Determinants for the effectiveness of lifestyle intervention in the Finnish Diabetes Prevention Study.
OBJECTIVE
Intensive lifestyle intervention significantly reduced diabetes incidence among the participants in the Finnish Diabetes Prevention Study. We investigated whether and to what extent risk factors for type 2 diabetes and other baseline characteristics of the study participants modified the effectiveness of the lifestyle intervention.


METHODS
Overweight, middle-aged volunteers with impaired glucose tolerance were randomly assigned to intensive lifestyle intervention (n = 265) or to a control group (n = 257) for a median of 4 years. Diabetes status was ascertained annually with repeated oral glucose tolerance testing. Incidence rates of diabetes and hazard ratios (HRs) comparing the intervention group with the control group were calculated by sex and baseline tertiles of age, BMI, waist circumference, plasma glucose concentration at fasting and 2 h after a glucose load, fasting serum insulin and insulin resistance index, and categories of composite baseline Finnish Diabetes Risk Score (FINDRISC). Interactions between the intervention assignment and baseline risk factors on diabetes risk were analyzed.


RESULTS
The intervention was most effective among the oldest individuals (HRs 0.77, 0.49, and 0.36 by increasing age tertiles, respectively; P(interaction) = 0.0130) and those with a high baseline FINDRISC (HRs 1.09, 0.84, 0.34, and 0.22 by increasing risk score category, respectively; P(interaction) = 0.0400). The effect of the intervention on diabetes risk was not modified by other baseline characteristics or risk factors.


CONCLUSIONS
The FINDRISC may be useful in identifying high-risk groups most likely to benefit from intensive lifestyle intervention to prevent type 2 diabetes.
Lindström
Jaana
J
Diabetes Unit, Department of Health Promotion and Chronic Disease Prevention, National Public Health Institute, Helsinki, Finland. jaana.lindstrom@ktl.fi
Peltonen
Markku
M
Eriksson
Johan G
JG
Aunola
Sirkka
S
Hämäläinen
Helena
H
Ilanne-Parikka
Pirjo
P
Keinänen-Kiukaanniemi
Sirkka
S
Uusitupa
Matti
M
Tuomilehto
Jaakko
J
D000328:Adult; D015992:Body Mass Index; D049628:Body Size; D003920:Diabetes Mellitus / Q000453:epidemiology / Q000517:prevention & control*; D018450:Disease Progression; D005260:Female; D005387:Finland / Q000453:epidemiology; D018149:Glucose Intolerance / Q000150:complications; D006339:Heart Rate; D006801:Humans; D015994:Incidence; D008019:Life Style; D008297:Male; D008875:Middle Aged; D050177:Overweight / Q000503:physiopathology; D016016:Proportional Hazards Models; D016032:Randomized Controlled Trials as Topic; D012307:Risk Factors; D011795:Surveys and Questionnaires