Rickard Claesson1, Claes Ignell2, Nael Shaat3, Kerstin Berntorp4. 1. Department of Clinical Sciences Malmö, Lund University, SE-205 02 Malmö, Sweden; Department of Obstetrics and Gynaecology, Office for Healthcare "Kryh", SE-271 82 Ystad, Sweden. Electronic address: rickard.claesson@med.lu.se. 2. Department of Clinical Sciences Malmö, Lund University, SE-205 02 Malmö, Sweden; Department of Obstetrics and Gynaecology, Office for Healthcare "Sund", SE-251 87 Helsingborg, Sweden. Electronic address: claes.ignell@med.lu.se. 3. Department of Clinical Sciences Malmö, Lund University, SE-205 02 Malmö, Sweden; Department of Endocrinology, Skåne University Hospital, SE-205 02 Malmö, Sweden. Electronic address: nael.shaat@med.lu.se. 4. Department of Clinical Sciences Malmö, Lund University, SE-205 02 Malmö, Sweden; Department of Endocrinology, Skåne University Hospital, SE-205 02 Malmö, Sweden. Electronic address: kerstin.berntorp@med.lu.se.
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 36mmol/mol (5.4%) could predict diabetes with 45% sensitivity and 92% specificity. For HbA1c ≥39mmol/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 (≥36mmol/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.
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 36mmol/mol (5.4%) could predict diabetes with 45% sensitivity and 92% specificity. For HbA1c ≥39mmol/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 (≥36mmol/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.