Family history of diabetes, lifestyle factors, and the 7-year incident risk of type 2 diabetes mellitus in middle-aged Japanese men and women.
OBJECTIVE
This cohort study of middle-aged Japanese participants investigated the relationship between family history of diabetes, the incident risk of type 2 diabetes and the interaction of these variables with other factors.


METHODS
Study participants were 3,517 employees (2,037 men and 1,480 women) of a metal products factory in Japan. Baseline health examinations included questions about medical history, physical examination, anthropometric measurements, questions about lifestyle factors, such as smoking, alcohol consumption and habitual exercise, and a self-administered diet history questionnaire. Family history of diabetes was defined as having at least one-first-degree relative with diabetes. The incidence of diabetes was determined in annual medical examinations over a 7-year period. Hazard ratios (HRs) for type 2 diabetes were estimated by Cox proportional hazards analysis.


RESULTS
Of the 3,517 participants, 630 (18%) had a family history of diabetes mellitus. During the study, 228 participants developed diabetes. The age and sex-adjusted HR for type 2 diabetes in participants with a family history of diabetes was 1.82 (95% confidence interval 1.36-2.43) as compared with those without a family history of diabetes. HRs did not change after adjustment for body mass index and lifestyle factors. We found no interactions with body mass index, insulin resistance, pancreatic β-cell function or lifestyle factors.


CONCLUSIONS
Family history of diabetes was associated with the incident risk of diabetes, and these associations were independent of other risk factors, such as obesity, insulin resistance, and lifestyle factors in Japanese men and women.
Department of Epidemiology and Public Health Kanazawa Medical University Ishikawa Japan ; Department of Preventive Medicine Northwestern University Feinberg School of Medicine Chicago Illinois USA.
Masaru
M
Sakurai
Department of Epidemiology and Public Health Kanazawa Medical University Ishikawa Japan.
Koshi
K
Nakamura
Department of Health Science Shiga University of Medical Science Kanazawa University Kanazawa Japan.
Katsuyuki
K
Miura
Department of Disease Control and Homeostasis Kanazawa University Graduate School of Medical Science Kanazawa University Kanazawa Japan.
Toshinari
T
Takamura
Department of Food Science and Nutrition Graduate School of Human Life Science Osaka City University Osaka Japan.
Katsushi
K
Yoshita
Department of Social and Preventive Epidemiology School of Public Health the University of Tokyo Tokyo Japan.
Satoshi
S
Sasaki
Department of Epidemiology and Public Health Kanazawa Medical University Ishikawa Japan.
Shin-Ya
SY
Nagasawa
Department of Epidemiology and Public Health Kanazawa Medical University Ishikawa Japan.
Yuko
Y
Morikawa
Department of Social and Environmental Medicine Kanazawa Medical University Ishikawa.
Masao
M
Ishizaki
School of Health Sciences College of Medical, Pharmaceutical and Health Sciences Kanazawa University Kanazawa Japan.
Teruhiko
T
Kido
Department of Community and Geriatric Nursing Toyama University Toyama Japan.
Yuchi
Y
Naruse
Department of Occupation and Environmental Medicine Graduate School of Medicine Chiba University Chiba Japan.
Yasushi
Y
Suwazono
Department of Epidemiology and Public Health Kanazawa Medical University Ishikawa Japan.
Hideaki
H
Nakagawa
Cohort study; Epidemiology; Family history