Physical activity and IgG N-glycosylation in medical students: a cross-sectional study

To examine differences in IgG N-glycan composition between physical activity (PA) categories and to assess associations between PA domains and IgG N-glycan traits in medical students.

This cross-sectional study enrolled first-year and second-year medical students at the University Josip Juraj Strossmayer, Osijek. PA was assessed using the International Physical Activity Questionnaire-Short Form (IPAQ-SF), capturing walking, moderate, and vigorous PA, total PA, and sitting time. Participants were classified as health-enhancing physical activity (HEPA)-active or non-HEPA-active. IgG was isolated from plasma, and N-glycan composition was assessed using capillary gel electrophoresis with laser-induced fluorescence detection. Twenty-seven glycan peaks and eight derived glycan traits (G0, G1, G2, S0, S1, S2, B, and CF) were quantified.

Seventy-nine students (56 women; median age, 20 [range, 18-25] years) were enrolled: 23 were HEPA-active and 56 non-HEPA-active. The groups did not significantly differ in individual IgG N-glycan peaks or derived glycan traits. In unadjusted analyses, vigorous PA was weakly positively correlated with G1 (ρ=0.24, P=0.034) and total PA with G1 (ρ=0.27, P=0.017), while total PA was negatively correlated with G2 (ρ=-0.34, P=0.002). However, none of these associations remained significant after adjustment for multiple testing.

Self-reported PA was not associated with IgG N-glycosylation after correction, and no differences were observed between PA categories. These findings indicate no robust association between PA and the IgG glycome.