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- den Hoed, Marcel, 1980-, et al.
(författare)
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Genetic susceptibility to obesity and related traits in childhood and adolescence influence of loci identified by genome-wide association studies
- 2010
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Ingår i: Diabetes. - Alexandria, USA : American Diabetes Association. - 0012-1797 .- 1939-327X. ; 59:11, s. 2980-2988
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Tidskriftsartikel (refereegranskat)abstract
- Objective: Large-scale genome-wide association (GWA) studies have thus far identified 16 loci incontrovertibly associated with obesity-related traits in adults. We examined associations of variants in these loci with anthropometric traits in children and adolescents.Research design and methods: Seventeen variants representing 16 obesity susceptibility loci were genotyped in 1,252 children (mean +/- SD age 9.7 +/- 0.4 years) and 790 adolescents (15.5 +/- 0.5 years) from the European Youth Heart Study (EYHS). We tested for association of individual variants and a genetic predisposition score (GPS-17), calculated by summing the number of effect alleles, with anthropometric traits. For 13 variants, summary statistics for associations with BMI were meta-analyzed with previously reported data (N-total = 13,071 children and adolescents). Results: In EYHS, 15 variants showed associations or trends with anthropometric traits that were directionally consistent with earlier reports in adults. The meta-analysis showed directionally consistent associations with BMI for all 13 variants, of which 9 were significant (0.033-0.098 SD/allele; P < 0.05). The near-TMEM18 variant had the strongest effect (0.098 SD/allele P = 8.5 x 10(-11)). Effect sizes for BMI tended to be more pronounced in children and adolescents than reported earlier in adults for variants in or near SEC16B, TMEM18, and KCTD15, (0.028-0.035 SD/allele higher) and less pronounced for rs925946 in BDNF (0.028 SD/allele lower). Each additional effect allele in the GPS-17 was associated with an increase of 0.034 SD in BMI (P = 3.6 x 10(-5)), 0.039 SD, in sum of skinfolds (P = 1.7 x 10(-7)), and 0.022 SD in waist circumference (P = 1.7 X 10(-4)), which is comparable with reported results in adults (0.039 SD/allele for BMI and 0.033 SD/allele for waist circumference).Conclusions: Most obesity susceptibility loci identified by GWA studies in adults are already associated with anthropometric traits in children/adolescents. Whereas the association of some variants may differ with age, the cumulative effect size is similar. Diabetes 59:2980-2988, 2010
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| 2. |
- den Hoed, Marcel, et al.
(författare)
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Heritability of objectively assessed daily physical activity and sedentary behavior
- 2013
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Ingår i: American Journal of Clinical Nutrition. - : Elsevier BV. - 0002-9165 .- 1938-3207. ; 98:5, s. 1317-1325
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Tidskriftsartikel (refereegranskat)abstract
- Background: Twin and family studies that estimated the heritability of daily physical activity have been limited by poor measurement quality and a small sample size. Objective: We examined the heritability of daily physical activity and sedentary behavior assessed objectively by using combined heart rate and movement sensing in a large twin study. Design: Physical activity traits were assessed in daily life for a mean (+/- SD) 6.7 +/- 1.1 d in 1654 twins from 420 monozygotic and 352 dizygotic same-sex twin pairs aged 56.3 +/- 10.4 y with body mass index (in kg/m(2)) of 26.1 +/- 4.8. We estimated the average daily movement, physical activity energy expenditure, and time spent in moderate-to-vigorous intensity physical activity and sedentary behavior from heart rate and acceleration data. We used structural equation modeling to examine the contribution of additive genetic, shared environmental, and unique environmental factors to between-individual variation in traits. Results: Additive genetic factors (le, heritability) explained 47% of the variance in physical activity energy expenditure (95% CI: 23%, 53%) and time spent in moderate-to-vigorous intensity physical activity (95% CI: 29%, 54%), 35% of the variance in acceleration of the trunk (95% CI: 0%, 44%), and 31% of the variance in the time spent in sedentary behavior (95% CI: 9%, 51%). The remaining variance was predominantly explained by unique environmental factors and random error, whereas shared environmental factors played only a marginal role for all traits with a range of 0-15%. Conclusions: The between-individual variation in daily physical activity and sedentary behavior is mainly a result of environmental influences. Nevertheless, genetic factors explain up to one-half of the variance, suggesting that innate biological processes may be driving some of our daily physical activity.
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