Stress response pattern in obesity and systemic hypertension

Area of Science:

• Cardiovascular Physiology
• Hypertension Research
• Obesity Medicine

Background:

• Obese hypertensive patients typically present with higher cardiac output and lower total peripheral resistance at rest.
• Understanding hemodynamic responses to stress is crucial for managing hypertension in obese individuals.

Purpose of the Study:

• To investigate the hemodynamic patterns of obese versus lean hypertensive patients under mental stress and isometric exercise.
• To determine if obesity influences cardiovascular responses to physiological stressors.

Main Methods:

• Two cohorts of untreated stage I or II essential hypertensive patients (obese BMI > 27 kg/m2, lean BMI < 27 kg/m2) were studied.
• Hemodynamic responses to a mental stress test and an isometric exercise test were measured.
• Data were analyzed to compare responses between obese and lean groups and identify determinants of these responses.

Main Results:

• During mental stress, obese patients showed a greater increase in total peripheral resistance and lower increases in heart rate and cardiac output compared to lean patients.
• During isometric exercise, obese patients exhibited exaggerated increases in systolic and diastolic blood pressure and heart rate.
• Body mass index was an independent determinant of increased arterial pressure and heart rate during isometric exercise.

Conclusions:

• Obese hypertensive patients respond to mental stress with vasoconstriction, contrary to expected vasodilation.
• Obese hypertensive patients display an exaggerated increase in arterial pressure and heart rate during isometric exercise.
• Obesity significantly impacts hemodynamic responses to stress in hypertensive individuals, suggesting distinct pathophysiological mechanisms.