Endocrine Abstracts

Evidence from actuarial studies suggests that people with hypopituitarism are at high risk of premature death from vascular disease. The risk is increased both for myocardial infarction and stroke, and applies more to women than men. During life, there is evidence of premature vascular disease. In several populations, carotid intima:media thickness has been increased, as has the prevalence of atheromatous plaques in the carotid and femoral arteries. Abnormal carotid wall dynamics (reduced distensibility and compliance, increased stiffness) have also been reported. A variety of abnormalities of myocardial function, especially diastolic dysfunction, have been observed in hypopituitary patients compared with controls. Patients exhibit risk factors such as elevated serum cholesterol and triglyceride levels, and in some studies, low HDL cholesterol. Some of these abnormalities are particularly marked in women and persist throughout the day. They are associated with abnormal VLDL apolipoprotien B kinetics and with potentially atherogenic VLDL composition. Body composition is abnormal, with reduced lean body mass and increased central obesity. Non-alcoholic fatty liver disease is an area of investigation currently. People with hypopituitarism on conventional replacement are insulin resistant. They may also have abnormalities of the thrombotic:thrombolytic system and of endothelium function. The mechanisms underlying these abnormalities are the subject of intensive investigation. Some of the features improve with growth hormone replacement. An increase in lean body mass and in exercise tolerance have been reported, as have potential benefits for cardiac and arterial structure and function. A reduction in central adiposity has been observed and serum cholesterol has declined. Effects on insulin sensitivity have been variable and there is little change in serum triglyceride. Other factors which could contribute to premature vascular disease include conventional replacement regimens (glucocorticoid, thyroid and sex hormones) and radiotherapy. Much remains to be learned about the origins of the vascular disease and optimal management.

Generously supported by the Clinical Endocrinology Trust.