How Muscle Dysmorphia Affects GLP-1, Asprosin, and BDNF Levels in Sports Students | Research

The takeaway

Sports science students with higher bigorexia nervosa levels showed differences in salivary GLP-1, asprosin, and BDNF levels, with males showing higher bigorexia scores and distinct hormonal patterns compared to females.

120 students studied
with salivary GLP-1, asprosin, and BDNF measured in relation to muscle dysmorphia severity

What the researchers found

Among 120 sports science students (63 females, 57 males, ages 18-25), males scored significantly higher on the Muscle Dysmorphic Disorder Inventory than females. Salivary asprosin levels were significantly higher in males compared to females. The study found associations between bigorexia nervosa levels and endocrine markers (asprosin, GLP-1) as well as the cerebral marker BDNF, though no significant correlation was found between BMI and GLP-1 or BDNF levels (p>0.05).

The average MET value was 4.53, indicating moderate-intensity physical activity across participants. The study suggests bigorexia nervosa influences physiological and hormonal responses beyond just behavioral patterns.

Why it matters

Bigorexia nervosa is an increasingly recognized but understudied condition, especially among fitness-oriented young adults. Understanding its hormonal underpinnings — including effects on metabolic peptides like GLP-1 and asprosin — could help identify biomarkers for the condition and develop targeted interventions. This is one of the first studies to examine the endocrine-cerebral axis in relation to muscle dysmorphia.

How the study worked

This cross-sectional study enrolled 120 university sports science students (18-25 years). Participants completed the Muscle Dysmorphic Disorder (Bigorexia) Inventory, a food frequency questionnaire, and a demographic questionnaire via face-to-face interviews. Physical activity was assessed using the 6-Minute Walk Test with MET calculations. Saliva samples were analyzed for asprosin, GLP-1, and BDNF using ELISA. Data were analyzed with chi-square, t-test, Pearson correlation, and ANOVA.

What this study cannot tell us

This is a cross-sectional study, so it cannot determine whether hormonal differences cause or result from bigorexia nervosa. The sample was limited to sports science students, who may not represent the general population. Salivary hormone measurement is less established than blood measurement for these markers. The sample size of 120 is relatively small for subgroup analyses. The abstract does not report specific effect sizes for the hormone-bigorexia associations.

How to read the evidence

This is a cross-sectional observational study with a relatively small sample of 120 participants. While it provides interesting associations, it cannot establish causation and uses salivary rather than serum hormone measurements.

When this study was published

Published in 2025, this is a recent study addressing an emerging area of research linking body dysmorphia to endocrine peptide profiles.

The bigger picture

This study sits at the intersection of endocrinology, sports medicine, and body image psychology. As bigorexia nervosa gains recognition as a distinct condition, understanding how it relates to metabolic and neurotrophic peptides could open new diagnostic and therapeutic avenues. The focus on GLP-1 is particularly timely given the explosion of interest in GLP-1 biology beyond diabetes treatment.

Questions still open

Do GLP-1 and asprosin levels change over time as bigorexia severity worsens or improves?
Would these hormonal differences be replicated in blood-based measurements and larger populations?
Could hormonal profiling help identify individuals at risk for developing muscle dysmorphia?

Common questions

What is bigorexia nervosa?

Bigorexia nervosa, also called muscle dysmorphia, is a condition where a person becomes obsessed with the idea that they are not muscular or lean enough, despite often being quite fit. It can lead to excessive exercise, restrictive dieting, and psychological distress, and is more common in men.

Why would bigorexia affect GLP-1 and asprosin levels?

People with bigorexia often have altered eating patterns and exercise habits, which can directly affect metabolic hormones like GLP-1 (involved in appetite and blood sugar) and asprosin (a fasting-induced hunger hormone). The hormonal differences may reflect both the behavioral patterns and underlying neurobiological aspects of the condition.

Read the original research

Investigation of endocrine and cerebral response and nutrition and physical performance parameters according to bigorexia nervosa levels: a cross-sectional study in sports sciences faculty students.

Scientific reports, 15(1), 43989

View on PubMed ↗Publisher’s paper ↗

Citation

Erkılıç, Ali Ozan; Bayraktar, Bülent; Erkiliç, Tuğçe Orkun; Türkmen, Mutlu; Kul, Murat; Yönal, Mehmet. (2025). Investigation of endocrine and cerebral response and nutrition and physical performance parameters according to bigorexia nervosa levels: a cross-sectional study in sports sciences faculty students.. Scientific reports, 15(1), 43989. https://doi.org/10.1038/s41598-025-27706-2