title: Gestational diabetes is a herald of NIDDM in Navajo women. High rate of abnormal glucose tolerance after GDM.
abstract: OBJECTIVE
  To estimate the rate of deterioration of glucose tolerance and evaluate risk factors for development of NIDDM in Navajo women with a history of gestational diabetes mellitus (GDM).
  
  
  METHODS
  A retrospective analysis of 111 GDM deliveries over a 4-year period, 1983-1987, was conducted in 1994 to determine glucose tolerance status. Patients who had not developed NIDDM were recalled for a 2-h glucose tolerance test (GTT). Tested and non-tested patients were compared, as estimate of conversion to NIDDM was calculated, and risk factors for NIDDM were evaluated. A life-table analysis was developed to estimate the probability of NIDDM after GDM.
  
  
  RESULTS
  At the time of chart review, 32 patients (29%) had already been diagnosed with NIDDM. Of the patients, 79 were offered GTT testing, and 56 (71%) returned for follow-up; 15 were diagnosed with NIDDM and 17 with impaired glucose tolerance (IGT); 47 (42%) and 64 (58%) patients in the cohort had developed NIDDM or NIDDM/IGT at the conclusion of the study period. Patients who developed NIDDM had greater BMIs, parity, and infant weights. Fasting blood glucose > 5.83 mmol/l, GTT > 41.63 mmol/l, and recurrence of GDM were associated with later NIDDM. A life-table analysis estimated a 53% likelihood of having NIDDM at an 11-year follow-up; a second model, based only on patients with known NIDDM status, predicted a 70% rate of NIDDM at an 11-year follow-up.
  
  
  CONCLUSIONS
  A high proportion of Navajo women with GDM progressed to NIDDM. Postpartum counseling and periodic GTTs are recommended.
authors.affiliation: Northern Navajo Medical Center, Public Health Service Indian Hospital, Shiprock, New Mexico 87420, USA. jsteinh532@aol.com
authors.forename: J R
authors.initials: JR
authors.lastname: Steinhart
authors.forename: J R
authors.initials: JR
authors.lastname: Sugarman
authors.forename: F A
authors.initials: FA
authors.lastname: Connell
mesh_terms: D000328:Adult; D001724:Birth Weight; D001786:Blood Glucose / Q000378:metabolism; D015992:Body Mass Index; D003924:Diabetes Mellitus, Type 2 / Q000453:epidemiology*; D016640:Diabetes, Gestational; D005260:Female; D005500:Follow-Up Studies; D018149:Glucose Intolerance / Q000453:epidemiology*; D005951:Glucose Tolerance Test; D006801:Humans; D007198:Indians, North American; D007231:Infant, Newborn; D015993:Life Tables; D009516:New Mexico; D010298:Parity; D011247:Pregnancy; D012189:Retrospective Studies
chemical_list: D001786:Blood Glucose