Modulation of Blood Pressure Reactivity to Cold Stress After Bariatric Surgery in Patients with Severe Obesity
Name: LETICIA SCHWAMBACH
Publication date: 06/08/2026
Examining board:
Name |
Role |
|---|---|
| ALEXANDRE CARDOSO DA CUNHA | Examinador Interno |
| ANDRESSA BOLSONI LOPES | Presidente |
| FABIANO KENJI HARAGUCHI | Coorientador |
| INGRIDY REINHOLZ GRAFITES SCHEREIDER | Examinador Externo |
Summary: Background: Autonomic dysfunction represents an important mechanism linking
obesity to cardiovascular disease, contributing to elevated blood pressure and
impaired cardiovascular responses to stress. Individuals with obesity frequently
exhibit reduced blood pressure (BP) reactivity during stress challenges, including the
cold pressor test (CPT), reflecting altered autonomic regulation. Although Roux-en-Y
gastric bypass (RYGB) is known to induce marked weight loss, improve metabolic
health, and reduce resting BP, its influence on cardiovascular stress reactivity
remains insufficiently investigated. This study therefore examined the effects of
RYGB on BP responses to cold-induced stress and explored their relationships with
body composition and metabolic, inflammatory, and oxidative stress biomarkers.
Methods: This prospective longitudinal study included 30 adults with obesity (BMI
35–55 kg/m²) treated at a public hospital. Clinical, anthropometric, biochemical, and
cardiovascular assessments were performed before surgery and at two and six
months following RYGB. Cardiovascular reactivity was evaluated using the CPT by
measuring BP, heart rate (HR), and rate–pressure product (RPP). Results: Bariatric
surgery promoted significant reductions in body weight, fat mass, waist
circumference, fasting glucose, insulin, HOMA-IR, total cholesterol, triglycerides,
C-reactive protein, and advanced oxidation protein products (all p < 0.05). Resting
systolic and diastolic BP, HR, and RPP were also significantly lower after surgery,
indicating improved cardiovascular function at baseline. The diminished pressor
response observed before surgery was restored after RYGB, as demonstrated by
significant increases in systolic and diastolic BP during the CPT. Furthermore, greater
BP reactivity was associated with lower levels of adiposity, insulin resistance,
cholesterol, and oxidative stress. Conclusion: RYGB restores blood pressure
reactivity to cold-induced stress within six months after surgery while simultaneously
reducing adiposity, improving insulin sensitivity, and attenuating oxidative stress.
These findings support the role of bariatric surgery in reversing obesity-related
autonomic dysfunction and reducing cardiovascular risk.
