Baroreceptor sensitivity, cardiovascular responses and ECG left ventricular hypertrophy in men: the SABPA study.

AIM. Research has shown a significant relationship between hypertension and attenuated baroreceptor sensitivity (BRS), which in turn reflects alterations of autonomic control of the cardiovascular system. The objective of this study was to compare the BRS of African and Caucasian men and determine possible associations with blood pressure and left ventricular hypertrophy. MATERIALS AND METHODS. Participants included African (n = 82) and Caucasian (n = 100) male teachers, aged between 20 and 65 years, recruited in the North-West Province, South Africa. Ambulatory blood pressure monitoring was conducted for a 22-23-h period and, thereafter, cardiovascular parameters were recorded with a Finometer and 12-lead ECG during rest and while challenging the cardiovascular system with the cold pressor and Stroop color?word conflict tests. Spontaneous BRS was calculated as well as the Cornell product [marker of left ventricular hypertrophy (LVH)]. RESULTS. The African men had significantly lower BRS stress responses. Attenuated BRS coupled to an ?-adrenergic response pattern predicted elevation of blood pressure in the African men. BRS reduction did not prove to be a significant predictor of LVH. CONCLUSION. Lower BRS, especially during stress, may pose a significant health threat for African men regarding earlier development or promotion of α -adrenergic-driven hypertension and greater risk for cardiovascular disease.