Pulmonary vascular function and exercise capacity in black sub-Saharan Africans

Area of Science:

• Cardiovascular Physiology
• Pulmonary Circulation
• Exercise Physiology

Background:

• Pulmonary vascular function is influenced by sex and age, but racial differences remain unexplored.
• Understanding these differences is crucial for a comprehensive view of cardiovascular health across diverse populations.

Purpose of the Study:

• To investigate potential racial differences in pulmonary vascular function between White European Caucasian and Black Sub-Saharan African individuals.
• To assess the impact of these differences on exercise capacity.

Main Methods:

• Cardiopulmonary exercise testing and exercise stress echocardiography were performed on 30 White and 30 Black participants.
• Pulmonary artery pressure (PAP) and cardiac output (CO) were measured, and a pulmonary vascular distensibility coefficient (α) was determined.
• Mean PAP (mPAP)-CO relationships were analyzed to assess pulmonary vascular resistance and distensibility.

Main Results:

• While resting pulmonary hemodynamics were similar, Black men exhibited higher pulmonary vascular resistance and lower distensibility (α-coefficient) during exercise compared to White men.
• These differences in men were linked to steeper mPAP-CO relationships and were inversely correlated with maximum oxygen uptake (V̇o2max).
• No significant racial differences in pulmonary vascular function or exercise hemodynamics were observed in women.

Conclusions:

• The pulmonary circulation in Black men is intrinsically less distensible than in White men, correlating with reduced exercise capacity.
• These findings highlight sex-specific racial variations in pulmonary vascular physiology.
• Further research is needed to elucidate the mechanisms behind these observed differences.