A nationwide follow-up study of occupational organic dust exposure and risk of chronic obstructive pulmonary disease (COPD)

Objectives To study exposure-response relations between cumulative organic dust exposure and incident chronic obstructive pulmonary disease (COPD) among subjects employed in the Danish farming and wood industry. Methods We studied exposure-response relations between cumulative organic dust exposure and incident COPD (1997–2013) among individuals born during 1950–1977 in Denmark ever employed in the farming or wood industry (n=1 75 409). Industry-specific employment history (1964–2007), combined with time-dependent farming and wood industry-specific exposure matrices defined cumulative exposure. We used logistic regression analysis with discrete survival function adjusting for age, sex and calendar year. Adjustment for smoking status was explored in a subgroup of 4023 with smoking information available. Results Cumulative organic dust exposure was inversely associated with COPD (adjusted rate ratios (RRadj (95% CIs) of 0.90 (0.82 to 0.99), 0.76 (0.69 to 0.84) and 0.52 (0.47 to 0.58) for intermediate-low, intermediatehigh and high exposure quartiles, respectively, compared with the lowest exposure quartile). Lagging exposure 10 years was not consistently suggestive of an association between cumulative exposure and COPD; RRadj (95% CI): 1.05 (0.94 to 1.16), 0

Subfecundity in overweight and obese couples

BACKGROUND: Recent studies indicate that not only women’s but also men’s obesity has adverse effects on fecun-dity and since fecundity is a couple concept, we examined fecundity in relation to overweight and obesity of the couple. We also examined the association between weight changes and fecundity over time. METHODS: Between 1996 and 2002, 64 167 pregnant women enrolled in the Danish National Birth Cohort were interviewed during and 18 months after pregnancy. Information on body mass index (BMI) and waiting time to pregnancy (TTP) was available for 47 835 couples. RESULTS: Among men and women with a BMI of 18.5 kg/m2 or more, we found a dose-response relationship between increasing BMI group and subfecundity (a TTP of more than 12 months): Odds ratio (OR)5 1.32 (95 % CI: 1.26–1.37) for women and OR5 1.19 (95 % CI: 1.14–1.24) for men. Among 2374 women with an initial BMI of 18.5 kg/m2 or more, who participated more than once in the Danish National Birth Cohort, each kilogram increment in weight between the two pregnancies was associated with a 2.84 (95% CI: 1.33–4.35) days longer TTP. CONCLUSIONS: Couples have a high risk of being subfecund if they are both obese. Key words: fecundity/fertility/obesity/overweigh

Maternal use of oral contraceptives and risk of fetal death

Udgivelsesdato: 2008-JulIntrauterine exposure to artificial sex hormones such as oral contraceptives may be associated with an increased risk of fetal death. Between 1996 and 2002, a total of 92 719 women were recruited to The Danish National Birth Cohort and interviewed about exposures during pregnancy. Outcome of pregnancy was identified through linkage to the Civil Registration System and the National Discharge Registry. The authors analysed the risk of fetal death after recruitment to the cohort by using proportional hazards regression models with gestational age as the underlying time scale. In total, 1102 (1.2%) women took oral contraceptives during pregnancy. Use of combined oestrogen and progesterone oral contraceptives (COC) or progesterone-only oral contraceptives (POC) during pregnancy was not associated with increased hazard ratios of fetal death compared with non-users, HR 1.01 [95% CI 0.71, 1.45] and HR 1.37 [95% CI 0.65, 2.89] respectively. Neither use of COC nor POC prior to pregnancy was associated with fetal death. Stratification by maternal age and smoking showed elevated risks of fetal death for women <30 years and smokers using oral contraception during pregnancy, but the interactions were not significant. In conclusion, there was no evidence that oral contraceptive use before or during pregnancy is associated with an increased risk of fetal death