Endocrine Abstracts

Acromegaly is due to increased GH secretion usually sustained by a GH-secreting pituitary adenoma. Somatostatin analogues (SSA) can control GH hypersecretion in 60% of patients and tumor volume in 30%. The disease control is, in turn, associated with lower mortality and therefore to verify the optimal control of the disease activity is of critical importance to adapt the dose and the choice of alternative treatment. The criteria for optimized disease control had been assumed as mean GH <2.5 ng/ml and normal for age IGF1 levels. In 2010 a consensus proposed as new criteria GH random (GHR) <1 ng/ml and normal for age IGF1 levels. We compared the reliability of mean GH profile (GHP) <2.5 and GHR <1 ng/dl as good marker of disease activity in acromegaly; we also evaluated the association between GH levels (mean and random) and IGF1/IGFBP3 levels. To this goal in an observational and retrospective study, we enrolled 34 responsive to SSA treatment acromegalic patients (25F, 33–86 years). The clinical response had been defined by normal IGF1 levels and no clinical activity. In all subjects the dose of SSA had been stable in last 2–5 years. In all subjects in phase 1 (before 2010) mean GHP, IGF1, and IGFBP3 and in phase 2 (after 2010) GHR, IGF1, and IGFBP3 had been evaluated. In all subjects in both phases of the study IGF1 (phase 1: 186.8±10.0 and phase 2: 175.0±37.3) and IGFBP3 (phase 1: 2.7±0.1 and phase 2: 2.5±0.1) levels were normal for age. GHR (2.2±0.48 ng/ml) levels are higher (P=0.1) than GHP (1.17±0.57 ng/ml). Concordance between GHP <2.5 ng/ml and normal IGF1 was demonstrated in 85.3% of patients while between GHR <1 ng/ml and normal IGF1 just in 29.4% (P<0.01). Our study shows that in acromegalic patients responsive to SSA, GHP <2.5 ng/ml better than GHR <1 correlate with normal IGF1 levels, thus indicating that evaluation by GHP would more reliably reflect an appropriate disease control.