The role of cumulative growth hormone exposure in determining mortality and morbidity in acromegaly: a single centre study

Purpose Acromegaly has traditionally been associated with significant mortality and cardiovascular morbidity. The aim of this study was to assess the overall mortality and improvement in mortality and morbidity in acromegaly and correlate these with cumulative growth hormone exposure. Methods All patients treated for acromegaly at our centre until 2012 were analysed in this retrospective observational study. Baseline demographic details such as age at diagnoses, radiological features and pituitary status were obtained on these 167 patients. Cumulative GH levels (GHy) were calculated as a sum of average of GH readings in consecutive years. Mortality rates and development of new diabetes, hypertension and cardiovascular events (stroke, congestive cardiac failure and ischaemic heart disease) were assessed. Results The SMR for overall cohort was 1.6. There has been a significant improvement in SMR over the past two decades (SMR until 1992 2.5; SMR since 1992 1.0). Cumulative GH exposure was significantly high in patients who died (35.2 vs 24.1, p < 0.01) and in those with incident metabolic or vascular events during follow up (51.6 vs 24.4, p = 0.0001). The cardiovascular event rate of the 'new' cohort was significantly better than the 'old' cohort (8.0 vs. 29.1 %, p < 0.001). Conclusion There has been significant improvement in mortality and morbidity associated with acromegaly, in the setting of routine care in a specialized endocrine unit. Early and effective treatment to 'control' acromegaly could reduce GH exposure and hence vascular comorbidities.