Open Access

Magdalena E. Haid, Stephanie Zylla, Marcello Ricardo Paulista Markus, Nele Friedrich, Ralf Ewert, Sven Gläser, Stephan B. Felix, Marcus Dörr, Martin Bahls

• Aims Low cardiorespiratory fitness (CRF) is associated with greater mortality and morbidity. Galectin-3 (Gal-3) is a prognostic biomarker for fibrosis and heart failure. Gal-3 is also associated with a greater risk for cardiovascular mortality. Whether CRF is related with Gal-3 is unclear. The objective of this study was to assess the sex-specific associations of CRF and Gal-3 levels in the general population. Methods Gal-3 concentrations were determined using a sandwich enzyme immunoassay in the population-based Study of Health in Pomerania (SHIP-TREND-0). Sex-stratified linear regression models adjusted for age, current smoking status, and renal function were used. Individuals with left ventricular ejection fraction (LVEF) <40%, previous myocardial infarction, atrial fibrillation, chronic lung disease, severe renal disease (estimated glomerular filtration rate <30 mL/min/mm2), a history of cancer, and extreme values for Gal-3 (<1st percentile; >99th percentile) were excluded. Results A total of n = 1515 participants with a median age of 49 (IQR: 39–60 years, 48% males) were included. In men, a 1 L/min greater VO2peak was significantly related to 0.50 ng/mL (95% CI −0.8068 to −0.1938, P < 0.01) less Gal-3. In males, a 1 mL/min/kg higher VO2peak adjusted for body weight was associated with −0.0286 ng/mL (95% CI −0.0052 to −0.0005, P = 0.02) less Gal-3. When VO2peak was adjusted for lean mass 1 mL/kg/min more was correlated with a −0.0022 ng/mL (95% CI −0.0043 to -0.0007, P = 0.04) less Gal-3. In women, VO2peak (β −0.2046 95% CI −0.6541 to 0.2449, P = 0.37) and VO2peak adjusted for lean mass (β −0.0019 95% CI −0.0421 to –0.0050, P = 0.12) were not related with Gal-3, whereas a 1 mL/min/kg higher VO2peak adjusted for body weight was significantly associated with a −0.0064 ng/mL lower Gal-3 (95% CI −0.0092 to -0.0035, P < 0.01). There were no differences between pre-menopausal and post-menopausal women. Conclusions VO2peak was associated with Gal-3 only in men, but VO2peak adjusted for body weight in women and men. Our results suggest that the adverse consequences of low CRF may be mediated by Gal-3. Further research is needed to understand the sex-specific association between CRF and Gal-3 and whether they are clinically relevant.