Unveiled Threat: Research Discovers One in Three Type 2 Diabetics Might Have Hidden Heart Disease

A study by Johns Hopkins Bloomberg School of Public Health has revealed that a third of adults with Type 2 diabetes might be silently suffering from cardiovascular disease, identified by elevated levels of two protein biomarkers. This finding suggests that regular screenings for these biomarkers, typically used in diagnosing heart conditions, can aid in identifying patients at greater risk and thereby assist in formulating preventative treatments for cardiovascular disease in those diagnosed with Type 2 diabetes.

Recently, a study in the Journal of the American Heart Association disclosed that one in three adults with Type 2 diabetes demonstrate higher levels of two biomarkers connected to heart disease.

The research, published in the Journal of the American Heart Association, established a correlation between elevated levels of two protein biomarkers indicative of heart damage and unseen or symptomless cardiovascular disease in Type 2 diabetic adults in contrast to those without diabetes.

Tests that measure the concentration of high-sensitivity cardiac troponin T and N-terminal pro-B-type natriuretic peptide biomarkers are routinely used to detect injury and stress to the heart and are standard in diagnosing heart attack and heart failure. However, even marginally increased levels of these proteins in the blood could be an early signal of changes in heart structure and function, possibly increasing the risk of future heart failure, coronary heart disease, or death.

Elizabeth Selvin, Ph.D., M.P.H., a professor of epidemiology at Johns Hopkins Bloomberg School of Public Health and co-author of the study, observed that many Type 2 diabetic individuals without a history of heart attack or cardiovascular disease are at high risk for cardiovascular complications. She suggested that these cardiac biomarkers could help identify the highest risk individuals within the large population of Type 2 diabetes diagnosed adults, estimated by the CDC to be around 27 million in the U.S.

Health information and blood samples from over 10,300 adults, collected during the U.S. National Health and Nutrition Examination Survey from 1999 to 2004, were analyzed in the study. The researchers aimed to ascertain if symptomless, previously unidentified cardiovascular disease could be identified by elevated levels of the cardiac protein biomarkers among individuals with and without Type 2 diabetes. The participants had reported no history of cardiovascular disease at the time they entered the study.

Researchers examined stored blood samples from all participants and measured two cardiac biomarkers levels. Mortality statistics were obtained from the National Death Index. After adjusting for factors like age, race, income, and cardiovascular risk, the associations between elevated troponin and N-terminal pro-B-type natriuretic peptide and risk of death from cardiovascular disease or all causes were assessed.

The study’s findings included:

1. One-third (33.4%) of adults with Type 2 diabetes showed indications of undetected cardiovascular disease, as indicated by elevated levels of two protein markers, compared to only 16.1% of those without diabetes.

2. Among adults with Type 2 diabetes, increased levels of troponin and N-terminal pro-B-type natriuretic peptide were associated with an increased risk of all-cause death (77% and 78% increased risk, respectively) and cardiovascular death (54% and over double the increased risk, respectively), compared to normal levels of these proteins in the blood. This elevated risk persisted even after adjusting for other cardiovascular risk factors.

3. After adjusting for age, elevated troponin levels were found more frequently in people with Type 2 diabetes, across categories of age, sex, race/ethnicity, and weight. In contrast, levels of N-terminal pro-B-type natriuretic peptide were not elevated in people with Type 2 diabetes compared to those without, when adjusted for age.

4. The prevalence of elevated troponin was notably higher in individuals who had Type 2 diabetes for a prolonged period and whose blood sugar levels were not well-regulated.

Selvin noted that while cholesterol is often targeted to reduce cardiovascular disease risk in Type 2 diabetics, the disease may directly affect the heart unrelated to cholesterol levels. She posits that if Type 2 diabetes is causing damage to the small vessels in the heart independent of cholesterol plaque buildup, then cholesterol-lowering medications will not prevent cardiac damage. The research implies that additional non-statin-related treatments are required to lower the risk of cardiovascular disease in people with Type 2 diabetes.

Though traditional risk factors like high blood pressure and cholesterol have been extensively studied in terms of their impact on cardiovascular health, recent evidence advocates that screenings for specific cardiac biomarkers should be incorporated into the routine evaluation of traditional cardiovascular risk factors.

Selvin added that the biomarkers examined in this study could efficiently classify patients based on their health status. She suggested that more regular biomarker measurement could help target cardiovascular prevention therapies for higher-risk Type 2 diabetes patients.

This study is among the first to use participants that accurately represent the general population. However, as the data does not permit the identification of heart disease, heart failure, stroke events, or cardiovascular complications, more research is needed to determine if routine biomarker measurement might mitigate cardiovascular complications in this population.

The study was financially supported by the Biomarkers Consortium of the Foundation for the National Institutes of Health. The reference for this research is “Subclinical Cardiovascular Disease in US Adults With and Without Diabetes” by Michael Fang, Dan Wang, Olive Tang, John William McEvoy, Justin B. Echouffo‐Tcheugui, Robert H. Christenson, and Elizabeth Selvin, published on May 31, 2023, in the Journal of the American Heart Association.
DOI: 10.1161/JAHA.122.029083

Frequently Asked Questions (FAQs) about Type 2 Diabetes and Heart Disease

More about Type 2 Diabetes and Heart Disease

• Johns Hopkins Bloomberg School of Public Health
• Journal of the American Heart Association
• National Health and Nutrition Examination Survey
• Biomarkers Consortium of the Foundation for the National Institutes of Health
• Information about Type 2 Diabetes from CDC