Participant characteristics among women with gestational diabetes (GDM) and their matched* controls: the NICHD Fetal Growth Studies-Singleton Cohort
| Characteristics | N | GDM cases (n=107) | Non-GDM controls (n=214) | P value |
| Age, years | 321 | 30.4±5.7 | 30.5±5.4 | |
| Race/Ethnicity | 321 | |||
| Non-Hispanic white | 25 (23.4%) | 50 (23.4%) | ||
| Non-Hispanic black | 15 (14.0%) | 30 (14.0%) | ||
| Hispanic | 41 (38.3%) | 82 (38.3%) | ||
| Asian/Pacific Islander | 26 (24.3%) | 52 (24.3%) | ||
| Enrollment BMI, kg/m2 | 321 | 27.8±6.2 | 25.6±5.3 | 0.0005 |
| Family history of diabetes | 321 | 40 (37.4%) | 48 (22.4%) | 0.003 |
| Alcohol use before pregnancy | 321 | 61 (57.0%) | 137 (64.0%) | 0.22 |
| Smoking before pregnancy | 321 | 4 (3.7%) | 1 (0.5%) | 0.02 |
| Fasting glucose†, mg/dL | 313 | 91.92±14.6 | 83.38±7.9 | <0.001 |
| Fasting insulin†, pmol/L | 313 | 135.41±204.6 | 66.87±95.2 | <0.001 |
| Fasting C-peptide†, nmol/L | 313 | 0.92±0.7 | 0.60±0.4 | <0.001 |
| Fasting HbA1c†, % | 313 | 5.18±0.5 | 4.95±0.3 | 0.002 |
Values are n (%) or mean±SD.
P values were not shown for matching variables: age and race/ethnicity.
*Matching factors: age (±2 years), race/ethnicity (non-Hispanic white, non-Hispanic black, Hispanic or Asian/Pacific Islander) and the gestational week of blood collection (±2 weeks).
†Glycemic biomarkers were measured in fasting samples at 15–26 weeks (visit 1). Sample size for fasting glucose was 98 cases and 213 controls and for fasting insulin, C-peptide and HbA1c was 99 cases and 212 controls. Values were log transformed before fitting into linear mixed effect models.
BMI, body mass index; HbA1c, glycated hemoglobin; NICHD, National Institute of Child Health and Human Development.