The aim ()I' this study is to investigate the plasma cndothelin-I (ET-I) in obese
essential hypertensive men to assess whether ET-1 changes are related to
elevated blood pressure and/or obesity. The subjects of this study were selected
from the out patient clinic of the internal medicine department of Bertha
I Iniversily Ilospitals. They were classified into 4groups: group-I includes 40
obese hypertensive men ( mean age was 49.5 ± 8.7,body mass index was > 30
kg /m2 and blood pressure was > 160/95mml Ig), group-11 includes 40 obese
normotensive men (mean age was 47.8 ± 7.3,body mass index was > 30 kg/m2
and blood pressure 14118 135/85 mmHg), group-Ill includes ,I0 non obese
hypertensive men (mean age was 48.3 ± 6.7, body mass index was <26 kg/m2
and blood pressure was >160/95 mmHg),and group-IV includes 40 non obese
normotensive men (mean age was 46.9 ± 8.1, body mass index was <26 kg/m2
and blood pressure was _c135/85 mmHg),and served as a control group and
matched with the other groups regarding the age. This study revealed that, the
mean levels of plasma endothelin-1(ET-1) in obese hypertensive, obese
normotensive and non obese hypertensive groups were significantly higher
than the control group (P<0.001, P<0.001 & P< 0.01 respectively) while the
differences in between them were statistically insignificant (P>0.05)
respectively. Regarding the presence or absence of metabolic abnormalities
(impaired glucose tolerance and/or hyperlipidaemia) in each studied group, the
mean levels of plasma ET-1 in cases with metabolic abnormalities were
significantly higher than cases without metabolic abnormalities and than the
control group (P< 0.001 ) respectively, while the differences in between them
were statistically insignificant (P> 0.05) respectively. However, in comparing
the mean levels of plasma ET-1 in cases without metabolic abnormalities with
the control group the differences were statistically significant ( P<0.05), except
in non obese hypertensive group the difference was statistically insignificant
(P>0.05). Plasma ET-1 levels were significantly correlated with fasting serum
insulin in different studied groups (r=0.739, P<0.01, r=0.697, P<0.01 &
r=0.672, P<0.01 respectively) and with diastolic blood Pressure in obese
hypertensive and non obese hypertensive groups (r=0.412,P<0.05 &r=-0.329,
P<0.05 respectively). It is concluded from this study that plasma ET-1 levels
are increased in human obesity and/or essential hypertension particularly in the
presence of metabolic abnormalities (impaired glucose tolerance and/or
hyperlipidaemia). This increase of plasma ET-1 could depend on fasting serum
insulin and diastolic blood pressure. We recommend a further study on a large
scale to clarify the role of ET-I as a possible independent risk factor for the
development of vascular lesions and contributor to insulin resistance in
hypertensive patients with metabolic abnormalities. |
