DISCUSSION
In our study, we found a significantly worse quality of life (RHINASTHMA
total and subdomain scores) and symptoms control (CARAT total and
subdomain scores) in AR patients with comorbid asthma than in patients
with AR alone. Such associations were not influenced by any
physiological variables. However, we found that the association was
significantly higher among non-obese participants compared to obese
ones, when assessed through RHINASTHMA-upper symptoms score but not with
CARAT. We also observed country-specific variations in the RHINASTHMA
and CARAT total scores. Although one previous study compared the
individual/social burden of disease between asthmatics and asthmatics
with concomitant AR, unlike ours, that study did not compare the
difference of disease control and HRQoL between the two groups of
patients24.
It is well-known that several triggers such as seasonal meteorological
changes, pollen season, air pollution, or even occupational exposures
may lead to poor quality of life of asthmatic patients with or without
AR 8,25-27. It has also been observed that AR patients
are often reported to have poor control over their symptoms if
persistent comorbid asthma is present28-31. Although
no direct comparative study on the control and HRQoL of AR and AR with
asthma has been reported yet, our findings well reciprocate the previous
results. Asthma and AR share eight common genes (CLC, EMR4P,
IL5RA, FRRS1, HRH4, SLC29A1, SIGLEC8, IL1RL1 ) that are presumed to
describe the link for multimorbidity32. They also
share common risk factors such as atopic genetic background (for the
allergic endotypes), environmental exposures (allergens, moulds, indoor
and outdoor air pollution, some respiratory viruses, etc.), type of
occupation, and active tobacco smoking.
Our findings add important clinical knowledge to the existing strategies
for the management of AR with concomitant asthma. Although AR and asthma
are two different diseases with distinct clinical features, when AR
persists with asthma, either condition is often
overlooked31,33 due to the lack of a combined tool for
monitoring control and HRQoL of both diseases at the same time. Despite
the well-established guidelines of ARIA and GARD for a new management
protocol for AR and asthma together10,12,34-37,
reports adopting these guidelines in the management of AR with
persistent asthma are still lacking. Our findings would help guide
practitioners to use the appropriate assessment tools while treating
such patients. Our findings underline the impact of respiratory
hypersensitivity conditions in the quality of life of patients and call
for prevention and public health strategies to diminish the burden of
these conditions. Currently there are effective treatments for AR and
asthma, several risk factors are known (e.g., allergies,
rhinitis, tobacco smoke) and tools to control the disease have been
developed. However, we are still uncertain how to prevent AR patients
from developing asthma, allergen immunotherapy being the current only
attempt. Preventive measures should be able to change the natural
history of the disorder, avoiding asthma development in patients with AR
and/or evolution through providing its control38.
Our study has some limitations. Firstly, considering that subjective
symptom-rating scales may not be entirely accurate, the risk for
potential bias could not be completely avoided. However, we used
standardized instruments, and therefore the possibility of such bias was
marginal. Secondly, the considered period might be insufficient to
evaluate the quality of life and the control appropriately. Thirdly,
other comorbidities might have modified the patients’ responses. Despite
these limitations, our findings are derived from incident patients drawn
from the general population of three European countries in which AR and
asthma diagnoses were made by a doctor. However, due to the small sample
size, it is not possible to indicate whether these results may be
generalized. Further studies, after controlling for potential
confounders and biases in larger populations, are therefore warranted.