title: The relative importance of modifiable potential risk factors of type 2 diabetes: a meta-analysis of two cohorts.
abstract: Lifestyle factors predict type 2 diabetes occurrence, but their effect in high- and low-risk populations is poorly known. This study determines the prediction of low-risk lifestyle on type 2 diabetes in those with and without metabolic syndrome in a pooled sample of two representative Finnish cohorts, collected in 1978-1980 and 2000-2001. Altogether 8,627 individuals, aged 40-79 years, and free of diabetes and cardiovascular disease at baseline were included in this study. A low-risk lifestyle was defined based on body mass index, exercise, alcohol consumption, smoking, and serum vitamin D concentration. The metabolic syndrome was defined according to the International Diabetes Federation including obesity, blood pressure, serum HDL cholesterol, serum triglycerides, and fasting glucose. During a 10-year follow-up, altogether 226 type 2 diabetes cases occurred. Overweight was the strongest predictor of type 2 diabetes (population attributable fraction (PAF) = 77%, 95% confidence interval (CI): 53, 88%). Together with lack of exercise, unsatisfactory alcohol consumption, smoking, and low vitamin D concentration it explained 82% of the cases. Altogether 62% (CI: 47, 73%) of the cases were attributable to the metabolic syndrome and 92% (CI: 67, 98%) to the most unfavourable combination of its components. The metabolic syndrome did not modify the prediction of lifestyle factors but persons with normal blood pressure benefited more from positive changes in exercise, alcohol consumption, and smoking than those with elevated blood pressure (P for interaction = 0.01). In conclusion, modification of lifestyle factors apparently reduces type 2 diabetes risk, especially in persons with normal blood pressure.
authors.affiliation: National Institute for Health and Welfare, Helsinki, Finland.
authors.forename: Maarit A
authors.initials: MA
authors.lastname: Laaksonen
authors.forename: Paul
authors.initials: P
authors.lastname: Knekt
authors.forename: Harri
authors.initials: H
authors.lastname: Rissanen
authors.forename: Tommi
authors.initials: T
authors.lastname: Härkänen
authors.forename: Esa
authors.initials: E
authors.lastname: Virtala
authors.forename: Jukka
authors.initials: J
authors.lastname: Marniemi
authors.forename: Arpo
authors.initials: A
authors.lastname: Aromaa
authors.forename: Markku
authors.initials: M
authors.lastname: Heliövaara
authors.forename: Antti
authors.initials: A
authors.lastname: Reunanen
mesh_terms: D000328:Adult; D000368:Aged; D015992:Body Mass Index; D015331:Cohort Studies; D003924:Diabetes Mellitus, Type 2 / Q000453:epidemiology / Q000209:etiology* / Q000517:prevention & control*; D005260:Female; D005387:Finland / Q000453:epidemiology; D015438:Health Behavior; D006801:Humans; D008019:Life Style; D008297:Male; D024821:Metabolic Syndrome / Q000150:complications / Q000453:epidemiology; D008875:Middle Aged; D050177:Overweight / Q000150:complications / Q000453:epidemiology; D016016:Proportional Hazards Models; D012307:Risk Factors; D011795:Surveys and Questionnaires