Leptin relates to prolonged cardiovascular recovery after acute stress in Africans: The SABPA study

Heightened cardiovascular reactivity and delayed recovery to stress are associated with an increased risk of cardiovascular disease. Africans, who are more prone to develop hypertension, show greater cardiovascular reactivity to stress. However, causal factors underlying individual and ethnic differences in stress reactivity and recovery remain largely unexplored. Leptin, which is known for its sympatho-activating effects, is higher in Africans compared to Caucasians for any given body mass index. We compared how cardiovascular reactivity and recovery relate to leptin in African (n = 200) and Caucasian (n = 209) teachers.

We measured leptin in serum and cardiovascular baseline and reactivity continuously with the Finometer device during the cold pressor test for 1 min, and recovery at intervals of 1, 3 and 5 min. Africans had higher body mass index, leptin and blood pressure (all P < 0.001). After full adjustment in multiple regression analyses, associations were seen mainly at the 5 min recovery interval. In Africans, cardiac output reactivity (β = -0.335; P = 0.0018) and arterial compliance- (β = -0.241; P = 0.048) associated negatively and total peripheral resistance- (β = 0.227; P = 0.047) positively with leptin. In Caucasians, diastolic blood pressure correlated positively with leptin (β = 0.200; P = 0.015).

In Africans, higher circulating leptin levels associated with prolonged cardiovascular recovery after exposure to stress which could explain their increased vulnerability to hypertension development.