Levels of fasting plasma glucose are normal in adults with GH deficiency, but those of fasting insulin and C-peptide are increased, particularly in patients who are overweight, suggesting a state of insulin resistance. Plasma glucose, insulin and C-peptide levels rise following GH replacement therapy and remain elevated after six months.
The insulin: C-peptide ratio increases progressively, thus suggesting an alteration in postsecretory insulin metabolism, possibly related to the reduction in abdominal fat. No changes in HbA1 have been noted.
