Educational attainment and mental health conditions: a within-sibship Mendelian randomization study.

Importance: Observational studies have demonstrated consistent protective effects of higher educational attainment (EA) on the risk of suffering mental health conditions (MHC). Determining whether these beneficial effects are causal is challenging given the potential role of dynastic effects and demographic factors (assortative mating and population structure) in this association.

Objective: To evaluate to what extent the relationship between EA and various MHC is independent from dynastic effects and demographic factors.

Educational attainment, health outcomes and mortality: a within-sibship Mendelian randomization study.

Background: Previous Mendelian randomization (MR) studies using population samples (population MR) have provided evidence for beneficial effects of educational attainment on health outcomes in adulthood. However, estimates from these studies may have been susceptible to bias from population stratification, assortative mating and indirect genetic effects due to unadjusted parental genotypes. MR using genetic association estimates derived from within-sibship models (within-sibship MR) can avoid these potential biases because genetic differences between siblings are due to random segregation at meiosis.

Nucleated red blood cells explain most of the association between DNA methylation and gestational age.

Determining if specific cell type(s) are responsible for an association between DNA methylation (DNAm) and a given phenotype is important for understanding the biological mechanisms underlying the association. Our EWAS of gestational age (GA) in 953 newborns from the Norwegian MoBa study identified 13,660 CpGs significantly associated with GA (p<0.05) after adjustment for cell type composition.

Preconception leisure-time physical activity and family history of stroke and myocardial infarction associate with preterm delivery: findings from a Norwegian cohort.

Background: Preterm birth poses short and long-term health consequences for mothers and offspring including cardiovascular disease sequelae. However, studies evaluating preexisting family history of cardiovascular disease and risk factors, such as physical activity, as they relate prospectively to risk of delivering preterm are lacking.

Objectives: To evaluate whether preconception past-year weekly leisure-time physical activity or a family history of stroke or of myocardical infarction prior to age 60 years in first degree relatives associated, prospectively, with preterm delivery.

Early adulthood weight, subsequent midlife weight change and risk of cardiovascular disease mortality: an analysis of Norwegian cardiovascular surveys.

Background: The time between early adulthood and midlife is important for obesity development. There is paucity of studies using objectively measured body mass index (BMI) at both time points with full range of midlife cardiovascular risk factors. We aimed to investigate the risk of cardiovascular disease (CVD) mortality associated with different levels of objectively measured change in body weight from early adulthood to midlife, and to assess whether risk is primarily explained by midlife cardiovascular risk factors.

Divergent associations of drinking frequency and binge consumption of alcohol with mortality within the same cohort.

Background: Observational studies show beneficial effects of moderate alcohol drinking on all-cause and cardiovascular disease (CVD) mortality, while binge drinking has been linked with increased mortality. The aim of this study was to assess the associations of alcohol use with mortality in a population with a hybrid of drinking patterns.

Method: Participants in a population based cardiovascular health survey in Finnmark county in 1987-1988, aged 20-62 years, constituted the study cohort.

The short-term effect of 24-h average and peak air pollution on mortality in Oslo, Norway.

Numerous epidemiological studies have shown associations between increases in outdoor air pollution and all-cause mortality as well as cardiovascular and respiratory related mortality. The majority of studies has used the routine monitoring network and thus has not been able to characterize the small-scale variation in daily averages and peak concentrations within urban settings. To address possible short term impact on mortally by air pollution we used a time-stratified case-crossover design to estimate associations of traffic-related air pollution and wood burning and daily mortality during a period of 10 years among residents above 50 years of age in Oslo, Norway.