IGF-I and mortality in patients with acromegaly.

There are several studies in the literature relating mortality in patients with acromegaly to GH levels either as random samples or as a mean of several spontaneous samples or GH nadir after oral glucose load. Fewer articles have been published until now on the relationship between IGF-I and mortality, with several of these studies reporting a clear association, while two databases did not find an association between mortality and IGF and have instead shown an interrelationship between mortality and GH levels. These latter studies report databases in which fewer individuals have been sampled for IGF-I than for GH. Moreover, reliable immunoassays for GH measurement have existed for almost 20 yr more than immunoassays for IGF-I. Since between-method results diverge for both GH and IGF-I, it appears desirable to have levels of both biochemical markers measured in the follow-up of acromegaly, preferably in a central laboratory setting. Only by this prospective effort, it will be possible in the future to evaluate the relative ability of IGF-I and GH in predicting the residual risk of patients with acromegaly in relation to mortality, but also to co-morbidities.