Familial clustering studies indicate that breast cancer risk has a substantial genetic component. To identify new breast cancer risk variants, we genotyped approximately 300,000 SNPs in 1,600 Icelandic individuals with breast cancer and 11,563 controls using the Illumina Hap300 platform. We then tested selected SNPs in five replication sample sets. Overall, we studied 4,554 affected individuals and 17,577 controls. Two SNPs consistently associated with breast cancer: approximately 25% of individuals of European descent are homozygous for allele A of rs13387042 on chromosome 2q35 and have an estimated 1.44-fold greater risk than noncarriers, and for allele T of rs3803662 on 16q12, about 7% are homozygous and have a 1.64-fold greater risk. Risk from both alleles was confined to estrogen receptor-positive tumors. At present, no genes have been identified in the linkage disequilibrium block containing rs13387042. rs3803662 is near the 5' end of TNRC9 , a high mobility group chromatin-associated protein whose expression is implicated in breast cancer metastasis to bone.

We carried out a genome-wide association study of breast cancer predisposition with replication and refinement studies involving 6,145 cases and 33,016 controls and identified two SNPs (rs4415084 and rs10941679) on 5p12 that confer risk, preferentially for estrogen receptor (ER)-positive tumors (OR = 1.27, P = 2.5 x 10(-12) for rs10941679). The nearest gene, MRPS30, was previously implicated in apoptosis, ER-positive tumors and favorable prognosis. A recently reported signal in FGFR2 was also found to associate specifically with ER-positive breast cancer.

sedentary time is high in this Icelandic cohort, which has high life-expectancy and is living north of 60° northern latitude.

No abstract

The aim of this study was to assess the effects of a 2-year cluster-randomized physical activity and dietary intervention program among 7-year-old (at baseline) elementary school participants on body composition and objectively measured cardiorespiratory fitness. Three pairs of schools were selected and matched, then randomly selected as either an intervention (n = 151) or control school (n = 170). None of the effect sizes of body composition were statistically significant. Children in the intervention group increased their fitness by an average of 0.37 z score units more than the controls (95% CI:-0.27 to 1.01, P = 0.18), representing an improvement of 0.286 W/kg. Boys had higher fitness (mean(diff) = 0.35 z scores, 95% CI: 0.13-0.58, P = 0.001) than girls, independent of study group, fitness z score at baseline and body mass index. Post hoc analysis showed that the intervention school with the highest fitness z score change was significantly different from two of the lowest control schools (mean(diff) = 0.83 z scores, 95% CI: 0.44-1.21, P < 0.0001 and mean(diff) = 0.70 z scores, 95% CI: 0.29-1.10, P = 0.01), but it was also significantly different from the lowest intervention school (mean(diff) = 0.59 z scores, 95% CI: 0.19-0.99, P = 0.05). The results of this intervention are inconclusive as regards to the effects on fitness, but the intervention did not have any statistically significant effect on body composition.

Objective: To investigate the prevalence and tracking of overweight and obesity in childhood cohorts born 1988 and 1994 in a population of high birth weight. Subjects: Icelandic cohorts born in 1988 and 1994. Materials and methods: Out of 1328, 9-and 15-year-old children from 18 randomly selected schools all over Iceland, 934 participated (71%). Height and mass were measured by the investigators. Also, height and mass at birth, and at age 2.5, 6, 9, and 12 years, were collected from maternity wards and school health registers. Results: The prevalence of overweight children ranged from 10.1% for 2.5-year-olds to 18.7% for 9-year-olds. No difference was observed between the two cohorts or sex. The prevalence of obesity in the 1994 cohort (4.3%) was significantly higher (P ¼ 0.01) at age 6 years, compared to the 1988 cohort (1.1%). The children who were overweight at age 2.5 years were more likely to be overweight at age 6 (OR ¼ 12.2) and 9 years (OR ¼ 4.9), but not significantly at age 12 or 15 years, compared with normal weight 2.5-year-olds. Overweight children at age 6 or 9 years were much more likely (OR 10.4 and OR 18.6, respectively) to be overweight at age 15 years compared to their normal weight peers. Of overweight 6-year-olds, 51% were overweight at 15 years, and were about one-third of all overweight children at that age. The children that weighed above the 85th percentile at birth were more likely than the other children to be overweight at the age of 6 years (OR ¼ 1.8), 9 years (OR ¼ 2.1), and 15 (OR ¼ 2.0) years. Conclusion:The results show high prevalence of overweight and obesity even before the start of compulsory schooling. Approximately, 51% of overweight 6-year-olds were still overweight after puberty. Therefore, preschool overweight prevention, along with prevention at school age, seems to be of uttermost importance.

The results indicate a higher rate of overuse injuries in low back/pelvic region and shoulders than in comparable studies.

Background Sedentary behavior is associated with adverse health effects. To prevent sedentary behavior and limit health risks, insights into associated determinants are essential. Sedentary behavior should be viewed as a distinct health behavior, therefore its determinants should be independently identified. Purpose This study examines the prospective associations between a wide-range of midlife determinants and objectively measured sedentary time in old age. Methods Data from 565 participants (aged 73–92 years) of the AGESII-Reykjavik Study were used. Participants wore an accelerometer (ActiGraph GT3X) on the right hip for 7 consecutive days. On average 31 years earlier (during midlife) demographic, socioeconomic, lifestyle and biomedical factors were collected. Linear regression models were used to examine prospective associations between midlife determinants and sedentary time (<100 counts per minute) in old age. Results After adjustment for sex, age, follow-up time, minutes of moderate to vigorous physical activity, BMI, health status, mobility limitation and joint pain in old age, the midlife determinants not being married, primary education, living in a duplex or living in an apartment (vs. villa), being obese and having a heart disease were associated with, respectively, on average 15.3, 12.4, 13.5, 13.3, 21.8, 38.9 sedentary minutes more per day in old age. Conclusions This study shows that demographic, socioeconomic and biomedical determinants in midlife were associated with considerably more sedentary time per day in old age. These results can indicate the possibility of predicting sedentariness in old age, which could be used to identify target groups for prevention programs reducing sedentary time in older adults.