Comparison of diagnostic screening methods for diabetes in patients with heart failure

Aims

The objective of the study was to compare screening performances of HbA1c, fasting plasma glucose (FPG), and two-hour plasma glucose (2hPG) in heart failure (HF) patients.

Methods

We included 237 HF patients aged >20 years without history of diabetes, using National Health and Nutrition Examination Survey data (2005–2016). American Diabetes Association diabetes screening criteria were used: (1) HbA1c ≥6.5%, (2) FPG ≥126 mg/dL, and (3) 2hPG ≥200 mg/dL. Sensitivity, specificity, predictive values, and Receiver Operating Characteristic (ROC) curves for HbA1c and FPG were examined against reference methods.

Results

N = 50 patients (20.5%) met at least 1 of 3 clinical criteria for diabetes. 2hPG alone identified 70.5% of patients, whereas HbA1c alone identified only 27.0% of patients. Sensitivity and specificity using a HbA1c cutoff at ≥6.5% were 24.4% and 97.6%, respectively. The Youden's J statistic for HbA1c was maximized at 6.1%. The area under the ROC curve of HbA1c against 2hPG was significantly lower compared to FPG (0.79, 95% CI 0.70-0.88; 0.89, 95% CI 0.84-0.94, respectively; p = 0.04).

Conclusions

Blood glucose criteria are more sensitive than HbA1c when screening HF patients for diabetes. Future studies should test performance of a HbA1c cutoff at 6.1% when FPG or 2hPG cannot be completed.