Air pollution does not increase asthma risk (Environ Int. 2020 Jan 18;136:105474)

There is uncertainty regarding the role of air pollution on pediatric asthma and allergic conditions, especially as air pollution levels have started to decrease in recent decades in many parts of the world. In five European countries, the association of long-term air pollution levels at the home with pediatric eczema, rhinoconjunctivitis and asthma prevalence in five birth cohorts was studied. Current eczema, rhinoconjunctivitis and asthma were assessed in children aged four (n = 6527) and eight years (n = 2489). Individual outdoor levels of nitrogen dioxide (NO2), nitrogen oxides, mass of particulate matter with a diameter <10 ìm (PM10), 10-2.5 ìm (PMcoarse) and <2.5 ìm (PM2.5), and PM2.5 absorbance were assigned to the birth, four- and eight-year home addresses using highly defined spatial air pollution exposure models. The overall prevalence of pediatric eczema, rhinoconjunctivitis and asthma at four years was 15.4%, 5.9% and 12.4%. No increase was found in the prevalence of these outcomes at four or eight years with increasing air pollution exposure.

In this large meta-analysis of five birth cohorts, there was no indication of adverse effects of long-term air pollution exposure on the prevalence of current pediatric eczema, rhinoconjunctivitis or asthma.

Continuous positive airway pressure (CPAP) has been used in infants with bronchiolitis for decades. Recently, high flow nasal cannula (HFNC) therapy has been introduced. In this study, 50 children with bronchiolitis  were randomized to treatment with CPAP or HFNC. Objectives were to compare the respiratory rate, pCO2, and Modified Woods Clinical Asthma Score (M-WCAS) in groups receiving CPAP or HFNC. Neonatal Infant Pain Score (NIPS), treatment duration, treatment failure, and hospitalization length were also compared. No differences were observed in development of respiratory rate, pCO2, or M-WCAS. NIPS was higher in the CPAP group. Treatment failure was scarce in both groups. No significant differences in treatment duration or length of hospitalization were observed.

In infants and young children with bronchiolitis, HFNC may be an effective and pleasant alternative to CPAP. Larger multicenter studies are needed to further explore differences in treatment failure and treatment duration.

Pregnancy and breastfeeding prevent ovulation and may slow the depletion of the ovarian follicle pool. These factors may lower the risk of early menopause, a condition associated with increased risk of cardiovascular disease and other adverse health outcomes. In this study the association of parity and breastfeeding with the risk of early menopause was studied.

This population-based cohort study within the Nurses’ Health Study II cohort (1989-2015) included premenopausal participants who were aged 25 to 42 years at baseline. Response rates were 85% to 90% for each cycle, and follow-up continued until menopause, age 45 years, hysterectomy, oophorectomy, death, cancer diagnosis, loss to follow-up, or end of follow-up in May, 2015. History and duration of total and exclusive breastfeeding were assessed three times during follow-up. Menopause status and age were assessed every 2 years.

In a stratified analysis of parous women, risk of early menopause was lowest among those reporting exclusive breastfeeding for 7 to 12 months in each level of parity (women with 2 pregnancies and 7-12 months of breastfeeding: HR, 0.79; 95% CI, 0.66-0.96; ³3 pregnancies and 7-12 months of breastfeeding: HR, 0.68; 95% CI, 0.52-0.88; 2 pregnancies and ³13 months of breastfeeding: HR, 0.87; 95% CI, 0.66-1.15; ³3 pregnancies and 13-18 months of breastfeeding: HR, 0.86; 95% CI, 0.66-1.13; and ³3 pregnancies and ³19 months of breastfeeding: HR, 0.98; 95% CI, 0.72-1.32).

In this study, an inverse association of parity with risk of early menopause was observed. Breastfeeding was associated with significantly lower risk, even after accounting for parity.