Conversion of gestational diabetes mellitus to future Type 2 diabetes mellitus and the predictive value of HbA1c in an Indian cohort

Diabet Med. 2017 Jan;34(1):37-43. doi: 10.1111/dme.13102. Epub 2016 Mar 17.

Abstract

Aim: To investigate the distribution of and risk factors for dysglycaemia (Type 2 diabetes and prediabetes) in women with previous gestational diabetes mellitus in India.

Methods: All women (n = 989) from two obstetric units in New Delhi and Hyderabad with a history of gestational diabetes were invited to participate, of whom 366 (37%) agreed. Sociodemographic, medical and anthropometric data were collected and 75-g oral glucose tolerance test were carried out.

Results: Within 5 years (median 14 months) of the pregnancy in which they were diagnosed with gestational diabetes, 263 (72%) women were dysglycaemic, including 119 (32%) and 144 (40%) with Type 2 diabetes and prediabetes, respectively. A higher BMI [odds ratio 1.16 per 1-kg/m2 greater BMI (95% CI 1.10, 1.28)], presence of acanthosis nigricans [odds ratio 3.10, 95% CI (1.64, 5.87)], postpartum screening interval [odds ratio 1.02 per 1 month greater screening interval 95% CI (1.01, 1.04)] and age [odds ratio 1.10 per 1-year older age 95% CI (1.04, 1.16)] had a higher likelihood of having dysglycaemia. The American Diabetes Association-recommended threshold HbA1c value of ≥ 48 mmol/mol (6.5%) had a sensitivity and specificity of 81.4 and 90.7%, respectively, for determining the presence of Type 2 diabetes postpartum.

Conclusion: The high post-pregnancy conversion rates of gestational diabetes to diabetes reported in the present study reinforce the need for mandatory postpartum screening and identification of strategies for preventing progression to Type 2 diabetes. Use of the American Diabetes Association-recommended HbA1c threshold for diabetes may lead to significant under-diagnosis.

Publication types

  • Multicenter Study
  • Research Support, Non-U.S. Gov't

MeSH terms

  • Adult
  • Cohort Studies
  • Diabetes Mellitus, Type 2 / diagnosis
  • Diabetes Mellitus, Type 2 / epidemiology
  • Diabetes Mellitus, Type 2 / ethnology
  • Diabetes Mellitus, Type 2 / etiology*
  • Diabetes, Gestational / blood
  • Diabetes, Gestational / ethnology
  • Diabetes, Gestational / physiopathology*
  • Disease Progression
  • Female
  • Follow-Up Studies
  • Glucose Intolerance / diagnosis
  • Glucose Intolerance / epidemiology
  • Glucose Intolerance / ethnology
  • Glucose Intolerance / etiology*
  • Glucose Tolerance Test
  • Glycated Hemoglobin / analysis*
  • Humans
  • India / epidemiology
  • Postpartum Period
  • Prediabetic State / diagnosis
  • Prediabetic State / epidemiology
  • Prediabetic State / ethnology
  • Prediabetic State / etiology*
  • Predictive Value of Tests
  • Pregnancy
  • Prevalence
  • Prospective Studies
  • Risk Factors
  • Sensitivity and Specificity

Substances

  • Glycated Hemoglobin A
  • hemoglobin A1c protein, human