Objective: To examine all-cause mortality rates in patients with acromegaly on pegvisomant and identify pertinent risk factors, including insulin-like growth factor I (IGF-I).
Design: Retrospective cohort analysis of data from ACROSTUDY (global surveillance study of patients with acromegaly treated with pegvisomant).
Methods: Kaplan-Meier analyses and Cox regression techniques were used to examine survival rates. Standardized mortality ratios (SMR) with reference to general population (WHO GBD 2016) were estimated. Multiplicative multiple Poisson regression models were used to characterize the association between SMR, IGF-I, and other risk factors associated with mortality risk.
Results: The study consisted of 2077 subjects who were followed for a median interval of 4.1 years, contributing to 8957 patient-years. Higher on-treatment IGF-I (P = 0.0035), older attained age (P < 0.0001), and longer duration of acromegaly (>10 years) before starting pegvisomant (P = 0.05) were associated with higher mortality rates. In reference to general population rates, higher SMR (1.10, 1.42, and 2.62, at attained age 55 years) were observed with higher serum IGF-I category (SMR trend: 1.44 (44%)/per fold level of IGF-I/ULN (95% CI: 1.10, 1.87), P = 0.0075). SMR increased per year of younger attained age (1.04 (1.02-1.04), P < 0.0001) and were higher for longer disease duration (>10 years) before starting pegvisomant (1.57 (1.02, 2.43), P = 0.042). Serum IGF-I levels within the normal range during pegvisomant therapy were associated with all-cause mortality rates that were indistinguishable from the general population.
Conclusions: Higher on-treatment IGF-I, older attained age, and longer duration of acromegaly before starting pegvisomant are associated with higher all-cause mortality rates. Younger patients with uncontrolled acromegaly have higher excess all-cause mortality rates in comparison with older patients.