Prevalence of gestational fasting and postload single dysglycemia in Mexican-American women and their relative significance in identifying carbohydrate intolerance.

This study investigated the prevalence of gestational dysglycemia in a largely Hispanic population in a U.S.-Mexico border city and the influence of single plasma glucose (PG) result on the identification of gestational carbohydrate intolerance. Gestational dysglycemia was studied in a largely Mexican-American population using retrospective data. Gestational diabetes (GDM), gestational impaired fasting glucose (GIFG), and gestational impaired glucose tolerance (GIGT) were identified with Carpenter-Coustan thresholds. Glucose challenge test result was abnormal in 32.7% of 18307 women screened; 47% of them had one or more dysglycemic results in the confirmatory oral glucose tolerance test (OGTT). The prevalence of GDM, GIFG, and GIGT in these women was 8.7, 2.2, and 4.5%, respectively. Fasting, 1-hour, 2-hour, and 3-hour PGs were elevated in 20.5, 28.5, 25.0, and 15.0% of OGTT, respectively (GIFG: 6.0%; 1-hour GIGT: 6.5%; 2-hour GIGT: 4.4%; and 3-hour GIGT: 3.1%). Twelve percent of OGTTs showed dysglycemia at 1 hour with normal 2-hour PG. Isolated dysglycemia, similar to GDM, is prevalent in Mexican-American women. The minimal impact of 3-hour PG supports a 2-hour OGTT. But our results question the use of an "OGTT protocol without a first-hour specimen." © Thieme Medical Publishers.