Cardiac biomarkers aid microvascular risk prediction in diabetics

Jun 6 2014

By Eleanor McDermid, Senior medwireNews Reporter

Assessing cardiac biomarkers results in a moderate improvement in the ability to predict microvascular complications in patients with Type 2 diabetes, say researchers.

Study author Naveed Sattar (University of Glasgow, UK) and colleagues note that prediction of microvascular events is not currently recommended in guidelines, but say that this “is largely due to a lack of evidence at present regarding evidence-based therapies to prevent onset of microvascular events.”

They say: “Our results are thus important, since prediction of microvascular events, in particular nephropathy, would be useful for future trials of new agents designed to prevent or slow progression of nephropathy, an area of intense interest and activity.”

The team’s findings are based on data from 439 diabetes patients who had microvascular events (283 nephropathy, 183 retinopathy) during a median 5 years of follow-up in a clinical trial.

Patients with microvascular complications had significantly higher baseline levels of high-sensitivity troponin T (hsTnT) compared with 2946 patients who remained free of complications, at 8 versus 5 ng/L. They also had significantly higher N-terminal pro–B-type natriuretic peptide (NT-proBNP) levels, at 119 versus 78 pg/mL.

Each standard deviation increase in hsTnT and NT-proBNP was associated with significant 67% and 63% respective increases in the risk of microvascular events. These were attenuated to 40% and 41% after accounting for confounders including vascular risk factors and history of cardiovascular disease, but remained significant.

The team found that a prediction model composed of routinely collected baseline clinical variables distinguished between patients with and without microvascular events moderately well, and was particularly accurate for predicting nephropathy events.

Adding the cardiac biomarkers to this model did not improve the C statistic, but did significantly improve the net reclassification index (NRI) in both continuous and categorical models, ie, a significantly larger proportion of patients was correctly classified.

“We suggest that subclinical cardiac disease might be an antecedent of peripheral microvascular disease”, the researchers write in Diabetes Care. They therefore suggest that combining cardiac biomarkers with clinical predictors may help to identify patients for intervention to reduce microvascular risk.

However, the effect of the biomarkers on the NRI was strongest for nephropathy, with little effect seen for retinopathy. The team also notes that there appeared to be different risk mechanisms involved in the two outcomes; the strongest risk factor for nephropathy was the albumin-to-creatinine ratio, whereas retinopathy was better predicted by diabetes duration and glycated haemoglobin level.

“As such, specific prediction of retinopathy (without retinal scanning data) remains challenging using conventional risk factors and cardiac biomarkers”, conclude the researchers.

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