The influence of cardiac and vascular responses on baseline cardiovascular parameters in Black African children.
BACKGROUND
The prevalence of hypertension among Black adults in South Africa is high. Because cardiovascular reactivity can be used to predict hypertension in later life, we attempted to determine whether cardiac and vascular responses to a task in Black South African children influence their cardiovascular parameters.


METHODS
This study was embedded in the Transition and Health during Urbanization in South Africa in Children study, which studied the health status of children. During the study, cardiovascular reactivity was determined with a hand dynamometer in 670 Black African children. Systolic blood pressure, diastolic blood pressure, mean arterial pressure, heart rate, stroke volume, cardiac output, total peripheral resistance, and Windkessel compliance of the arterial system were obtained by means of the Finapres (finger arterial pressure) apparatus and the Fast Modelflow software program. Anthropometric measurements were performed according to standard methods. Cardiac and vascular responders were classified with a regression-based approach.


RESULTS
Cardiac responders had higher stroke volume; a trend to higher cardiac output; lower diastolic blood pressure; and a tendency toward lower systolic blood pressure, heart rate, and total peripheral resistance. Vascular responders showed no significant changes in cardiovascular parameters when responders and nonresponders were compared.


CONCLUSIONS
Cardiac responders had higher stroke volume and a trend toward higher cardiac output, which may be an early indication of hypertension.
School for Physiology, Nutrition and Consumer Sciences, Subject Group: Physiology, North-West University, Potchefstroom Campus, Potchefstroom, South Africa.
Carla M T
CM
Fourie
Johannes M
JM
van Rooyen
Hugo W
HW
Huisman
Nicolaas T
NT
Malan
Rudolph
R
Schutte
Leoné
L
Malan
Aletta E
AE
Schutte
D000293:Adolescent; D000886:Anthropometry; D044383:Black People; D001794:Blood Pressure; D002320:Cardiovascular Physiological Phenomena; D002648:Child; D005260:Female; D018737:Hand Strength / Q000502:physiology*; D006801:Humans; D006973:Hypertension / Q000453:epidemiology / Q000208:ethnology / Q000503:physiopathology*; D008297:Male; D012044:Regression Analysis; D012307:Risk Factors; D012574:Schools; D013019:South Africa / Q000453:epidemiology; D013318:Stroke Volume