Insulin-like growth factor-1, growth hormone and disease outcomes in acromegaly: A population study.

Context: A lack of consensus remains about the relative importance of insulin-like growth factor-1 (IGF-1) and growth hormone (GH) in predicting adverse outcomes in patients with acromegaly.

Objective: To describe the differing association between IGF-1 and GH and major disease outcomes in acromegaly.

Design: Retrospective cohort study.

Patients: United Kingdom National Health Service patients with acromegaly who had an IGF-1 and/or a GH measurement recorded following diagnosis, prior to December 2019.

Measurements: A composite endpoint including all-cause mortality (ACM), type 2 diabetes (DM), major adverse cardiovascular events (MACE) or cancer was the primary outcome. These outcomes were also analysed individually. Follow-up period was capped at 5 years.

Results: A maximum of 417 cases and 332 cases were eligible for the IGF-1 and GH analyses, respectively, comprising 1041.5 and 938.9 years of follow-up. There was a direct association between increased IGF-1 concentration and adjusted event risk for the composite endpoint (hazard ratio [HR] = 1.2; 95% confidence interval [CI] = 1.02-1.5); in GH, the HR was 1.1 (1.0-1.2). For the individual endpoints in relation to IGF-1 level, the HRs were ACM (1.2; 0.93-1.5), MACE (1.2; 0.64-2.1), DM (1.53; 1.09-2.2) and cancer (1.3; 0.95-1.7). For GH, the HRs were ACM (1.1; 0.97-1.2), MACE (0.99; 0.73-1.3), DM (1.1; 0.99-1.2) and cancer (0.90; 0.66-1.2).

Conclusions: In this contemporary data set with extended follow-up, IGF-1 and GH concentrations showed an association with major adverse outcomes from acromegaly.