AIMS/HYPOTHESIS: We aimed to investigate metabolic risk factors, insulin sensitivity and insulin secretion in adolescent offspring of mothers with type 1 diabetes compared with offspring of non-diabetic mothers.

METHODS: During 1993-1999, pregnancies of women with type 1 diabetes in Denmark were prospectively reported to a central registry in the Danish Diabetes Association. Data included information on maternal demography, diabetes status and pregnancy outcome. We invited 746 eligible children from this cohort (index offspring) to a follow-up examination. Control offspring were identified through The Danish Central Office of Civil Registration and matched with respect to date of birth, sex and postal code. Anthropometric measurements and blood sampling for metabolic characterisation, including an oral glucose tolerance test, were performed.

RESULTS: We examined 278 index offspring (mean age 16.7 years; range 13.0-19.8 years) and 303 control offspring (mean age 16.8 years; range 13.5-20.4 years). Index offspring had higher BMI SD score (0.44: 95% CI 0.21, 0.66) compared with controls, after adjustments for pubertal development and maternal pre-pregnancy BMI. Furthermore, index offspring had a higher prevalence of components included in metabolic syndrome and prediabetes (impaired fasting glucose and/or impaired glucose tolerance), with reduced insulin sensitivity and relative insulin secretion deficiency, compared with controls. Maternal HbA1c levels in pregnancy were not directly associated with offspring metabolic outcomes.

CONCLUSIONS/INTERPRETATION: Adolescent offspring of mothers with type 1 diabetes had a less favourable metabolic profile and higher frequency of prediabetes than the background population. Significant associations between these outcomes and maternal HbA1c levels in pregnancy could not be demonstrated.

TRIAL REGISTRATION: ClinicalTrials.gov NCT01559181.