Age and sex as predictors of biochemical activity in acromegaly: analysis of 1485 patients from the German Acromegaly Register

Summary Objective  We evaluated the German Acromegaly Register for clinical variables associated with the initial biochemical activity of patients with acromegaly. Design  Retrospective analysis of data in the registry. Patients  A total of 1485 patients with acromegaly (males 45·6%, females 54·4%) were treated in 42 German endocrine centres until November 2005. Linear regression models were used to estimate the influence of various parameters on biochemical activity. Results  Male patients with acromegaly were significantly younger at the time of diagnosis than female patients (41 vs. 47 years, P < 0·0001) and had significantly higher random GH levels than females (21 vs. 14 ng/ml, P < 0·005) and IGF-1 levels (773 vs. 679 ng/ml, P < 0·0001), respectively. Age at initial presentation turned out to be the most important independent risk factor associated with random GH levels, oral glucose tolerance test-suppressed GH levels, IGF-1 levels, body mass index (BMI), tumour size and prevalence of hypopituitarism. Sex was an independent risk factor for IGF-1 levels, BMI and prevalence of hypopituitarism. Tumour size was an independent risk factor for both GH and IGF-1 levels. Conclusions  In summary, initial biochemical activity of acromegaly is influenced by patient’s age and to a lesser degree by patient’s sex. Male patients are on an average 6 years younger than females.