Comorbidities in patients with non-functioning pituitary adenoma: influence of long-term growth hormone replacement

BACKGROUND: Patients with hypopituitarism have an increased mortality. The aim of this study was to investigate comorbidities including cerebral infarction, type 2 diabetes mellitus (T2DM) and malignant tumours in patients with non-functioning pituitary adenomas (NFPA) with and without growth hormone replacement therapy (GHRT). METHOD: Observational cohort study in patients with NFPA within the western region of Sweden. Subjects were identified through the National Patient Registry and followed between 1987-2014. Patient records were reviewed and standardized incidence ratios (SIRs) with 95% confidence intervals (CIs) for comorbidities were calculated. RESULTS: In total, 426 patients were included, 206 with GHRT and 219 without. Median (range) follow-up time for patients with and without GHRT was 12.2 (0-24) and 8.2 (0-27) years, respectively. Mean±SD body mass index (BMI) was 28.5±4.5 and 26.5±4.4 for patients with and without GHRT, respectively (P<0.001). Incidence of cerebral infarction was increased (SIR 1.39; 95% CI 1.03-1.84; P=0.032), with no difference between patients with and without GHRT. SIR for T2DM in patients not receiving GHRT was increased (1.65; 1.06-2.46; P=0.018), whereas the incidence in patients receiving GHRT was not (0.99; 0.55-1.63; P=0.99). The incidence of malignant tumours was not increased, neither in patients with nor without GHRT. CONCLUSION: The incidence of cerebral infarction is increased in patients with NFPA irrespective of GHRT. Patients without GHRT had an increased risk of T2DM, whereas patients with GHRT, had a normal incidence of T2DM, despite having higher BMI. Incidence of malignant tumours was not increased. Thus, long-term GHRT seems to be safe regarding risk of comorbidities.