Subjects and Methods
Participants:
50 healthy adult athletes between the ages of 18 and 35 will be engaged in the research
(power analysis with 80% power and an alpha error of 5% shows that 32 subjects in two groups
are sufficient).
Exclusion criteria: Bacterial or viral acute inflammation of the upper respiratory system,
chronic obstruction of one or both nostrils with significant deformation of the septum,
surgery on the nose or nasal septum within one month of the start of the study
Isotonic seawater:
product from the market, Aqua Maris nasal spray (manufacturer JGL, Rijeka), applied in
accordance with the approved Instructions for Consumers
Study design:
A randomized, interventional prospective cohort study.
Intervention:
The participants will be divided into two groups using the binary coin-toss method
(random.org) with similar physical and demographic characteristics. The first group will use
an isotonic seawater solution as a nasal spray for 10 days, while the control group will not
use such a solution. The group with the isotonic seawater solution applied as a nasal spray
will use it at least three times a day, and necessarily before exercise (about 20 minutes
before).
Outcome measures:
The primary outcome measures will be nasal airflow measured with a peak nasal inspiratory
flow meter (PNIF) and subjective impression of nasal obstruction symptoms before and after
exercise by completing the NOSE questionnaire. The NOSE contains five statements about nasal
obstruction, divided on a 4-point Likert scale for each statement.
Remark:
PNIF meters will be provided by JGL (measurement with them takes < 1 min/athlete) The NOSE
questionnaire (abbreviated from Nasal Obstruction Symptom Evaluation) is an internationally
recognized and validated scale for assessing the intensity of nasal obstruction.
The time points for the collection of measures will be:
Day 1: before the start of the research, before the first training session (first
interval), respectively:
NOSE
PNIF
Day 1: after the first use of the spray, (within 20 minutes after the first training
session - second interval), i.e. after the first training session in the control group,
respectively:
NOSE
PNIF
Day 7: after ten days of daily use of the spray, after training (third interval) or
after the first training in the control group, respectively:
NOSE
PNIF
Data analysis:
Descriptive statistics and inferential statistics will be used to compare outcomes
between two groups (no less than 16 participants in the nasal spray group vs. no less
than 16 participants without the spray).
Each couple from the test group will be joined by a couple from the control group with
as similar physical and demographic characteristics as possible.
The Wilcoxon signed rank test and the Friedman test for paired samples will be used depending
on the distribution of the data.
Ethical considerations This study will be conducted in accordance with ethical principles and
guidelines (1996 Helsinki Declaration, in accordance with current Croatian regulations, and
after approval by the competent hospital ethics committee). Written informed consent will be
obtained from all participants.
Participants will be informed of the risks and benefits of the study by the examining
physician. The confidentiality of the participant's data will be ensured in such a way as to
comply with GDPR provisions in accordance with EU and national legislation.
Conclusion
This study aims to investigate the effects of an isotonic solution of seawater from the
Adriatic Sea applied as a nasal spray on:
The results of this research could help athletes improve performance by improving nasal
airflow and nasal function.