Race specific altitude effects on blood pressure

Area of Science:

• Human Physiology
• Altitude Medicine
• Ethnic Health Disparities

Background:

• High altitude exposure significantly impacts blood pressure (BP), but research has predominantly focused on Caucasian populations.
• The differential effects of altitude on BP between ethnic groups, specifically Black and White individuals, remain largely unexplored.
• Understanding these variations is crucial for assessing health risks associated with high-altitude environments.

Purpose of the Study:

• To investigate whether Black and White individuals exhibit different blood pressure responses during high-altitude exposure.
• To compare changes in systolic blood pressure (SBP), diastolic blood pressure (DBP), and body weight between ethnic groups during a mountain ascent.
• To identify potential factors that may explain observed ethnic differences in physiological responses to altitude.

Main Methods:

• A 6-day expedition climb of Mount Kilimanjaro was undertaken by five White and four Black participants with prior high-altitude experience.
• Blood pressure (systolic and diastolic) and body weight were measured at base camp and during ascent to 4600 meters.
• Statistical analysis was performed to compare physiological changes between the two ethnic groups.

Main Results:

• During ascent, systolic blood pressure (SBP) increased significantly in White participants (+6.5 mm Hg) but decreased in Black participants (-7.3 mm Hg; P = 0.02).
• Body weight increased in Whites (+1.0 kg) and decreased in Blacks (-1.9 kg) during ascent (P = 0.02), with partial normalization upon descent.
• Diastolic blood pressure and heart rate remained constant across both groups throughout the expedition.

Conclusions:

• Significant ethnic differences exist in systolic blood pressure and body weight changes during high-altitude exposure.
• Black individuals experienced a decrease in SBP and body weight, contrasting with an increase observed in White individuals.
• Factors such as fluid balance, acclimatization rates, physical fitness, or genetic predispositions may underlie these observed ethnic variations.