Acromegaly, IGF1 bioactivity, and S-Klotho

The value of measuring IGF1 bioactivity in active acromegaly is unknown. Soluble Klotho (S-Klotho) level is elevated in active acromegaly and it has been suggested that S-Klotho can inhibit activation of the IGF1 receptor (IGF1R). A cross-sectional study was carried out in 15 patients with active acromegaly, finding that IGF1 bioactivity was within the reference range in a considerable number of subjects with active acromegaly and that elevated S-Klotho levels may have reduced IGF1 bioactivity. Moreover, IGF1 bioactivity was more strongly related to physical measures of QoL than total IGF1, suggesting that IGF1 bioactivity may better reflect physical limitations perceived in active acromegaly.

Read the full article at Varewijck et al. (2014) Endocrine Connections 3 85–92 http://dx.doi.org/10.1530/EC-14-0028