Bariatric surgery reverses blunted blood pressure reactivity to cold-induced stress in patients with severe obesity

Autonomic dysfunction is a pathway linking obesity to cardiovascular disease, contributing to hypertension and impaired pressor control. Individuals with obesity often show blunted blood pressure (BP) reactivity to stressors, such as the cold pressor test (CPT), consistent with maladaptive autonomic adjustments. Roux-en-Y gastric bypass (RYGB) produces substantial weight loss and metabolic improvements, and lowers resting BP, yet its effects on stress reactivity are underexplored. Therefore, this study evaluated the impact RYGB on BP reactivity to cold-induced stress and its associations with body composition, metabolic, inflammatory, and oxidative stress markers. A prospective longitudinal study was conducted with 30 adults with obesity (BMI 35–55 kg/m²) in a public hospital. Participants underwent clinical, anthropometric, biochemical, and cardiovascular evaluations preoperatively and at two- and six-months post-surgery. The CPT assessed BP, heart rate (HR), and rate–pressure product (RPP) responses. Bariatric surgery significantly reduced body weight, fat mass, waist circumference, glucose, insulin, HOMA-IR, cholesterol, triglycerides, C-reactive protein, and advanced oxidation protein products (p < 0.05). Resting systolic and diastolic BP, HR, and RPP also decreased, indicating improved baseline cardiovascular status. Pressor reactivity to CPT, blunted preoperatively, was restored postoperatively, with significant systolic and diastolic BP increases during cold exposure. Correlations showed that greater pressor reactivity was associated with lower adiposity, insulin resistance, cholesterol, and oxidative stress. RYGB restores pressor reactivity to the CPT within six months, alongside reduced adiposity, improved insulin sensitivity, and lower oxidative stress, underscoring its role in reversing obesity-related autonomic dysfunction and mitigating cardiovascular risk.