The role of insulin-like growth factor-1 and growth hormone in the mortality of patients with acromegaly after trans-sphenoidal surgery

Abstract

Context Acromegaly is associated with a significant increase in mortality. With the development of new modalities of treatment, it has become important to identify prognostic factors relating to mortality. Objective This study aimed to determine the all-cause mortality of patients with acromegaly after trans-sphenoidal surgery, and assess the impact of biochemical markers on survival. Design Two hundred thirty-four patients were admitted to the Taipei Veterans General Hospital for acromegaly between 1979 and 2007. Of the 163 patients who underwent trans-sphenoidal surgery, 142 had data available for insulin-like growth factor-1 (IGF-1), and their survival status was analyzed. Serial data for fasting growth hormone (GH) and IGF-1 were collected. This study also used the last follow-up data for mortality analysis. The patients with acromegaly were grouped according to the last follow-up GH level (≤ 2 or > 2 μg/L) and IGF-1 SD score (≤ 2 or > 2). All-cause mortality was followed to the end of 2007 and compared to the general Taiwanese population by standardized mortality ratios. Results Serial GH and IGF-1 data revealed that the GH levels in the first 3 years after surgery were important predictors of mortality in acromegaly. However, there are insufficient IGF-1 data for deceased patients to determine the significance of a raised IGF-1 immediately following treatment. Comparison of crude death rates suggests that a fasting GH level of 2 μg/L and normalization of the IGF-1 level are appropriate targets. After subgroup analysis to assess the impact of discordant GH and IGF-1 levels on survival, the data showed that the elevated GH group had a trend toward a higher mortality than the elevated IGF-1 group. Conclusions An elevated GH value in the first 3 years after surgery may be the best predictor of mortality. Thus, the follow-up of patients with acromegaly at relatively frequent intervals after trans-sphenoidal surgery should be routine.