To investigate whether children with a family history of diabetes (FHD) in second-degree relatives (grandparents, aunts/uncles) are at increased risk of developing obesity and diabetes, and whether the risk differs between maternal or paternal transmission.

In the multiethnic population-based cohort Amsterdam-Born Children and Their Development (ABCD) Study, body mass index (BMI), waist-to-height ratio (WHR), fat percentage (fat%), fasting glucose and C-peptide in 5- or 6-year-old children with no second-degree FHD (n=2226) were compared with children with maternal-only (n=353), paternal-only (n=281) or both maternal and paternal (n=164) second-degree FHD. Children of diabetic mothers or fathers were excluded.

None of the children in any of our FHD categories differed in body composition after adjusting for maternal, paternal and childhood lifestyle covariates. However, children with both maternal and paternal second-degree FHD had increased C-peptide levels (0.03nmol, 95% CI: 0.01–0.05) compared with those in the other three study groups. Results were similar when analyses were restricted to only the Dutch children.

Children with FHD in second-degree relatives on both maternal and paternal sides already have higher C-peptide levels at an early age. This might be the result of a double burden of a shared obesogenic lifestyle, or of more diverse diabetogenic genes compared to children without FHD or with only FHD in one side of the family. In any case, second-degree FHD could be used as a public-health screening tool to identify children at risk of adverse metabolic outcomes and of possible future disease.