Changing trends in the prevalence of childhood asthma over 40 years in Greece

Trends (2007-2019) of major atopic diseases throughout the life span in a large Mexican population

Background

Major atopic diseases such as atopic dermatitis (AD), allergic rhinitis (AR), and asthma share the same atopic background, but they often show differences in their epidemiological behavior.

Objective

We aimed to report the profile of these atopic diseases in a large Mexican population, including their age-related incidences, male:female (M:F) ratios, recent time trends, and association with altitude.

Methods

Registries from the largest, nationwide health institution in Mexico (more than 34 million insured subjects), were reviewed. New cases of AD, AR, and asthma diagnosed each year by family physicians from 2007 to 2019 were adjusted by the corresponding insured population to estimate incidence rates.

Results

Incidences of the 3 atopic diseases were highest in the 0-4 years age-group and progressively decreased thereafter until adolescence. Asthma and AR, but not AD, were more frequent in males during childhood (M:F ratios of 1.5, 1.3, and 0.95, respectively), but predominated in females during adulthood (M:F ratios of 0.52, 0.68, and 0.73, respectively). Time trends showed an initial increasing trend of annual incidences, with a peak around 2009-2011, and a downward trend afterward. This decreasing trend was seen in all age-groups and was more evident for AD (∼50% drop) and asthma (∼40% drop) than for AR (∼20% drop). Geographical distribution suggested that incidences of asthma and AR, but not of AD, had an inverse association with altitude.

Conclusion

Annual incidences of the 3 major atopic diseases have declined in recent years in almost all age groups, and their epidemiological profile during the life span showed contrasting differences according to age, sex, and ecological association with altitude, mainly regarding AD.

Diverging trends of respiratory allergies and eczema in Greek schoolchildren: Six surveys during 1991-2018

Background: The prevalence of childhood asthma, rhinoconjunctivitis, and eczema in the city of Patras, Greece, has been followed in four consecutive surveys since 1991. After a continuous rise in the prevalence of all three of these disorders, a plateau was reached for asthma between 2003 and 2008, whereas the prevalence of rhinoconjunctivitis and eczema continued to increase. Objective: To investigate these trends in the same population into the following decade. Methods: We repeated two methodologically identical cross-sectional parental questionnaire surveys in 2013 and 2018 among 8-9-year-old schoolchildren (N = 2554 and N = 2648, respectively). In 2018, spirometry and fractional exhaled nitric oxide (FeNO) measurements were also performed. Results: Current asthma (i.e., wheeze/asthma in the past 2 years) decreased from 6.9% in 2008 to 5.2% in 2013 and 4.3% in 2018 (p for trend < 0.001). The prevalence of lifetime ("ever had") rhinoconjunctivitis also declined (5.1% in 2008, 4.4% in 2013, 3.0% in 2018; p for trend < 0.001), whereas that of lifetime eczema increased (10.8%, 13.6%, and 16.1%, respectively; p for trend < 0.001). The relative risk of current asthma in children with ever-had rhinoconjundtivitis was 7.73 in 2008, 6.00 in 2013, and 6.69 in 2018, whereas the relative risk in those with ever-had eczema was 5.15, 2.80, and 2.22, respectively. Among children with asthma, those with rhinoconjunctivitis had lower forced expiratory volume in the first second of expiration and higher FeNO values than those with eczema. Conclusion: The prevalence of asthma and rhinoconjunctivitis declined during the past decade in Greek schoolchildren, whereas the prevalence of eczema continued to rise. Nevertheless, the relationship between rhinoconjunctivitis and asthma remained strong, whereas the association between eczema and asthma appears to have weakened.

Exploring the Relation between Atopic Diseases and Lifestyle Patterns among Adolescents Living in Greece: Evidence from the Greek Global Asthma Network (GAN) Cross-Sectional Study

Introduction: Diet and physical activity might be associated with the risk of allergic diseases in childhood. However, evidence in literature is sparse and diverse. We aim to examine the associations between four healthy dietary consumption pattern drinks, plus the adherence to a physically active lifestyle with atopic diseases (asthma, allergic rhinitis and eczema) in adolescence and their relative importance. Methods: A total of 1934 adolescents (921 boys, 47.5%) and their parents completed a validated questionnaire assessing atopic diseases’ symptoms prevalence in the past 12 months, as well as nutritional and physical activity information. Four healthy dietary and one physical active lifestyle patterns were identified and logistic regression was applied to assess their relation with allergic diseases. Results: A high weekly consumption of fruits, vegetables and pulses and low consumption of unhealthy foods was negatively associated with all atopic symptoms while adherence to a physical active lifestyle was inversely associated with asthma and allergic rhinitis symptoms and dairy products with asthma and eczema symptoms in the past 12 months after adjustment for several confounders (all p < 0.05). Fruits, vegetables and pulses consumption per week emerged as the most important lifestyle pattern negatively associated for all atopic diseases, after the adjustment for all the remaining lifestyle patterns and confounders (all p < 0.05) Conclusions: Our findings suggest that a high fruit, vegetable and pulse intake should be the first lifestyle intervention every clinician and public health care worker evolving in the management of atopic adolescents should encourage and promote.