title: Effects of 32-year leisure time physical activity discordance in twin pairs on health (TWINACTIVE study): aims, design and results for physical fitness.
abstract: The physically active lifestyle is associated with low future morbidity and mortality, but the causality between physical activity and health is not always clear. As some inherited biological characteristics and childhood experiences may cause selection bias in observational studies, we sought to take them into account by identifying 16 twin pairs (7 MZ, 9 DZ, mean age 60 years) discordant for leisure time physical activity habits for thirty years. We conducted detailed health-related examinations among these twin pairs. Our main aims were to study the effects of physical activity and genes on fitness and body composition, with special reference to body fat compartments, metabolic syndrome components and related diseases and risk factor levels, status of arteries, structure and function of the heart, bone properties, and muscle and fat tissue-related mechanisms linked to physical activity and chronic disease development. Our physical activity assessments showed that inactive co-twins were on average 8.8 MET hours/day less active than their active co-twins through out their midlife (2.2+/-2.3 vs. 11.0+/-4.1 MET h/day, p< .001). Follow-up fitness tests showed that physically inactive co-twins were less fit than their active co-twins (estimated VO(2peak) 26.4+/-4.9 vs. 32.5+/-5.5 ml/kg/min, p< .001). Similar differences were found in both MZ and DZ pairs. On the basis of earlier epidemiological observations on nonrelated individuals, these physical activity and fitness differences are large enough to cause differences in many mechanisms and risk factors related to the development of chronic diseases and to permit future analyses.
authors.affiliation: Department of Health Sciences, University of Jyväskylä, Finland.
authors.forename: Tuija
authors.initials: T
authors.lastname: Leskinen
authors.forename: Katja
authors.initials: K
authors.lastname: Waller
authors.forename: Sara
authors.initials: S
authors.lastname: Mutikainen
authors.forename: Sari
authors.initials: S
authors.lastname: Aaltonen
authors.forename: Paula H A
authors.initials: PH
authors.lastname: Ronkainen
authors.forename: Markku
authors.initials: M
authors.lastname: Alén
authors.forename: Sarianna
authors.initials: S
authors.lastname: Sipilä
authors.forename: Vuokko
authors.initials: V
authors.lastname: Kovanen
authors.forename: Merja
authors.initials: M
authors.lastname: Perhonen
authors.forename: Kirsi H
authors.initials: KH
authors.lastname: Pietiläinen
authors.forename: Sulin
authors.initials: S
authors.lastname: Cheng
authors.forename: Harri
authors.initials: H
authors.lastname: Suominen
authors.forename: Heikki
authors.initials: H
authors.lastname: Kainulainen
authors.forename: Jaakko
authors.initials: J
authors.lastname: Kaprio
authors.forename: Urho M
authors.initials: UM
authors.lastname: Kujala
mesh_terms: D000273:Adipose Tissue; D000293:Adolescent; D000328:Adult; D002908:Chronic Disease; D005260:Female; D005500:Follow-Up Studies; D006801:Humans; D008297:Male; D024821:Metabolic Syndrome / Q000235:genetics*; D008875:Middle Aged; D010809:Physical Fitness; D012189:Retrospective Studies; D014429:Twins, Dizygotic / Q000235:genetics*; D014430:Twins, Monozygotic / Q000235:genetics*