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. DESIGN: Cohort study. Baseline data from Cohort Norway (1994-2003) health surveys were linked to the Medical Birth Registry of Norway for identification of all subsequent births (1994-2012). Logistic regression models provided odds ratios (OR) and 95% confidence intervals (CI) for preterm delivery (< 37 weeks gestation); multinomial logistic regression provided OR for early preterm (< 34 weeks) and late preterm (34 through to end of 36 weeks gestation) relative to term deliveries. RESULTS: Mean (SD) length of time from baseline health survey participation to delivery was 5.6 (3.5) years. A family history of stroke associated with a 62% greater risk for late preterm deliveries (OR 1.62; CI 1.07-2.47), while a family history of myocardial infarction associated with a 66% greater risk of early preterm deliveries (OR 1.66; CI 1.11-2.49). Sensitivity analyses, removing pregnancies complicated by hypertensive disorders of pregnancy, diabetes mellitus, and stillbirth deliveries, gave similar results. Preconception vigorous physical activity of three or more hours relative to less than 1 h per week associated with increased risk of early preterm delivery (OR 1.52; 95% CI 1.01-2.30), but not late or total preterm deliveries. Light physical activity of three or more hours per week relative to less activity prior to pregnancy was not associated with early, late, or total preterm deliveries. CONCLUSIONS: Results suggest that family history of cardiovascular disease may help identify women at risk for preterm delivery. Further, research is needed regarding preconception and very early pregnancy vigorous physical activity and associated risks.

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. METHODS: Pooled data from Norwegian health surveys (1985-2003), Tuberculosis screenings, Conscript data and the Norwegian Educational database were linked to the Cause of Death Registry. Health survey participants with data on objectively measured weight and height in both early adulthood (18-20 years) and midlife (40-50 years) were included, n = 148,021. Cox regression models were used to assess associations between weight change and CVD mortality. RESULTS: Total analysis time included 2,841,174 person years. Mean follow-up was 19 (standard deviation 4) years. Participants being normal weight in early adulthood and obese in midlife had a hazard ratio (HR) of CVD mortality of 2.09 (95% CI 1.74-2.50) relative to those who were normal weight at both times. The corresponding HR of those being obese at both times was 5.15 (3.61-7.36). Adjustment for CVD risk factors attenuated these associations. Gaining ≥15 kg between early adulthood and midlife was associated with higher CVD mortality after adjustment for early adulthood weight (HR 1.51 (1.20-1.89)), and for smoking and education (HR 1.63 (1.30-2.04)), however not after adjustment for mediating CVD risk factors. CONCLUSIONS: Obesity both in early adulthood and in midlife was associated with CVD mortality. Weight gain of ≥15 kg from early adulthood to midlife was also associated with CVD mortality, but not after adjustment for mediating CVD risk factors.

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. Design: Within-sibship Mendelian randomization (MR) study. Setting: One-sample MR analyses included participants' data from the Trøndelag Health Study (HUNT, Norway) and UK Biobank (United Kingdom). For two-sample MR analyses we used summary statistics from publicly available genome-wide-association-studies. Participants: 61 880 siblings (27 507 sibships). Exposure: Years of education. Main outcomes: Scores for symptoms of anxiety, depression and neuroticism using the Hospital Anxiety Depression Scale (HADS), the 7-item Generalized Anxiety Disorder Scale (GAD-7), the 9-item Patient Health Questionnaire (PHQ-9), and the Eysenck Personality Questionnaire, as well as self-reported consumption of psychotropic medication. Results: One standard deviation (SD) unit increase in years of education was associated with a lower symptom score of anxiety (-0.20 SD [95%CI: -0.26, -0.14]), depression (-0.11 SD [-0.43, 0.22]), neuroticism (-0.30 SD [-0.53, -0.06]), and lower odds of psychotropic medication consumption (OR: 0.60 [0.52, 0.69]). Estimates from the within-sibship MR analyses showed some attenuation, which however were suggestive of a causal association (anxiety: -0.17 SD [-0.33, -0.00]; depression: -0.18 SD [-1.26, 0.89]; neuroticism: -0.29 SD [-0.43, -0.15]); psychotropic medication consumption: OR, 0.52 [0.34, 0.82]). Conclusions and Relevance: Associations between EA and MHC in adulthood, although to some extend explained by dynastic effects and demographic factors, overall remain robust, indicative of a causal effect. However, larger studies are warranted to improve statistical power and further validate our conclusions.

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. A dispersion model was used to assess short-term air pollution for daily (24-h) averages and peak concentrations of nitrogen dioxide (NO(2)) from exhaust and particulate matter with a diameter of 2.5 µm or less (PM(2.5)) from exhaust and wood-burning at residential neighbourhood level for each individual. We found an overall increased risk from exposure at the lag of 0-5 days before the day of death for both pollutants. The excess risk was highest for PM(2.5) with a 2.8 % (95 % confidence interval: 1.2-4.4) increase per 10 µg per cubic meter change in daily exposure. Short-term traffic-related air pollution was associated with increased risk for mortality among individuals above 50 years of age, especially for circulatory outcomes.

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. Alcohol use was self-reported by use of questions on frequency of beer, wine and liquor intake, and one question on intake of around five drinks or more per occasion (binge drinking). Information on education, income and use of alcohol in an earlier and in a later survey was linked to the file. Mortality was assessed throughout 2009 by Cox regression, with adjustment for potential confounding factors. In the analysis of mortality by frequency of any alcohol use, we adjusted for binge consumption and vice versa. RESULTS: Two opposite trends appeared: a higher all-cause mortality in both sexes, and higher CVD mortality in men, with increasing frequency of binge drinking, compared with non-bingers. Second, in both sexes low-frequent use of any alcohol was associated with lower all-cause and CVD mortality, compared with abstention. The combination of any use of alcohol at least weekly and binge consumption at least monthly was common, particularly in men. CONCLUSIONS: Questions on drinking frequency and a specific question on binge drinking capture different effects of alcohol use on all-cause and CVD mortality.