Physical activity, body mass index, and risk of type 2 diabetes in patients with normal or impaired glucose regulation.
BACKGROUND
Sedentary lifestyle, obesity, and impaired glucose regulation are associated with the risk of type 2 diabetes. However, the joint associations of these risk factors are not known.


METHODS
We prospectively followed up 2017 Finnish men and 2352 Finnish women aged between 45 and 64 years without a history of known or newly diagnosed diabetes at baseline. Single and joint associations of physical activity, body mass index (BMI), and blood glucose levels with risk of type 2 diabetes were examined using Cox proportional hazards models.


RESULTS
During a mean follow-up of 9.4 years, there were 120 incident cases of type 2 diabetes. After adjustment for confounding factors (age, study year, sex, systolic blood pressure, smoking, and education), physical activity was found to be inversely associated with the risk of type 2 diabetes. This association was persistent in subjects with (1) both obesity and impaired glucose regulation, (2) either obesity or impaired glucose regulation, and (3) a normal BMI and glucose regulation. Similarly, the multivariate-adjusted positive association between BMI and risk of type 2 diabetes was consistently observed. Obesity in subjects who reported being inactive and had normal glucose levels was associated with an increased risk of diabetes compared with a normal BMI in subjects who reported being active and had impaired glucose regulation.


CONCLUSIONS
Increasing physical activity can reduce the risk of type 2 diabetes. The protective effect of physical activity was observed in subjects with an excessive BMI and elevated glucose levels. Physical activity and weight control are critical factors in diabetes prevention in subjects with both normal and impaired blood glucose regulation.
Hu
Gang
G
Department of Epidemiology and Health Promotion, National Public Health Institute, Mannerheimintie 166, FIN-00300 Helsinki, Finland. hu.gang@ktl.fi
Lindström
Jaana
J
Valle
Timo T
TT
Eriksson
Johan G
JG
Jousilahti
Pekka
P
Silventoinen
Karri
K
Qiao
Qing
Q
Tuomilehto
Jaakko
J
D001786:Blood Glucose / Q000378:metabolism; D015992:Body Mass Index; D015331:Cohort Studies; D003920:Diabetes Mellitus / Q000453:epidemiology / Q000503:physiopathology; D003924:Diabetes Mellitus, Type 2 / Q000453:epidemiology* / Q000517:prevention & control; D015444:Exercise; D005260:Female; D005387:Finland / Q000453:epidemiology; D005951:Glucose Tolerance Test; D006801:Humans; D008297:Male; D008875:Middle Aged; D009765:Obesity; D016016:Proportional Hazards Models; D012307:Risk Factors
D001786:Blood Glucose