[The role of insulin-like-growth-factor-binding protein 3 in the evaluation of disease activity in acromegaly]

Studied the diagnostic value of measurements of insulin-like growth factor binding protein-3 compared to insulin-like growth factor-1 as a parameter of disease activity in patients with active (n = 12, 8 females, 4 males, 29-69 years old) and inactive (n = 14, 11 females, 3 males, 28-58 years old) acromegaly. Patients were assigned to the active group if they had GH levels > or = 2 ng/ml, to the inactive group if they had growth hormone levels < 2 ng/ml after 75 g glucose challenge. The absolute serum insulin-like growth factor-1 concentration (526 +/- 66 ng/ml vs. 272 +/- 61 ng/ml, p = 0.015; mean +/- SE) and the insulin-like growth factor-1 standard deviation score (3.23 +/- 0.33 vs. 0.67 +/- 0.58, p = 0.0013) was higher in the active than in the inactive group, but no significant difference was seen between the corresponding insulin-like growth factor binding protein-3 values (7270 +/- 1500 vs. 5340 +/- 1050 ng/ml). Positive significant correlation was found between insulin-like growth factor-1 and insulin-like growth factor binding protein-3 both in the active (n = 12, r = 0.55, p < 0.05) and in the inactive (n = 14, r = 0.61, p < 0.05) group. A significant negative correlation existed between insulin-like growth factor binding protein-3 and age in the inactive (r = 0.58, n = 14; p < 0.05), but not in the active (r = 0.35, n = 12) group. The diagnostic value of insulin-like growth factor binding protein-3 is less than that of the insulin-like growth factor-1. Conclude that the insulin-like growth factor binding protein-3 has smaller suitability to determine the activity of acromegaly than the insulin like-growth factor-1 measurement.