Prevalence and risk factors for wheezing in infants in the region of Pamplona, Spain

Residential greenness and pollen exposure across gestational trimesters in relation to preschool wheezing: Results for the PIPO birth cohort

INTRODUCTION

Previous studies on prenatal green space exposure and early respiratory health show inconsistent results. This may reflect stage-specific in utero effects and pollen influence. We examine associations of surrounding greenness and pollen exposure during pregnancy (overall and by trimester) with preschool wheezing, and assess potential mediation by pollen.

METHODS

We used data from the PIPO birth cohort (n = 860). Wheezing was reported biannually between 18 and 48 months of age. Residential greenness was measured with Normalized Difference Vegetation Index (NDVI) in 100 and 250 m buffer. Cumulative grass and birch pollen was estimated using modelled airborne pollen counts and categorized per trimester into no, low and high. All exposures were assessed for the overall pregnancy and per trimester. We used Generalized Estimated Equations to obtain odds ratios (OR) and 95% confidence intervals (CI). To assess mediation by pollen we used a data duplication algorithm with a generalized estimation approach.

RESULTS

Approximately 10% of participants wheezed. During pregnancy, greenness (OR = 1.07, CI: 1.05-1.08) and grass pollen exposure (OR = 1.09, CI: 1.03-1.15) increased the odds of wheezing, while birch pollen decreased it (OR = 0.86, CI:0.87-1.00). Per trimester, more greenness during the 2nd trimester increased the odds (OR = 1.21, CI: 1.16-1.26), whereas third-trimester greenness decreased it (OR = 0.87, CI: 0.84-0.91). Grass pollen exposure in the 1st and 3rd trimesters increased the odds of wheezing (OR = 1.23, CI: 1.12-1.34 and OR = 1.13, CI: 1.00-1.27, respectively), while birch pollen exposure in the 1st and 2nd trimesters decreased the odds (OR = 0.88, CI: 0.77-1.00 and OR = 0.83, CI: 0.73-0.95, respectively). No significant associations were found for greenness in the 1st trimester, grass pollen in the 2nd trimester, and birch pollen in the 1st and 3rd trimester. Mediation analysis showed large uncertainty.

DISCUSSION

Surrounding greenness and pollen exposure during pregnancy may impact the likelihood of preschool wheezing differently depending on the timing of exposure and the pollen type.

Risk factors associated with wheezing in severe pediatric community-acquired pneumonia: a retrospective study

BACKGROUND

Wheezing is a common clinical manifestation in children with pneumonia. However, the risk factors associated with the development of wheezing pneumonia and its clinical features are not fully characterized, especially in children with severe pneumonia.

METHODS

We retrospectively recruited 1434 pediatric patients diagnosed with severe pneumonia between April 2012 and September 2019 in Fujian Maternity and Child Health Hospital. The medical records regarding demographic information, clinical manifestations, radiographic/laboratory findings, and complications were collected. Based on the presence or absence of wheezing symptoms and signs, subjects were divided into wheezing cohort (N.=684) and non-wheezing cohort (N.=750), and their clinical data were compared. Multivariate cox regression analysis was performed to identify independent risk factors of wheezing.

RESULTS

Demographic features including gender, weigh, onset season, birth weight, full-term birth or not, history of pneumonia were significantly associated with the occurrence of wheezing in severe CAP (P<0.05). Specifically, male gender, onset seasons in autumn/winter, and absence of a history of pneumonia were identified as independent risk factors of wheezing in multivariate analysis (P<0.05). As for clinical features, wheezing cohort differed from the non-wheezing one in terms of clinical manifestation (higher incidence of cough and breathless, but lower incidence of fever), laboratory finding (higher levels of red blood cells, hemoglobin, and albumin and lower levels of total or indirect bilirubin and creatine), pathogen detection (higher incidence of respiratory syncytial viral infection), and clinical complications (lesser risk of sepsis and hydrothorax) (P<0.05).

CONCLUSIONS

Severe CAP with wheezing is a special clinical entity of severe pneumonia in children, which has specific risk factors and differ from non-wheezing pneumonia in terms of clinical features and etiologic pathogens.

Meta-analysis of prevalence of wheezing and recurrent wheezing in infants

BACKGROUND

Wheezing affects children's quality of life, and is related with asthma in childhood. Although prevalence of wheezing has been previously studied in several countries, there is no reference of worldwide prevalence in infants. The aim of this meta-analysis is to estimate the prevalence of wheezing and recurrent wheezing in infants aged up to two years, and compare the prevalence across world regions.

METHODS

Literature search was conducted in MEDLINE and SCOPUS databases, looking for observational studies published up to June 2016, including as keywords "prevalence" or "epidemiology" combined with "wheeze", "wheezing" or "asthma symptoms" and "infant" or "preschool". Fast*Pro software and random effects Bayesian model were used. Heterogeneity was estimated using I² statistic, and sensitivity analyses were performed.

RESULTS

We identified 109 studies after duplicates were removed. After exclusions, 14 studies were included in the meta-analysis. Prevalence of wheezing and recurrent wheezing were 36.06% (95% CI 35.17-36.96), and 17.41% (95% CI 16.74-18.09), respectively. In European countries, prevalence of wheezing was 30.68% (95% CI 28.97-32.45), and 12.35% (95% CI 11.27-13.47) for recurrent wheezing. Prevalence of wheezing and recurrent wheezing in Latin America were higher, 40.55% (95% CI 39.40-41.71), and 19.27% (95% CI 18.44-20.11), respectively. In Africa, prevalence of wheezing was 15.97% (95% CI 14.05-18.00). Low or no heterogeneity was found in all cases.

CONCLUSIONS

More than one third of infants suffer from wheezing and almost one fifth from recurrent wheezing, being these illnesses especially prevalent in Latin American countries, pointing out an important public health problem.

Influence of the Mediterranean diet during pregnancy in the development of wheezing and eczema in infants in Pamplona, Spain

BACKGROUND

This study examined the relationship between different food groups and the adherence to a Mediterranean diet during pregnancy and the risk of wheezing and eczema in children aged 12-15 months.

METHODS

The study involves 1087 Spanish infants from the International Study of Wheezing in Infants (Estudio Internacional de Sibilancias en Lactantes, EISL). The study of the association of the different food consumption and Mediterranean diet with wheezing, recurrent wheezing and eczema was performed using different models of unconditional logistic regression to obtain adjusted prevalence odds ratios (OR) and 95% confidence intervals (95% CI).

RESULTS

No association was found between a good adherence to the Mediterranean diet during pregnancy and the development of wheezing (p=0.372), recurrent wheezing (p=0.118) and eczema (p=0.315). The consumption once or twice a week of white fish (OR: 1.95[1.01-3.75]), cooked potatoes (OR: 1.75[1.22-2.51]) and industrial pastry (OR: 1.59[1.13-2.24]), and the consumption more than three times a week of industrial pastry (OR: 1.47 [1.01-2.13]) during pregnancy increases the risk of "wheezing" at 12 months. Instead, high fruit consumption during the pregnancy has a protective effect against "wheezing" in 12-month-old infants (OR: 0.44 [0.20-0.99]). No statistically significant differences were observed between food intake during pregnancy and "recurrent wheezing". No statistically significant differences were observed between the consumption of any food during pregnancy and the presence of eczema at 12 months.

CONCLUSIONS

The present study showed that the consumption of Mediterranean diet during pregnancy did not have a protective effect for wheezing, recurrent wheezing or eczema.