Endocrine Abstracts

Introduction

Type 2 diabetes mellitus chronic hyperglycemia resulting from a defect in the secretion of insulin or the action of insulin or from these two associated abnormalities.

Aim of the study

To try to establish an optimal threshold of HbA1C to predict diabetes mellitus on a sample of Algiers population not known to be diabetic but at high risk compared to the gold standard OGPO.

Method

500 patients (345 women, 155 men) aged ≥ 40 years consulting at the level of primary care structures, volunteers, but at high risk of diabetes, are subjected to a questionnaire, then to screening by carrying out a hyperglycemia caused by oral route (OGTT), HbA1c (HPLC TOSOH G8 method), SNSF, and ophthalmologic examination (fundus). The sensitivity and specificity of HbA1c at different thresholds for the diagnosis of diabetes and pre-diabetes were studied by ROC curve. The diagnostic performance of HbA1c was assessed by the areas under the ROC curve (AUC) estimated by the DeLong method.

Results

53.2% of patients present with dysglycemia: 23.8% with diabetes mellitus, 29.4% with pre-diabetes: 6.8% with moderate fasting hyperglycemia (HMJ). 22.6% ITG glucose intolerance. The optimal HbA1c threshold for the diagnosis of diabetes mellitus is 6.27% with a sensitivity of 78% CI (0.9134–0.924) and a specificity of 88%, PPV: 67.88%, NPV: 92.83%. For the diagnosis of pre-diabetes, the optimal HbA1c threshold is 5.83%, with a sensitivity of 71% CI (0.6221–0.8016) and a specificity of 81% (0.7268 - 0.8950), PPV: 80.6%, NPV: 72 %. The HbA1c at the threshold ≥ 5.7% of ADA seems more interesting for screening the maximum number of diabetics (98%) than that of prediabetes (67%). Our HbA1c threshold ≥ 5.83% being less sensitive to detect dysglycemia compared to that of ADA (92% of type 2 diabetes mellitus and 54% of prediabetes).

Conclusion

The use of HbA1c by the standardized method may be a means of screening in high-risk subjects. This HbA1C screening strategy must be verified at the level of the general Algerian population and involves periodic evaluation.