Low Awareness of Diabetes as a Major Risk Factor for Cardiovascular Disease in Middle- and High-Income Countries

The global prevalence of diabetes is projected to rise from 463 million in 2019 to almost 700 million in 2045, a 51% increase over two and a half decades (1,2). This worrisome trend is attributed to an aging population, changing dietary patterns, increasingly sedentary lifestyles, and increasing levels of obesity and is likely to affect all countries regardless of socioeconomic development (3,4). Because individuals with diabetes have a two- to four-times increased risk of atherosclerotic cardiovascular disease (CVD) compared with adults without diabetes (5), the increasing burden of diabetes is projected to produce a corresponding increase in the global CVD burden (6). Recognizing that diabetes is a major risk factor for CVD may motivate lifestyle choices to decrease diabetes risk, promote screening and treatment for diabetes, and boost uptake of primary prevention of CVD (7). However, the level of global awareness of diabetes as a CVD risk factor has not previously been characterized (8). As part of its global quality improvement efforts, the American Heart Association (AHA) designed and implemented a survey to quantify global public awareness of CVD risk factors. This study, which analyzes a subset of these data, sought to generate country-level estimates of the awareness of diabetes as a CVD risk factor and examine whether awareness varies by sex, age, country, geographic region, or country-level economic development.

This is a secondary analysis of an online quality improvement survey administered through the YouGov omnibus platform to participants in 50 countries in 2021. YouGov is one of the world’s largest research data and analytics groups, with a panel of >9 million respondents globally who have consented to the use of their responses for research purposes. An e-mail with the survey questions was sent to a selected subset of respondents in 50 countries. The countries were chosen based on the capability of the survey vendor to generate accurate nationally representative estimates from online responses. Within each country, participants were selected from the YouGov panel based on data regarding their age, sex, race, and education (additional survey details are provided in the Supplementary Material). In each country, a nationally representative sample of adults age ≥18 years or older were surveyed in their native language.

The questions and survey format were based on an existing and validated public health awareness survey conducted by the AHA in the U.S. triennially for 15 years and published elsewhere (9). The survey consisted of six questions on topics broadly related to heart disease (Supplementary Table 1). Of relevance to this study, one question asked participants to identify major risk factors for heart disease: “Based on what you know, which, if any, of the following are the major causes of heart disease (please select all that apply)?” Answer choices included high blood pressure, high cholesterol, smoking, being overweight, lack of sleep, diabetes, lack of exercise, poor diet, drinking alcohol, stress, family history of heart disease, other, not applicable, and unknown.

For this study, the outcome of interest was the proportion of survey respondents who correctly identified diabetes as a major cause of CVD. For each country, crude survey results were weighted by age, sex, race, educational attainment, region, and income level to generate nationally representative estimates. We also examined awareness levels stratified by sex, age group, country, World Health Organization (WHO) region, and World Bank income category. For analyses by region and income category, country-level proportions were weighted by the estimated population in 2022 of the surveyed countries in the region or income category. Cochran-Armitage trend testing was used for comparisons across age categories, and Pearson χ² tests were performed for sex, WHO region, and World Bank classification comparisons. Because this analysis relied on deidentified aggregated data collected by YouGov and AHA as part of the global quality improvement survey, it was not considered human subjects research by the institutional review board of Beth Israel Deaconess Medical Center.

A total of 48,988 individuals (50.8% male) from 50 countries responded to the survey (Table 1). The 50 countries represented all six WHO regions and included 29 high-income, 12 upper-middle-income, nine lower-middle-income, and zero low-income countries. A total of 15,747 (32.1%) survey respondents correctly identified diabetes as a major risk factor for CVD. Awareness was similar among men and women (32.3% vs. 31.9%; P = 0.34) but increased with age (from 30.0% among respondents age 18–24 years to 36.1% in respondents age >65 years; P < 0.001 for trend). Awareness varied by country, ranging from 7.4% in Slovenia to 47.3% in Lithuania (Fig. 1). There were also marked differences by WHO geographic region; awareness was lowest in the Western Pacific region (23.8%) and highest in the Americas (36.5%; P < 0.001). High-income countries had higher levels of awareness than lower-middle-income and upper-middle-income countries (P < 0.001).

In an online survey of nationally representative samples of individuals from 50 high- and middle-income countries that collectively account for 454 million adults living with diabetes (10), two in three respondents did not identify diabetes as a major CVD risk factor. These findings are alarming in the context of the substantial projected increase in diabetes over the coming 25 years, given that recognizing the connection between diabetes and CVD may be crucial to individual and systemic investments in primary prevention. Our findings therefore underscore the need for concerted efforts to increase public awareness of this common major CVD risk factor. Low awareness among working-age adults seen in this study is a particular cause for concern, because cardiovascular risk is rising rapidly in this group, and they can derive substantial benefits from preventive efforts (11,12).

Key strengths of this study include the large and diverse sample of respondents representing all WHO regions, with countries representing an aggregate population in excess of 5.5 billion. This is also the first study to characterize awareness of the link between diabetes and CVD on this international scale. A key limitation of this study is that the online nature of the survey precludes accurate assessment of response rates; we are therefore unable to quantify nonresponse bias. Although YouGov makes substantial efforts to ensure a diverse and representative sample of respondents, online surveys may be affected by selection bias in that individuals who engage in an online survey may be systematically different from those who are unable or unwilling to do so. Another limitation is the lack of data on low-income countries. As noted above, selection of countries was based on the capacity of the survey vendor to generate nationally representative estimates based on online responses and was therefore a limitation of the survey mechanism rather than an omission in the survey design. Future surveys should work with online and in-person survey vendors and partner with in-country stakeholders to generate representative results in low-income countries, many of which are likely to see severe epidemics of diabetes and CVD in the coming decades.

The strong link between diabetes and CVD is well established, but there continue to be substantial gaps in the identification and treatment of patients with diabetes, particularly in countries with limited health care resources, such as the low-middle-income countries included in this study (13). Diabetes prevention and control are reliant on individual- and community-level health literacy, lifestyle modification, and social determinants of health, and diabetes treatment requires sustained engagement of the motivated patient with the health system (14,15). Patient awareness of diabetes and its sequelae has been proven to be crucial for improving clinical and psychosocial outcomes; however, awareness levels remain low (16). The knowledge gap identified in our study has important public health consequences. Individuals who do not recognize the cardiovascular risk associated with diabetes may be less likely to make the lifestyle changes necessary to prevent diabetes, get screened and treated once they develop diabetes, or adhere to strategies for CVD prevention. Lack of awareness may fuel misconceptions related to disease prevention and management, further perpetuating the social stigma associated with diabetes in some settings (17).

Addressing this knowledge gap will require a complex multifaceted strategy that includes public health campaigns, patient outreach, and provider engagement (18). These interventions should be tailored by country and age group, given the substantial differences in how different populations now access credible health information. This may be modeled on the successful Go Red for Women initiative, an international campaign to increase awareness of heart disease and stroke in women (19). This program, which was created after a prior AHA survey showed low levels of awareness of CVD in women, is active in 42 countries, with in-country stakeholders regularly organizing provider-, patient-, and community-oriented awareness campaigns. The AHA also recently partnered with the American Diabetes Association to launch Know Diabetes by Heart, a campaign to highlight the link between diabetes and CVD and provide resources and support to help individuals living with diabetes better manage their risk of heart disease and stroke (20). In order for these campaigns to be successful, however, they must be coupled with private and public investments in cost-effective and scalable strategies to support primordial and primary prevention of CVD, including resources to address social determinants of health, assist individuals in making healthy lifestyle choices, and promote appropriate screening of at-risk populations.

Funding. The global survey was funded by the AHA. D.S.K. is supported by grant R01HL157530 from the National Heart, Lung, and Blood Institute.

Duality of Interest. M.B.T. is an employee of the AHA. L.S.M. and S.C.S. are volunteer members of the international committee of the AHA. D.S.K. serves as the volunteer co-chair of the international committee of the AHA. No other potential conflicts of interest relevant to this article were reported.

Author Contributions. R.S.C., N.M.A.-R., and D.S.K. analyzed data, created the figure/table and Supplementary Material, and wrote the manuscript. M.B.T. collected data and advised on data analysis. M.B.T., L.S.M., and S.C.S. reviewed and edited the manuscript. L.S.M., S.C.S., and D.S.K. advised on data analysis. R.S.C. and D.S.K. are the guarantors of this work and, as such, had full access to all the data in the study and take responsibility for the integrity of the data and the accuracy of the data analysis.