Subclinical CVD in One-Third of US Adults With Diabetes

There is growing interest in using biomarkers to screen patients for subclinical CVD to ensure they are detected and treated as early as possible. “Cardiac troponins can be measured with high sensitivity assays to detect previously unrecognized chronic damage to the heart,” explains Elizabeth Selvin, PhD, MPH. “People with type 2 diabetes have a high risk for CVD events, but cardiac biomarkers may give us a window into what is going on before someone develops a cardiovascular event.

” Research has shown that elevated levels of high sensitivity cardiac troponin (hs-cTnT) and  Nterminal pro-B-type natriuretic peptide (NT-proBNP) may confer substantial risk for major cardiac events and mortality. Understanding the burden and prognosis of subclinical CVD is critical for implementing effective screening measures, but national data are lacking, and little is known about the burden and long-term consequences of subclinical CVD among adults with diabetes.

Assessing the Burden & Prognostic Value of Subclinical CVD

Dr. Selvin and colleagues published a study in the Journal of the American Heart Association that sought to characterize the burden and prognostic value of subclinical CVD using cardiac biomarkers in adults with or without diabetes. The researchers measured cardiac troponin and NT-proBNP in blood samples from participants in NHANES.

The prevalence of subclinical CVD—defined as elevated hs-cTnT or NT-proBNP—was estimated overall and by demographic characteristics, diabetes duration, and glycemic control. The researchers also examined independent associations of cardiac biomarkers with all-cause and cardiovascular mortality. The prevalence of elevated hs-cTnT (defined as ≥14 ng/L) and NT-proBNP (defined as ≥125 pg/mL) was estimated in people with and without diabetes.

Subclinical CVD Twice as High in People With Diabetes

According to the results, the crude prevalence of subclinical CVD was roughly twice as high for adults with diabetes than for those without diabetes (Figure). “We found that 33.4% of US adults with type 2 diabetes had undetected or subclinical CVD, compared with a 16.1% rate that was seen in people without diabetes,” Dr. Selvin says. Notably, 19% of patients with diabetes had elevated hs-cTnT levels, compared with 5% of those without diabetes. The prevalence of adults with diabetes having both elevated hs-cTnT and NTproBNP levels was low overall but significantly higher in adults with diabetes than in those without it (9% vs 3%).

“Our study found that adults with type 2 diabetes who had no signs or symptoms of CVD were more likely to have elevated levels of hs-cTnT or NT-proBNP than people without type 2 diabetes,” Dr. Selvin says. “These cardiac biomarkers were associated with an increased risk for death from any cause and death from CVD.” After adjusting for age, the prevalence of elevated hs-cTnT was significantly higher in people with longer diabetes duration and worse glycemic control.

Routine Screening for Cardiac Biomarkers May Unmask CVD Risks

“Our findings suggest that routine screening for cardiac biomarkers, such as high-sensitivity cardiac troponin, and tailored interventions may help reduce CVD risks in people with type 2 diabetes,” says Dr. Selvin. “CVD can be present for a long time before patients experience signs or symptoms of disease. Our study demonstrated that cardiac biomarkers measured in a blood sample can help unmask CVD that would otherwise go unrecognized. The findings suggest there may be a role for hs-cTnT and NT-proBNP in the routine monitoring of cardiovascular risk.” Dr. Selvin notes that additional studies are needed to better understand how to manage subclinical CVD in people with and without type 2 diabetes. “Our study looked at FDA-cleared tests that are commercially available at many laboratories, but clinical guidelines are not yet clear on when and how to use these tests as routine screening in the general population,” she says. “The next step is to understand which interventions should be used to lower levels of these cardiac biomarkers in the blood and improve cardiovascular health in people with diabetes.”