Sibling and parental history in type 2 diabetes risk among ethnic Chinese: The Chin-Shan Community Cardiovascular Cohort Study

This study aims to compare various family history profiles as predictors of diabetes in a community-based prospective cohort because few prospective studies have examined the association of family history with diabetes risk in ethnic Chinese populations. Among 2960 participants free from baseline diabetes through the Chin-Shan Community Cardiovascular Cohort Study, there were 548 cases that developed diabetes after a median 9 years of follow-up. After multivariate adjustment, sibling history was associated with diabetes [Relative risk (RR): 2.08, 95% confidence interval (CI): 1.42–3.06, P = 0.0002]. Both maternal and paternal histories had similar effects (RR: 1.62, 95% CI: 1.04–2.51 for paternal history, RR: 1.36, 95% CI: 0.98–1.89 for maternal history). Obese participants with sibling history increased the risk of diabetes by 4.6-fold (RR: 4.61, 95% CI: 2.93–7.26), compared with those with neither obesity nor family history. The findings support the hypothesis that sibling history is more important than parental history for diabetes risk.