Aim: The aim of the study was to assess the differences between patients in remission in acromegaly and those with active ongoing disease, using cumulative GH measurement as risk factor for various complications.
Methods: A retrospective observational analysis of all patients with acromegaly treated at a tertiary referral centre since the initiation of service (~50 years) was conducted. Cumulative GH exposure was calculated as a sum of averages of GH levels measured in each calendar year, added up to the entire duration of follow up of the patient at our centre. Basic biochemical and metabolic details were collected by review of case notes. All GH values were converted to μg/l. Control was achieved if latest GH was consistently <1.5 μg/l. Development of diabetes, hypertension or new cardiovascular events and mortality were assessed.
Results: Results of 141 patients were analysed. Mean age was 48.2 years and mean duration of follow up was 146 months (4467). Control of acromegaly had been achieved in 107 patients and mean duration to achieve control was 60 months (1273). Comparing the control-achieved vs the active disease groups: mortality 29.9% vs 55.9% (P<0.01); Radiotherapy used 54.2% vs 61.8% (P=NS); Surgery attempted 62.6% vs 70.6% (P=NS); new incident hypertension 20.6% vs 17.6% (P=NS); incident diabetes 8.4% vs 8.8% (P=NS); new incident cardiovascular events 16.8% vs 23.5% (P=NS). The cumulative GH measurement was 42.7 μg/l in patients who achieved control, compared to 81.8 μg/l during the follow up period (P=0.01). The last measured GH was 0.7 μg/l vs 6.2 μg/l (P<0.0001).
Conclusion: The study shows that despite control being achieved in a significant proportion of patients with acromegaly, the risk of morbidity from acromegaly remains higher. Mortality was higher in active disease group. The latest GH may not be a good predictor of this risk. Cumulative GH exposure, which measures magnitude and duration of GH exposure, could be an important predictor of morbidity and mortality in acromegaly.