Association between the type of family history of diabetes and the risk and age at onset of diabetes in the Japanese general population

Aim: The objective of this cross-sectional study was to clarify the relationship between the type of first-degree family history of diabetes (FHD) and the presence and age at onset of diabetes (AOD) in the Japanese general population. Material and methods: Using anonymized processed data collected from community-based health checkups, we classified 10,691 subjects into 5 groups according to the type of FHD as follows: (1) no FHD; (2) diabetes only in a sibling (sFHD); (3) diabetes only in the mother (mFHD); (4) diabetes only in the father (pFHD); and (5) diabetes in ≥ 2 family members, e.g., one parent plus a sibling or both parents (FHD in ≥ 2 family members). Result: Results of multivariate logistic regression analysis performed using the no FHD group as reference revealed a significant association between a positive FHD and the presence of diabetes (odds ratio: sFHD, 3.67; mFHD, 3.70; pFHD, 2.88; FHD in ≥ 2 family members, 6.35; P < 0.0001 for all). Moreover, the AOD was significantly younger in all the four groups with FHD than in the group without FHD (P < 0.01), being the youngest in the group of FHD in ≥ 2 family members. Conclusion: Our results revealed that the degree of associations between a positive FHD and the presence of diabetes and AOD differ according to the type of FHD. In particular, FHD in ≥ 2 family members appears to be especially strongly associated with a high risk of diabetes and a younger AOD.