Gender- and age-related differences in the endocrine parameters of acromegaly

Acromegaly is a severe slow-developing disease associated with a poor prognosis for cardiovascular disease. To evaluate the impact of age and gender on the severity of the disease, 151 de novo patients with acromegaly (79 women, 72 men, age range 19-77 yr) were included in this open retrospective multi-center cohort study. Basal GH and IGF-I levels, GH response after glucose load and maximal tumor diameter at MRI were measured in all patients at diagnosis. Fasting GH levels and maximal tumor diameter were similar in women and men, while serum IGF-I levels were lower (664.9+/-24.9 vs 755.9+/-32 microg/l; p=0.02) and GH nadir after glucose load was higher (27.5+/-3.7 vs 18.5+/-2.2 microg/l; p=0.04) in women than in men. In both sexes, patients' age was negatively correlated with basal and nadir GH, IGF-I levels and tumor size; fasting GH levels were positively correlated with IGF-I levels and nadir GH after glucose. No interaction between age and gender was found on biochemical and morphological parameters. At diagnosis, elderly patients with acromegaly have lower GH and IGF-I levels, lower GH nadir after glucose load and smaller adenomas than young patients. Women have lower IGF-I levels but higher GH nadir after glucose load than men. These age and gender differences should be considered to appropriately evaluate the activity of acromegaly throughout a life-span.