Joint effect of family history of diabetes with obesity on prevalence of type 2 diabetes mellitus among Chinese and Finnish men and women.
OBJECTIVE
To study joint effect of family history of diabetes (FHD) with obesity on prevalence of type 2 diabetes mellitus in the Chinese and in the Finns.


METHODS
A total of 1091 Chinese men and 1706 women, 1472 Finnish men and 1694 women, 45-74 years of age were studied. The probability and odds ratio (OR) of having diabetes were estimated using logistic regression analysis. The synergy index (SI) and relative excess risk due to interaction (RERI) of FHD with body mass index (BMI) or waist circumference (WC) was calculated.


RESULTS
Age-standardized prevalence of diabetes was higher in individuals with FHD than in those without in both the Chinese and Finns. Compared with individuals without FHD and with BMI <30 kg/m(2), ORs (95% confidence intervals [CI]) for diabetes were 2.7 (1.8, 4.0), 2.8 (1.9, 4.0), 9.1 (5.9, 13.9), respectively, in Finnish men with BMI ≥30 kg/m(2) alone, with FHD alone and with both (SI [95% CI] = 2.4 [1.4, 3.9], RERI = 4.6 [1.3, 8.0]); the corresponding figures were 1.7 (1.0, 2.9), 2.7 (1.8, 4.2) and 4.4 (1.9, 10.4) in Chinese men (SI = 1.4 [0.4, 4.9] RERI = 1.0 [-2.9, 5.0]). They were 3.5 (2.1, 5.8), 2.1 (1.3, 3.4) and 6.8 (4.1, 11.2) in Finnish women (SI = 1.6 [0.9, 2.8], RERI = 2.2 [-0.4, 4.9]), and 1.6 (1.1, 2.2), 2.1 (1.5, 3.0), 3.5 (1.9, 6.4) in Chinese women (SI = 1.5 [0.6, 3.8], RERI = 0.8 [-1.4, 3.0]). The pattern of synergistic effect of FHD with WC on diabetes was similar to that seen with BMI in the Finns but no effect was seen in the Chinese.


CONCLUSIONS
Both obesity and FHD are independent risk factors for diabetes, but their joint effect is significant only in Finnish men.
Department of Public Health, Hjelt Institute, University of Helsinki, Helsinki, Finland. Electronic address: feng.ning@helsinki.fi.
Feng
F
Ning
Zengchang
Z
Pang
Tiina
T
Laatikainen
Weiguo
W
Gao
Shaojie
S
Wang
Lei
L
Zhang
Jaakko
J
Tuomilehto
Qing
Q
Qiao
D002681:China / Q000453:epidemiology; D003430:Cross-Sectional Studies; D003924:Diabetes Mellitus, Type 2 / Q000453:epidemiology*; D005260:Female; D005387:Finland / Q000453:epidemiology; D006801:Humans; D008297:Male; D008875:Middle Aged; D009765:Obesity / Q000453:epidemiology*; D015995:Prevalence; D012307:Risk Factors
antécédents familiaux de diabète; diabète de type 2; effet synergique; family history of diabetes; obesity; obésité; prevalence; prévalence; synergistic effect; type 2 diabetes