Evaluation of bile-scid profiles and functional capacity before and after bariatric surgery

Abstract Background Obesity profoundly affects cardiovascular function and overall physical capacity, yet the biological mechanisms underlying these impairments remain incompletely defined. Recent findings suggest that circulating bile acids play a relevant role in cardiovascular health and disease. Purpose The associations between circulating bile-acid subspecies composition and key indicators of cardiorespiratory functional capacity were evaluated in patients with severe obesity, including a subgroup undergoing bariatric surgery. Methods Sixty patients with severe obesity were examined, of whom 21 subsequently underwent bariatric surgery. All participants completed a maximal cardiopulmonary exercise test and a maximal handgrip-strength assessment, and underwent detailed serum bile-acid profiling using liquid chromatography–high resolution-mass spectrometry (triple quadrupole mass spectrometer). Results At baseline 60 patients had a mean BMI 44.8 ± 6.8 kg/m²; mean age 46 ± 10 years; 56.7% female. Mean VO2peak/kg was 19.6 ± 4.2 mL/min/kg, and 67.9% showed handgrip strength below the 50th percentile. VO2peak/kg demonstrated a modest but significant association only with taurodeoxycholic acid (rho = –.260). The percentage of predicted O2 pulse at peak exercise—an indirect marker of left ventricular compliance and contractile performance—was inversely associated with multiple bile acids: glycocholic acid, glycodeoxycholic acid, taurocholic acid, taurodeoxycholic acid, and total bile acids were each related to a lower percentage of predicted O2 pulse. Peak peripheral oxygen saturation also showed significant inverse associations with chenodeoxycholic acid, taurochenodeoxycholic acid, and total bile acids. In contrast, handgrip strength was positively associated with both glycodeoxycholic acid and glycoursodeoxycholic acid. Notably, glycoursodeoxycholic acid was negatively correlated with resting, peak, and recovery blood pressure. In the twenty-one patients who underwent bariatric surgery (mean follow-up 11.1 ± 2.0 months, BMI median (IQR) 31.8 (27.6-33.6), 52.9% female) levels of chenodeoxycholic acid decreased significantly, whereas glycoursodeoxycholic acid levels increased. Furthermore, the postoperative reduction in absolute VO2 (mean –7.5%) correlated directly with deoxycholic acid and inversely with glycochenodeoxycholic acid. Conclusions Circulating bile acids exhibit significant associations with muscular strength, cardiopulmonary performance parameters, and their postoperative adaptations following bariatric surgery. These findings suggest that bile acids may contribute to functional limitations in severe obesity, particularly in relation to cardiovascular and peripheral physiological function.