Pituitary, Gut & Metabolic Hormones

Convert ACTH between pg/mL, ng/L and pmol/L. pg/mL and ng/L are the same number — the harder problem is that ACTH decays in a warm tube, so a low result may be the specimen rather than the patient.

Convert fasting gastrin between pg/mL, ng/L and pmol/L. Before reading a raised result: proton pump inhibitors raise gastrin substantially, so a high value in someone taking one is expected rather than diagnostic.

Convert plasma glucagon between pg/mL, ng/L and pmol/L. A rarely measured hormone with essentially one indication — suspected glucagonoma — and a mild elevation that is usually something else entirely.

Convert growth hormone between ng/mL, µg/L, mIU/L and µIU/mL using the WHO standard of 3.0 IU per mg — and see why that factor was different before 2001, and why a single random GH answers almost nothing.

Convert IGF-1 (somatomedin C) between ng/mL, µg/L and nmol/L, and read it against an age- and sex-matched adult interval — because an IGF-1 without an age to compare it with is not a result at all.

Convert IGFBP-3 between mg/L, µg/mL, ng/mL and nmol/L, against age-matched adult intervals — and note that the molar figure is an approximation, because the circulating protein is glycosylated and its mass is not fixed.