MedicalResearch.com Interview with:
Joshua J. Joseph, MD
Christopher D. Saudek M.D. Fellow in Diabetes Research
Division of Endocrinology, Diabetes and Metabolism
Johns Hopkins University School of Medicine
MedicalResearch.com: What does your study explore?
Response: Our study explores two basic questions:
(a) Are multi-ethnic people with higher levels of cardiovascular health less likely to develop diabetes based on the AHA ideal cardiovascular health metric?
(b) Do these associations vary by race/ethnicity (non-Hispanic white, Chinese American, African American, and Hispanic American)?
MedicalResearch.com: Why did you choose this topic to explore?
Response: The literature has shown a strong association between lifestyle factors and elevated risk of diabetes in majority non-Hispanic white studies. One study of American Indians showed that meeting a greater number of ideal cardiovascular health goals was associated with a reduced risk of diabetes. We aimed to assess the association of baseline ideal cardiovascular health with incident diabetes within a multi-ethnic population, due to variation of ideal cardiovascular health by race/ethnicity.
MedicalResearch.com: How was the study conducted? (data collection, length of study, etc.)
Response: We used data from the Multi-Ethnic Study of Atherosclerosis, a study of cardiovascular disease that also has data on diabetes status. Participants were 45 to 84 years old at baseline and represented four different ethnic groups—Caucasians (38%), African-Americans (28%), Hispanic-Americans (22%), and Chinese-Americans (12%). Participants joined the study between 2000 and 2002 and underwent a “baseline” exam consisting of a standardised questionnaire and a series of medical tests.
Ideal cardiovascular health components (total cholesterol, blood pressure, dietary intake, tobacco use, physical activity and BMI) were assessed at baseline and participants were categorised as having ideal, intermediate or poor cardiovascular health, as defined by the AHA 2020 impact goals. We developed a scoring system based on the number of ideal cardiovascular health components (0–1 ‘poor’, 2–3 ‘intermediate’, and ≥4 ‘ideal’).
We did two analyses:
(a) We first examined the risk of developing type 2 diabetes over approximately 11 years in people with poor, intermediate and ideal cardiovascular health at baseline adjusted for baseline study site, age, sex, race/ethnicity, education, occupational status, alcohol use and estimated glomerular filtration rate. These people did not have diabetes at the start of the study.
(b) Second, we examined the risk of developing diabetes among the 4 racial/ethnic groups over approximately 11 years by poor, intermediate and ideal cardiovascular health at baseline.
MedicalResearch.com: What are the major findings of your study?
(A) Only one in four study participants were found to have attained four or more of the ICH components and among racial/ethnic minorities, this proportion was just one in six. These differences were not solely limited to lifestyle factors such as tobacco use or physical activity. Hispanic Americans and African Americans participants were found to have significantly higher BMI, systolic blood pressure and fasting glucose compared to NHWs.
(B) Rates of incident diabetes developed during the follow-up period of the study were highest in Hispanic Americans and African American populations at 15.3 and 12.3 cases per 1000 people per year respectively, compared to 11.1 cases per 1000 person-years in the study population as a whole. CA had diabetes rates of 11.6 cases and NHW 8.3 cases per 1000 people per year. Every ICH goal that was achieved in both the cohort as a whole as well as the individual race/ethnic groups resulted in lower rates of incident diabetes. Participants categorised as having “intermediate” or “ideal” cardiovascular health had a 34% and 75% lower diabetes incidence, respectively, than individuals whose cardiovascular health was considered to be “poor”.
(C) Ideal vs poor cardiovascular health was associated with a greater reduction in diabetes risk in non-Hispanic whites and Chinese Americans (87% and 88%) vs African Americans and Hispanic Americans (66% and 50%).
MedicalResearch.com: What is new and different about your study and/or its findings?
(a) Our study is the first to show an association between ideal cardiovascular health and type 2 diabetes in a multi-ethnic population.
(b) Our study shows that these associations vary by race/ethnicity with greater magnitude of association among non-Hispanic whites and Chinese Americans compared with African Americans and Hispanic Americans.
MedicalResearch.com: Does your study include an explanation of how/why these findings occurred?
Response: Among risk factors not directly in the causal pathway, BMI was the predominant risk factor for diabetes, with a 48% and 77% lower diabetes risk for overweight BMI and normal BMI, respectively, vs obese BMI. This is consistent with previous studies showing increasing BMI as the primary risk factor increasing diabetes prevalence in the USA over the last 30 years.
MedicalResearch.com: Were you surprised by anything that your study revealed?
Response: We were surprised about the racial/ethnic variation in the association of ideal cardiovascular health with incident diabetes. Other literature has shown differences in prevalence of ideal cardiovascular health by race/ethnicity, but we expected to finds similar associations of lower risk among the racial/ethnic groups. Given the differences in associations we are currently exploring other risk factors for diabetes that may have greater predominance in US racial/ethnic groups.
MedicalResearch.com: Does your study include any recommendations based on the findings?
MedicalResearch.com: Our study showed that increasing levels of ideal cardiovascular health within the guidelines set out by the AHA 2020 impact goals may reduce the burden of diabetes in the US. The lower prevalence of ideal cardiovascular health, combined with lower magnitude of diabetes reduction with ideal cardiovascular health among African Americans and Hispanic Americans, further research on promotion, attainment and ethnic differences of ideal cardiovascular health in US racial/ethnic minority groups is of paramount importance to lower risk of cardiovascular disease and diabetes.
MedicalResearch.com: Thank you for your contribution to the MedicalResearch.com community.
The association of ideal cardiovascular health with incident type 2 diabetes mellitus: the Multi-Ethnic Study of Atherosclerosis
Joshua J. Joseph, Justin B. Echouffo Tcheugui, Mercedes R. Carnethon, Alain G. Bertoni,Christina M. Shay, Haitham M. Ahmed, Roger S. Blumenthal, Mary Cushman, Sherita H. Golden
Diabetologia First online: 08 June 2016
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