HbA1c as a predictor of diabetes after gestational diabetes mellitus. Issue 1 (February 2017)

• Record Type: Journal Article
• Authors: Claesson, Rickard; Ignell, Claes; Shaat, Nael; Berntorp, Kerstin
• Is Part Of: Primary care diabetes. Volume 11:Issue 1(2017)
• Page Start: 46
• Page End: 51
• Publication Date: 2017-02
• Subjects: AUC area under the curve -- BMI body mass index -- CI confidence interval -- EASD European Association for the Study of Diabetes -- GDM gestational diabetes mellitus -- IFG impaired fasting glucose -- IGT impaired glucose tolerance -- NGT normal glucose tolerance -- NPV negative predictive value -- OGTT oral glucose tolerance test -- OR odds ratio -- PPV positive predictive value -- ROC receiver-operating characteristic -- SD standard deviation -- WHO World Health Organization; Gestational diabetes -- HbA1c -- OGTT -- Post-partum diabetes -- Prediction; Diabetes -- Periodicals; 616.462
• DOI: 10.1016/j.pcd.2016.09.002
• Languages: English
• ISSNs: 1751-9918

Abstract

Highlights: Third-trimester HbA1c was investigated as a predictor of diabetes following GDM. After five years, 73/196 (37%) of the women had developed diabetes. HbA1c ≥36 mmol/mol (≥5.4%) was associated with a 5.5-fold increased risk of diabetes. HbA1c showed high specificity but low sensitivity to predict diabetes post-partum. HbA1c could be used as a means of selecting high-risk women for interventions. Abstract: Aim: We wanted to investigate third-trimester HbA1c as a predictor of diabetes after gestational diabetes mellitus (GDM). Methods: Women with GDM were followed up prospectively for five years from pregnancy to detect the development of diabetes. The ability of HbA1c to predict diabetes was evaluated with receiver-operating characteristic (ROC) curves and logistic regression analysis. Results: By five years, 73 of 196 women had been diagnosed with diabetes. An optimal cut-off point for HbA1c of 36 mmol/mol (5.4%) could predict diabetes with 45% sensitivity and 92% specificity. For HbA1c ≥39 mmol/mol (≥5.7%), sensitivity, specificity, and positive predictive value were 30%, 97%, and 91%, respectively. In logistic regression analysis, adjusting for the diagnostic glucose concentration during pregnancy, HbA1c levels in the upper quartile (≥36 mmol/mol) were associated with a 5.5-fold increased risk of diabetes. Conclusion: Third-trimester HbA1c levels in the pre-diabetes range revealed women with post-partum diabetes with high specificity and high positive predictive value. HbA1c testing could be used as a strategy to select high-risk women for lifestyle interventions aimed at prevention of diabetes starting during pregnancy. The results should encourage further validation in other populations using new diagnostic criteria for GDM.