Research Paper

Monitoring and surveillance

Synergy of BMI and family history on diabetes: the Humboldt Study

Yue Chen^a1 c1, Donna C Rennie^a2a3 and James A Dosman^a2

^a1 Department of Epidemiology and Community Medicine, Faculty of Medicine, University of Ottawa, 451 Smyth Road, Ottawa, Ontario, Canada, K1H 8M5

^a2 Institute of Agricultural Rural and Environmental Health, University of Saskatchewan, Saskatoon, Saskatchewan, Canada

^a3 College of Nursing, University of Saskatchewan, Saskatoon, Saskatchewan, Canada

Abstract

Objective To examine the joint effect of family history and BMI on diabetes.

Design Cross-sectional study.

Setting A rural community in Saskatchewan, Canada.

Subjects The analysis was based on data from 2081 adults, 18–79 years of age, who participated in the Humboldt Study conducted in 2003. Doctor-diagnosed diabetes and family history of diabetes of biological parents and siblings were self-reported. Body weight and height were objectively measured. The interaction of family history and BMI on diabetes was assessed on an additive scale.

Results The prevalence of diabetes was 7·9 %, and BMI and history of diabetes were two important predictors. The adjusted prevalence ratios were 1·76 (95 % CI 1·37, 2·27) and 2·59 (95 % CI 2·05, 3·31) for those with a BMI of 25·0–29·9 kg/m² and of at least 30 kg/m², respectively, compared with a BMI of less than 25 kg/m², and was 2·41 (95 % CI 2·08, 2·80) for those with a family history of diabetes v. those without. The data indicated an additive interaction of family history and BMI on diabetes.

Conclusions When exposed to both family history and overweight/obesity, individuals would have an increased risk that was greater than the sum of their single effects. Reduction of BMI would also reduce the risk of diabetes associated family history.

(Received December 05 2008)

(Accepted July 20 2009)

(Online publication August 26 2009)

Keywords

• Body mass index;
• Family history;
• Obesity;
• Overweight

Correspondence:

^c1 Corresponding author: Email ychen@uottawa.ca