GHR and type 2 diabetes mellitus: For instance, increased IGF-1 plasma levels are associated with reduced T2DM risk, and IGF-1 gene polymorphisms have been linked to T2DM and other age related disorders.17-19 Therefore, altered GHR responsiveness caused by GHR exon-3 deletion alleles may influence IGF-1 secretion levels and contribute to T2DM.