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

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.