1990–1992 became smaller by the time of the last survey in 2008–2011.

Health-related behavior and obesity

Two exceptions to the general statement above are smoking and obesity, whose prevalences did not decline in the age group that was analyzed. From 1990 to 2011, the prevalence of current smoking fell only among men in western Germany. The marked decline of smoking since 2003 among 18-to-25-year-olds in Germany, which was documented by the Robert Koch Institute in a telephone survey as part of its regular health monitoring program (18), is not reflected in the findings of the present study because of the limited age range.

The increased prevalence of obesity is largely attributable to a markedly increased prevalence among men. Other studies, too, have revealed an increased prevalence of obesity among adults (19, 20). The observed decline in the prevalence of lack of physical exercise is in line with other studies. However, because of the simultaneously observed marked decline in occupational and daily physical activity, it could be that overall physical activity may actually have declined despite increased participation in sports and exercise (21, 22). There remains a large untapped potential for disease prevention with respect to all of the risk factors studied. In Germany, national health goals for the reduction of tobacco use, the prevention of obesity, the improvement of nutrition, and the encouragement of exercise have been incorporated into the federal Law for the Promotion of Health and Prevention of Disease (Gesetz zur Stärkung der Gesundheitsförderung und der Prävention, „Präventionsgesetz“) (23, 24).

Blood pressure, cholesterol, blood sugar, hypertension, hyperlipidemia, and diabetes

The observed decline in the mean measured values of systolic blood pressure and total cholesterol in the interval between the two periods 1990–1992 and 2008–2011 generally accords with comparable declines that have been reported in international meta-analyses for other high-income countries over the past two decades (25, 26). This does not hold for serum glucose, however, which has increased in most other countries (27). The simultaneously observed rise in the prevalence of self-reported high blood pressure and diabetes might be explicable with reference to the findings of other studies, which suggest that such apparent rises may reflect a higher detection rate of undiagnosed cases, rather than a true increase in incidence (28–30). Higher detection rates also lead to the more common prescribing, and use, of drugs (31), with resulting lower (i.e., better) mean values of blood pressure, cholesterol, and blood sugar. The increased prevalence of hypertension also partly reflects the lowering of blood pressure thresholds for the diagnosis and treatment of hypertension in recent medical guidelines (32, 33).

East-west differences

The differences between eastern and western Germany that were observed in 1990–1992 became much smaller, or even nonexistent, by 2008–2011, specifically with regard to (lack of) exercise, smoking, obesity, blood pressure, serum glucose, self-reported hyperlipidemia, and the use of cholesterol-lowering drugs. This evening out of differences was generally, but not always, in the direction of a more favorable cardiometabolic risk profile; the exceptions were the higher prevalences of obesity among men in western Germany and of increased smoking among women in eastern Germany. These developments were already pointed out in previous analyses based on only two periods of observation (34, 35); this is the first study with three periods of observation spanning a period of 20 years. The gradually more uniform living and working conditions in eastern and western Germany, along with increasingly similar patterns of health care, presumably account for the evening out of differences in risk factors. Nonetheless, there are still regional differences in cardiovascular diseases (36, 37) that tend to be less intense as one proceeds from northeast to southwest, reflecting underlying differences in regional economies and in the socioeconomics of living and working conditions (35).

Strengths and weaknesses

The three representative examination surveys provide a unique database for the analysis of secular trends in health and health-related behavior among persons living in Germany over a period of more than 20 years. A particular strength of the present study is its ability to demonstrate the gradual evening out of differences in health between eastern and western Germany.

An inherent limitation of the database comes from differences between surveys with regard to method, particularly between the two surveys of 1990–1992 and 1997–1999, which were carried out before the health monitoring program of the Robert Koch Institute was established. Moreover, a long time interval such as the one spanned by the three surveys in the present study is inevitably accompanied by changes in laboratory analytical techniques, measuring methods, questionnaire instruments, care guidelines, and other standards, and these changes make all comparisons over time more difficult. We have paid due attention to these aspects and performed sensitivity analyses to estimate the effect of altered methods. Moreover, selection effects cannot be excluded (the survey participation rate declined over time), and the self-reported items may have been affected by reporting bias (social desirability and recall bias). The methodological differences and the ways we dealt with them are summarized in eTable 2. Because of the cross-sectional design of the study, we cannot make any causal inferences from the findings. Further in-depth analyses are planned.

Overview

This study reveals an overall improvement in cardiovascular risk factors from 1990 to 2011 among men and women in Germany aged 25 to 69. The differences between eastern and western Germany observed in 1990–1992 were smaller or even nonexistent by 2008–2011. The need remains for health intervention and preventive measures in both eastern and western Germany.

The trends in cardiometabolic risk factors that we detected by analyzing data from the RKI’s health monitoring program are consistent with the reported downward trend in mortality due to cardiometabolic risk factors and heart disease in Germany since 1990, a trend which is stronger in eastern than in western Germany (35, 37, 38). This welcome development is presumably due in part to better health care, with improved detection and treatment of cardiometabolic disorders, as suggested by the observed increases in the self-reported prevalence of high blood pressure and diabetes and the use of drugs to treat these conditions. Yet it is presumably also due in part to improved health-related behavior, e.g., more exercise, healthier nutrition, and decreased smoking. This has come about through general changes in lifestyle as well as through changes in the societal framework conditions by deliberate political intervention, e.g., national action plans and legislative initiatives to combat smoking (and protect nonsmokers), promote exercise, and lessen overweight and obesity. It is to be hoped that the health-promoting lifestyle changes taken as targets in the federal Law for the Promotion of Health and Prevention of Disease (24) will help sustain and prolong the favorable secular trends in cardiometabolic risk factors that we have observed over the past two decades.

Conflict of interest statement

The authors state that they have no conflict of interest.

Manuscript submitted on 15 April 2016, revised version accepted on
7 July 2016.

Translated from the original German by Ethan Taub, M.D.

Corresponding author
Dr. Bärbel-Maria Kurth

Robert Koch-Institut

Abteilung für Epidemiologie und Gesundheitsmonitoring

General-Pape-Str. 62–66

D-12101 Berlin, Germany

Supplementary material
eTables:
www.aerzteblatt-international.de/16m712

References

1. World Health Organization: Cardiovascular Diseases (CVDs). Fact sheet N°317; Geneva: WHO 2015.

2. Institute for Health Metrics and Evaluation: Global burden of disease data visualisation. Washington: University of Washington 2016.

3. Schwerpunktheft Bundes-Gesundheitssurvey 1997/98: Ziele, Aufbau, Kooperationspartner. Stuttgart: Thieme 1998.

4. Hoffmeister H, Bellach BM: Die Gesundheit der Deutschen. Ein Ost-West-Vergleich von Gesundheitsdaten. Berlin: Robert Koch-Institut 1995.

5. Nicolai T, Bellach B, Mutius EV, Thefeld W, Hoffmeister H: Increased prevalence of sensitization against aeroallergens in adults in West compared with East Germany. Clin Exp Allergy 1997; 27: 886–92

6. Kurth B-M: [The RKI health monitoring – What it contains and how it can be used]. Public Health Forum 2012; 20: 4. e1–4. e3.

7. Scheidt-Nave C, Kamtsiuris P, Gosswald A, et al.: German health interview and examination survey for adults (DEGS)—design, objectives and implementation of the first data collection wave. BMC Public Health 2012; 12: 730

8. Kurth B-M, Ziese T, Tiemann F: Gesundheitsmonitoring auf Bundesebene. Bundesgesundheitsblatt Gesundheitsforschung Gesundheitsschutz 2005; 48: 261–72

9. von Troschke J, Klaes L, Maschewsky-Schneider U, Scheuermann W: Die Deutsche Herz-Kreislauf- Präventionsstudie: Design und Ergebnisse. Bern, Göttingen, Toronto, Seattle: Forschungsverbund DHP 1998.

10. Kamtsiuris P, Lange M, Hoffmann R, et al.: Die erste Welle der Studie zur Gesundheit Erwachsener in Deutschland (DEGS1): Stichprobendesign, Response, Gewichtung und Reprasentativität. Bundesgesundheitsblatt Gesundheitsforschung Gesundheitsschutz 2013; 56: 620–30

11. Truthmann J, Schienkiewitz A, Busch MA et al.: Changes in mean serum lipids among adults in Germany: results from National Health Surveys 1997–99 and 2008–11. BMC Public Health 2016; 16; 240

12. Hagstromer M, Oja P, Sjostrom M: The International Physical Activity Questionnaire (IPAQ): a study of concurrent and construct validity. Public Health Nutr. 2006, 9: 755–76

13. Adams SA, Matthews CE, Ebbeling CB, et al.: The effect of social desirability and social approval on self-reports of physical activity. Am J Epidemiol. 2005, 161: 389–398

14. Wong SL, Shields M, Leatherdale S et al.: Assessment of validity of self-reported smoking status. Health Report 2015; 23: 1.

15. World Health Organization: Obesity: preventing and managing the global epidemic. Report of a WHO consultation. Geneva: WHO 2000.

16. Knopf H, Grams D: [Medication use of adults in Germany: results of the German Health Interview and Examination Survey for adults (DEGS1)]. Bundesgesundheitsblatt Gesundheitsforschung Gesundheitsschutz 2013; 56: 868–77

17. Statistisches Bundesamt: GENESIS-Online Datenbank. Bonn: DESTATIS Statistisches Bundesamt 2015.

18. Lampert T: Rauchen – Aktuelle Entwicklungen bei Erwachsenen. Robert Koch-Institut (ed.); GBE kompakt 2011; 2.

19. Ng M, Fleming T, Robinson M, et al.: Global, regional, and national prevalence of overweight and obesity in children and adults during 1980–2013: a systematic analysis for the Global Burden of Disease Study 2013. Lancet 2014; 384: 766–81

20. Mensink GB, Schienkiewitz A, Haftenberger M, Lampert T, Ziese T, Scheidt-Nave C: Übergewicht und Adipositas in Deutschland. Ergebnisse der Studie zur Gesundheit Erwachsener in Deutschland (DEGS1). Bundesgesundheitsblatt Gesundheitsforschung Gesundheitsschutz 2013; 56: 786–94

21. Knuth AG, Hallal PC: Temporal trends in physical activity: a systematic review. J Phys Act Health 2009; 6: 548–59

22. Brownson RC, Boehmer TK, Luke DA: Declining rates of physical activity in the United States: what are the contributors? Annu Rev of Public Health 2005; 26: 421–43

23. Gesellschaft für Versicherungswirtschaft und -gestaltung e.V.: Gesundheitsziele.de – Forum Gesundheitsziele Deutschland. gesundheitsziele.de (last accessed 31 March 2016).

24. Bundesanzeiger: Gesetz zur Stärkung der Gesundheitsförderung und der Prävention (Präventionsgesetz – PrävG). Bundesgesetzblatt 2015; 31: 1368–79.

25. Danaei G, Finucane MM, Lin JK, et al.: National, regional, and global trends in systolic blood pressure since 1980: systematic analysis of health examination surveys and epidemiological studies with 786 country-years and 5.4 million participants. Lancet 2011; 377: 568–77

26. Farzadfar F, Finucane MM, Danaei G, et al.: National, regional, and global trends in serum total cholesterol since 1980: systematic analysis of health examination surveys and epidemiological studies with 321 country-years and 3.0 million participants. Lancet 2011; 377: 578–86

27. Danaei G, Finucane MM, Lu Y, et al.: National, regional, and global trends in fasting plasma glucose and diabetes prevalence since 1980: systematic analysis of health examination surveys and epidemiological studies with 370 country-years and 2.7 million participants. Lancet 2011; 378: 31–40

28. Bartholomeeusen S, Vandenbroucke JP, Truyers C, Buntinx F: Trends in total cholesterol screening and in prescribing lipid-lowering drugs in general practice in the period 1994–2003. BMC Fam Pract 2008; 9: 39

29. Du Y, Heidemann C, Schaffrath Rosario A, et al.: Changes in diabetes care indicators: findings from German National Health Interview and Examination Surveys 1997–1999 and 2008–2011. BMJ Open Diabetes Res Care 2015; 3: e000135

30. Heidemann C, Du Y, Paprott R, Haftenberger M, Rathmann W, Scheidt-Nave C: Temporal changes in the prevalence of diagnosed diabetes, undiagnosed diabetes and prediabetes: findings from the German Health Interview and Examination Surveys in 1997–1999 and 2008–2011. Diabet Med 2015 [Epub ahead of print]

31. Sarganas G, Knopf H, Grams D, Neuhauser HK: Trends in antihypertensive medication use and blood pressure control among adults with hypertension in Germany. Am J Hypertens 2016; 29: 104–13

32. The sixth report of the Joint National Committee on prevention, detection, evaluation, and treatment of high blood pressure. Arch Intern Med 1997; 157: 2413–46

33. 1999 World Health Organization-International Society of Hypertension Guidelines for the Management of Hypertension. Guidelines Subcommittee. J Hypertens 1999; 17: 151–83

34. Robert Koch-Institut: 20 Jahre nach dem Fall der Mauer: Wie hat sich die Gesundheit in Deutschland entwickelt? Beiträge zur Gesundheitsberichterstattung des Bundes. Berlin: RKI; 2010.

35. Robert Koch-Institut: 25 Jahre nach dem Fall der Mauer: regionale Unterschiede in der Gesundheit. GBE kompakt 3/2014. www.rki.de/gbe-kompakt (last accessed 18 August 2016).

36. Völzke H, Ittermann T, Schmidt CO, et al.: Prevalence trends in lifestyle-related risk factors. Dtsch Arztebl Int 2015; 112: 185–92

37. Deutsche Herzstiftung: Deutscher Herzbericht 2015. Frankfurt am Main: Deutsche Herzstiftung e. V. 2015; 46.

38. Robert Koch-Institut: Wie steht’s um unsere Gesundheit? Krankheitslast. Herz-Kreislauf-Krankheiten. In: RKI, (ed.): Gesundheit in Deutschland – Gesundheitsberichterstattung des Bundes. Berlin: RKI 2006; 23–29.