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

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.