Modestly Elevated Glucose Levels During Pregnancy Are Associated with A Higher Risk of Future Diabetes Among Women Without Gestational Diabetes

doi:10.2337/dc07-1957

Modestly Elevated Glucose Levels During Pregnancy Are Associated with A Higher Risk of Future Diabetes Among Women Without Gestational Diabetes

Darcy B Carr, MD, MS (darcarr{at}u.washington.edu)¹,
Katherine M Newton, PhD^2,,³,
Kristina M Utzschneider, MD⁴,
Jenny Tong, MD, MPH⁴,
Fernando Gerchman, MD⁴,
Steven E Kahn, MB, ChB⁴ and
Susan R Heckbert, MD, PhD^2,,^3,,⁵

¹Obstetrics & Gynecology, University of Washington
²the Group Health Center for Health Studies
³Epidemiology
⁴University of Washington, the Division of Metabolism, Endocrinology, and Nutrition, VA Puget Sound Health Care System and the University of Washington
⁵and Cardiovascular Health Research Unit, Seattle, WA

Abstract

Objective: To determine whether 1-hour oral glucose challenge test (OGCT) or 3-hour oral glucose tolerance test (OGTT) results below gestational diabetes criteria are associated with developing future diabetes.

Research Design and Methods: A retrospective cohort study was performed among women without gestational diabetes who had a pregnancy OGCT (N=24,780) or OGTT (N=6,222). The risk of subsequent diabetes was ascertained by ICD-9 codes, pharmacy or laboratory data over a median follow-up of 8.8 years.

Results: Future diabetes risk increased across OGCT quartiles: adjusted hazard ratio, HR, 1.67 (95%CI 1.07–2.61) for 5.4–6.2 mmol/l; 2.13 (95%CI 1.39–3.25) for 6.3–7.3 mmol/l; and 3.60 (95%CI 2.41–5.39) for ≥7.4 mmol/l compared to ≤5.3 mmol/l. Women with one abnormal OGTT result had a higher risk compared to those with normal values (adjusted HR, 2.08, 95%CI 1.35–3.20).

Conclusions: Women with modestly elevated glucose levels below the threshold for gestational diabetes had a higher risk of future diabetes.