Physical Activity from Early Adulthood and Risk of Prostate Cancer: A 24-Year Follow-Up Study among Icelandic Men.

Physical activity in adult life may reduce prostate cancer risk. Data are scarce on the role of activity during early adulthood, as well as combined recreational and occupational physical activity on prostate cancer risk and mortality. We undertook a prospective study of 8,221 Icelandic men (born 1907 to 1935) in the population-based Reykjavik Study. At enrollment, between 1967 and 1987, the men provided information on regular recreational physical activity since the age of 20 years as well as current occupational activity. Through linkage to nationwide cancer and mortality registers, the men were followed for prostate cancer diagnosis and mortality through 2009. We used Cox models to calculate the relative risk of prostate cancer by level of physical activity. During a mean follow-up of 24.8 years, 1,052 men were diagnosed with prostate cancer, of whom 349 had advanced disease (stage 3+ or prostate cancer death). Neither recreational nor occupational physical activity was, independently or combined, associated with overall or localized prostate cancer. Compared with physically inactive men, we observed a nonsignificant lower risk of advanced prostate cancer [HR, 0.67; 95% confidence interval (CI), 0.42-1.07] among men reporting both recreational and occupational physical activities (P value for interaction = 0.03). Awaiting confirmation in larger studies with detailed assessment of physical activity, our data suggest that extensive physical activity beginning in early adulthood may reduce the risk of advanced prostate cancer.

Association of BMI and fasting insulin with cardiovascular disease risk factors in seven-year-old Icelandic children.

OBJECTIVE: . To look at overweight and common cardiovascular disease (CVD) risk factors, and associations with body mass index (BMI) and fasting insulin in seven-year-old schoolchildren in Reykjavik, Iceland. STUDY DESIGN: Cross-sectional study of seven-year-old schoolchildren. SETTING: Six elementary schools in Reykjavik. SUBJECTS: All children attending second grade in these six schools were invited to participate. MAIN OUTCOME MEASURES: Overweight, fasting serum insulin, CVD risk factors. RESULTS: Some 14% of the participating children were classified as overweight. Overweight children had higher fasting insulin, higher fasting glucose, and higher systolic and diastolic blood pressure. Furthermore, they had significantly lower total cholesterol (TC), lower high-density lipoprotein (HDL), and lower low-density lipoprotein (LDL) but a similar TC/LDL ratio to normal-weight children. The factors that were strongly associated with BMI were serum fasting insulin, systolic blood pressure (SBP), HDL and fasting glucose, while the sum of four skinfolds, triglycerides, glucose, and LDL were highly associated with fasting insulin. CONCLUSION: Overweight children are likelier to have unfavourable levels of common CVD risk factors included in metabolic syndrome, but surprisingly had lower LDL and TC. Skinfold thickness, higher triglyceride and glucose levels, and being female were associated with increased serum insulin.

Predictors of fatness and physical fitness in nine-year-old Icelandic school children.

INTRODUCTION: In recent years, the prevalence of overweight and obese children has increased in Iceland, as in most Westernized countries. The main objectives of this study were to assess predictors of fitness and fatness of 9-year-old school children in Iceland. METHODS: In total, 488 subjects (73.3% participation rate) from 18 randomly selected primary schools participated in this cross-sectional study. Height, weight, sum of four skinfolds and other anthropometric measures were performed on all children. Fitness was assessed via a maximal cycle ergometer test in 229 children and of those, 177 wore Actigraph accelerometers to measure physical activity over five consecutive days. Questionnaires regarding family background and lifestyle were completed by 361 mothers and 332 fathers. RESULTS: The main findings from our study showed fatness, area of living and sex, as well as background variables, such as fathers' smoking and income, and number of sport practices attended per week were important predictors of fitness (best-fit model: R-sq=0.48, p<0.0001). In addition, parental body mass index (BMI), mothers' smoking and physical activity and children's objective measure of physical activity were found to be important predictors of children's fatness (best-fit model: R-sq=0.23, p<0.0001). CONCLUSION: These results provide information about predictors of fitness and fatness of 9-year-old children and emphasize the inverse association between the two. Further, our results suggest that mothers have a stronger influence on children's weight than fathers but the opposite may be true for fitness.

Socioeconomic position and the metabolic syndrome in early, middle, and late life: evidence from NHANES 1999-2002.

PURPOSE: To evaluate whether there is an association between socioeconomic position (SEP) and the metabolic syndrome at various ages, including adolescent, middle-aged and older participants in gender-specific analyses. METHODS: Participants were from the 1999-2002 National Health and Nutrition Examination Survey. SEP was measured by income and years of education. Metabolic syndrome was measured in adults using the American Heart Association guidelines and in adolescents using methods based on national reference data. Cross-sectional multivariable-adjusted logistic regression analyses were performed. RESULTS: In women aged 25 to 45 and 46 to 65 years, income below the poverty line (poverty income ratio [PIR] less than one) was associated with higher odds of metabolic syndrome compared with PIR greater than 3 (odds ratio [OR] = 4.90; 95% confidence interval (CI) = 2.24, 10.71, and OR = 2.54; CI = 1.38, 4.67, for the respective age groups) after adjustment for age, race/ethnicity, and menopause. Similar findings were observed for educational attainment. In adolescents, older adults (aged >65 years), and males, income and education were not related to the metabolic syndrome. CONCLUSIONS: This report demonstrates that SEP is associated with the metabolic syndrome in females aged 25 to 65 years and is less strongly associated in males, adolescents, or older participants. These findings provide physiologic mechanistic evidence linking SEP to risk for coronary heart disease.