Influence of constipation on atopic dermatitis: A nationwide
population-based cohort study in Taiwan
Background Atopic dermatitis (AD) is the chronic inflammatory disorder
that affects both in childhood and adulthood. Mounting evidence
indicates that gut dysbiosis contributes to AD via the gut-skin axis.
Constipation can result in alteration of the gut microflora. The
clinical impact of constipation on AD has not been researched.
Therefore, we aim to assess the risk of AD in constipated patients by
the population-based cohort study. Methods We collected 87015
constipated people and 87015 people without constipation between 1999
and 2013 from the Taiwanese National Health Insurance Research Database.
Propensity score analysis was administrated to match age, gender,
comorbidities, and medications at a ratio of 1:1. Multiple Cox
regression analysis was utilized to evaluate the adjusted hazard ratio
of AD. In addition, sensitivity tests and a stratified analysis were
conducted. Results The incidence of AD was 4.7 per 1,000 person-years in
the constipation group, which was higher than the rate of 2.2 per 1,000
person-years observed in the non-constipation group. After adjustment
for age, gender, comorbidities, corticosteroids, and antihistamine,
constipated people had a 2.11-fold greater risk of AD compared to those
without constipation (adjusted hazard ratio [aHR]: 2.11 (95% C.I.
1.98-2.24). Moreover, constipated people had a higher likelihood of AD,
regardless of gender, comorbidities, as well as the usage of
corticosteroids, and antihistamines. Conclusion Constipation is
associated with a significantly risk factor of AD. Clinicians should be
careful of the possibility of AD in constipated people. Further study is
warranted to investigate the possible pathological mechanisms of this