Does imatinib mesylate therapy cause growth hormone deficiency?

The purpose of this study was to determine whether or not imatinib mesylate therapy induces growth hormone deficiency (GHD).

Seventeen patients with chronic myloid leukemia (CML) were enrolled in the study. The glucagon stimulation test (GST), and standard deviation scores (SDSs) of insulin-like growth fac- tor 1 (IGF-I) and insulin-like growth factor binding protein (IGFBP-3) were used to determine GHD. The L-dopa test was performed on those with IGF-I SDSs above the -1.8 cut-off level.

Of the 17 patients in the study, 12 (70%) had severe GHD (serum GH level <3 microg/l after GST). IGF-I SDSs and IGFBP-3 SDSs were below -1.8 in 12 patients (70%) and below -0.9 in 10 subjects (58%). Four of the 5 remaining subjects with IGF-I SDS >-1.8 showed insufficient GH response to L-dopa stimulation. Nine subjects (52%) had both severe GHD based on GST response and IGF-I SDS below -1.8. If an IGF-I SDS cut-off value l<-3 were used,5 out of 17 subjects (30%) would be classified as GH deficient. These same patients also showed severe GHD based on GST response.

The data showed that a large number of patients on imatinib mesylate therapy had GH deficiency. A study involving a larger number of patients with a matched control group is needed to confirm the present observations.