Cardiopulmonary Exercise Responses in Individuals with Metabolic Syndrome: The Ball State Adult Fitness Longitudinal Lifestyle Study.

Background: The association between cardiorespiratory fitness (CRF) and metabolic syndrome (MetSyn) is well established. Additional variables derived from cardiopulmonary exercise testing (CPET) have shown prognostic value in some chronic diseases, however, there is limited information on how cardiopulmonary responses to exercise may be altered in individuals with MetSyn. Thus, the purpose of this study was to examine the association between cardiopulmonary variables derived from CPET and MetSyn. Methods: A cohort of 3181 participants (1714 men, 1467 women), aged 20-79 years, completed CPET and metabolic risk factor assessment between January 1, 1971, and November 1, 2020. Cardiopulmonary variables assessed included CRF defined as the maximum volume of oxygen uptake (VO 2max ), ventilatory threshold (VO 2 @VT), oxygen uptake efficiency slope (OUES), the ratio of ventilation to VO 2 at peak exercise (peak V E /VO 2 ) and the V E /VCO 2slope . MetSyn was defined using the National Cholesterol Education Program/Adult Treatment Panel. Results: VO 2max , VO 2 @VT, and OUES were lower ( P  < 0.001) and V E /VCO 2slope was higher ( P  < 0.001) in individuals with MetSyn ( n  = 774), whereas no difference between groups existed for peak V E /VO 2 . Logistic regression analysis revealed that VO 2max [0.91, 0.89-0.93; odds ratio (OR), 95% confidence interval (CI)], VO 2 @VT (0.91, 0.87-0.95; OR, 95% CI), OUES (0.32, 0.20-0.52; OR, 95% CI), and V E /VCO 2slope (1.03, 1.01-1.05 OR, 95% CI) were all associated with the presence of MetSyn ( P  ≤ 0.001). Conclusion: These results indicate that MetSyn is associated with altered cardiopulomary function that may provide insight into the underlying pathophysiology of MetSyn.