The importance of the arachidonic acid/eicosapentaenoic acid (AA/EPA) ratio and omega-3 index on the incidence of running-related injuries

ISRCTN ISRCTN12847156
DOI https://doi.org/10.1186/ISRCTN12847156
Secondary identifying numbers NO. Rf. 200617
Submission date
16/12/2017
Registration date
13/03/2018
Last edited
19/05/2023
Recruitment status
No longer recruiting
Overall study status
Completed
Condition category
Injury, Occupational Diseases, Poisoning
Prospectively registered
Protocol
Statistical analysis plan
Results
Individual participant data

Plain English Summary

Background and study aims.
Running is one of the most common kind of exercise among athletes. A "runner" is generally defined as a person who runs a minimum distance of about 20-30 km per week, from a period of time ranging between 1 and 3 years. However, both amateur and professional athletes are largely affected by overuse injuries at different districts. After intense physical exercise or after injury, an inflammatory process occurs. The activation and the subsequent inflammation resolution are necessary processes to start tissues healing. Since distinct lipid mediators can be synthesized from omega-6 (ω-6) and omega-3(ω-3), pro-inflammatory and pro-resolving lipid mediators respectively, the scientific community focused on the possible efficacy of the polyunsaturated fatty acids omega-6 (ω-6) and (ω-3) in the modulation of inflammatory processes. Furthermore, it is questioned if an imbalance of ω-6/ω-3 fatty acids can result in a higher incidence of overuse injuries in runners. The aim of this study is to evaluate whether the arachidonic acid/eicopsapentaenoic acid ratio (AA/EPA) or the deficiency of ω-3 index is related to an increased risk of overload injury ("overuse", bone microfracture, muscle or tendon rupture) in this population of athletes.

Who can participate?
Healthy runners and triathletes, males and females, who usually train at least 2 times per week from at least 12 months

What does the study involve?
Previously collected data is collected from a database. A statistical analysis to evaluate the potential association between fatty acid composition and risk of injuries.

What are the possible benefits and risks of participating?
By taking part in this study there are no risks of physical injury or harm. The anonymity of the participants was guaranteed.

Where is the study run from?
1. Sannio Tech Consortium (Italy)
2. Sport Campus of Varese (Italy)

When is study starting and how long is it expected to run for?
September 2016 to December 2017

Who is funding the study?
Investigator initiated and funded (Italy)

Who is the main contact?
Dr Giovanni Scapagnini
giovanni.scapagnini@unimol.it

Contact information

Prof Giovanni Scapagnini
Scientific

Via de sanctis snc III Edificio Polifunzionale University of Molise
Campobasso
86100
Italy

Study information

Study designRetrospective osbervational
Primary study designObservational
Secondary study designCohort study
Study setting(s)Other
Study typeOther
Participant information sheet Not available in web format, please use the contact details below to request a patient information sheet
Scientific titleLong-chain omega-3 fatty acids and incidence of running-related injuries: an observational study on the role of AA/EPA ratio and omega-3 index
Study hypothesisConsidering that the activation and the resolution of the inflammation have a fundamental role in the recovery of an injured tissue, this retrospective observational study verified whether an imbalance of the AA/EPA ratio and an altered ω-3 index can be related to an increased risk of overuse injury in runners and triathletes. In particular, this study was designed to evaluate the link between variation of these parameters (AA/EPA ratio; ω-3 index) and the risk of injury associated with training load and athletes characteristics.
Ethics approval(s)Insubria Ethical Committee, 29/09/2017, ref: 10.2692017
ConditionRunning-related injuries
InterventionThe study includes a retrospective statistical analysis of clinical, laboratoristic and sports practice data of 275 runners and triathletes.

Participants completed a questionnaire that allows researchers to collect the following information:
1. Anthropometric characteristics
2. Potential use of anti-inflammatory drugs and/or ω-3 food supplements
3. Years of training
4. Hours of physical activity performed weekly
5. Kilometers of run weekly
6. Any overuse injuries occurred in the last 6 months.

Dried whole blood spot samples, obtained using lancet finger sticks, are collected to perform lipidomic analysis using gas chromatography-mass spectrometry. The ω-3 PUFAs that str quantified, including ALA, EPA, DHA, and docosapentaenoic acid (DPA). The ω-6 PUFAs are also quantified, including linoleic acid (LA) and arachidonic acid (AA). Explorative bivariate statistical analyses are performed to investigate the possible association and confounding role of each variable considered. Chi-squared test, Spearman correlation coefficient, Wilcoxon- Mann-Whitney and Kruskal-Wallis tests are used for categorical, continuous variables and continuous on categorical variables, respectively. The association between the AA/EPA ratio, ω-3 index and the other covariates are assessed by using the linear regression model. The association between the risk of injuries, the AA/EPA ratio, ω-3 index and the other covariates are assessed by using the logistic model. The results of the statistical modelling are considered statistically significant whenever a 2-sided P value less than 0.05 was achieved.
Intervention typeOther
Primary outcome measure1. Potential association between alterations of AA/EPA ratio and risk of running-related injuries.
2. Polyunsaturated fatty acids (PUFAs) [EPA, AA, and DHA] were measured using gas chromatography.
Secondary outcome measuresPossible association between the value of ω-3 index and risk of running-related injuries. The levels of PUFAs to determine ω-3 index were measured using gas chromatography.
Overall study start date30/09/2016
Overall study end date15/12/2017

Eligibility

Participant type(s)Healthy volunteer
Age groupAdult
Lower age limit18 Years
SexBoth
Target number of participants275
Total final enrolment275
Participant inclusion criteria1. Healthy Caucasian males and females
2. Runners or triathletes
3. Age ≥18 years
4. Subjects who did not participated in similar studies in the last 3 months
5. Absence of eating disorders
6. Subjects informed about the procedures and who have signed an informed consent appropriately prepared by the proponents
7. Subjects usually train at least 2 times a week for at least 12 months
Participant exclusion criteria1. Subjects that do not meet the inclusion criteria
2. Currently pregnant
Recruitment start date10/01/2017
Recruitment end date30/09/2017

Locations

Countries of recruitment

  • Italy

Study participating centres

Sannio Tech Consortium
82030
Italy
Sports Medicine Campus of Varese
21100
Italy

Sponsor information

Equipe Enervit srl
Not defined

Via Garavaglia, 2
Zelbio (CO)
22020
Italy

Funders

Funder type

Other

Investigator initiated and funded

No information available

Results and Publications

Intention to publish date01/09/2018
Individual participant data (IPD) Intention to shareYes
IPD sharing plan summaryAvailable on request
Publication and dissemination planPlanned publication in a high-impact peer reviewed journal.
IPD sharing planThe datasets generated during and/or analysed during the current study are/will be available upon request from Professor Giovanni Scapagnini, University of Molise Department of Medicine and Health Sciences at g.scapagnini@gmail.com or giovanni.scapagnini@unimol.it

Study outputs

Output type Details Date created Date added Peer reviewed? Patient-facing?
Results article 25/10/2021 26/10/2021 Yes No
Results article 26/04/2019 19/05/2023 Yes No

Editorial Notes

19/05/2023: Publication reference added.
26/10/2021: The following changes were made to the trial record:
1. Publication reference added.
2. The total final enrolment was added.