Plasma endothelin-1 is not increased in overweight/obese hypertensive African women.
BACKGROUND
Endothelin-1 (ET-1) has been found to be higher in hypertensive African Americans and obese hypertensive Caucasians compared to normotensive controls with an enhanced ET-1-dependent vasoconstrictor tone. ET-1 levels and the associations thereof with cardiovascular function in overweight/obese normotensive and hypertensive African women have not been investigated. It is therefore hypothesized that ET-1 levels are elevated in overweight/obese hypertensive African women compared to overweight/obese and lean normotensive controls. Additionally, it is hypothesized that these elevated ET-1 levels are associated with increased total peripheral resistance (TPR) and decreased arterial compliance (C(W)).


METHODS
A case-case control study was performed which included 98 African women. The subjects were divided into lean normotensive (lean NT), overweight/obese normotensive (OW/OB NT) and overweight/obese hypertensive (OW/OB HT). The Finometer apparatus was used to obtain a more elaborate cardiovascular profile and plasma immunoreactive ET-1 levels were determined.


RESULTS
ET-1 levels were similar for the three groups. Although a decrease in vascular function was observed in the OW/OB HT group, no correlations were obtained between ET-1 and the cardiovascular profile, before and after adjusting for age.


CONCLUSIONS
In African women, ET-1 levels did not differ between lean and overweight/obese and normotensive and hypertensive subjects. The lack of significant associations between ET-1 and decreased vascular function in the overweight/obese hypertensive group suggests that ET-1 is not implicated in obesity-related hypertension in African women.
Schutte
R
R
School of Physiology, Nutrition and Consumer Sciences, North-West University, Potchefstroom Campus, South Africa. flgrus@puk.ac.za
Huisman
H W
HW
Schutte
A E
AE
Malan
N T
NT
D000328:Adult; D000349:Africa / Q000453:epidemiology; D001794:Blood Pressure / Q000187:drug effects; D016022:Case-Control Studies; D019332:Endothelin-1 / Q000097:blood*; D005260:Female; D006801:Humans; D006973:Hypertension / Q000097:blood*; D008875:Middle Aged; D009765:Obesity / Q000097:blood*; D050177:Overweight; D014655:Vascular Resistance / Q000187:drug effects
D019332:Endothelin-1