Prevalence and risk of diabetes based on family history in the Shanghai High-Risk Diabetic Screen (SHiDS) study.

AIMS

To evaluate the prevalence and risk of diabetes based on family history in high-risk subjects and also to evaluate insulin sensitivity and insulin secretion in these subjects.

METHODS

Data were analysed from 9756 participants in the Shanghai High-Risk Diabetic Screen (SHiDS) Project. Family history of diabetes was classified according to parental and sibling diabetes status. The prevalence and odds ratios were calculated for each grouping after adjusting for other risk factors. Insulin resistance and sensitivity were evaluated using oral glucose tolerance test-derived indices that were validated by hyperinsulinaemic-euglycaemic and hyperglycaemic clamps.

RESULTS

A total of 30.4% of the subjects had a family history of diabetes in a first-degree relative. The proportions of subjects with a father, mother or sibling with diabetes were 7.5, 11.9 and 5.5%, respectively. The prevalence rates of diabetes in subjects with sibling history, maternal history or paternal history of diabetes were 39.3, 38.3 and 36.4%, respectively. Sibling history was a strong risk factor for diabetes (odds ratio 1.53, 95% CI 1.27-1.84; P < 0.05). Insulin secretion was significantly lower in those with a maternal or sibling history of diabetes; however, insulin sensitivity was not significantly different among subjects with a family history of diabetes.

CONCLUSIONS

Sibling history of diabetes was more strongly associated with diabetes risk than parental history among high-risk subjects. Subjects with a sibling or maternal history of diabetes had significantly lower insulin secretion. Sibling history is an important and independent risk factor for diabetes even among multi-risk populations. Those with a sibling history of diabetes warrant intensive care and follow-up screening.