Evaluation of cardiovascular risk and endothelial function in hypopituitarism
Adult hypopituitarism is associated with increased mortality and morbidity mostly
from cardiovascular disease. This thesis examines lipid profile, coronary risk,
homocysteine level and endothelial function in a group of hypopituitary patients
compared to matched controls.
Triglycerides, total and LDL-cholesterol were elevated in patients of both genders;
HDL-cholesterol was significantly reduced in females. HDL-cholesterol correlated
negatively with adiposity. Total to HDL-cholesterol ratio was increased in both
genders. The lipid abnormalities appear to be related to GH-deficiency either
directly (LDL) or indirectly through increased central obesity (HDL).
Absolute 5-years risk of a coronary event, using the Framingham risk equation,
was greater in patients. Relative risk (RR) was higher in patients but not in the
controls, mostly because female patients had significantly higher RR. RR for
controls was not different from the local population. Lipid changes explained the
increased risk in patients, particularly females.
Plasma homocysteine was not increased in hypopituitary patients, and therefore
does not appear to contribute to the increased cardiovascular mortality.
Biochemical markers of endothelial dysfunction, e-selectin, ICAM-1, TM, and vWF,
were higher in patients. Brachial artery EDD was lower in patients than controls.
This difference in EDD was more marked in females, though it disappeared when
comparing the oestrogen sufficient female patients with controls. However, the
female patients who were not replaced with oestrogen continued to show a striking
difference compared to oestrogen deficient control females, There was no
difference in carotid IMT between patients of both genders and controls.
EDD correlated inversely with ICAM-1; ICAM-1 correlated positively with e-selectin
and negatively with IGF-1; e-selectin correlated positively with TM, vWF, and
negatively with IGF-1; TM correlated positively with vWF and inversely with IGF-1.
The results confirm significant endothelial dysfunction in hypopituitarism and
suggest a role for GH-deficiency and oestrogen deficiency in endothelial